自动化专业毕业设计方案中英文翻译

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电气自动化专业毕业设计英文翻译

电气自动化专业毕业设计英文翻译1 Computer structure and functionThis section introduces the internal architecture of a computer and describes how instructions are stored and interpreted and explains how the instruction execution cycle is broken down into its various components.At the most basic level, a computer simply executes binary-coded results. For a general-purpose programmable computer, four necessary elements are the memory, central processing unit (CPU, or simply processor), an external processor bus, and an input/output system as indicated in Fig.3-1 A-1.Fig. 3-1A-1 Basic elements of a computerThe memory stores instructions and data.The CPU reads and interprets the instructions, reads the data required by each instruction, executes the action required by the instruction, and stores the results back in memory. One of the actions that is required of the CPU is to read data from or write data to an external device. This is carried out using the input/output system.The external processor bus is a set of electric conductors that carries data, address and control information between the other computer elements.1-1 The memoryThe memory of a computer consists of a set of sequentially numbered locations. Each location is a register in which binary information can be stored. The “number”of a location is called its address. The lowest address is 0. The manufacturer defines a word length for the processor that is an integral number of locations long. In each word the bits can represent either data or instructions. For the Intel 8086/87 and Motorola MC6800 microprocessors, a word is 16 bits long, but each memory locationhas only 8 bits and thus two 8-bit locations must be accessed to obtain each data word. In order to use the contents of memory, the processor must fetch the contents of the right location. To carry out a fetch, the processor places (enables) the binary-coded address of the desired location onto the address lines of the external processor bus. The memory then allows the contents of the addressed memory location to be read by the processor. The process of fetching the contents of a memory location does not alter the contents of that location.Instructions in memory Instructions stored in memory are fetched by the CPU and unless program branches occur, they are executed in the sequence they appear in memory. An instruction written as a binary pattern is called a machine-language instruction. One way to achieve meaningful patterns is to divide up the bits into fields as indicated in Fig. 3-1A-2, with each field containing a code for a different type of information.0001 0101 1000 XXXX 0100 0001 1000 XXXX 0011 XXXX XXXX 0100 Fields Opcode Immediate code Operand data Branch addressSet ‘5’ in location 8 Subtract ‘1’ f rom location 8 If zero, bran ch to location 416-bit instruction words... ... XXXX : not u sed (or “don ’t care”)Fig. 3-1A-2 Arrangement of program and data in memoryEach instruction in our simple computer can be divided up into four fields of 4 bits each. Each instruction can contain operation code (or opcode, each instruction has a unique opcode), operand address, immediate operands, branch address.In a real instruction set there are many more instructions. There is also a much large number of memory locations in which to store instructions and data. In order to increase the number of memory locations, the address fields and hence theinstructions must be longer than 16 bits if we use the same approach. There are a number of ways to increase the addressing range of the microprocessor without increasing the instruction length: variable instruction field, multiword instructions, multiple addressing modes, variable instruction length. We will not discuss them in detail.Data in memory data is information that is represented in memory as a code. For efficient use of the memory space and processing time, most computers provide the capability of manipulating data of different lengths and representations in memory. The various different representations recognized by the processor are called its data types. The data types normally used are: bit, binary-coded decimal digit (4-bit nibble, BCD), byte (8 bits), word (2 bytes), double word (4 bytes).Some processors provide instructions that manipulate other data types such as single-precision floating-point data types (32bits) and double-precision floating-point data types (64 bits). There is another type of data—character data. It is also usually represented in 8 bits. Each computer terminal key and key combination (such as shift and control functions) on a standard terminal keyboard has a 7-bits code defined by the American Standard Code for Information Interchange (ASCII).Type of memory In the applications of digital control system, we also concerned with the characteristics of different memory techniques. For primary memory, we need it to be stored information temporarily and to be written and got information from successive or from widely different locations. This type memory is called random-access memory (RAM). In some case we do not want the information in memory to be lost. So we are willing to use special techniques to write into memory. If writing is accomplished only once by physically changing connections, the memory is called a read-only memory (ROM). If the interconnection pattern can be programmed to be set, the memory is called a programmable read-only memory (PROM). If rewriting can be accomplished when it is necessary, we have an erasable programmable read-only memory (EPROM). An electronically erasable PROM is abbreviated EEPROM.1-2 The CPUThe CPU’s job is to fetch instructions from memory and execute these instructions. The structure of the CPU is shown in Fig. 3-1A-3. It has four main components: an arithmetic and logical unit (ALU), a set of registers, an internal processor bus and controller.Fig.3-1A-3 Central processing unit (CPU)These and other components of the CPU and their participation in the instruction cycle are described in the following sections.Arithmetic and Logical Unit (ALU) The ALU provides a wide arithmetic operations, including add, subtract, multiply, and divide. It can also perform Boolean logic operations such as AND, OR, and COMPLEMENT on binary data. Other operations, such as word compares, are also available. The majority of computer tasks involve the ALU, but a great amount of data movement is required in order to make use of the ALU instructions.Registers A set of registers inside the CPU in used to store information.Instruction register When an instruction is fetched, it is copied into the instruction register, where it is decoded. Decoding means that the operation code is examined and used to determine the steps of the execution sequence.Programmer’s model of the CPU The collection of registers that can be examined or modified by a programmer is called the programmer’s model of the CPU.The only registers that can be manipulated by the instruction set, or are visibly affected by hardware inputs or the results of operations upon data, are the registers represented in the model.Flag register The execution sequence is determined not only by the instruction but also by the results of the previous instructions. For example, if an addition is carried out in the ALU, data on the result of the addition (whether the result is positive, negative, or zero, for example) is stored in what is known as a flag register, status register, or condition register. If the next instruction is a conditional branch instruction, the flag word is tested in that instruction to determine if a branch if a branch is required.Program counter (instruction pointer)The address of the next instruction is located in a register called the program counter.Data registers When an instruction uses the registers to store data, the reference to the register in the instruction is called register addressing. The reasons of making use of the internal registers to store data are that they can make the instructions shorter and make execution faster.Address registers The internal registers can also be used for the storage of address of data in memory data. In such a case, the instruction word contains a register number (i.e. a register address). In the register is contained the address of memory data to be used in the instruction. This form of addressing is called register indirect addressing. The contents of the register are said to point to the data in memory.Internal Processor Bus The internal processor bus moves data between internal register. A bus is a set of closely grouped electric conductors that transfers data, address, and control information between functional blocks of the CPU. Data from a source register can be passed to a destination register when both are enabled onto (connected to) the bus.Controller The controller provides the proper sequence of control signals for each instruction in a program cycle to be fetched from memory. A total program cycle comprises many instruction cycle, each instruction cycle can be divided up into itscomponent machine cycles and each machine cycle comprises a number of clock cycle.In order to fetch an instruction, for example illustrated in Fig.3-1A-4, the address in the program counter is placed on the address lines of the external bus (AB) at the onset of clock cycle C1. Simultaneously, using a code on the control lines of the bus (CB), the CPU informs all devices attached to the bus that an “opcode” fetch machine cycle is being executed by the CPU. The memory allows the memory address to select the memory location containing the instruction. At C2 the controller places a “read”command onto the control bus which allows the memory data to be placed onto the data bus. The controller then gates the data into the instruction register and removes the read command from the control bus in C3. At C4, the controller removes the address from the address bus and begins to decode the operation-code portion of the instruction to see what steps are required for execution. The decoding operation may take several more clock cycle at the end of which the “opcode fetch” machine cycle.Fig. 3-1A-4 A timing diagram for "operation-code fetch "External attention requests It is often necessary to stop the normal instruction processing sequence. One type of external attention request is the reset request. In thecase of an unrecoverable error, a computer system may be required to reset itself .This would have the effect of initializing all important registers in the system and starting instruction execution from a standard memory location-usually location 0.An input that is more commonly activated during the normal course of events is the interrupt request. An interrupt request signal from an external device can cause the CPU to immediately execute a service subroutine which carries out the necessary actions. After completing the service subroutine, the processor will continue the task from which it was originally interrupted.The third type of input is the bus request, or direct memory access(DMA) request. It is possible to have a terminal interface that stores up all the characters in a line of text until it receives a "carriage return." Then the interface requests the use of the system bus, at which time the complete line of data is transferred to memory as fast as possible. In this way the processor simply becomes inactive until the transfer is completed.1-3 BusesThe bus is the most important communication system in a computer system. Under control of the CPU, a data source device and a data destination device are "enabled" onto(equivalent to being connected to) the bus wires for a short transmission.External processor bus The internal processor bus described in Sec. is connected to the external processor bus by a set of bus buffers located on the microprocessor integrated circuit.System bus The microcomputer board can communicate with other boards by connecting its bus to an external system bus through a connector.1-4Computer Input and OutputA set of registers external to the CPU is associated with what is known as the input/output (I/O) system. The I/O system is connected to the external processor bus using control, address, and data buses through an I/O registers in an interface. There are basically two ways that are used to address I/O register.In the first method, called I/O-mapped input/output, the operation code itself hasspecial I/O instructions that address a numbered register in the interface called an I/O port.The second method of addressing I/O registers gives the I/O ports addresses that lie within the memory address range of the CPU. This is called memory-mapped I/O. Of course there must not be any memory locations at the same address as I/O locations.One of the benefits of the memory-mapped approach is that the full range of memory addressing modes is available to the addressing of I/O registers.2Fundamentals of Computer and Networks2-1 Organization of Computer SystemA computer is a fast and accurate symbol manipulating system that is organized to accept, store, and process data and produce output results under the direction of a stored program of instructions. This section explains why a computer is a system and how a computer system is organized. Key elements in a computer system include input, processing, and output devices. Let's examine each component of the system in more detail.Input Devices Computer system use many devices for input purpose. Some INPUT DEVICES allow direct human/machine communication, while some first require data to be recorded on an input medium such as a magnetizable material. Devices that read data magnetically recorded on specially coated plastic tapes or flexible or floppy plastic disks are popular. The keyboard of a workstation connected directly to (or ONLINE to) a computer is an example of a direct input device. Additional direct input devices include the mouse, input pen, touch screen, and microphone. Regardless of the type of device used, all are components for interpretation and communication between people and computer systems.Central Processing Unit The heart of any computer system is the central processing unit (CPU). There are three main sections found in the CPU of a typical personal computer system: the primary storage section, the arithmetic-logic section,and the control section. But these three sections aren't unique to personal computers. They are found in CPUs of all sizes.Output Device Like input units, output device are instruments of interpretation and communication between humans and computer system of all size. These device take output results from the CPU in machine-coded form and convert them into a form that can be used (a) by people (e.g. a printed and /or displayed report) or (b) as machine input in another processing cycle.In personal computer systems, display screen and desktop printers are popular output devices. Larger and faster printers, many on-line workstations, and magnetic tape drives commonly found in large systems.The input/output and secondary storage units are sometimes called peripheral devices (or just peripherals). This terminology refers to the fact that although these devices are not a part of the CPU, they are often located near it. Besides, a computer system also includes buses, ROM(read only memory), RAM(random access memory), parallel port and serial port, hard disk, floppies and CD(compact disk)drive, and so on.2-2 Operating SystemOperating systems have developed over the past thirty years for two main purposes. First, they provide a convenient environment for the development and execution of programs. Second, operating systems attempt to schedule computational activities to ensure good performance of the computing system.The operating system must ensure correct operation of the computer system. To prevent user programs form interfering with the proper operation of the system, the hardware was modified to create two modes: user mode and monitor mode. Various instructions (such as I/O instructions and halt instructions) are privileged and can only be executed in monitor mode. The memory in which the monitor resides must also be protected from modification by the user. A timer prevents infinite loops. Once these changes (dual mode, privileged instructions, memory protection, timer interrupt) have been made to the basic computer architecture, it is possible to write a correct operating system.As we have stated, operating systems are normally unique to their manufacturers and the hardware in which they are run. Generally, when a new computer system is installed, operational software suitable to that hardware is purchased. Users want reliable operational software that can effectively support their processing activities.Though operational software varies between manufacturers, it has similar characteristics. Modern hardware, because of its sophistication, requires that operating systems meet certain specific standards. For example, considering the present state of the field, an operating system must support some form of on-line processing. Functions normally associated with operational software are:1)Job management;2)Resource management;3)Control of I/O operations4)Error recovery;5)Memory management.2-3 NetworksCommunication between distributed communities of computers is required for many reasons. At a national level, for example, computers located in different parts of the country use public communication services to exchange electronic messages (mail) and to transfer files of information from one computer to another. Similarly, at a local level within, say, a single building, distributed communities of computer-based workstations use local communication networks to access expensive shared resources—for example, printers and disks tapes and copiers, etc.—that are also managed by computers. Clearly, as the range of computer-based products and associated public and local communication networks proliferate, computer-to-computer communication will expand rapidly and ultimately dominate the field of distributed systems.Although the physical separation of the communicating computers may vary considerably from one type of application to another, or, at the heart of any computer communication network is the data communication facility which, may be a PSDN, aprivate LAN or perhaps a number of such networks interconnected together. However, irrespective of the type of data communication facility, an amount of hardware and software is required within each attached computer to handle the appropriate network-dependent protocols. Typically, these are concerned with the establishment of a communication channel access the network and with the control of the flow of messages across this channel. The provision of such facilities is only part of the network requirements, however, since in many applications the communicating computers may be of different forms of data representation interface between user (application) programs, normally referred to as application processes or APs, and the underlying communication services may be different. For example, one computer may be a small single-user computer, while another may be a large multi-user system.3 Stepper motorStepper motor is the electric pulse signals into angular displacement or linear displacement of the open-loop stepper motor control element pieces. In the case of non-overloaded, the motor speed, stop position depends only on the pulse frequency and pulse number, regardless of load changes, when the driver receives a step pulse signal, it will drive a stepper motor to Set the direction of rotation of a fixed angle, called the "step angle", which the angle of rotation is fixed step by step operation. Number of pulses can be controlled by controlling the angular displacement, so as to achieve accurate positioning purposes; the same time by controlling the pulse frequency to control the motor rotation speed and acceleration, to achieve speed control purposes.3-1 WorkInduction motor is a stepper motor, does it work is the use of electronic circuits, the DC power supply into a time-sharing, multi-phase timing control current, this current stepper motor power supply, the stepper motor to work properly , The drive is sharing power supply for the stepper motor, the polyphase timing controller.Although the stepper motor has been widely used, but the stepper motor does notlike a normal DC motor, AC motor in the conventional use. It must be double-ring pulse signal; power driver circuit composed of the control system can be used. Therefore, it is not easy with a good stepping motor, which involves mechanical, electrical, electronics and computers, and much other specialized knowledge.As the stepper motor actuators, electromechanical integration, one of the key products, widely used in a variety of automatic control systems. With the development of microelectronics and computer technology, increasing demand for stepper motor has applications in all areas of the national economy.3-2 CategoriesNow more commonly used include the reaction of step motor stepper motor (VR), permanent magnet stepper motor (PM), hybrid stepper motors (HB) and single-phase stepper motor.3-3 Permanent magnet stepper motorPermanent magnet stepper motor is generally two-phase, torque, and smaller, usually 7.5 degree step angle or 15 degrees;Permanent magnet stepper motor output torque, dynamic performance, but a large step angle.3-4 Reaction Stepper MotorReaction is generally three-phase stepping motor can achieve high torque output, step angle of 1.5 degrees is generally, but the noise and vibration are large. Reaction by the stepper motor rotor magnetic circuit made of soft magnetic materials, a number of the stator phase excitation winding, the use of permeability changes in torque.Step Motor simple structure, low production costs, step angle is small; but the dynamic performance is poor.3-5 Hybrid Stepping MotorHybrid Step Motor combines reactive, permanent magnet stepper motors of both, it's a small step angle, contribute a large, dynamic performance, is currently the highest performance stepper motor. It is also sometimes referred to as PermanentMagnet Induction Stepping Motor. It consists of two phases and the five-phase: the general two-phase step angle of 1.8 degrees and the general five-phase step angle 0.72 degrees. The most widely used Stepper Motor. Stepper motor drive for energy saving 3-6 Three-phase stepper motor drive special features:◆180% low torque output, low frequency characteristics of a good run◆Maximum output frequency 600Hz, high-speed motor control◆full range of detection of protection (over voltage, under voltage, overload)instantaneous power failure restart◆acceleration, deceleration, such as dynamic change in the stall protection functionto prevent◆Electrical dynamic parameters of automatic recognition function to ensurestability and accuracy of the system◆quick response and high-speed shutdown◆abundant and flexible input and output interface and control, versatility◆use of SMT production and three full-mount anti-paint treatment process, productstability and high◆full range of Siemens IGBT power devices using the latest, to ensure the qualityof high-quality3-7 Basic principlesUsually for the permanent magnet rotor motor, when current flows through the stator windings, the stator windings produce a magnetic field vector. The magnetic field will lead to a rotor angle of the magnetic field makes the direction of a rotor and the stator's magnetic field direction. When the stator magnetic field vector rotating at an angle. As the rotor magnetic field is also transferred from another perspective. An electrical pulse for each input, the motor turning a point forward. It is the angular displacement of the output and input the number of pulses proportional to speed and pulse frequency is proportional to. Power to change the order of winding, the motor will reverse. Therefore, the number of available control pulse, frequency and power the motor windings of each phase in order to control the stepper motor rotation.3-8 Induction Stepping Motor3-8-1 features: Induction, compared with the traditional reactive, structural reinforced with a permanent magnet rotor, in order to provide the working point of soft magnetic materials, and the stator excitation magnetic field changes only need to provide to provide the operating point of the consumption of magnetic materials energy, so the motor efficiency, current, low heat. Due to the presence of permanent magnets, the motor has a strong EMF, the damping effect of its own good, it is relatively stable during operation, low noise, low frequency vibration. Induction can be seen as somewhat low-speed synchronous motor. A four-phase motor can be used for four-phase operation, but also can be used for two-phase operation. (Must be bipolar voltage drive), while the motor is not so reactive. For example: four phase, eight-phase operation (A-AB-B-BC-C-CD-D-DA-A) can use two-phase eight-shot run. Not difficult to find the conditions for C =, D =. a two-phase motor's internal winding consistent with the four-phase motors, small power motors are generally directly connected to the second phase, the power of larger motor, in order to facilitate the use and flexible to change the dynamic characteristics of the motor, its external connections often lead to eight (four-phase), so that when used either as a four-phase motors used, can be used for two-phase motor winding in series or parallel.3-8-2 classification：Induction motors can be divided in phases: two-phase motor, three phase motor, four-phase motor, five-phase motor. The frame size (motor diameter) can be divided into: 42BYG (BYG the Induction Stepping motor code), 57BYG, 86BYG, 110BYG, (international standard), and like 70BYG, 90BYG, 130BYG and so are the national standards.3-8-3 the stepper motor phase number of static indicators of terms: very differently on the N, S the number of magnetic field excitation coil. Common m said. Beat number: complete the necessary cyclical changes in a magnetic field pulses or conducting state with n said, or that turned a pitch angle of the motor pulses needed to four-phase motor, for example, a four-phase four-shot operation mode that AB -BC-CD-DA-AB, shot eight four-phase operation mode that A-AB-B-BC-C-CD-D-DA-A. Step angle: corresponds to a pulse signal, the angulardisplacement of the rotor turne d with θ said. θ = 360 degrees (the rotor teeth number of J * run shot), the conventional two, four-phase, the rotor teeth 50 tooth motor as an example. Four step run-time step angle θ = 360 ° / (50 * 4) = 1.8 degrees (commonly called the whole step), eight-shot running step angle θ = 360 ° / (50 * 8) = 0.9 degrees (commonly known as half step.) Location torque: the motor is not energized in the state, its locked rotor torque (as well as by the magnetic field profile of harmonics caused by mechanical error) static torque: the motor under the rated static electricity, the motor without rotation, the motor shaft locking torque. The motor torque is a measure of volume (geometry) standards, and drive voltage and drive power, etc. has nothing to do. Although the static torque is proportional to the electromagnetic magnetizing ampere turns, and fixed air gap between the rotor teeth on, but over-use of reduced air gap, increase the excitation ampere-turns to increase the static torque is not desirable, this will cause the motor heating and mechanical noise.3-9 Characteristics of the stepper motor1. The general accuracy of the stepper motor step angle of 3-5%, and not cumulative.2. Appearance of the stepper motor to allow the maximum temperature.Stepper motor causes the motor temperature is too high the first magnetic demagnetization, resulting in loss of torque down even further, so the motor surface temperature should be the maximum allowed depending on the motor demagnetization of magnetic material points; Generally speaking, the magnetic demagnetization points are above 130 degrees Celsius, and some even as high as 200 degrees Celsius, so the stepper motor surface temperature of 80-90 degrees Celsius is normal.3. Stepper motor torque will decrease with the increase of speed.When the stepper motor rotates, the motor winding inductance of each phase will form a reverse electromotive force; the higher the frequency the greater the back emf. In its role, the motor with frequency (or speed) increases with the phase current decreases, resulting in decreased torque.4. Low-speed stepper motor can operate normally, but if not higher than a certain speed to start, accompanied by howling.。

自动化专业英语原文和翻译

自动化专业英语原文和翻译Title: Original Text and Translation of Automation Professional EnglishIntroduction:In the field of automation, it is essential to have a good command of professional English, as many resources and documents are written in English. In this article, we will explore the original text and translation of automation professional English, providing a comprehensive guide for those looking to improve their language skills in this area.1. Original Text and Translation of Automation Terminology1.1 The original text of automation terminology includes terms such as PLC (Programmable Logic Controller), HMI (Human-Machine Interface), and SCADA (Supervisory Control and Data Acquisition).1.2 The translation of these terms into other languages must be accurate and consistent to ensure clear communication in an international context.1.3 It is important for professionals in the automation industry to be familiar with these terms in both English and their native language to facilitate effective communication with colleagues and clients.2. Original Text and Translation of Automation Standards2.1 Automation standards, such as ISO 9001 and IEC 61131, are crucial for ensuring quality and safety in automation systems.2.2 Translating these standards accurately is essential to ensure compliance with regulations and best practices in different countries.2.3 Professionals in the automation industry should be well-versed in the original text of these standards and their translations to ensure the successful implementation of automation projects worldwide.3. Original Text and Translation of Automation Documentation3.1 Automation documentation, including user manuals, technical specifications, and maintenance guides, is often written in English.3.2 Translating this documentation accurately is essential to ensure that users and technicians can understand and operate automation systems effectively.3.3 Professionals in the automation industry should be proficient in both the original text and translated versions of documentation to facilitate training, troubleshooting, and maintenance of automation systems.4. Original Text and Translation of Automation Research Papers4.1 Research papers on automation topics are often published in English-language journals and conferences.4.2 Translating these papers accurately is crucial for sharing knowledge and advancements in the field of automation with a global audience.4.3 Professionals in the automation industry should be able to read and understand original research papers in English and be familiar with translations in other languages to stay informed about the latest developments in the field.5. Original Text and Translation of Automation Software5.1 Automation software, such as CAD (Computer-Aided Design) and CAM (Computer-Aided Manufacturing) programs, often have interfaces and documentation in English.5.2 Translating this software accurately is essential for ensuring that engineers and technicians can use these tools effectively.5.3 Professionals in the automation industry should be proficient in both the original text and translated versions of automation software to maximize their productivity and efficiency in their work.Conclusion:In conclusion, having a good command of professional English in the field of automation is essential for effective communication, compliance with standards, and staying informed about the latest developments. By understanding the original text and translations of automation terminology, standards, documentation, research papers, and software, professionals in the industry can enhance their language skills and excel in their careers.。

(自动化专业)毕业论文文献翻译中英文对照

(自动化专业)毕业论文文献翻译中英文对照毕业设计外文资料翻译题目可编程控制器技术讨论与未来发展专业电气工程及其自动化PLC technique discussion and future developmentK. Begain, M. ErmelChair for Telecommunications, Dresden University of Technology,01062 Dresden, GermanyAbstract: Programmable Logic Controllers (PLC), a computing device invented by Richard E.Morley in 1968, have been widely used in industry including manufacturing systems, transportation systems, chemical process facilities, and many others. At that time, the PLC placed the hardwired logic with soft-wired logic or so-called relay ladder logic(RLL), a programming language visually resembling the hardwired logic, and reduced thereby the configuration time from 6 months down to 6 days [Moody and Morley,1999].Although PC based control has started to come into place, PLC based control will remain the technique to which the majority of industrial applications will adhere due to its higher performance, lower price, and superior reliability in harsh environments. Moreover, according to a study on the PLC market of Frost and Sullivan [1995], an increase of the annual sales volume to 15 million PLCs per year with the hardware value of more than 8 billion US dollars has been predicted, though the prices of computing hardware is steadily dropping. The inventor of the PLC, Richard E Morley, fairly considers the PLC market as a 5-billion industry at the present time.Key Words：PLC ，performance ，market1 IntroductionAlong with the development of the ages, the technique that is nowadays is also gradually perfect, the competition plays more more strong; the operation that list depends the artificial has already can't satisfied with the current manufacturing industry foreground, also can't guarantee the request of the higher quantity and high new the image of the technique business enterprise.The people see in produce practice, automate brought the tremendous convenience and the product quantities for people up of assurance, also eased the personnel's labor strength, reduce the establishment on the personnel. The target control of the hard realization in many complicated production lines, whole and excellent turn, the best decision etc., well-trained operation work, technical personnel or expert, governor but can judge and operate easily, can acquire the satisfied result. The research target of the artificial intelligence makes use of the calculator exactly to carry out, imitate these intelligences behavior, moderating the work through person's brain and calculators, with the mode that person's machine combine, for resolve the very complicated problem to look for the best pathWe come in sight of the control that links after the electric appliances in various situation, that is already the that time generation past, now of after use in the mold a perhaps simple equipments of grass-roots control that the electric appliances can do for the low level only;And the PLC emergence also became the epoch-making topic, adding the vivid software control through a very and stable hardware, making the automation head for the new high tide.2 PLC characteristics and containment2.1 The PLC biggest characteristicsThe PLC biggest characteristics lie in: The electrical engineering teacher already no longer electric hardware up too many calculationses of cost, as long as order the importation that the button switch or the importation of the sensors order to link the PLC up can solve problem, pass to output to order the conjunction contact machine or control the start equipments of the big power after the electric appliances, but the exportation equipments direct conjunction of the small power can.Figure 1. Open frame PLC2.2 PLC internal containmentPLC internal containment have CPU, and take to have an I/ O for expand of exterior to connect a people's address and saving machine three big pieces to constitute, CPU core is from an or many is tired to add the machine to constitute, mathematics that they have the logic operation ability, and can read the procedure save the contents of the machine to drive the homologous saving machine and I/ Os to connect after pass the calculation; The I/ O add inner part is tired the input and output system of the machine and exterior link, and deposit the related data into the procedure saving machine or data saving machine; The saving machine can deposit the data that the I/ O input in the saving machine, and in work adjusting to become tired to add the machine and I/ Os to connect, saving machine separately saving machine RAM of the procedure saving machine ROM and datas, the ROM can can do deposit of the data permanence in the saving machine, but RAM only for the CPU computes the temporary calculation usage of hour of buffer space.Figure 2. PLC input and output circuits2.3 PLC advantageThe PLC anti- interference is very and excellent, our root need not concern its service life and the work situation bad, these all problems have already no longer become the topic that we fail, but stay to our is a concern to come to internal resources of make use of the PLC to strengthen the control ability of the equipments for us, make our equipments more gentle.PLC language is not we imagine of edit collected materials the language or language of Cs to carry on weaving the distance, but the trapezoid diagram that the adoption is original after the electric appliances to control, make the electrical engineering teacher while weaving to write the procedure very easy comprehended the PLC language, and a lot of non- electricity professional also very quickly know and go deep into to the PLC.3 HMIIs PLC one of the advantage above and only, this is also one part that the people comprehend more and easily, in a lot of equipmentses, the people have already no longer hoped to see too many control buttons, they damage not only and easily and produce the artificial error easiest, small is not a main error perhaps you can still accept; But lead even is a fatal error greatly is what we can't is tolerant of. New technique always for bringing more safe and convenient operation for us, make we a lot of problems for face on sweep but light, do you understand the HMI? Says the HMI here you basically not clear what it is, also have no interest understanding, change one inside text explains it into the touch to hold or man-machine interface you knew, it combines with the PLC to our larger space.HMI the control not only only is reduced the control press button, increase the vivid of the control, more main of it is can sequence of, and at can the change data input to output the feedback with data, control in the temperature curve of imitate but also can keep the manifestation of view to come out. And can write the function help procedure through a plait to provide the help of various what lies in one's power, the one who make operate reduces the otiose error. Currently the HMI factory is also more and more, the function is also more and more strong, the price is also more and more low, the noodles of the usage are wide more and more. The HMI foreground can say that think ° to be good very.4 PLC correspondence and data transmissionAt a lot of situations, the list is is a smooth movement that can't guarantee theequipments by the control of the single machine, but pass the information exchanges of the equipments and equipments to attain the result that we want. For example fore pack and the examination of the empress work preface, we will arrive wrapping information feedback to examine the place, and examine the information of the place to also want the feedback to packing. Pass the information share thus to make both the chain connect, becoming a total body, the match of your that thus make is more close, at each other attain to reflect the result that mutually flick.The PLC correspondence has already come more more body now its value, at the PLC and correspondence between PLCs, can pass the communication of the information and the share of the datas to guarantee that of the equipments moderates mutually, the result that arrive already to repair with each other. Data conversion the adoption RS232 between PLC connect to come to the transmission data, but the RS232 pick up a people and can guarantee 10 meters only of deliver the distance, if in the distance of 1000 meters we can pass the RS485 to carry on the correspondence, the longer distance can pass the MODEL only to carry on deliver.The PLC data transmission is just to be called a form to it in a piece of and continuous address that the data of the inner part delivers the other party, we, the PLC of the other party passes to read data in the watch to carry on the operation. If the data that data in the watch is a to establish generally, that is just the general data transmission, for example today of oil price rise, I want to deliver the price of the oil price to lose the oil ally on board, that is the share of the data; But take data in the watch for an instruction procedure that controls the PLC, that had the difficulty very much, for example you have to control one pedestal robot to press the action work that you imagine, you will draw up for it the form that a procedure combine with the data sends out to pass by.Figure 3. PLC connection with experiments board.4.1 Form of information transmission4.1.1 Simplex and DuplexThe form that information transport contain Simplex, the Half duplex and the Full duplex.The meaning of the Simplex also is to say both, a can send out only, but a can receive only, for example a spy he can receive the designation of the superior only, but can't give the superior reply; Half duplex is also 2 and can can send out similar to accept the data, but can't send out and accept at the same time, for example when you make a phone call is to can't answer the phone, the other party also; But the Half duplex is both can send out and accept the data, and can send out and accept at the same time. Be like the Internet is a typical example.4.1.2 Synchronous and AsynchronousThe process that information transport also has synchronous and asynchronous: The data line and the clock lines are synchronous when synchronous meaning lie in sending out the data, is also the data signal and the clock signals to be carry on by the CPU to send out at the same time, this needs to all want the specialized clock signal each other to carry on the transmission and connect to send, and is constrained, the characteristics of this kind of method lies in its speed very quick, but correspond work time of take up the CPU and also want to be long oppositely, at the same time the technique difficulty also very big. Itsrequest lies in can'ting have an error margins in a datas deliver, otherwise the whole pieceaccording to compare the occurrence mistake, this on the hardware is a bigger difficulty. Applied more and more extensive in some appropriative equipmentses, be like the appropriative medical treatment equipments, the numerical signal equipments...etc., in compare the one data deliver, its result is very good.And asynchronous is an application the most extensive, this receive benefit in it of technique difficulty is opposite and want to be small, at the same time not need to prepare the specialized clock signal, its characteristics to lie in, its data is partition, the long-lost send out and accept, be the CPU is too busy of time can grind to a stop sex to work, also reduced the difficulty on the hardware, the data throw to lose at the same time opposite want to be little, we can pass the examination of the data to observe whether the data that we send out has the mistake or not, be like strange accidentally the method, tired addition and eight efficacies method etc., can use to helps whether the data that we examine to send out have or not the mistake occurrence, pass the feedback to carry on the discriminator.4.1.3 Parallel and SerialA line of transmission of the information contain a string of and combine the cent of: The usual PLC is 8 machines, certainly also having 16 machines. We can be an at the time of sending out the data a send out to the other party, also can be 88 send out the data to the other party, an and 8 differentiationses are also the as that we say to send out the data and combine sends out the data. A speed is more and slowly, but as long as 2 or three lines can solve problem, and can use the telephone line to carry on the long range control. But combine the oscular transmission speed is very quick of, it is a string of oscular of 25600%, occupy the advantage in the short distance, the in view of the fact TTL electricity is even, being limited by the scope of one meter generally, it combine unwell used for the data transmission of the long pull, thus the cost is too expensive.Under a lot of circumstances we are total to like to adopt the string to combine the conversion chip to carry on deliver, under this kind of circumstance not need us to carry on to depositted the machine to establish too and complicatedly, but carry on the data exchanges through the data transmission instruction directly, but is not a very viable way in the correspondence, because the PLC of the other party must has been wait for your data exportation at the time of sending out the data, it can't do other works.4.2 InterruptWhen you are reading the book, you hear someone knock on door, you stop to start up of affair, open the door and combine to continue with the one who knock on door a dialogue, the telephone of this time rang, you signal hint to connect a telephone, afterconnecting the telephone through, return overdo come together knock on door to have a conversation, after dialogue complete, you continue again to see your book, this kind of circumstance we are called the interruption to it, it has the authority, also having sex of have the initiative, the PLC had such function .Its characteristics lie in us and may meet the urgently abrupt affairs in the operation process of the equipments, we want to stop to start immediately up of work, the whereabouts manages the more important affair, this kind of circumstance is we usually meet of, PLC while carry out urgent mission, total will keep the current appearance first, for example the address of the procedure, CPU of tired add the machine data etc., be like to to stick down which the book that we see is when we open the door the page or simply make a mark, because we treat and would still need to continue immediately after book of see the behind. The CPU always does the affair that should do according to our will, but your mistake of give it an affair, it also would be same to do, this we must notice.The interruption is not only a, sometimes existing jointly with the hour several inside break, break off to have the preferred Class, they will carry out the interruption of the higher Class according to person's request. This kind of breaks off the medium interruption to also became to break off the set. The Class that certainly break off is relevant according to various resources of CPU with internal PLC, also following a heap of capacity size of also relevant fasten.The contents that break off has a lot of kinds, for example the exterior break off, correspondence in of send out and accept the interruption and settle and the clock that count break off, still have the WDT to reset the interruption etc., they enriched the CPU to respond to the category while handle various business. Speak thus perhaps you can't comprehend the internal structure and operation orders of the interruption completely also, we do a very small example to explain.4.3 Emergency stop buttonEach equipments always will not forget a button, it also is at we meet the urgent circumstance use of, that is nasty to stop the button. When we meet the Human body trouble and surprised circumstances we as long as press it, the machine stops all operations immediately, and wait for processing the over surprised empress recover the operation again.Nasty stop the internal I/ O of the internal CPU of the button conjunction PLC to connect up, be to press button an exterior to trigger signal for CPU, the CPU carries on to the I/ O to examine again, being to confirm to have the exterior to trigger the signal, CPU protection the spot breaks off procedure counts the machine turn the homologous exteriorI/ O automatically in the procedure to go to also, be exterior interruption procedure processing complete, the procedure counts the machine to return the main procedure to continue to work.Have 1:00 can what to explain is we generally would nasty stop the button of exterior break off to rise to the tallest Class, thus guarantee the safety.4.4 PLC Counting functionWhen we are work a work piece, giving the PLC a signal, counting PLC inner part the machine add 1 to compute us for a day of workload, a count the machine and can solve problem in brief, certainly they also can keep the data under the condition of dropping the electricity, urging the data not to throw to lose, this is also what we hope earnestly.The PLC still has the function that the high class counts the machine, being us while accept some datas of high speed, the high speed that here say is the data of the in all aspects tiny second class, for example the bar code scanner is scanning the data continuously, calculating high-speed signal of the data processor DSP etc., we will adopt the high class to count the machine to help we carry on count. It at the PLC carries out the procedure once discover that the high class counts the machine to should of interruption, will let go of the work on the hand immediately. The trapezoid diagram procedure that passes by to weave the distance again explains the high class for us to carry out procedure to count machine would automatic performance to should of work, thus rise the Class that the high class counts the machine to high one Class.You heard too many this phrases perhaps:" crash", the meaning that is mostly is a workload of CPU to lead greatly, the internal resources shortage etc. the circumstance can't result in procedure circulate. The PLC also has the similar circumstance, there is a watchdog WDT in the inner part of PLC, we can establish time that a procedure of WDT circulate, being to appear the procedure to jump to turn the mistake in the procedure movement process or the procedure is busy, movement time of the procedure exceeds WDT constitution time, the CPU turn but the WDT reset the appearance. The procedure restarts the movement, but will not carry on the breakage to the interruption.Figure 4. Overall board design.5 PLC development in the futureThe PLC development has already entered for network ages of correspondence from the mode of the one, and together other works control the net plank and I/ O card planks to carry on the share easily. A state software can pass all se hardwares link, more animation picture of keep the view to carries on the control, and cans pass the Internet to carry on the control in the foreign land, the blast-off that is like the absolute being boat No.5 is to adopt this kind of way to make airship go up the sky.The development of the higher layer needs our continuous effort to obtain.The PLC emergence has already affected a few persons fully, we also obtained more knowledge and precepts from the top one experience of the generation, coming to the continuous development PLC technique, push it toward higher wave tide.References[1] R. Alur, C. Courcoubetis, and D. Dill. Model-Checking for Real-Time Systems.In Fifth Annual IEEE Symp. on Logic in Computer Science, pages 414{425.IEEE Press, 1990. [2] R. Alur and D.L. Dill. A theory of timed automata. Theoret. Comput. Sci.,126:183{235, 1994.[3] R. Alur, T. Henzinger, and E. Sontag, editors. Hybrid Systems III, volume 1066 of Lecture Notes in Computer Science. Springer-Verlag, 1996.[4] J. Bengtsson, K.G. Larsen, F. Larsson, P. Pettersson, and Wang Yi. Uppaal {a ToolSuite for Automatic Verification of Real-Time Systems. In Alur et al.[3]. 232{243.[5] D. Bosscher, I. Polak, and F. Vaandrager. Verification of an Audio Control Protocol. InH. Langmaack, W.-P. de Roever, and J. Vytopil, editors, Formal Techniques in Real-Time and Fault-Tolerant Systems, volume 863 of Lecture Notes in Computer Science, pages 170{192. Springer-Verlag, 1994.PLC technique discussion and future development, 2010, 130(9): 2436-2443.可编程控制器技术讨论与未来发展K.培根, M. 厄米尔通信教授, 德累斯顿科技大学,01062德累斯顿，德国摘要可编程逻辑控制器（PLC）是Richard E.Morley在1968年发明的一种具备运算功能的设备，现已被广泛的应用到工业中，包括制造系统、交通系统、化工过程设备等。

电气工程与自动化毕业论文中英文资料外文翻译

电气工程与自动化毕业论文中英文资料外文翻译The Transformer on load ﹠Introduction to DC MachinesIt has been shown that a primary input voltage 1V can be transformed to any desired open-circuit secondary voltage 2E by a suitable choice of turns ratio. 2E is available for circulating a load current impedance. For the moment, a lagging power factor will be considered. The secondary current and the resulting ampere-turns 22N I will change the flux, tending to demagnetize the core, reduce m Φ and with it 1E . Because the primary leakage impedance drop is so low, a small alteration to 1Ewill cause an appreciable increase of primary current from 0I to a new value of 1Iequal to ()()i jX R E V ++111/. The extra primary current and ampere-turns nearly cancel the whole of the secondary ampere-turns. This being so , the mutual flux suffers only a slight modification and requires practically the same net ampere-turns 10N I as on no load. The total primary ampere-turns are increased by an amount 22N I necessary to neutralize the same amount of secondary ampere-turns. In thevector equation , 102211N I N I N I =+; alternatively, 221011N I N I N I -=. At full load,the current 0I is only about 5% of the full-load current and so 1I is nearly equalto 122/N N I . Because in mind that 2121/N N E E =, the input kV A which is approximately 11I E is also approximately equal to the output kV A, 22I E .The physical current has increased, and with in the primary leakage flux towhich it is proportional. The total flux linking the primary ,111Φ=Φ+Φ=Φm p , isshown unchanged because the total back e.m.f.,（dt d N E /111Φ-）is still equal and opposite to 1V . However, there has been a redistribution of flux and the mutual component has fallen due to the increase of 1Φ with 1I . Although the change is small, the secondary demand could not be met without a mutual flux and e.m.f.alteration to permit primary current to change. The net flux s Φlinking thesecondary winding has been further reduced by the establishment of secondaryleakage flux due to 2I , and this opposes m Φ. Although m Φ and 2Φ are indicatedseparately , they combine to one resultant in the core which will be downwards at theinstant shown. Thus the secondary terminal voltage is reduced to dt d N V S /22Φ-=which can be considered in two components, i.e. dt d N dt d N V m //2222Φ-Φ-=orvectorially 2222I jX E V -=. As for the primary, 2Φ is responsible for a substantiallyconstant secondary leakage inductance222222/Λ=ΦN i N . It will be noticed that the primary leakage flux is responsible for part of the change in the secondary terminal voltage due to its effects on the mutual flux. The two leakage fluxes are closely related; 2Φ, for example, by its demagnetizing action on m Φ has caused the changes on the primary side which led to the establishment of primary leakage flux.If a low enough leading power factor is considered, the total secondary flux and the mutual flux are increased causing the secondary terminal voltage to rise with load. p Φ is unchanged in magnitude from the no load condition since, neglecting resistance, it still has to provide a total back e.m.f. equal to 1V . It is virtually the same as 11Φ, though now produced by the combined effect of primary and secondary ampere-turns. The mutual flux must still change with load to give a change of 1E and permit more primary current to flow. 1E has increased this time but due to the vector combination with 1V there is still an increase of primary current.Two more points should be made about the figures. Firstly, a unity turns ratio has been assumed for convenience so that '21E E =. Secondly, the physical picture is drawn for a different instant of time from the vector diagrams which show 0=Φm , if the horizontal axis is taken as usual, to be the zero time reference. There are instants in the cycle when primary leakage flux is zero, when the secondary leakage flux is zero, and when primary and secondary leakage flux is zero, and when primary and secondary leakage fluxes are in the same sense.The equivalent circuit already derived for the transformer with the secondary terminals open, can easily be extended to cover the loaded secondary by the addition of the secondary resistance and leakage reactance.Practically all transformers have a turns ratio different from unity although such an arrangement is sometimes employed for the purposes of electrically isolating one circuit from another operating at the same voltage. To explain the case where 21N N ≠ the reaction of the secondary will be viewed from the primary winding. The reaction is experienced only in terms of the magnetizing force due to the secondary ampere-turns. There is no way of detecting from the primary side whether 2I is large and 2N small or vice versa, it is the product of current and turns which causesthe reaction. Consequently, a secondary winding can be replaced by any number of different equivalent windings and load circuits which will give rise to an identical reaction on the primary .It is clearly convenient to change the secondary winding to an equivalent winding having the same number of turns 1N as the primary.With 2N changes to 1N , since the e.m.f.s are proportional to turns, 2212)/('E N N E = which is the same as 1E .For current, since the reaction ampere turns must be unchanged 1222'''N I N I = must be equal to 22N I .i.e. 2122)/(I N N I =.For impedance , since any secondary voltage V becomes V N N )/(21, and secondary current I becomes I N N )/(12, then any secondary impedance, including load impedance, must becomeI V N N I V /)/('/'221=. Consequently,22212)/('R N N R = and 22212)/('X N N X = . If the primary turns are taken as reference turns, the process is called referring to the primary side.There are a few checks which can be made to see if the procedure outlined is valid.For example, the copper loss in the referred secondary winding must be the same as in the original secondary otherwise the primary would have to supply a differentloss power. ''222R I must be equal to 222R I . ）222122122/()/(N N R N N I •• does infact reduce to 222R I .Similarly the stored magnetic energy in the leakage field)2/1(2LI which is proportional to 22'X I will be found to check as ''22X I . The referred secondary 2212221222)/()/(''I E N N I N N E I E kVA =•==.The argument is sound, though at first it may have seemed suspect. In fact, if the actual secondary winding was removed physically from the core and replaced by the equivalent winding and load circuit designed to give the parameters 1N ,'2R ,'2X and '2I , measurements from the primary terminals would be unable to detect any difference in secondary ampere-turns, kVA demand or copper loss, under normal power frequency operation.There is no point in choosing any basis other than equal turns on primary andreferred secondary, but it is sometimes convenient to refer the primary to the secondary winding. In this case, if all the subscript 1’s are interchanged for the subscript 2’s, the necessary referring constants are easily found; e.g. 2'1R R ≈,21'X X ≈; similarly 1'2R R ≈ and 12'X X ≈.The equivalent circuit for the general case where 21N N ≠ except that m r hasbeen added to allow for iron loss and an ideal lossless transformation has been included before the secondary terminals to return '2V to 2V .All calculations of internal voltage and power losses are made before this ideal transformation is applied. The behaviour of a transformer as detected at both sets of terminals is the same as the behaviour detected at the corresponding terminals of this circuit when the appropriate parameters are inserted. The slightly different representation showing the coils 1N and 2N side by side with a core in between is only used for convenience. On the transformer itself, the coils are , of course , wound round the same core.Very little error is introduced if the magnetising branch is transferred to the primary terminals, but a few anomalies will arise. For example ,the current shown flowing through the primary impedance is no longer the whole of the primary current.The error is quite small since 0I is usually such a small fraction of 1I . Slightlydifferent answers may be obtained to a particular problem depending on whether or not allowance is made for this error. With this simplified circuit, the primary and referred secondary impedances can be added to give:221211)/(Re N N R R += and 221211)/(N N X X Xe +=It should be pointed out that the equivalent circuit as derived here is only valid for normal operation at power frequencies; capacitance effects must be taken into account whenever the rate of change of voltage would give rise to appreciablecapacitance currents, dt CdV I c /=. They are important at high voltages and atfrequencies much beyond 100 cycles/sec. A further point is not the only possible equivalent circuit even for power frequencies .An alternative , treating the transformer as a three-or four-terminal network, gives rise to a representation which is just as accurate and has some advantages for the circuit engineer who treats all devices as circuit elements with certain transfer properties. The circuit on this basiswould have a turns ratio having a phase shift as well as a magnitude change, and the impedances would not be the same as those of the windings. The circuit would not explain the phenomena within the device like the effects of saturation, so for an understanding of internal behaviour .There are two ways of looking at the equivalent circuit:(a) viewed from the primary as a sink but the referred load impedance connected across '2V ,or(b) viewed from the secondary as a source of constant voltage 1V with internal drops due to 1Re and 1Xe . The magnetizing branch is sometimes omitted in this representation and so the circuit reduces to a generator producing a constant voltage 1E (actually equal to 1V ) and having an internal impedance jX R + (actually equal to 11Re jXe +).In either case, the parameters could be referred to the secondary winding and this may save calculation time .The resistances and reactances can be obtained from two simple light load tests. Introduction to DC MachinesDC machines are characterized by their versatility. By means of various combination of shunt, series, and separately excited field windings they can be designed to display a wide variety of volt-ampere or speed-torque characteristics for both dynamic and steadystate operation. Because of the ease with which they can be controlled , systems of DC machines are often used in applications requiring a wide range of motor speeds or precise control of motor output.The essential features of a DC machine are shown schematically. The stator has salient poles and is excited by one or more field coils. The air-gap flux distribution created by the field winding is symmetrical about the centerline of the field poles. This axis is called the field axis or direct axis.As we know , the AC voltage generated in each rotating armature coil is converted to DC in the external armature terminals by means of a rotating commutator and stationary brushes to which the armature leads are connected. The commutator-brush combination forms a mechanical rectifier, resulting in a DCarmature voltage as well as an armature m.m.f. wave which is fixed in space. The brushes are located so that commutation occurs when the coil sides are in the neutral zone , midway between the field poles. The axis of the armature m.m.f. wave then in 90 electrical degrees from the axis of the field poles, i.e., in the quadrature axis. In the schematic representation the brushes are shown in quarature axis because this is the position of the coils to which they are connected. The armature m.m.f. wave then is along the brush axis as shown.. (The geometrical position of the brushes in an actual machine is approximately 90 electrical degrees from their position in the schematic diagram because of the shape of the end connections to the commutator.)The magnetic torque and the speed voltage appearing at the brushes are independent of the spatial waveform of the flux distribution; for convenience we shall continue to assume a sinusoidal flux-density wave in the air gap. The torque can then be found from the magnetic field viewpoint.The torque can be expressed in terms of the interaction of the direct-axis air-gapflux per pole d Φ and the space-fundamental component 1a F of the armature m.m.f.wave . With the brushes in the quadrature axis, the angle between these fields is 90 electrical degrees, and its sine equals unity. For a P pole machine 12)2(2a d F P T ϕπ=In which the minus sign has been dropped because the positive direction of thetorque can be determined from physical reasoning. The space fundamental 1a F ofthe sawtooth armature m.m.f. wave is 8/2π times its peak. Substitution in above equation then givesa d a a d a i K i m PC T ϕϕπ==2 Where a i =current in external armature circuit;a C =total number of conductors in armature winding;m =number of parallel paths through winding;Andm PC K aa π2=Is a constant fixed by the design of the winding.The rectified voltage generated in the armature has already been discussedbefore for an elementary single-coil armature. The effect of distributing the winding in several slots is shown in figure ,in which each of the rectified sine waves is the voltage generated in one of the coils, commutation taking place at the moment when the coil sides are in the neutral zone. The generated voltage as observed from the brushes is the sum of the rectified voltages of all the coils in series between brushesand is shown by the rippling line labeled a e in figure. With a dozen or socommutator segments per pole, the ripple becomes very small and the average generated voltage observed from the brushes equals the sum of the average values ofthe rectified coil voltages. The rectified voltage a e between brushes, known also asthe speed voltage, ism d a m d a a W K W m PC e ϕϕπ==2 Where a K is the design constant. The rectified voltage of a distributed winding has the same average value as that of a concentrated coil. The difference is that the ripple is greatly reduced.From the above equations, with all variable expressed in SI units:m a a Tw i e =This equation simply says that the instantaneous electric power associated with the speed voltage equals the instantaneous mechanical power associated with the magnetic torque , the direction of power flow being determined by whether the machine is acting as a motor or generator.The direct-axis air-gap flux is produced by the combined m.m.f. f f i N ∑ of the field windings, the flux-m.m.f. characteristic being the magnetization curve for the particular iron geometry of the machine. In the magnetization curve, it is assumed that the armature m.m.f. wave is perpendicular to the field axis. It will be necessary to reexamine this assumption later in this chapter, where the effects of saturation are investigated more thoroughly. Because the armature e.m.f. is proportional to flux times speed, it is usually more convenient to express the magnetization curve in termsof the armature e.m.f. 0a e at a constant speed 0m w . The voltage a e for a given fluxat any other speed m w is proportional to the speed,i.e. 00a m m a e w w e =Figure shows the magnetization curve with only one field winding excited. This curve can easily be obtained by test methods, no knowledge of any design details being required.Over a fairly wide range of excitation the reluctance of the iron is negligible compared with that of the air gap. In this region the flux is linearly proportional to the total m.m.f. of the field windings, the constant of proportionality being the direct-axis air-gap permeance.The outstanding advantages of DC machines arise from the wide variety of operating characteristics which can be obtained by selection of the method of excitation of the field windings. The field windings may be separately excited from an external DC source, or they may be self-excited; i.e., the machine may supply its own excitation. The method of excitation profoundly influences not only the steady-state characteristics, but also the dynamic behavior of the machine in control systems.The connection diagram of a separately excited generator is given. The required field current is a very small fraction of the rated armature current. A small amount of power in the field circuit may control a relatively large amount of power in the armature circuit; i.e., the generator is a power amplifier. Separately excited generators are often used in feedback control systems when control of the armature voltage over a wide range is required. The field windings of self-excited generators may be supplied in three different ways. The field may be connected in series with the armature, resulting in a shunt generator, or the field may be in two sections, one of which is connected in series and the other in shunt with the armature, resulting in a compound generator. With self-excited generators residual magnetism must be present in the machine iron to get the self-excitation process started.In the typical steady-state volt-ampere characteristics, constant-speed primemovers being assumed. The relation between the steady-state generated e.m.f. a Eand the terminal voltage t V isa a a t R I E V -=Where a I is the armature current output and a R is the armature circuitresistance. In a generator, a E is large than t V ; and the electromagnetic torque T is acountertorque opposing rotation.The terminal voltage of a separately excited generator decreases slightly with increase in the load current, principally because of the voltage drop in the armature resistance. The field current of a series generator is the same as the load current, so that the air-gap flux and hence the voltage vary widely with load. As a consequence, series generators are not often used. The voltage of shunt generators drops off somewhat with load. Compound generators are normally connected so that the m.m.f. of the series winding aids that of the shunt winding. The advantage is that through the action of the series winding the flux per pole can increase with load, resulting in a voltage output which is nearly constant. Usually, shunt winding contains many turns of comparatively heavy conductor because it must carry the full armature current of the machine. The voltage of both shunt and compound generators can be controlled over reasonable limits by means of rheostats in the shunt field. Any of the methods of excitation used for generators can also be used for motors. In the typical steady-state speed-torque characteristics, it is assumed that the motor terminals are supplied froma constant-voltage source. In a motor the relation between the e.m.f. a E generated inthe armature and the terminal voltage t V isa a a t R I E V +=Where a I is now the armature current input. The generated e.m.f. a E is nowsmaller than the terminal voltage t V , the armature current is in the oppositedirection to that in a motor, and the electromagnetic torque is in the direction to sustain rotation of the armature.In shunt and separately excited motors the field flux is nearly constant. Consequently, increased torque must be accompanied by a very nearly proportional increase in armature current and hence by a small decrease in counter e.m.f. to allow this increased current through the small armature resistance. Since counter e.m.f. is determined by flux and speed, the speed must drop slightly. Like the squirrel-cage induction motor ,the shunt motor is substantially a constant-speed motor having about 5 percent drop in speed from no load to full load. Starting torque and maximum torque are limited by the armature current that can be commutatedsuccessfully.An outstanding advantage of the shunt motor is ease of speed control. With a rheostat in the shunt-field circuit, the field current and flux per pole can be varied at will, and variation of flux causes the inverse variation of speed to maintain counter e.m.f. approximately equal to the impressed terminal voltage. A maximum speed range of about 4 or 5 to 1 can be obtained by this method, the limitation again being commutating conditions. By variation of the impressed armature voltage, very wide speed ranges can be obtained.In the series motor, increase in load is accompanied by increase in the armature current and m.m.f. and the stator field flux (provided the iron is not completely saturated). Because flux increases with load, speed must drop in order to maintain the balance between impressed voltage and counter e.m.f.; moreover, the increase in armature current caused by increased torque is smaller than in the shunt motor because of the increased flux. The series motor is therefore a varying-speed motor with a markedly drooping speed-load characteristic. For applications requiring heavy torque overloads, this characteristic is particularly advantageous because the corresponding power overloads are held to more reasonable values by the associated speed drops. Very favorable starting characteristics also result from the increase in flux with increased armature current.In the compound motor the series field may be connected either cumulatively, so that its.m.m.f.adds to that of the shunt field, or differentially, so that it opposes. The differential connection is very rarely used. A cumulatively compounded motor has speed-load characteristic intermediate between those of a shunt and a series motor, the drop of speed with load depending on the relative number of ampere-turns in the shunt and series fields. It does not have the disadvantage of very high light-load speed associated with a series motor, but it retains to a considerable degree the advantages of series excitation.The application advantages of DC machines lie in the variety of performance characteristics offered by the possibilities of shunt, series, and compound excitation. Some of these characteristics have been touched upon briefly in this article. Stillgreater possibilities exist if additional sets of brushes are added so that other voltages can be obtained from the commutator. Thus the versatility of DC machine systems and their adaptability to control, both manual and automatic, are their outstanding features.中文翻译负载运行的变压器及直流电机导论通过选择合适的匝数比，一次侧输入电压1V 可任意转换成所希望的二次侧开路电压2E 。

自动化专业英文文献翻译2

西南交通大学毕业设计（英文翻译）节能型机房温湿度远程控制系统测控节点设计年级:学号:姓名:专业:指导老师:二零一一年六月MosixMosix修改bsdi上的BSD/ OS来提供电脑上的跨网络的动态负载平衡组和先发制人进程迁移。

这是不错的东西，不只是为并行处理，但对于通常使用一个集群很像一个可扩展的SMP。

是否有Linux版本？详细信息，请看.cs.huji.ac.il/mosix/。

NOW (工作站网络)伯克利工作站网络项目，/，已经极大地推广了并行计算中使用工作站网络，这里还有很多工作在进行中，都致力于“在未来几年内展示一个实际的100处理器系统”。

唉，他们不使用linux。

并行处理使用linux并行处理使用Linux 站点，/LDP/,是这些指南和许多相关文件包括为全日制量身订造的在线幻灯片的家园。

除了在报纸项目上，普渡大学电机与计算机工程系已经是并行处理的领先者，这个的设立是为了帮助别人申请并行处理的Linux电脑。

自从普渡大学的第一组Linux个人电脑在1994年2月组装以来，已经诞生了许多的Linux PC集群，有些还包括视频墙。

然而这些集群使用386，486和奔腾系统（没有奔腾Pro系统），英特尔最近获得普渡大学的捐赠，将允许它的奔腾II系统构建多个大型集群（与单个群集计划多达165机）。

并且这些集群都将有论文网，也具有最传统的网络。

奔腾Pro集群研讨会1997年，4月10-11日，埃姆斯实验室在得梅因，爱荷华州举行了奔腾Pro集群研讨会。

在本次研讨会，/workshops/PPCworkshop.html，从云集的参加者中收集了很多丰富的PC集群信息。

TreadMarks帝斯曼(分布式共享内存)帝斯曼（分布式共享内存）是一种技术，即一个消息传递系统可以出现的行为作为一个SMP。

有不少这样的系统，其中大部分使用OS页故障触发消息传输机制。

TreadMarks，/~willy/TreadMarks/overview.html，是这种系统更有效地之一，并在Linux集群上运行。

自动化毕业设计英文翻译

自动化毕业设计英文翻译Automatic Graduation Project TranslationIntroductionIn today's fast-paced world, automation has become an integral part of various industries. It has revolutionized the way we work and has significantly improved efficiency and productivity. As a result, automation has become a popular choice for graduation projects among engineering students. In this article, we will delve into the topic of automatic graduation project translation and explore its significance and benefits.The Significance of Automatic Graduation Project TranslationAutomatic graduation project translation refers to the use of automated tools and techniques to translate project documentation and reports from one language to another. This process eliminates the need for manual translation, saving time and effort for students. Moreover, it ensures accuracy and consistency in the translation, reducing the risk of misinterpretation.Benefits of Automatic Graduation Project Translation1. Time-saving: Manual translation can be a time-consuming task, especially when dealing with lengthy project documents. By utilizing automatic translation tools, students can significantly reduce the time spent on translation, allowing them to focus on other important aspects of their project.2. Improved accuracy: Automated translation tools use advanced algorithms and machine learning techniques to ensure accurate translations. These tools havethe ability to learn from previous translations and improve their accuracy over time. This reduces the chances of errors and ensures the quality of the translated content.3. Cost-effective: Hiring professional translators can be expensive, especially for students on a limited budget. Automatic translation tools provide a cost-effective solution, as they are often available for free or at a minimal cost. This allows students to allocate their resources efficiently and invest in other project requirements.4. Enhanced collaboration: Automatic translation tools facilitate seamless collaboration among team members who may speak different languages. By translating project documentation, everyone can understand and contribute to the project without any language barriers. This promotes effective teamwork and improves overall project outcomes.Challenges and LimitationsWhile automatic graduation project translation offers numerous benefits, it is important to acknowledge its challenges and limitations. Some of these include: 1. Language nuances: Automated translation tools may struggle to accurately capture the nuances and subtleties of a language. This can result in the loss of context and potential misinterpretation of the translated content. Therefore, it is crucial for students to review and edit the translated material to ensure its accuracy.2. Technical jargon: Engineering projects often involve complex technical jargonand terminology. Automated translation tools may not have the capability to accurately translate these specialized terms. Students must be cautious and manually review the translated content to ensure the technical accuracy of their project documentation.3. Cultural differences: Different cultures have unique ways of expressing ideas and concepts. Automated translation tools may not always be able to capture these cultural nuances, leading to misunderstandings or misinterpretations. Students should be aware of these differences and make necessary adjustments to ensure effective communication.ConclusionAutomatic graduation project translation offers students a convenient and efficient way to translate project documentation. It saves time, improves accuracy, and promotes collaboration among team members. However, it is important to recognize the limitations of automated translation tools and take necessary precautions to ensure the quality and accuracy of the translated content. By leveraging the benefits of automatic translation while being mindful of its limitations, students can enhance their graduation projects and contribute to the advancement of automation in the engineering field.。

自动化专业毕业设计外文翻译--现地控制单元在水电厂自动化中的应用

英文资料及翻译Location Control Unit In Hydroelectric PowerPlant Automation Application1. ForewordThe hydraulic electricity generation compares with burns coal, the fuel oil, the nuclear power electricity generation, the energy is renewable, the never exhaustible clean energy. The country gives priority to development the hydraulic electricity generation achievement to do well at present the energy balance the strategic measure, and appeared a row measure to encourage to advance the hydroelectric power plant construction vigorously. In the water and electricity profession, was on duty " along with hydroelectric power plant " nobody (few person value to defend) and the condition overhaul work thoroughly develops unceasingly, adds water the power plant production to move and to manage set a higher request; “Separated take the factory net, competes the price to access the net” also adds water as the foundation electric power system reform the power plant automation technology to set the new request. Computer technology, information technology, networking, industry control technology rapid development, for hydroelectric power plant synthesis automated system regardless of in the structure in the function, has all provided a broad development space.The 70's intermediate stages, the overseas hydroelectric power plant starts the advanced computer technology to apply in the hydro-electric power station industrial control, raised the hydroelectric power plant automated level greatly, has obtained the good economic efficiency. At the end of the 70's, the original electric power department science and technology committee managed held “the national hydroelectric power plant automation technical background meeting”, formulated the hydroelectric power plant automation science and technology to develop 7 years plan, our country starts to introduce and the domestic independent research and development hydroelectric power plant computer supervisory system technology and to obtain the huge success. Through many year endeavors, the domestic independent development hydroelectric power plant automation technology development experienced had tried to find out, the experiment site, the promotion, enhanced these four stages, has obtained the very big result. In the recent 20 years, the domestic hydroelectric power plant automation level development are specially rapid, at present entered the world advanced ranks.The hydroelectric power plant computer supervisory system usually may divide into two major parts, one is carries on the common control to the entire factory equipment the part, calls it the factory level or the factory station level supervisory system; Another part is located the water wheel electricity generation level, the switching house and so on the equipment nearby control sections, is called the location control system. The location control system main constituent is location control unit LCU (Local Control Unit), the early on once has used with electrical network dispatch remote terminal RTU (Remote Terminal Unit) the similar name, considered LCU the meaning is more accurate, since 1991 “location control unit academic conference”, basically unifies calls it LCU. Now makes several discussions on LCU in Our country Hydroelectric powerplant automated system application and the development.2. LCU applicationIn the hydroelectric power plant computer supervisory system LCU with the power plant production process connection, is directly in the system most has the object-oriented distribution characteristic the control device. The location control unit controlled member mainly includes following several parts:(1) power plant generating set, mainly has the hydraulic turbine, the generator, the auxiliary engine, the transformer and so on;(2) switching house, mainly has the generatrix, the circuit breaker, the isolator, the earth knife switch and so on;(3) public utility, mainly has the factory to use electricity the system, the oil system, the aqueous system, the direct current system and so on;(4) strobe, mainly has the water inlet strobe, the flood discharge strobe and so on.The LCU general arrangement nearby the power plant production equipment, to is accused the object movement operating mode to carry on the real-time surveillance and the control, is the power plant computer supervisory system compares the first floor control section. The primary data carries on gathering and the pretreatment in this, each kind of control adjustment order all sends out and completes the control closed loop through it, it is in the entire supervisory system very important, to the reliable request very high control device. Uses in the hydroelectric power plant LCU may divide into unit LCU, public LCU, switching house LCU according to the monitoring object and the installment position and so on. But and disposes according to the LCU itself structure divides, then may divide into the single trigger --linear structure LCU, take programmable controller (PLC) as foundation LCU, the intelligent location controller and so on three kinds. First kind of LCU many for hydroelectric power plant automation initial period product, at present basic no longer has used in the new system. Moreover still had few small hydroelectric power plants to use based on industry PC machine (called labor controlled machine IPC) the control system, below only discussed is in the mainstream status PLC and the intelligent location controller (the recent several years still had is called PCC (Programmable Computer Controller), PAC (Programmable Automation Controller) product, should also be possible to classify).2.1 programmable controller (PLC)The PLC definition has many kinds. International electrician committee (IEC) to PLC the definition is: The programmable controller is one kind of digital operation electronic system, for designs specially in the industry environment application. It uses the programmable the memory, uses in its internally stored program, carries out the logic operation, the sequential control, fixed time, counts with the arithmetic operation and so on face user's instruction, and through digital, the simulation input and the output, controls each kind of type the machinery or the production process. The programmable controller and the related equipment, all should according to easy form a whole with the industry control system, easy to expand its function the principle design.At first, needed to produce as a result of the American automobile industry has been possible to say was primitive PLC. Although the PLC being published time does not calculate long too, but along with the microprocessor appearance, large-scale, the ultra large scale integrated circuit technique of manufacture and the data communication technology rapid development, the PLC application and the technology also obtained the rapid development, its developing processapproximately separable three stages:(1) early time PLC (at the end of 60's -70's intermediate stages): Early PLC is called the programmable logical controller generally.(2) intermediate stage PLC (in 70's intermediate stage - 80's, later period): Starts in the 70's to use the microprocessor to take PLC the central processing element (CPU). Thus, causes PLC to result in the function big enhancement. In the software aspect, in the original logic operation, fixed time, counted and so on in the function foundations to increase functions and so on arithmetic operation, data processing and data communication, from diagnosis. In the hardware aspect, has developed the simulation quantity module, the long-distance I/O module as well as each kind of special function module, enables PLC the application scope to expand rapidly to needs the automatic control very many professions.(3) near future PLC (in the 80's, later period until now) enters in for the 80's, the later period, because the microprocessor hardware technique of manufacture rapid development, simultaneously the market price large scale drop, will cause each PLC manufacturer to be possible to use a higher scale the microprocessor. In order to further enhance PLC the processing speed, the very many manufacture manufacturer also developed has developed the special-purpose logical processing chip. Afterwards PLC has also integrated Ethernet, technologies and so on Web Server, has provided the function rich necessary software, causes the user community to use handily.On the century 80's to the 90's intermediate stages, are PLC develops the quickest time, the yearly rate continuously maintenance is 30%~40%. In this time, the PLC data acquisition handling ability, the numeral operational capability, the man-machine connection and network traffic capacity all obtains the large scale enhancement, PLC enters the process control domain gradually, unified after the partial industry control device substitutes gradually in certain applications has been at the dominant position in the process control domain the DCS system. Because PLC has the versatility strongly, the reliability high, the easy to operate, the programming simple, the adaptation surface broad and so on the characteristics, caused it is specially in the sequential control obtained the extremely widespread application in the industrial automation control.Applies PLC in the hydroelectric power plant production equipment monitoring begins in on the century 80's, because PLC defers to the industry use environment the standard to carry on the design generally, the reliability high, antijamming ability strong, the programming simple practical, met inserts the performance good very quickly accepts by the power plant user and system integration business, obtained the good application. At present includes in Our country Hydroelectric power plant use widespread PLC: GE Fanuc Corporation's GE Fanuc 90 series, German Siemens Corporation's S5, S7 series, French Schneider Corporation's Modicon Premium, Atrium and Quantum, American Rockwell Corporation PLC5, Control Logix, Japanese OMRON Corporation's SU-5, SU-6, SU-8, Japanese MITSUBISHI Corporation's FX2 series and so on. Because each kind of PLC principle of design difference is big, the product function, the performance as well as may constitute the location system scale to have the very big difference. Generally speaking, according to the different power plant in the security performance (including reliability, maintainable and so on), aspect and so on application function, control scale, system structure actual demands carries on the choice, may find appropriate PLC. At present there is big part of power plants the automated system all uses the PLC constitution location control section, and matches through the reasonable disposition, they basically all can shoulder the corresponding responsibility in the system, completes the corresponding function.But PLC took but one kind of general automated installment, is by no means designs specially for the hydroelectric power plant automation, this has in the special request profession application in the water and electricity automation also to be able to have some not suitable place inevitably, presently lists following several points:(1) PLC by “scanning”the way work, cannot satisfy the event resolution and the system clock synchronization request. The hydroelectric power plant computer supervisory system all is a multi-computer system, in order to guarantee the event resolution should have certain event besides PLC itself to respond ability and the high accuracy clock, but also requests in the overall system between various part of main equipment clock synthesis precision also to have to guarantee in a millisecond level. But take PLC as the foundation location control device if does not take the special measure, is unable to guarantee the hydroelectric power plant safe operation to the event resolution and the system clock synchronization request.(2) general PLC origin mainly aims at the machine-finishing profession, later gradually will expand all the various trades and occupations. Although present PLC has strongly from diagnosis function, but regarding the input, the output unit, it only from diagnoses the module level. This produces this kind of emphasis regarding our country electric power “the safety first” the profession said that, has certain being short of, often needs to add seperately the special security measure.(3) general PLC all has certain surge suppression ability generally, basically may suit the majority of profession application. But says regarding the hydroelectric power plant automated system, as a result of the equipment working conditions particularity, three level of surge suppression ability which the general PLC surge suppression ability and the technology standard request also has some disparities.2.2 intelligent location controllerApplies the many another kind of location control unit in Hydroelectric power plant automated system to be supposed to be the intelligent location controller, like ABB Corporation AC450, south auspicious group's SJ-600 series, Elin Corporation's SAT1703 and so on.AC450 is being suitable which ABB Corporation produces in industry environment Advant Controller series location control unit one kind, mainly applies in other profession DCS. It has included the module which by Motorola 68040 primarily processor CPU modules and I/O, MasterBus and so on many kinds of may elect, supports centralized I/O and distributional I/O, may act according to the different application demand to use the different module to constitute the suitable location subsystem.SAT1703 is the multi-processor system which Austrian Elin Corporation produces, it is loaded with different connection processor subsystem AK1703, AME1703 and AM1703 including 3. Each sub-system by the host processor, the connection template (module), constitutions and so on connection module, can realize the data processing, the control and the correspondence function, uses SMI in the LCU interior (Serial Module Interconnector) to carry on the correspondence. SAT1703 location control unit uses OS/2 operating system, the movement control software is ToolBox.SJ-600 series is on the international telegram automation research institute the century at the end of 90's for the domestically produced intelligence distributional location control unit which moves under the bad industry environment produces, by the master control module, the intelligent I/O module, the power source module as well as connects various modules and the master controlmodule scene bus network is composed. Moved reliably in the national dozens of large and middle scale hydroelectric power plants. Below SJ-600 has the main characteristic:(1), the master control module uses conforms to IEEE1996.1's embedded module standard PC104, has the reliability high, the scene environment compatibility strong and so on the characteristics. Uses low power loss embedded CPU, may choose the CPU model from 486 to the Pentium series.(2) 32 intelligence I/O module. All modules use 32 embedded CPU, this CPU designs specially for the embedded control, on the software uses the board level real-time operating system and the unification procedure code, only is different moves the corresponding duty according to the module. Has used large-scale programmable logic chip (EPLD) and the Flash memory, simplified the system design, enhanced the reliability. The intellectualized I/O module except may complete the data acquisition and the pretreatment independently, but also has very strongly from the diagnosis function, has provided the reliable control security and the convenience breakdown localization ability.(3) has the field bus network system structure, the system uses two network architectures, first is the factory cascade control network, connects LCU and the factory level computer, constitutes the distributed computer supervisory system; Second is I/O main line network, the connection master control module and the intelligent I/O module (location or long-distance), constitutes the distributional location control subsystem. All I/O module provides two field bus network connection, these modules all may disperse the arrangement, forms the redundant reliable distributional redundant system.(4) LCU direct connection high speed network. The network has become in the computer supervisory system the important part, it involves to the power plant control strategy and the movement way. Beforehand location controller many is the use private network carries on the connection with on position machine system, but conforms to the open standard network. If AC450 uses MB300 network with on position machine system connection, but with uses TCP/IP agreement the system connection only to be able to carry on through the special-purpose module by the VIP way the data transmission which limits.(5) has provided the direct GPS synchronized clock connection, does not need to program and the establishment. GPS to when may go directly to the module level, satisfied had the special request situation to the clock, like SOE and so on.(6) provides based on IEC61131-3 standard control language, in retained trapezoidal programming language in and so on the chart, structure text, instruction list foundations, developed the use “to see namely obtained”the technical design visualization flow chart programming language. The support control flow online debugging and playbacking, suits the complex control flow extremely the production and the maintenance.(7) in view of hydroelectric power plant automation specialized application development special-purpose function module.现地控制单元在水电厂自动化中的应用1. 前言水力发电与燃煤、燃油、核能发电相比，能源是可再生的、永不枯竭的清洁能源。

精品机械工程及自动化专业毕业设计翻译

Studies in dynamic design of drilling machine using updated finite element modelsAbstractThe aim of the present work is to develop updated FE models of a drilling machine using analytical and experimental results. These updated FE models have been used to predict the effect of structural dynamic modifications on vibration characteristics of the drilling machine. Two studies have been carried out on the machine. In the first study, modal tests have been carried out on a drilling machine using instrumented impact hammer. Modal identification has been done using global method of modal identification. For analytical FE modeling of the machine, a computer program has been developed. The results obtained using FEM, have been correlated with the experimental ones using mode shape comparison and MAC values. Analytical FE model has been updated, with the help of a program, which has been developed using direct methods of model updating. In the second study, modal testing has been carried out using random noise generator and modal exciter. Global method has been used for modal identification. Analytical FE modeling has been done using I-DEAS software. Correlation of FE results with the experimental ones has been carried out using FEMtools software. Updating of the analytical FE model has also been done using the above software, based on an indirect technique viz. sensitivity based parameter estimation technique. The updated FE models, obtained from both the studies have been used for structural dynamic modifications (SDM), for the purpose of dynamic design and the results of SDM predictions are seen to be reasonably satisfactory.Article Outline1. Introduction2. Modal testing and identification3. Finite element formulation of drilling machine4. Comparison of analytical FE and experimental results (model correlation)5. Finite element model updating6. SDM studies using updated models for dynamic design7. ConclusionsReferences1. IntroductionDynamic design aims at obtaining desired dynamic characteristics in machines and structures, which may include shifting of natural frequencies, desired mode shapes and vibratory response. The ultimate objectives are to have a quieter and more comfortable environment, higher reliability and better quality of product. The conventional dynamic design is basically hit and trial method in which we try to achieve desired dynamic characteristics by making several prototypes. The disadvantage of this technique is that actual design cycle takes a lot of time and therefore it is not cost effective. However, model updating based dynamic design saves design cycle time as well as reduces the cost involved. Various tools used for updating based dynamic design are: experimental modal analysis (EMA) including modal testing and modal identification, model updating and structural dynamic modification.Ewins [1]and Maia and Silva [2]have explained the basic concepts of modal testing, which is an experimental approach to obtain mathematical model of a structure. In a modal test, the structure under test is excited either by an impact hammer or by a modal exciter, and the response of the structure is recorded at several experimental points, in the form of frequency response functions (FRFs), using a dual channel FFT analyzer. The experimental modal model gives information about the natural frequencies, corresponding mode shapes and modal damping factor and is useful for model updating. The model updating techniques helps us to bring analytical finite element models closer to real systems. In model updating an initial analytical FE model constructed for analyzing the dynamics of a structure is refined or updated using test data measured on actual structure such that the updated model describes the dynamic properties of the structure more correctly. The inaccuracies in FEM, when applied to dynamic problems are due to uncertainties in boundary conditions and structural damping etc.Friswell and Mottershead [3] have discussed the finite element model updating in structural dynamics. Baruch and Bar-Itzhack and Baruch [4] and [5] considered analytical mass matrix to be exact and developed a direct method for updating using test data. Berman and Nagy [6]developed a method of model updating, which uses measured modes and natural frequencies to improve analytical mass and stiffness matrices. Structural dynamic modification (SDM) techniques [7]and [8]are the methods by whichdynamic behaviour of the structure is improved by predicting the modified behaviour brought about by adding modifications like those of lumped masses, rigid links, dampers etc. Thus the dynamic design using updated model is expected to be helpful in order to predict accurately and quickly, the effect of possible modifications on the dynamic characteristics of the structure at computer level itself, thus saving time and cost.Sestieri [7]has discussed SDM application to machine tools and engines. Kundra [8]gave the method of structural dynamic modification via models. Modak [9] has discussed SDM predictions using updated FE model for an F-structure. He used constrained nonlinear optimization method for updating of a machine tool using stiffness parameters at the boundary [10]. The present paper deals with the FE model updating using direct as well as indirect method, and to use this updated FE model for dynamic design based on SDM predictions of a machine tool viz. a drilling machine. Two different studies are reported using different techniques for analytical and experimental analysis and for updating. Various objectives with which the present research work has been carried out are• To develop updated FE models of a complex structure like that of a drilling machine and to use these updated models to predict the effect of various modifications on modal properties of the machine.• To see whether hammer excitation yields good results for fairly complex structures like drilling machine or not, and to compare these results with those obtained from modal exciter.• To analyze the results of SDM predictions obtained using the updated models derived in the studies.2. Modal testing and identificationIn the two studies mentioned earlier, different techniques have been used, for modal testing and identification. In the first study, impact hammer is used to excite the drilling machine structure, at various points as shown in Fig. 1 and Fig. 2. Response is taken at a fixed point with the help of an accelerometer.(12K)Fig. 1. Experimental setup (Study 1).(4K)Fig. 2. Hammer excitation locations.In the present study, the drilling machine is excited at 30 locations and therefore, 30 FRFs are obtained. These FRFs are recorded in the form of inertance. The experimental FRFs, thus obtained are transferred to computer. Modal identification or modal parameter extraction consists of curve fitting a theoretical expression for an individual FRF to the actual measured data obtained. The experimental FRFs are analyzed by GRF-M method using modal analysis software ICATS [11] to obtain modal parameters of the drilling machine. In the second study, the machine tool structure has been excited at the base at point 28, referring to Fig. 2, using modal exciter and response has been measured at various points using piezoelectric accelerometers. The modal identification of the FRFs, thus measured has been carried out using global method GRF-M method in ICATS software.Table 1compares the experimental natural frequencies obtained from both the methods, which shows minor differences in the two modal frequenciesTable 1.3. Finite element formulation of drilling machineSeveral books have given the basic concepts of finite element analysis, some of them are: Zienkiewicz [12] and Bathe [13].The drilling machine structure is very complicated with different mountings and accessories. Therefore exact modeling and analysis of the actual structure is difficult and it takes more computational effort. However for analytical FE analysis, simplified model of drilling machines has been considered. In study 1, the finite element modelling has been done using a program developed in MATLAB. Beam elements have been used for the analysis. The joints and boundary conditions are considered to be rigid and influence of structural damping on modal model parameters, is ignored. The relevant data used for the drilling machine is given below:25 mm pillar type, height = 1.655 m, mass density = 7800 kg/m3, Young’s modulus= 200 Gpa, number of nodes = 30, number of elements = 29, number of nodes per element = 2, degrees of freedom per node = 3.Fig. 3shows the structure of the drilling machine with the node numbers given for study 1.(7K)Fig. 3. Drilling machine structure for FE analysis.The eigenvalues and eigenvectors have been calculated. The analytical FE model of the structure consists of 90 ×90-size mass and stiffness matrices (30 ×3, 30 nodes and 3 d.o.f. per node). But by experiment only 30 coordinates can be measured. Therefore FE model has been reduced using Guyan [14] reduction method with the help of a program developed in MATLAB.In study 2, the finite element modelling has been done using I-DEAS software. The model has been made using beam mesh. Although the FE model has been simplified but the beam elements has rotational degree of freedom, which cannot be measured experimentally. Therefore the FE model needs to be reduced. The FE model has been reduced using model reduction utility。

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中英文翻译Classification of control systems there are three ways: by automatic classification methods in order to participate in the control mode classification, to adjust the law category.One way to control category 1, the open-loop control system if the computer output of open loop control system to exercise control of the production process, but the control results --- the state of the production process does not affect the computer control systems, computer \ controller \ production and other sectors does not constitute a closed loop, is called open-loop control system computer. the production process of the state is no feedback to the computer, but by the operator to monitor the status of the production process, decision control program, and tell the computer to control the role of exercising control. 2, closed loop control system computer to the production of an object or process control, the state can directly influence the production process computer control system, called the closed-loop control system computer. Control of the computer monitor in the operator, the automatic acceptance of the production process state test results, calculate and determine the control scheme, the direct command and control units (devices> of action, the role of exercising control of the production process. In such systems, aircraft control components under control of control information sent to control device operation, the other running equipment condition as the output, measured by the detection part, the feedback as input to the control computer。

to make control Computer \ Control Components \ production \ test components form a closed loop. We will call this form of control computer control closed-loop control. Closed loop control system computer, using a mathematical model to set the value of the production process and test results of the best value of the deviation between the feedback and control the production process to run at their best. 3, line control system as long as the computer controlled production of the controlled object or process, to exercise direct control, without human intervention are called the control computer on-line control, or on-line control system. 4, offline control system control computer does not directly participate in the control object or the controlled production process. It only managed to complete the process of the controlled object or the status of testing, and testing of data processing。

and then develop control programs, the output control instruction, operator reference control instructions manually controlled operation to control parts of the object or subject control process control. This control form is called off-line computer control system. 5, real-time control system control computer real-time control system iscontrolled by the control of the object or process, or request when the request processing control, the control function in a timely manner to address and control systems, commonly used in the production process is interrupted for the occasion. Such as steel, each one refining furnace steel is a process。

and if the process rolling, rolling out each piece of steel considered a process, each process is repeated. Only enter the process only requires a computer control. Once control of the computer, it requires a computer from the production process information in the required time to respond to or control. Such systems often use sophisticated interrupt system and interrupt handling procedures to achieve. In summary, an online system is not necessarily a real-time system. But a real-time system must be an online system.Second, in order to participate in the control mode to Category 1, direct digital control system by the control computer to replace conventional analog instruments and direct regulation to control the production process, as the computer as digital signals, so named after the DDC control. Actually controlled the production process control components, control signals received by the process controller input / output channels of D / (D / A> converter output of the digital control computer volume to be converted into analog。

analog input control machine to go through the process of input / output channels of analog / digital (A / D> converter into a digital number into the computer. DDC control systems often use a small computer or microprocessor, the time-sharing system to achieve multiple points of control. Is in fact a discrete sampling with the controller, to achieve discrete multi-point control. DDC computer control system that has become the main control computer control system forms. DDC control of the advantage of flexibility, large, focused on high reliability and low cost. Can use several forms of digital computing circuits, or even dozens of loop production process, integral to proportional --- --- differential (PID> control to maintain the industrial state of the controlled object at a given value, the deviation small and stable. And as long as the change of control algorithms and applications can achieve more complex control. Such as feedforward control and the best control. Under normal circumstances, DDC-level control often more complex as the implementation of advanced control level. 2, supervisory computer control system supervisory computer control system for a particular production process, according to the production process of various states, according to the production process of the mathematical model to calculate the best production equipment should be running a given value, and the best value automatically or manually on the DDC Executive-level computer or analog meter to align the regulation or control of the target set. By a DDC or adjust the instrument at various points on the production process (running equipment> to exercise control. SCC system is that it can guarantee the production process is always controlled the situation in the best condition to run, so get the most benefit. SCC results directly affect the merits of the first of its mathematical model, this should always improve the operation process model, and modify the control algorithm, and application control procedures. 3, multi-level control systems in modern manufacturing enterprises in the production process not only the need to address the problem of online control, and Huan Zhi Li called for a solution of production problems, the daily product line, the number of arrangements for planning and scheduling, and Rose plans develop a long term planning, notice Xiaoshou prospects, there was multi-level control system. DDC class is mainly used for direct control of the production process, for PID, or feedforward control。