Wireless remote control design research

Wireless remote control design research

With the rapid development of modern science and technology, economic and other industries, the use of wireless remote control will also be widely applied to production practice, life. In industrial control field, often require large amounts of field data collection, such as temperature, humidity, barometric pressure, etc., after that information system by remote control, the control signal is transmitted to the site to perform various operations module. As can be seen, in the process of data collection and transmission, and ultimately to achieve data transmission between various devices, and then implement on-site control, wireless remote control is a very important part.

1.1 Design Significance

Currently, the wireless remote control technology in general can have the following ways: infrared remote control mode, the radio remote control mode, remote control mode and ultrasonic sound remotely. Infrared remote control mode, although low cost, fast response, but in control of the content of obstructions vulnerable, susceptible to outside interference; ultrasonic frequency band is narrow, with less information; voice remote control not only less information, the propagation distance is short. Radio as a new generation of information transmission, using a special codec technology to prevent interference of radio waves, not limited by the angle, the distance transmission is relatively far away. Over the last decade, with the rapid development of mobile communication technology, more and more data acquisition and control system uses a wireless data transmission technology, low-cost wireless transmission wiring, safe and easy, easy to move the advantages of using remote telemetry, areas of access control systems, and its application in the high-tech sector is also developing rapidly, such as satellites, missiles, unmanned reconnaissance aircraft and other places data acquisition, remote controlled robots ,, and some monitoring equipment. Furthermore, in terms of modern military field, wireless remote control technology has an important strategic position in the high-tech future, the wireless remote control system will also use more and more flexible and extensive.

1.2 The concept of wireless remote control

The concept of radio remote control: remote controlled object is to distance control, and operation of the controlled object according to instructions. Radio-controlled task is to become the various control instruction corresponding electrical signals and electrical signals transmitted by radio waves to the receiving end, the controlled object or remote control of various processes. 3, the classification remote control device: Press the controlled object and feature classification, a fixed remote control and remote control room. Former such as oil wells, wells, crane and other equipment operation, to play down the target drone control of fixed electrical equipment or appliances control; the latter, such as aircraft, launch vehicles, missiles, satellites of remote control, for model cars, model ships remote control and so on. Press control feature or characteristic of the controlled object control signals can be divided into two categories: one is a state controlled object single on-off control, and the other is the state of the controlled object is continuously adjusted.

1.3 wireless remote control

The transmitter includes coding circuit and a transmission circuit. Encoding circuit (manipulation switch or potentiometer, etc.) is controlled by the manipulator, the manipulator through a manipulator; encoding circuit generates the desired control command. These control commands are having certain characteristics, electrical signals easy to distinguish from each other, for example: a sinusoidal signal with a frequency of 270Hz as the command control left rudder, sinusoidal signal with a frequency of 350Hz as the command control right rudder, that is different the frequency of the sinusoidal signals representative of different control instructions. In addition to the use of the frequency characteristics, but also with the amplitude and phase characteristics of a sinusoidal signal, the amplitude of the pulse signal, width and phase characteristics and the code set of features like represent various instructions. Command signal coding circuit generates a low frequency electrical signals are not sent directly to the remote target up, but also the command signal to the transmitter circuit, it is contained in a high-frequency signal (carrier), and can be sent by the transmitting antenna out. Just as the transportation of goods by train,

aircraft and other vehicles as command signal corresponds to the cargo carrier equivalent means of delivery. We process the command signal carrier to carrier modulation called up, the modulation effect is completed by the modulator transmitting circuit. The main role is to generate a carrier transmitting circuit, the command signal by a modulator modulated on a carrier, the modulated carrier via the antenna transmitted. The receiver consists of a reception circuit and decoding circuit. Also includes a high-frequency reception circuit portion and a demodulator section. After selection and amplification by the receiving antenna signal sent by weak high-frequency part of the receiver, to the demodulator. After as trains, aircraft and other vehicles arriving, the unloaded circumstances, like the role of the demodulator is from the carrier "dumping" under the command signals. As the "unload" down various command signals are mixed together, but also to the decode circuit decoding. Work decoding circuit as the unloaded cargo triage, and then were sent to the site to use as its various commands do not check signals, sent to the appropriate implementation of the amplifier circuit. The instruction execution amplification circuit amplifies the signal to have a certain power to drive the actuator. Actuator electrical energy into mechanical motion, such as the rotation of the motor, electromagnet, etc. puff actuated to drive the accused adjustment mechanism (for example rudder), in order to achieve the goal of controlling the accused.

1.4 wireless remote control Type:

Radio remote control transmitter head T630 is a built-in miniature open lines without signal transmitter that emits a frequency of 265MHz,

When the 12V power supply, remote control distance of 100M, operating current of only 4mA, its volume 28X12X10mm. Radio receiver T631, a built-in antenna, the same as the TV tuner receiver, demodulator, its typical operating voltage of 6V, waiting for an operating current of 1mA, the reception frequency of 265MHz, its volume is only 31X23X10mm. Using them can easily create a variety of radio remote control device having a miniaturized, transmission distance, low power consumption, anti-interference ability and so on. It can easily replace the infrared, ultrasonic transmitter and receiver. Radio emission head T630 circuit shown in FIG. Circuit four

launch tubes V1 and external components C1, C2, L1, L2 frequencies like 265MHz UHF transmitter circuit, firing into the air via the loop antenna L2. L2 antenna using silver wire or wire diameter of 1.5mm, antenna size is 24mm (length) X9mm (high). Use high-frequency transistor V1 launch tube BE414 or 2SC3355.

FIG

T631 radio remote control receiver circuit shown in FIG. Receiving circuit mainly by V1, IC and other components, V1 and C7, C9, L2 and other components UHF receiver circuit, trimming C9 to change its receiving frequency to strict alignment of 265MHz transmission frequency. When the antenna L2 receives the modulated wave, the low-frequency component of the tuning amplifier V1, V2 and then after the preamplifier into the IC LM358, LM358 further amplified by the plastic after 7 feet out, the actual size of the printed circuit board is 31mmX23CC, antenna size of 27mm (length) X9mm (high). OUT signal output terminal, the transistor V1 selects BE415 or 2SC3355. Capacitor C9 can use a small adjustable capacitor. IC selects LM358. In the transmitting and receiving circuit for reduced size, all resistors are made of metal film resistors 1 / 8W or 1 / 16W; the electrolytic capacitor is also used in ultra-small capacitors other capacitors used in all high-frequency ceramic capacitors.

2.design method

FPGA Field Programmable Gate Array is the English abbreviation of the field programmable gate array, which is a product based on GAL, PAL, CPLD and other

programmable devices on further development. After 70 years of continuous development, FPGA development from the original 1200 into today's one million level. FPGA is a dedicated integrated (ASIC) in the field of a semi-custom circuits arise not only solve the shortage of custom circuits, but also to overcome the limited number of gates of programmable devices existing shortcomings. FPGA logic cell array using LCA (Logic Cell Array) such a new concept, including internal configurable logic block CLB (Configurable Logic Block), input-output module IOB (Input Output Block) and the interconnector (Interconnect) in three parts. FPGA is a program stored in the chip RAM to set their work status, and therefore, when work needs to be programmed on-chip RAM. Users can configure different patterns, using different programming.

FPGA's basic features are:

(1) FPGA ASIC circuit design, users do not need to cast film production, you can get the combination of chip.

(2) FPGA to do other full-custom or semi-custom ASIC circuit in the specimen.

(3) FPGA internal triggers and rich I / O pins.

(4) FPGA ASIC circuit is the shortest design cycle, the lowest development costs, one of the least risky devices.

(5) FPGA technology uses a high-speed CHMOS, low power, compatible with CMOS, TTL level.

3. wireless remote control : about distance

Transmitting power: transmitter power for big distance, but power consumption is large, prone to interference; receiving sensitivity: Receiver improve receiver sensitivity, remote control distance is increased, but susceptible to interference caused by malfunction or runaway ; Antenna: The antenna straight and parallel to each other, remote control distance, but occupies a large space, in the use of the antenna stretched, straightened increase the remote distance; height: the higher the antenna, remote control distance farther, but by objective conditions; barrier: currently used

wireless remote control uses state of the UHF band, whose propagation characteristics and light approximation, linear propagation, diffraction is small, if the walls of the barrier greatly discounted remote control distance between the transmitter and the receiver, if it is reinforced concrete walls, due to the absorption of the conductor on the radio, the impact even more. 7, the radio remote control radio remote control is the use of various institutions distant radio signals for controlling remote devices. Common modules commonly accepted radio transmitter radio remote control system is generally divided into two parts for transmitting and receiving. Emitting portion is generally divided into two types, namely remote control and the transmitter module, remote control and remote control module is used for the method, the remote control can be used independently as a whole, the external lead wire for wiring trailer coupling; and remote control module in the circuit when an element to be used for application in accordance with its pin definitions, the advantage of using a remote control module can seamlessly connect the application circuit, small size, low price. Generally accepted part is also divided into two types, namely super heterodyne with super-regenerative receiving mode, super-regenerative demodulator circuits also called the super-regenerative detector circuit, it actually works in a state of shock intermittent renewable detection circuit. Super heterodyne demodulation circuit super heterodyne receiver same, he was provided with a local oscillator circuit generates an oscillating signal, after the carrier frequency of the received signal is mixed to obtain the IF signal, the IF amplification and detection, demodulating data signal. Since the carrier frequency is fixed, so the circuit is simpler than the radio. Super heterodyne receiver stability, high sensitivity, anti-interference ability is relatively good; super-regenerative receiver is small and cheap.

Traditional mechanical switches increasingly unable to meet the needs of people's pursuit of the perfect life. With the continuous improvement of living standards, innovative science and technology, intelligent wireless remote control technology to replace traditional manual control, it has become a fashion of modern life. Using wireless remote light switch, anywhere in a space at any time, can be arbitrarily regulated lights and other electrical appliances, so that we really feel the charm of

high-tech and convenient. Compared with a wireless remote control infrared remote control, voice control, wireless remote control with wide coverage, control distance, penetration and other characteristics, such as blasting remote control, factory production control and some of the terrain advantageous, the operator inaccessible or inaccessible actual occasions, more attractive, doubly impressive.

Only a few decades of the historical development of radio-controlled technology: the 1920s radio-controlled prototype has just appeared. At that time, people are trying to remote control technology used on unmanned aircraft and ships, but because technology is not perfect but failed. After World War II, radio remote control technology is developing rapidly, and gradually has been widely used in military, defense, industrial and agricultural production as well as science and technology. Up to now, with the rapid development of electronic technology, emerging new large-scale integrated circuits remote control, remote control technology has been making rapid development. Center remote control device from the early part of discrete components, integrated circuits, and gradually developed into the present-chip microcomputer, intelligent greatly improved. In recent years, more and more widespread use of remote control technology in industrial production, household appliances, security and people's daily lives. In the field of wireless remote control, remote control mode before the usual main ultrasonic remote control, infrared remote control, radio remote control and the like. Because radio waves are transmitted by the launch point in all directions, they can pass through the barrier, and can spread to great distances, so it can achieve control over a large area and space, become the main way remote control, defense, military , production, construction and daily life and a wide range of applications. To this end, on the basis of previous studies on the design method to design an integrated chip multi-channel wireless remote control switch point system. Studies have shown that this method designed remote control switch system convenient, more suitable for the occasion containing controlled appliances, enabling multi-channel multi-function control.

4.summary

As society progresses, the continuous development of science and technology, the

radio remote control in all areas of society are playing an increasingly important role, whether it is the lifeblood of these related to the national defense industry, military, manufacturing, construction, or are we everyday life. Therefore, to study whether this knowledge is to the country, or to their daily lives will be beneficial, so I paper on radio remote control technology for simple overview. Of course, I'm still quite superficial understanding, learning in later life, I will be more efforts.