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液压动力系统中英文对照外文翻译文献

液压动力系统中英文对照外文翻译文献

中英文对照外文翻译文献(文档含英文原文和中文翻译)原文：FEATURE-BASED COMPONENT MODELS FOR VIRTUALPROTOTYPING OF HYDRAULIC SYSTERMAbstract:This paper proposes a feature-based approach for the virtual prototyping of hydraulic systems. It presents a framework which allows the designer to develop a virtual hydraulic system prototype in a more intuitive manner, i.e. through assembly of virtual components with engineering data. The approach is based on identifying the data required for the development of the virtual prototypes, and separating the information into behaviour, structural, and product attributes. Suitable representations of these attributes are presented, and the framework for the feature-based virtual prototyping approach is established,based on the hierarchical structure of components in a hydraulic system. The proposed framework not only provides a precise model of the hydraulic prototype but also offers the possibility of designing variation classes of prototypes whose members are derived by changing certain virtual components with different features.Key words: Computer-aided engineering; Fluid power systems;Virtualprototyping1.IntroductionHydraulic system design can be viewed as a function-to-form transformation process that maps an explicit set of requirements into a physical realisable fluid power system. The process involves three main stages: the functional specification stage,the configuration design stage, and the prototyping stage.The format for the description of the design in each stage is different.The functional specification stage constitutes the initial design work. The objective is to map the design requirements. To achieve this, the design problems are specified Correspondence and offprint requests to: Dr S. C. Fok, Schoool of Mechanical and Production Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798. The designer must identify the performance attributes, which can include pressure, force, speed, and flowrate, with the required properties such as size, cost, safety and operating sequence. performance requirements for each attribute. In this stage, the design is abstracted in terms of the performance attributes with associated values.The objective of the configuration design stage is to synthesise a hydraulic circuit that performs the required functions conforming to the performance standards within defined constraints. A typical hydraulic system is made up of many subsystems. The smallest building block in a subsystem is the standard hydraulic component (such as valves, cylinders,pumps, etc.). Each type of standard component serves a specific elemental function. The design effort in the configuration design stage is fundamentally a search for a set of optimal arrangements of standard components (i.e. hydraulic circuit) to fulfil the functional requirements of the system. Based on this framework, the designers would normally decompose the overall system functions in terms of subfunctions. This will partition the search space and confine the search for smaller hydraulic subcircuits to perform the subfunctions.Computers are often used to support the configuration design process. For example, Kota and Lee devised a graph-based strategy to automate the configuration of hydraulic circuits. After the development of the hydraulic circuits, digital simulation tools are often used to study and evaluate these configurations. With these tools, designers can compare the behaviour of different circuits and also analyse the effects when subcircuits are combined. In the configuration design stage, the design is traditionally represented as a circuit drawing using standard icons to symbolise the type of standard component. This is a form of directed graph S(C,E) where the circuit S contains components C in the form of nodes with relations between components denoted by edges E.The prototyping stage is the verification phase of the system design process where the proposed hydraulic circuit from the configuration design stage isdeveloped and evaluated. Physical prototyping aims to build a physical prototype of the hydraulic system 666 S. C. Fok et al. using industrial available components. The process of physical prototyping involves the following: Search for appropriate standard components from different manufacturers. Pre-evaluation and selection of components based on individual component cost, size, and specification, and compatibility factors between components. Procurement and assembly of the selected components.Test and evaluate the physical prototype based on the overall system requirements. Use other components or redesign the circuit (or subcircuits)if necessary.Besides dynamics, the development of the physical prototype must take into consideration other factors including structure,cost, and weight. The dynamics data are used to confirm the fluid power system behaviour whereas the geometric information is used to examine the assembly properties. The development of the physical prototype will provide the actual performance,structure, and cost of the design.The main disadvantage of physical prototyping is that it is very tedious and time consuming to look for a set of suitable combinations of standard components from among so many manufacturers. Although the basic functions of the same types of standard component from different manufacturers do not differ, their dynamics, structural and cost characteristics may not be similar, because of design variation. Hence, for a given hydraulic circuit, different combinations of parts from differentmanufacturers can have implications on the resulting system,in terms of dynamics, structure, and cost. Value engineering can be used at this stage to improve the system design by improving the attributes at the component level. This includes maximizing the performance-to-cost ratio and minimising the size-to-performance ratio. Virtual prototyping can be viewed as a computer-aided design process, which employs modelling and simulating tools to address the broad issues of physical layout, operationalconcept, functional specifications, and dynamics analysis under various operating environments. The main advantage of virtual prototyping is that a hydraulic system prototype can be assembled, analysed, and modified using digital computers without the need for physical components, thus saving lead time and cost.The main requirement of a virtual hydraulic system prototype is to provide the same information as a physical prototype for the designer to make decisions.To achieve this, the virtual prototype must provide suitable and comprehensive representations of different data. Furthermore, transformation from one representation to another should proceed formally. Xiang et al. have reviewed the past and current computer-aided design and prototyping tools for fluid power systems. The work revealed that the current tools could not provide a completerepresentation of the design abstractions at the prototyping stage for design judgement. Most of the tools concentrate on the dynamics behaviour. Vital geometrical and product information that relates to the system prototype consideration and evaluation is frequently missing.To advance the development of computer-aided virtual prototyping tools for fluid power systems, there is a need to address the formal representations of different abstractions of behaviour,structural, and product data along with their integration. This paper focuses on these issues and proposes the formalism of a unified component model and the taxonomy based on the feature-based approach. In Section 2, we discuss the feature- based approach focusing on the key information and their representations required for hydraulic system prototyping. Section 3 presents a formalism of the feature-based model and structure for the development of virtual hydraulic system prototypes.The structure is illustrated with an example. Future work and conclusions are given in Section 4.2. Feature-Based ApproachFeatures can be defined as information sets that refer to aspects of attributes that can be used in reasoning about the design, engineering or manufacturing processes. The concept of using features to integrate CAD/CAPP/CAM is not new and there are many papers on the application of this approach in CIM. In all these applications, the feature model is regarded as the basis whereas design by features is the key for the integration. To develop a feature model, the relevant information concerning the design must be identified and grouped into sets based on the nature of the information. The relevant information should contain sufficient knowledge for activities such as design, analysis, test, documentation, inspection, and assembly, as well as support various administrative and logistic functions. Design by features is the process of building a model of the design using features as primitive entities. The feature model provides the standardisation of relevant data. Through the design by features approach, vital knowledge of the design will be generated and stored. Together, the feature model and the design by features approach will provide the essential information, which can be used, not only for the simultaneous consideration of many different concerns with the design, but also to interface the many activities in the design realisation process, including the life cycle support operations. The main drawback of the feature-based design approach is that the feature model should be properly defined . This can be difficult, as features are sets of knowledge that are application dependent. The organisation of the features can also be application specific. Non-trivial data-management problems could arise if the feature model is not properly defined. To avoid these problems, the type,representation and structure of the features should be resolved prior to using the feature-based design methodology. The main concern when developing afeature model is that it is application-specific. In the domain of virtual prototyping of hydraulic systems, the details of the constituent standard components must be able to be used to describe the overall system. The component features are bearers of knowledge about that part. To create a suitable feature model for hydraulic system design based on the assembly of standard components, the relevant information associated with various standard components must be identified and classified. This definition Feature-Based Component Models 667 of the component feature set can then be extended to encompass the subsystem feature set based on the hierarchical structure between the components in the subsystem. In the same manner, a hierarchical structure for the hydraulic system feature representation would evolve by considering the system as a hierarchy of subsystems.The necessary information required for a proper description of the virtual prototype must be no less than that derived by the designer from a physical prototype for decision making. These data should generally include the shape, weight, performance properties, cost, dimensions, functionality data, etc. Comparison with the physical prototyping process, the information required for each standard component could be separated into three distinct groups: behaviour attributes, structural attributes, and product attributes.2.1 Behaviour AttributesThe behaviour of a hydraulic component can be defined in terms of the dynamics characteristics used to satisfy the functional requirements. Consider a hydraulic cylinder connected to a load. Its function is to transmit a force from the stroke of the piston to the load. The maximum force it can transmit can be used to define the functionality and the behaviour requirements can be specified in terms of the desired load acceleration characteristics. Hence for a hydraulic component, behaviour attributes express functionality and can be reflected in the dynamics characteristics. The designer is responsible for the proper definition of the overall system behaviour characteristics in terms of the desired dynamics. A standard component will have its own behaviour and provide a specific plex functions that cannot be achieved by a single standard component are derived using a combination of components. Hence, the behaviour of the standard component will play an important role as the individual behaviours of components together with their arrangement can alter the overall system function .The behaviour of a standard component can be nonlinear and can be dependent on the operating conditions. When two components are combined, it is possible that their behaviours can interact and produce undesired or unintended characteristics. These unwanted behaviours are assumed to have been resolved during the configuration design stage. The hydraulic circuit used in theprototyping stage is assumed to be realisable and without any undesirable interacting behaviours. This means that the output behaviour of a component will provide the input to the subsequent component.The representation of behaviours for hydraulic systems has been widely investigated. These representations include transfer functions, state-space and bond graphs. Transfer functions (for single-input–single-output systems) and state-space equations (for multiple-input–multiple-output systems) are based on the approximation of the dynamics about a nominal operating condition. The power bond graph model is based on the causal effects that describe the energy transformations in the hydraulic system. This approach is appealing for hydraulic system analysis. The main disadvantage is that the derivation of the dynamics equation in a bond graph of a complicated fluid power system can become very tedious. As a result, recent work has concentrated on the used of artificial intelligence to represent the nonlinear mapping between the input and output data, which can be obtained via experimental work. These nonlinear mappings can be accomplished using artificial neural networks .It is quite natural for a hydraulic system designer to use input–output data to describe the behaviour of a hydraulic component. The configuration design of a hydraulic system is often achieved through steps of function decomposition. To design a hydraulic system, the designer often tries to decompose the functions and their requirements down to the component level.译文：基于原型液压系统特征的机构模型摘要：本文为原型液压系统的设计提出了一种基于特征的方法。

中英文对照起重机术语大全修订版

中英文对照起重机术语大全修订版

中英文对照起重机术语大全修订版IBMT standardization office【IBMT5AB-IBMT08-IBMT2C-ZZT18】中英文对照起重机术语大全起重机（crane）moblie crane?移动式起重机truck crane?汽车式起重机wheel crane / wheeled crane?轮胎起重机crawler crane / caterpillar crane?履带吊;履带式起重机tower crane?塔吊;?塔式起重机-construction tower cranes / building tower crane?建筑塔式起重机，建筑塔机-luffing jib tower crane?动臂塔式起重机-tower jib crane?塔式挺杆起重机（含义与上同）bridge crane/traveling crane/overhead crane?桥吊；桥式吊车;?桥式起重机-electric traveling crane?电动桥式起重机（俗称行车、天车）-electric double-beam bridge crane?电动双梁桥式起重机portal crane / portal bridge crane门式起重机- semi-goliath crane?半门式起重机- semi-portal bridge crane?半龙门起重机gantry cranes?龙门起重机- rubber tyred gantry crane?轮胎式龙门吊- electric gantry crane?电动龙门式起重机- hook gantry crane?吊钩龙门吊- economical gantry crane?简单龙门起重机;?简易龙门起重机- rubber tyred container gantry crane?轮胎式集装箱龙门起重机barges / floating Cranes?船式起重机;?浮吊;?浮式起重机水上起重机boom crane?吊杆起重机;?桁梁起重机;?臂式起重机;?伸臂起重机bucket crane?料罐起重机;?吊斗起重机building crane?建筑起重机cable crane?索道起重机;?缆索起重机container crane?集装箱起重机electric crane?电动吊车;?电动起重机;?电力起重机electriomagnet crane?电磁铁起重机electric jib crane?电动单臂起重机fixed crane?固定式起重机climbing crane?爬升式起重机；攀爬式起重机fixed derrick crane?固定式动臂起重机fixed jib crane?固定式悬臂起重机flying crane helicopter?起重直升机hoist crane?起重葫芦hoisting crane?升降起重机hook type crane?钩式起重机twin hood crane?双钩吊车mobile crane?移动式吊车;?移动式起重机quay crane?码头起重机;?码头桥式起重机;?港岸起重机revolving track crane?回转式轨道起重机circular crane?旋转式吊车环形吊车roof crane?屋顶起重机transporter crane?桁架式起重机electric crane?电动吊车;?电动起重机gasoline crane?汽油起重机hydraulic crane?液力起重机;?液压起重机derrick crane?人字扒杆人字起重机-travelling derrick crane?移动式人字扒杆jib crane?/?cantilever crane?悬臂式起重机wall crane?壁式起重机heavy duty crane?重型起重机crane output / carrying capacity of crane / lifting capacity of crane?吊车起重能力crane load?起重机起重量;?起重机起重量crane rating?起重机定额;?起重机载重量crane radius?起重机起吊半径;?起重机伸臂活动半径;?起重机伸距craneage?吊车工时crane beam?行车梁起重机大梁crane stair?起重机楼梯hoist drive mechanism?起重机驱动机构travelling crab?起重机小车hoisting controller?起重控制器吊车控制手柄hoisting facility?起重设施lifting gear?起重装置crane (runway) girder?吊车梁crane support wall?吊车支承墙crane boom?起重机吊架;?起重架;?吊车臂;?吊车起重扒杆;?吊杆crane column?吊车柱crane hook / grab?（or lift hook）（?or dolly）起重机吊钩crane jib?起重机吊杆crane bridge?起重机桥crane buffer?吊车缓冲器crane rope / crane cable起重钢绳;?起重机吊索;?吊车钢丝绳crane carriage?起重小车;?横行小车crane carrier?起重机载运车crane controller?起重控制器crane fall?起重机索crane motor / crane hoist type motor?起重机电动机crane platform?起重机平台crane rail?吊车轨，起重机轨道crane runner?吊车司机crane runway?起重机走道;?天车滑道crane weigher?吊车秤crane wheel?吊车车轮crane winch?起重机绞车lifting tackle?起重滑车lever of crane?起重机臂hoisting tools?起重工具吊具lifting rope?吊绳起重钢丝绳起重吊装术语：hoist / load up?起升lower / load down?下降hoist slowly / load up slowly?微微起升lower slowly / load down slowly?微微下降use main hoist/use main line?使用主钩use whip hoist/use whip line?使用小钩raise boom / boom up（臂架类吊车）抬起主臂lower boom / boom down?（同上）降下主臂raise boom slowly / boom up slowly（臂架类吊车）微微抬起主臂lower boom slowly / boom down slowly?（同上）微微降下主臂swing?（根据指挥手势、旗语或）移动摆动stop?停止Emergency stop?紧急停止Extend boom / extend hydranlic boom?（汽车吊类）伸长主臂Retract boom / shorten hydranlic boom?（汽车吊类）缩回主臂raise the boom and lower the load /boom up and load down?（汽车吊类）抬主臂降主钩（俗称顿杆松钩）lower the boom and raise the load /boom dwon and load up?（汽车吊类）降主臂起主钩（俗称趴杆起钩）turn left?向左转turn right?向右转crane output? / carrying capacity of crane / lifting capacity of crane?吊车起重能力crane load?起重机起重量;?起重机起重量crane rating?起重机定额;?起重机载重量crane radius?起重机起吊半径;?起重机伸臂活动半径;?起重机伸距craneage?吊车工时crane beam?行车梁?起重机大梁crane stair?起重机楼梯hoist drive mechanism?起重机驱动机构travelling crab?起重机小车hoisting controller?起重控制器吊车控制手柄hoisting facility?起重设施lifting gear?起重装置crane (runway) girder?吊车梁crane support wall?吊车支承墙crane boom?起重机吊架;?起重架;?吊车臂;?吊车起重扒杆;?吊杆crane column?吊车柱crane hook / grab??（or? lift hook）（?or dolly）起重机吊钩crane jib???起重机吊杆crane bridge?起重机桥crane buffer?吊车缓冲器crane rope / crane cable起重钢绳;?起重机吊索;?吊车钢丝绳crane carriage?起重小车;?横行小车crane carrier?起重机载运车crane controller?起重控制器crane fall?起重机索crane motor / crane hoist type motor?起重机电动机crane platform?起重机平台crane rail?吊车轨，起重机轨道crane runner?吊车司机crane runway?起重机走道;?天车滑道crane weigher?吊车秤crane wheel?吊车车轮crane winch?起重机绞车lifting tackle?起重滑车lever of crane?起重机臂hoisting tools?起重工具?吊具lifting rope?吊绳?起重钢丝绳。

文献翻译-中文-液压汽车起重机的工作原理

文献翻译-中文-液压汽车起重机的工作原理

译文：液压汽车起重机的工作原理由飓风丹尼引起的暴雨淹没了北卡罗来纳州夏洛特市的许多地方，小糖溪的河水上涨很快，导致一条火车铁轨栈桥倒塌，一辆内燃机列车坠入河道内。

你可以想象一下，一个412,000磅（186880公斤）的机车是不容易打捞的。

当洪水退去过后，紧急救援队紧急救援队伍带来了三个大型液压汽车起重机——1辆500吨，一辆300吨和一辆175吨，用来把火车从河床里面打捞出来，放置回到轨道上面。

液压汽车起重机利用简单的点对点流体力学概念来举起上千磅重的物品。

液压汽车起重机的设计非常简单，但是他能完成一些看似不可能完成的艰巨任务。

在几分钟内，在公路上这些机器可以举起重达几吨的桥梁；在工厂里，这些机器可以举起重型设备；甚至，在建造海滨房屋的时候帮助打桩。

当有些地方比如海洋世界需要将鲸鱼运送到新的目的地的时候，液压汽车起重机同样可以用来举起装鲸鱼的水箱。

当看到这些液压汽车起重机运行的时候，很难相信它将这些如此重的物品相对轻松的移动，因为这些的物品都是上吨级的。

液压汽车起重机有各种不同的提升力。

只需要通过它的名字就可以轻松的知道许多特定的液压汽车起重机的起重能力，例如：一个40吨吊车能吊起40吨（80000磅或36287 kg ）。

在这里，你将学习起重机如何利用水力学（液压）举起数千英镑的物体，我们会爬进驾驶室向你展示如何操作这些机器。

这全是关于液压的液压起重机是基于一个简单的概念——通过点对点流体力学概念来进行力的传递。

大多数液压机使用的是一些密度很大大到不可压缩的液体。

油（石油）是最常见的被用来做液压机包括液压起重机的不可压缩的液体。

在一个简单的液压系统里面，当一个活塞推动油（石油），油（石油）就将所有的原动力传送到另一个需要带动的活塞。

在一个简单的液压系统里面，当一个活塞被推动，另一个活塞就会被带动。

液压泵产生的压力推动活塞。

在一个液压系统里面的压力由两种液压泵类型中的一种产生：可变排量泵（变量泵）齿轮泵大多数液压汽车起重机使用的是有一对齿合齿轮向液压油加压的双齿轮泵。

中英文文献翻译-起重机介绍

中英文文献翻译-起重机介绍

附录外文文献原文：The Introduction of cranesA crane is defined as a mechanism for lifting and lowering loads with a hoisting mechanism Shapiro, 1991. Cranes are the most useful and versatile piece of equipment on a vast majority of construction projects. They vary widely in configuration, capacity, mode of operation, intensity of utilization and cost. On a large project, a contractor may have an assortment of cranes for different purposes. Small mobile hydraulic cranes may be used for unloading materials from trucks and for small concrete placement operations, while larger crawler and tower cranes may be used for the erection and removal of forms, the installation of steel reinforcement, the placement of concrete, and the erection of structural steel and precast concrete beams.On many construction sites a crane is needed to lift loads such as concrete skips, reinforcement, and formwork. As the lifting needs of the construction industry have increased and diversified, a large number of general and special purpose cranes have been designed and manufactured. These cranes fall into two categories, those employed in industry and those employed in construction. The most common types of cranes used in construction are mobile, tower, and derrick cranes.1.Mobile cranesA mobile crane is a crane capable of moving under its own power without being restricted to predetermined travel. Mobility is provided by mounting or integrating the crane with trucks or all terrain carriers or rough terrain carriers or by providing crawlers. Truck-mounted cranes have the advantage of being able to move under their own power to the construction site. Additionally, mobile cranes can move about the site, and are often able to do the work of several stationary units.Mobile cranes are used for loading, mounting, carrying large loads and for work performed in the presence of obstacles of various kinds such as power lines and similar technological installations. The essential difficulty is here the swinging of the payload which occurs during working motion and also after the work is completed. This applies particularly to the slewing motion of the crane chassis, for which relatively large angular accelerations and negative accelerations of the chassis are characteristic. Inertia forces together with the centrifugal force and the Carioles force cause the payload to swing as a spherical pendulum. Proper control of the slewing motion of the crane serving to transport a payload to the defined point with simultaneous minimization of the swings when theworking motion is finished plays an important role in the model.Modern mobile cranes include the drive and the control systems. Control systems send the feedback signals from the mechanical structure to the drive systems. In general, they are closed chain mechanisms with flexible members [1].Rotation, load and boom hoisting are fundamental motions the mobile crane. During transfer of the load as well as at the end of the motion process, the motor drive forces, the structure inertia forces, the wind forces and the load inertia forces can result in substantial, undesired oscillations in crane. The structure inertia forces and the load inertia forces can be evaluated with numerical methods, such as the finite element method. However, the drive forces are difficult to describe. During start-up and breaking the output forces of the drive system significantly fluctuate. To reduce the speed variations during start-up and braking the controlled motor must produce torque other than constant [2,3], which in turn affects the performance of the crane.Modern mobile cranes that have been built till today have oft a maximal lifting capacity of 3000 tons and incorporate long booms. Crane structure and drive system must be safe, functionary and as light as possible. For economic and time reasons it is impossible to build prototypes for great cranes. Therefore, it is desirable to determinate the crane dynamic responses with the theoretical calculation.Several published articles on the dynamic responses of mobile crane are available in the open literature. In the mid-seventies Peeken et al. [4] have studied the dynamic forces of a mobile crane during rotation of the boom, using very few degrees of freedom for the dynamic equations and very simply spring-mass system for the crane structure. Later Maczynski et al. [5] studied the load swing of a mobile crane with a four mass-model for the crane structure. Posiadala et al. [6] have researched the lifted load motion with consideration for the change of rotating, booming and load hoisting. However, only the kinematics were studied. Later the influence of the flexibility of the support system on the load motion was investigated by the same author [7]. Recently, Kilicaslan et al. [1] have studied the characteristics of a mobile crane using a flexible multibody dynamics approach. Towarek [16] has concentrated the influence of flexible soil foundation on the dynamic stability of the boom crane. The drive forces, however, in all of those studies were presented by using so called the metho d of ……kinematics forcing‟‟ [6] with assumed velocities or accelerations. In practice this assumption could not comply with the motion during start-up and braking.A detailed and accurate model of a mobile crane can be achieved with the finite element method. Using non-linear finite element theory Gunthner and Kleeberger [9] studied the dynamic responses of lattice mobile cranes. About 2754 beam elements and 80 truss elements were used for modeling of the lattice-boom structure. On this basis a efficient software for mobile crane calculation––NODYA has been developed. However, the influences of the drive systems must be determined by measuring on hoisting of the load[10], or rotating of the crane [11]. This is neither efficient nor convenient for computer simulation of arbitrary crane motions.Studies on the problem of control for the dynamic response of rotary crane are also available. Sato et al. [14], derived a control law so that the transfer a load to a desired position will take place that at the end of the transfer of the swing of the load decays as soon as possible. Gustafsson [15] described a feedback control system for a rotary crane to move a cargo without oscillations and correctly align the cargo at the final position. However, only rigid bodies and elastic joint between the boom and the jib in those studies were considered. The dynamic response of the crane, for this reason, will be global.To improve this situation, a new method for dynamic calculation of mobile cranes will be presented in this paper. In this method, the flexible multibody model of the steel structure will be coupled with the model of the drive systems. In that way the elastic deformation, the rigid body motion of the structure and the dynamic behavior of the drive system can be determined with one integrated model. In this paper this method will be called ……complete dynamic calculation for driven “mechanism”.On the basis of flexible multibody theory and the Lagrangian equations, the system equations for complete dynamic calculation will be established. The drive- and control system will be described as differential equations. The complete system leads to a non-linear system of differential equations. The calculation method has been realized for a hydraulic mobile crane. In addition to the structural elements, the mathematical modeling of hydraulic drive- and control systems is decried. The simulations of crane rotations for arbitrary working conditions will be carried out. As result, a more exact representation of dynamic behavior not only for the crane structure, but also for the drive system will be achieved. Based on the results of these simulations the influences of the accelerations, velocities during start-up and braking of crane motions will be discussed.2.Tower cranesThe tower crane is a crane with a fixed vertical mast that is topped by a rotating boom and equipped with a winch for hoisting and lowering loads (Dickie, 990). Tower cranes are designed for situations which require operation in congested areas. Congestion may arise from the nature of the site or from the nature of the construction project. There is no limitation to the height of a high-rise building that can be constructed with a tower crane. The very high line speeds, up to 304.8 mrmin, available with some models yield good production rates at any height. They provide a considerable horizontal working radius, yet require a small work space on the ground (Chalabi, 1989). Some machines can also operate in winds of up to 72.4 km/h, which is far above mobile crane wind limits.The tower cranes are more economical only for longer term construction operations and higher lifting frequencies. This is because of the fairly extensive planning needed for installation, together with the transportation, erection and dismantling costs.3. Derrick cranesA derrick is a device for raising, lowering, and/or moving loads laterally. The simplest form of the derrick is called a Chicago boom and is usually installed by being mounted to building columns or frames during or after construction (Shapiro and Shapiro, 1991).This derrick arrangement. (i.e., Chicago boom) becomes a guy derrick when it is mounted to a mast and a stiff leg derrick when it is fixed to a frame.The selection of cranes is a central element of the life cycle of the project. Cranes must be selected to satisfy the requirements of the job. An appropriately selected crane contributes to the efficiency, timeliness, and profitability of the project. If the correct crane selection and configuration is not made, cost and safety implications might be created (Hanna, 1994). Decision to select a particular crane depends on many input parameters such as site conditions, cost, safety, and their variability. Many of these parameters are qualitative, and subjective judgments implicit in these terms cannot be directly incorporated into the classical decision making process. One way of selecting crane is achieved using fuzzy logic approach.Cranes are not merely the largest, the most conspicuous, and the most representative equipment of construction sites but also, at various stages of the project, a real “bottleneck” that slows the pace of the construction process. Although the crane can be found standing idle in many instances, yet once it is involved in a particular task ,it becomes an indispensable link in the activity chain, forcing at least two crews(in the loading and the unloading zones) to wait for the service. As analyzed in previous publications [6-8] it is feasible to automate (or, rather, semi-automate) crane navigation in order to achieve higher productivity, better economy, and safe operation. It is necessary to focus on the technical aspects of the conversion of existing crane into large semi-automatic manipulators. By mainly external devices mounted on the crane, it becomes capable of learning, memorizing, and autonomously navigation to reprogrammed targets or through prêt aught paths.The following sections describe various facets of crane automation:First, the necessary components and their technical characteristics are reviewed, along with some selection criteria. These are followed by installation and integration of the new components into an existing crane. Next, the Man –Machine –Interface (MMI) is presented with the different modes of operation it provides. Finally, the highlights of a set of controlled tests are reported followed by conclusions and recommendations.Manual versus automatic operation: The three major degrees of freedom of common tower cranes are illustrated in the picture. In some cases , the crane is mounted on tracks , which provide a fourth degree of freedom , while in other cases the tower is “telescope” or extendable , and /or the “jib” can be raised to a diagonal position. Since these additional degrees of freedom are not used routinely during normal operation but rather are fixed in a certain position for long periods (days or weeks), they are not included in the routineautomatic mode of operation, although their position must be “known” to the control system.外文文献中文翻译：起重机介绍起重机是用来举升机构、抬起或放下货物的器械。

液压英文文献及翻译

液压英文文献及翻译

液压英文文献及翻译液压系统1.绪论液压站称液压泵站，是独立的液压装置。

它是按逐级要求供油。

并控制液压油流方向、压力和流量，适用在主机与液压装置可分离的各种液压机械上面。

用户在购后只要将液压站与主机上执行机构（油缸或油马达）用不同的油管相连，液压机械即实现各种规定的动作与工作循环。

液压站是由集成块、泵装置或阀组合、电气盒、油箱电气盒组合而成。

各个部件功能为：泵装置——上装有电机和油泵，其是液压站的动力源，能将机械能转化为液压油压力能。

阀组合－－其板式阀装在立板上，板后管连接，与集成块的功能相同。

油集成块－－是由液压阀及通道体组装而成。

其对液压油实行压力、方向和流量调节。

箱－－是板焊的半封闭容器，上面还装有滤油网、空气滤清器等，是用来储油与油的冷却及过滤。

电气盒－－分两种型式：一种是设置外接引线的端子板；一种是配置了全套控制电器。

液压站工作原理：电机带动油泵转动，然后泵从油箱中吸油并供油，将机械能转化为液压站压力能，液压油通过集成块（或阀组合）实现方向、压力、流量调节后经过外接管路并至液压机械里的油缸或油马达中，从而控制液动机方向变换、力量的大小及速度的快慢，来推动各种液压机械做功。

(1)液压的发展历程在我国液压（含液力，下同）、气动和密封件工业的发展历程，大致可分成三个阶段，即：在20世纪50年代初到60年代初是起步阶段；60-70年代为专业化生产体系的成长阶段；80-90年代为快速发展阶段。

在其中，液压工业始于50年代初从机床行业生产的仿苏的磨床、拉床、仿形车床等液压传动来起步，液压元件由机床厂里的液压车间生产，自产自用。

在进入60年代后，液压技术应用从机床逐渐推广到农业机械与工程机械等领域，原来附属于主机厂里的液压车间有些独立出来，成为液压件的专业生产厂。

在60年代末、70年代初，随着生产机械化的不断发展，特别是在为第二汽车制造厂等提供了高效、自动化设备的带动下，液压元件制造业出现了不断迅速发展的局面，一批中小企业也开始成为液压件专业制造厂。

随车起重装置的结构与设计中英文翻译、外文文献翻译

随车起重装置的结构与设计中英文翻译、外文文献翻译

附录 1：外文翻译随车起重装置的结构与设计相对传统的举升机构,该举升机构只采用了液压缸,使液压系统的管路简单,控制方便,液压系统的可靠性高,且安装方便。

上述的分析与计算,为该机构建立了结构与性能等参数间的数学关系。

有关推销与套筒间的摩擦与磨损,套筒导槽角和翻转角度与举升高度的适应性等问题,将有待进一步的分析研究和结构发。

随车起重装置在国外称为随车吊。

本文按国家标准称其为随车起重装置。

一辆安装了随车起重装置的厢式货车在货物运输中, 不仅显示其防雨防尘的专有功能,而且在货物的装卸方面实现了机械化。

1 随车起重装置的发展随车起重装置的发展, 在国外大体上可分为四个时期。

第一代产品产生于本世纪30 年代末, 其特点主要是单缸举升, 而栏板翻转靠手动, 起升质量为500kg 左右, 栏板(又称载物平台) 触地倾角9°～10°。

目前, 这种产品在东南亚、日本仍在使用, 90 年代, 还在美国得到了新的发展。

第二代产品产生于50 年代初的欧洲市场, 在第一代产品的基础上增加了翻转关门油缸。

举升与翻转分别由二个独立油缸实现。

最常见的是四只油缸的型式, 也有双缸的。

起升质量在500 kg 以上, 载物平台触地倾角10°, 翻转动作凭操作者经验控制。

该种产品目前主要用于美洲及东南亚地区。

第三代产品产生于70 年代末的欧洲市场, 是在第二代产品的基础上增加第五只油缸。

这只油缸在液压系统中主要起相对位置的记忆功能, 使载物平台触地、离地的翻转动作不再由操作者控制而由液压系统本身控制, 从而使升降过程相对平稳与安全。

触地倾角一般为8°～10°。

若兼作厢门用, 因平台尺寸增大, 倾角也可能小于8°。

目前该类产品普遍用于欧美地区。

第四代产品产生于90 年代初, 其液压系统及功能原理同第三代产品, 只增加了记忆油缸的尺寸, 使记忆动作的范围进一步增大。

它不同于第三代产品的关键在于其载物平台增加特殊结构, 由一体改为两体活动联接, 使平台触地后不仅能自动翻转, 而且有一个下沉的动作, 使触地倾角达到6°, 甚至在6以下。

起重机中英文对照外文翻译文献

起重机中英文对照外文翻译文献

起重机中英⽂对照外⽂翻译⽂献中英⽂对照外⽂翻译(⽂档含英⽂原⽂和中⽂翻译)Control of Tower Cranes WithDouble-Pendulum Payload DynamicsAbstract：The usefulness of cranes is limited because the payload is supported by an overhead suspension cable that allows oscilation to occur during crane motion. Under certain conditions, the payload dynamics may introduce an additional oscillatory mode that creates a double pendulum. This paper presents an analysis of this effect on tower cranes. This paper also reviews a command generation technique to suppress the oscillatory dynamics with robustness to frequency changes. Experimental results are presented to verify that the proposed method can improve the ability of crane operators to drive a double-pendulum tower crane. The performance improvements occurred during both local and teleoperated control.Key words：Crane , input shaping , tower crane oscillation , vibrationI. INTRODUCTIONThe study of crane dynamics and advanced control methods has received significant attention. Cranes can roughly be divided into three categories based upontheir primary dynamic properties and the coordinate system that most naturally describes the location of the suspension cable connection point. The first category, bridge cranes, operate in Cartesian space, as shown in Fig. 1(a). The trolley moves along a bridge, whose motion is perpendicular to that of the trolley. Bridge cranes that can travel on a mobile base are often called gantry cranes. Bridge cranes are common in factories, warehouses, and shipyards.The second major category of cranes is boom cranes, such as the one sketched in Fig. 1(b). Boom cranes are best described in spherical coordinates, where a boom rotates aboutaxes both perpendicular and parallel to the ground. In Fig. 1(b), ψis the rotation aboutthe vertical, Z-axis, and θis the rotation about the horizontal, Y -axis. The payload is supported from a suspension cable at the end of the boom. Boom cranes are often placed on a mobile base that allows them to change their workspace.The third major category of cranes is tower cranes, like the one sketched in Fig. 1(c). These are most naturally described by cylindrical coordinates. A horizontal jib arm rotates around a vertical tower. The payload is supported by a cable from the trolley, which moves radially along the jib arm. Tower cranes are commonly used in the construction of multistory buildings and have the advantage of having a small footprint-to-workspace ratio. Primary disadvantages of tower and boom cranes, from a control design viewpoint, are the nonlinear dynamics due to the rotational nature of the cranes, in addition to the less intuitive natural coordinate systems.A common characteristic among all cranes is that the pay- load is supported via an overhead suspension cable. While this provides the hoisting functionality of the crane, it also presents several challenges, the primary of which is payload oscillation. Motion of the crane will often lead to large payload oscillations. These payload oscillations have many detrimental effects including degrading payload positioning accuracy, increasing task completion time, and decreasing safety. A large research effort has been directed at reducing oscillations. An overview of these efforts in crane control, concentrating mainly on feedback methods, is provided in [1]. Some researchers have proposed smooth commands to reduce excitation of system flexible modes [2]–[5]. Crane control methods based on command shaping are reviewed in [6]. Many researchers have focused on feedback methods, which necessitate the addition necessitate the addition of sensors to the crane and can prove difficult to use in conjunction with human operators. For example, some quayside cranes have been equipped with sophisticated feedback control systems to dampen payload sway. However, the motions induced by the computer control annoyed some of the human operators. As a result, the human operators disabled the feedback controllers. Given that the vast majority of cranes are driven by human operators and will never be equipped with computer-based feedback, feedback methods are not considered in this paper.Input shaping [7], [8] is one control method that dramatically reduces payload oscillation by intelligently shaping the commands generated by human operators [9], [10]. Using rough estimates of system natural frequencies and damping ratios, a series of impulses, called the input shaper, is designed. The convolution of the input shaper and the original command is then used to drive the system. This process is demonstrated with atwo-impulse input shaper and a step command in Fig. 2. Note that the rise time of the command is increased by the duration of the input shaper. This small increase in the rise time isnormally on the order of 0.5–1 periods of the dominant vibration mode.Fig. 1. Sketches of (a) bridge crane, (b) boom crane, (c) and tower crane.Fig. 2. Input-shaping process.Input shaping has been successfully implemented on many vibratory systems including bridge [11]–[13], tower [14]–[16], and boom [17], [18] cranes, coordinate measurement machines[19]–[21], robotic arms [8], [22], [23], demining robots [24], and micro-milling machines [25].Most input-shaping techniques are based upon linear system theory. However, some research efforts have examined the extension of input shaping to nonlinear systems [26], [14]. Input shapers that are effective despite system nonlinearities have been developed. These include input shapers for nonlinear actuator dynamics, friction, and dynamic nonlinearities [14], [27]–[31]. One method of dealing with nonlinearities is the use of adaptive or learning input shapers [32]–[34].Despite these efforts, the simplest and most common way to address system nonlinearities is to utilize a robust input shaper [35]. An input shaper that is more robust to changes in system parameters will generally be more robust to system nonlinearities that manifest themselves as changes in the linearized frequencies. In addition to designing robust shapers, input shapers can also be designed to suppress multiple modes of vibration [36]–[38].In Section II, the mobile tower crane used during experimental tests for this paper is presented. In Section III, planar and 3-D models of a tower crane are examined to highlight important dynamic effects. Section IV presents a method to design multimode input shapers with specified levels of robustness. InSection V, these methods are implemented on a tower crane with double-pendulum payload dynamics. Finally, in Section VI, the effect of the robust shapers on human operator performance is presented for both local and teleoperated control.II. MOBILE TOWER CRANEThe mobile tower crane, shown in Fig. 3, has teleoperation capabilities that allow it to be operated in real-time from anywhere in the world via the Internet [15]. The tower portion of the crane, shown in Fig. 3(a), is approximately 2 m tall with a 1 m jib arm. It is actuated by Siemens synchronous, AC servomotors. The jib is capable of 340°rotation about the tower. The trolley moves radially along the jib via a lead screw, and a hoisting motor controls the suspension cable length. Motor encoders are used for PD feedback control of trolley motion in the slewing and radial directions. A Siemens digital camera is mounted to the trolley and records the swing deflection of the hook at a sampling rate of 50 Hz [15].The measurement resolution of the camera depends on the suspension cable length. For the cable lengths used in this research, the resolution is approximately 0.08°. This is equivalent to a 1.4 mm hook displacement at a cable length of 1 m. In this work, the camera is not used for feedback control of the payload oscillation. The experimental results presented in this paper utilize encoder data to describe jib and trolley position and camera data to measure the deflection angles of the hook. Base mobility is provided by DC motors with omnidirectional wheels attached to each support leg, as shown in Fig. 3(b). The base is under PD control using two HiBot SH2-based microcontrollers, with feedback from motor-shaft-mounted encoders. The mobile base was kept stationary during all experiments presented in this paper. Therefore, the mobile tower crane operated as a standard tower crane.Table I summarizes the performance characteristics of the tower crane. It should be noted that most of these limits areenforced via software and are not the physical limitations of the system. These limitations are enforced to more closely match theoperational parameters of full-sized tower cranes.Fig. 3. Mobile, portable tower crane, (a) mobile tower crane, (b) mobile crane base.TABLE I MOBILE TOWER CRANE PERFORMANCE LIMITSFig. 4 Sketch of tower crane with a double-pendulum dynamics.III. TOWER CRANE MODELFig.4 shows a sketch of a tower crane with a double-pendulum payload configuration. The jib rotates by an angle around the vertical axis Z parallelto the tower column. The trolley moves radially along the jib; its position along the jib is described by r . The suspension cable length from the trolley to the hook is represented by an inflexible, massless cable of variable length 1l . The payload is connected to the hook via an inflexible, massless cable of length 2l . Both the hook and the payload are represented as point masses having masses h m and p m , respectively.The angles describing the position of the hook are shown in Fig. 5(a). The angle φrepresents a deflection in the radial direction, along the jib. The angle χ represents a tangential deflection, perpendicular to the jib. In Fig. 5(a), φ is in the plane of the page, and χ lies in a plane out of the page. The angles describing the payload position are shown in Fig. 5(b). Notice that these angles are defined relative to a line from the trolley to the hook. If there is no deflection of the hook, then the angleγ describes radial deflections, along the jib, and the angle α represents deflections perpendicular to the jib, in the tangential direction. The equations of motion for this model were derived using a commercial dynamics package, but they are too complex to show in their entirety here, as they are each over a page in length.To give some insight into the double-pendulum model, the position of the hook and payload within the Newtonian frame XYZ are written as —h q and —p q , respectivelyWhere -I , -J and -K are unit vectors in the X , Y , and Z directions. The Lagrangian may then be written asFig. 5. (a) Angles describing hook motion. (b) Angles describing payload motion.Fig. 6. Experimental and simulated responses of radial motion.(a) Hook responses (φ) for m 48.01=l ，(b) Hook responses for m 28.11=lThe motion of the trolley can be represented in terms of the system inputs. The position of the trolley —tr q in the Newtonian frame is described byThis position, or its derivatives, can be used as the input to any number of models of a spherical double-pendulum. More detailed discussion of the dynamics of spherical double pendulums can be found in [39]–[42].The addition of the second mass and resulting double-pendulum dramatically increases the complexity of the equations of motion beyond the more commonly used single-pendulum tower model [1], [16], [43]–[46]. This fact can been seen in the Lagrangian. In (3), the terms in the square brackets represent those that remain for the single-pendulum model; no —p q terms appear. This significantly reduces the complexity of the equations because —p q is a function of the inputs and all four angles shown in Fig. 5.It should be reiterated that such a complex dynamic model is not used to design the input-shaping controllers presented in later sections. The model was developed as a vehicle to evaluate the proposed control method over a variety of operating conditions and demonstrate its effectiveness. The controller is designed using a much simpler, planar model.A. Experimental V erification of the ModelThe full, nonlinear equations of motion were experimentally verified using several test cases. Fig.6 shows two cases involving only radial motion. The trolley was driven at maximum velocity for a distance of 0.30 m, with 2l =0.45m .The payload mass p m for both cases was 0.15 kg and the hook mass h m was approximately 0.105 kg. The two cases shown in Fig. 6 present extremes of suspension cable lengths 1l . In Fig. 6(a), 1l is 0.48 m , close to the minimum length that can be measured by the overhead camera. At this length, the double-pendulum effect is immediately noticeable. One can see that the experimental and simulated responses closely match. In Fig. 6(b), 1l is 1.28 m, the maximum length possible while keeping the payload from hitting the ground. At this length, the second mode of oscillation has much less effect on the response. The model closely matches the experimental response for this case as well. The responses for a linearized, planar model, which will be developed in Section III-B, are also shown in Fig. 6. The responses from this planar model closely match both the experimental results and the responses of the full, nonlinear model for both suspension cable lengths.Fig. 7. Hook responses to 20°jib rotation:(a) φ (radial) response;(b) χ (tangential) response.Fig. 8. Hook responses to 90°jib rotation:φ(radial) response;(b) χ(tangential) response.(a)If the trolley position is held constant and the jib is rotated, then the rotational and centripetal accelerations cause oscillation in both the radial and tangential directions. This can be seen in the simulation responses from the full nonlinear model in Figs. 7 and 8. In Fig. 7, the trolley is held at a fixed position of r = 0.75 m, while the jib is rotated 20°. This relatively small rotation only slightly excites oscillation in the radial direction, as shown in Fig. 7(a). The vibratory dynamics are dominated byoscillations in the tangential direction, χ, as shown in Fig. 7(b). If, however, a large angular displacement of the jib occurs, then significant oscillation will occur in both the radial and tangential directions, as shown in Fig. 8. In this case, the trolley was fixed at r = 0.75 m and the jib was rotated 90°. Figs. 7 and 8 show that the experimental responses closely match those predicted by the model for these rotational motions. Part of the deviation in Fig. 8(b) can be attributed to the unevenness of the floor on which the crane sits. After the 90°jib rotation the hook and payload oscillate about a slightly different equilibrium point, as measured by the overhead camera.Fig.9.Planardouble-pendulummodel.B.Dynamic AnalysisIf the motion of the tower crane is limited to trolley motion, like the responses shown in Fig. 6, then the model may be simplified to that shown in Fig. 9. This model simplifies the analysis of the system dynamics and provides simple estimates of the two natural frequencies of the double pendulum. These estimates will be used to develop input shapers for the double-pendulum tower crane.The crane is moved by applying a force )(t u to the trolley. A cable of length 1l hangs below the trolley and supports a hook, of mass h m , to which the payload is attached using rigging cables. The rigging and payload are modeled as a second cable, of length 2l and point mass p m . Assuming that the cable and rigging lengths do not change during the motion, the linearized equations of motion, assuming zero initial conditions, arewhere φ and γ describe the angles of the two pendulums, R is the ratio of the payload mass to the hook mass, and g is the acceleration due to gravity.The linearized frequencies of the double-pendulum dynamics modeled in (5) are [47]Where Note that the frequencies depend on the two cable lengths and the mass ratio.Fig. 10. Variation of first and second mode frequencies when m l l 8.121=+.。

液压系统外文文献翻译中英文

液压系统外文文献翻译中英文

外文文献翻译(含：英文原文及中文译文)英文原文Hydraulic systemW Arnold1 IntroductionThe hydraulic station is called a hydraulic pump station and is an independent hydraulic device. It is step by step to supply oil. And control the direction of hydraulic oil flow, pressure and flow, suitable for the host and hydraulic equipment can be separated on the various hydraulic machinery.After the purchase, the user only needs to connect the hydraulic station and the actuator (hydraulic or oil motor) on the mainframe with different tubings. The hydraulic machine can realize various specified actions and working cycles.The hydraulic station is a combination of manifolds, pump units or valve assemblies, electrical boxes, and tank electrical boxes. Each part function is:The pump unit is equipped with a motor and an oil pump, which is the power source of the hydraulic station and can convert mechanical energy into hydraulic oil pressure energy.V alve combination - its plate valve is mounted on the vertical plate, and the rear plate is connected with the same function as the manifold.Oil manifolds - assembled from hydraulic valves and channel bodies. It regulates hydraulic oil pressure, direction and flow.Box--a semi-closed container for plate welding. It is also equipped with an oil screen, an air filter, etc., which is used for cooling and filtering of oil and oil.Electrical box - divided into two types: one is to set the external lead terminal board; one is equipped with a full set of control appliances.The working principle of the hydraulic station: The motor drives the oil pump to rotate, then the pump sucks oil from the oil tank and supplies oil, converts the mechanical energy into hydraulic pressure energy, and the hydraulic oil passes through the manifold (or valve assembly) to adjust the direction, pressure and flow and then passes through the external tube. The way to the hydraulic cylinder or oil motor in the hydraulic machinery, so as to control the direction of the hydraulic motor, the strength of the speed and speed, to promote all kinds of hydraulic machinery to do work.(1) Development history of hydraulic pressureThe development history of hydraulics (including hydraulic power, the same below), pneumatics, and seals industry in China can be roughly divided into three stages, namely: the starting stage in the early 1950s to the early 60s; and the professional in the 60s and 70s. The growth stage of the production system; the 80-90's is a stage of rapid development. Among them, the hydraulic industry began in the early 1950s with thedevelopment of hydraulic machines such as Grinding Machines, broaching machines, and profiling lathes, which were produced by the machine tool industry. The hydraulic components were produced by the hydraulic workshop in the machine tool factory, and were produced for self use. After entering the 1960s, the application of hydraulic technology was gradually promoted from the machine tool to the agricultural machinery and engineering machinery. The original hydraulic workshop attached to the main engine plant was independent and became a professional manufacturer of hydraulic components. In the late 1960s and early 1970s, with the continuous development of mechanization of production, particularly in the provision of highly efficient and automated equipment for the second automobile manufacturing plant, the hydraulic component manufacturing industry witnessed rapid development. The batch of small and medium-sized enterprises also began to become specialized manufacturers of hydraulic parts. In 1968, the annual output of hydraulic components in China was close to 200,000 pieces. In 1973, in the fields of machine tools, agricultural machinery, construction machinery and other industries, the professional factory for the production of hydraulic parts has grown to over 100, and its annual output exceeds 1 million pieces. Such an independent hydraulic component manufacturing industry has taken shape. At this time, the hydraulic product has evolved from the original imitation Su product intoa combination of imported technology and self-designed products. The pressure has been developed towards medium and high pressures, and electro-hydraulic servo valves and systems have been developed. The application of hydraulics has been further expanded. The pneumatic industry started a few years later than hydraulics, and it was only in 1967 that it began to establish a professional pneumatic components factory. Pneumatic components began to be manufactured and sold as commodities. Its sealing industry including rubber seals, flexible graphite seals, and mechanical seals started from the production of common O-rings, oil seals, and other extruded rubber seals and asbestos seal products in the early 1950s. In the early 1960s, it began to develop and produce flexible products. Graphite seals and mechanical seals and other products. In the 1970s, a batch of batches of professional production plants began to be established one after another in the systems of the former Ministry of Combustion, the Ministry of Agriculture, and the Ministry of Agricultural Machinery, formally forming the industry, which laid the foundation for the development of the seal industry.In the 1980s, under the guidance of the national policy of reform and opening up, with the continuous development of the machinery industry, the contradiction between the basic components lags behind the host computer has become increasingly prominent and caused the attention of all relevant departments. To this end, the former Ministry of Machinesestablished the General Infrastructure Industry Bureau in 1982, and unified the original pneumatic, hydraulic, and seal specialties that were scattered in the industries of machine tools, agricultural machinery, and construction machinery, etc. The management of a piece of office, so that the industry in the planning, investment, the introduction of technology and scientific research and development and other aspects of the basic parts of the bureau's guidance and support. This has entered a period of rapid development, it has introduced more than 60 foreign advanced technology, of which more than 40 hydraulic, pneumatic 7, after digestion and absorption and technological transformation, are now mass production, and has become the industry's leading products . In recent years, the industry has intensified its technological transformation. From 1991 to 1998, the total investment of national, local, and corporate self-raised funds totaled about 2 billion yuan, of which more than 1.6 billion were hydraulic. After continuous technological transformation and technological breakthroughs, the technical level of a group of major enterprises has been further improved, and technological equipment has also been greatly improved, laying a good foundation for forming a high starting point, specialization, and mass production. In recent years, under the guidance of the principle of common development of multiple ownership systems in the country, various small and medium-sized enterprises with different ownership have rapidly emerged and haveshown great vitality. With the further opening up of the country, foreign-funded enterprises have developed rapidly, which plays an important role in raising industry standards and expanding exports. So far China has established joint ventures with famous manufacturers in the United States, Germany, Japan and other countries or directly established piston pumps/motors, planetary speed reducers, hydraulic control valves, steering gears, hydraulic systems, hydrostatic transmissions, and hydraulic components. The company has more than 50 manufacturing enterprises such as castings, pneumatic control valves, cylinders, gas processing triplets, rubber seals, and mechanical seals, and has attracted more than 200 million U.S. dollars in foreign capital.(2) Current statusBasic profileAfter more than 40 years of hard work, China's hydraulics, pneumatics and seals industry has formed a complete industrial system with a certain level of production capacity and technical level. According to the statistics of the third n ational industrial census in 1995, China’s state-owned, privately-owned, cooperative, village-run, individual, and “funded enterprises” have annual sales income of more than 1 million yuan in hydraulic, pneumatic, and seal industrial townships and above. There are a total of more than 1,300 companies, including about 700 hydraulics, and about 300 pneumatic and sealing parts. According to thestatistics of the international industry in 1996, the total output value of the hydraulic industry in China was about 2.448 billion yuan, accounting for the 6th in the world; the total output value of the pneumatic industry was about 419 million yuan, accounting for the world’s10 people.2. Current supply and demand profileWith the introduction of technology, independent development and technological transformation, the technical level of the first batch of high-pressure plunger pumps, vane pumps, gear pumps, general hydraulic valves, oil cylinders, oil-free pneumatic components and various types of seals has become remarkable. Improve, and can be stable mass production, provide guarantees for all types of host to improve product quality. In addition, certain achievements have also been made in the aspects of CAD, pollution control, and proportional servo technology for hydraulic pneumatic components and systems, and have been used for production. So far, the hydraulic, pneumatic and seal products have a total of about 3,000 varieties and more than 23,000 specifications. Among them, there are about 1,200 types of hydraulic pressure, more than 10,000 specifications (including 60 types of hydrodynamic products, 500 specifications); about 1350 types of pneumatic, more than 8,000 specifications; there are also 350 types of rubber seals, more than 5000 The specifications are now basically able to adapt to the general needs ofvarious types of mainframe products. The matching rate for major equipment sets can reach more than 60%, and a small amount of exports has started.In 1998, the domestic production of hydraulic components was 4.8 million pieces, with sales of about 2.8 billion yuan (of which mechanical systems accounted for 70%); output of pneumatic components was 3.6 million pieces, and sales were about 550 million yuan (including mechanical systems accounting for about 60%) The production of seals is about 800 million pieces, and the sales volume is about 1 billion yuan (including about 50% of mechanical systems). According to the statistics of the annual report of the China Hydraulic and Pneumatic Sealing Industry Association in 1998, the production and sales rate of hydraulic products was 97.5% (101% of hydraulic power), 95.9% of air pressure, and 98.7% of seal. This fully reflects the basic convergence of production and sales.Although China's hydraulic, pneumatic and sealing industries have made great progress, there are still many gaps compared with the development needs of the mainframe and the world's advanced level, which are mainly reflected in the variety, performance and reliability of products. . Take hydraulic products as an example, the product varieties are only 1/3 of the foreign country, and the life expectancy is 1/2 of that of foreign countries. In order to meet the needs of key hosts, imported hosts, and majortechnical equipment, China has a large number of imported hydraulic, pneumatic, and sealing products every year. According to customs statistics and relevant data analysis, in 1998, the import volume of hydraulic, pneumatic and seal products was about 200 million U.S. dollars, of which the hydraulic pressure was about 140 million U.S. dollars, the pneumatics were 30 million U.S. dollars, and the seal was about 0.3 billion U.S. dollars. The year is slightly lower. In terms of amount, the current domestic market share of imported products is about 30%. In 1998, the total demand for hydraulic parts in the domestic market was about 6 million pieces, and the total sales volume was 4 billion yuan; the total demand for pneumatic parts was about 5 million pieces, and the total sales volume was over 700 million yuan; the total demand for seals was about 1.1 billion yuan. Pieces, total sales of about 1.3 billion yuan. (3) Future developments1. The main factors affecting development(1) The company's product development capability is not strong, and the level and speed of technology development can not fully meet the current needs for advanced mainframe products, major technical equipment and imported equipment and maintenance;(2) Many companies have lagged behind in manufacturing process, equipment level and management level, and their sense of quality is not strong, resulting in low level of product performance, unstable quality,poor reliability, and insufficiency of service, and lack of user satisfaction. And trusted branded products;(3) The degree of professional specialization in the industry is low, the power is scattered, the duplication of the low level is serious, the product convergence between the region and the enterprise leads to blind competition, and the prices are reduced each other, thus the efficiency of the enterprise is reduced, the funds are lacking, and the turnover is difficult. Insufficient investment in development and technological transformation has severely restricted the overall level of the industry and its competitive strength.(4) When the degree of internationalization of the domestic market is increasing, foreign companies have gradually entered the Chinese market to participate in competition, coupled with the rise of domestic private, cooperative, foreign-funded, and individual enterprises, resulting in increasing impact on state-owned enterprises. .2. Development trendWith the continuous deepening of the socialist market economy, the relationship between supply and demand in the hydraulic, pneumatic and sealed products has undergone major changes. The seller market characterized by “shortage” has basically become a buyer’s market characterized by “structured surplus”. Replaced by. From the perspective of overall capacity, it is already in a trend of oversupply, and in particular,general low-grade hydraulic, pneumatic and seals are generally oversupply; and like high-tech products with high technological content and high value and high value-added products that are urgently needed by the host, Can not meet the needs of the market, can only rely on imports. After China's entry into the WTO, its impact may be greater. Therefore, during the “10th Five-Y ear Plan” period, the growth of the industry’s output value must not only rely on the growth of quantity. Instead, it should focus on the structural contradiction of the industry and intensify efforts to adjust the industrial structure and product structure. It should be based on the improvement of quality. Product technology upgrades in order to adapt to and stimulate market demand, and seek greater development.2. Hydraulic application on power slide(1) Introduction of Power Sliding TableUsing the binding force curve diagram and the state space analysis method to analyze and study the sliding effect and the smoothness of the sliding table of the combined machine tool, the dynamics of the hydraulic drive system of the sliding table—the self-regulating back pressure regulating system are established. mathematical model. Through the digital simulation system of the computer, the causes and main influencing factors of the slide impact and the motion instability are analyzed. What kind of conclusions can be drawn from those, if we canreasonably design the structural dimensions of hydraulic cylinders and self-regulating back pressure regulators ——The symbols used in the text are as follows:s 1 - flow source, that is, the flow rate of the governor valve outlet;S el —— sliding friction of the sliding table;R - the equivalent viscous friction coefficient of the slide;I 1 - quality of slides and cylinders;12 - self-adjusting back pressure valve core quality;C 1, c 2 - liquid volume without cylinder chamber and rod chamber;C 2 - Self-adjusting back pressure valve spring compliance;R 1, R2 - Self-adjusting back pressure valve damping orifice fluid resistance;R 9 - Self-adjusting back pressure valve valve fluid resistance;S e2——initial pre-tightening force of self-adjusting back pressure valve spring;I 4, I5 - Equivalent liquid sense of the pipeline;C 5, C 6 - equivalent liquid capacity of the pipeline;R 5, R7 - Equivalent liquid resistance of the pipeline;V 3, V4 - cylinder rodless cavity and rod cavity volume;P 3, P4—pressure of the rodless cavity and rod cavity of the cylinder;F - the slide bears the load;V - speed of slide motion;In this paper, the power bond diagram and the state space splitting method are used to establish the system's motion mathematical model, and the dynamic characteristics of the slide table can be significantly improved.In the normal operation of the combined machine tool, the magnitude of the speed of the slide, its direction and the load changes it undergoes will affect its performance in varying degrees. Especially in the process of work-in-process, the unsteady movement caused by the advancing of the load on the slide table and the cyclical change of the load will affect the surface quality of the workpiece to be machined. In severe cases, the tool will break. According to the requirements of the Dalian Machine Tool Plant, the author used the binding force curve diagram and the state space analysis method to establish a dynamic mathematical model of a self-adjusting back pressure and speed adjustment system for the new hydraulic drive system of the combined machine tool slide. In order to improve the dynamic characteristics of the sliding table, it is necessary to analyze the causes and main influencing factors of the impetus and movement of the sliding table. However, it must pass the computer's digital simulation and the final results obtained from the research.(2) Dynamic Mathematical ModelThe working principle diagram of the self-adjusting back pressure speedregulation system of the combined machine tool slide hydraulic drive system is shown in the figure. This system is used to complete the work-cycle-stop-rewind. When the sliding table is working, the three-position four-way reversing valve is in the illustrated position. The oil supply pressure of the oil pump will remain approximately constant under the effective action of the overflow valve, and the oil flow passes through the reversing valve and adjusts the speed. The valve enters the rodless chamber of the cylinder to push the slide forward. At the same time, the pressurized oil discharged from the rod chamber of the cylinder will flow back to the tank through the self-regulating back pressure valve and the reversing valve. During this process, there was no change in the operating status of both the one-way valve and the relief valve. The complex and nonlinear system of the hydraulic drive system of the self-adjusting back pressure governor system is a kind of self-adjusting back-pressure governor system. To facilitate the study of its dynamic characteristics, a simple and reasonable dynamic mathematical model that only considers the main influencing factors is established. Especially important [1][2]. From the theoretical analysis and the experimental study, we can see that the system process time is much longer than the process time of the speed control valve. When the effective pressure bearing area of the rodless cavity of the fuel tank is large, the flow rate at the outlet of the speed control valve is instantaneous. The overshoot is reflected in thesmall change in speed of the slide motion [2]. In order to further broaden and deeply study the dynamic characteristics of the system so that the research work can be effectively performed on a miniature computer, this article will further simplify the original model [2], assuming that the speed control valve is output during the entire system pass. When the flow is constant, this is considered to be the source of the flow. The schematic diagram of the dynamic model structure of this system is shown in Fig. 2. It consists of a cylinder, a sliding table, a self-adjusting back pressure valve, and a connecting pipe.The power bond graph is a power flow graph. It is based on the transmission mode of the system energy, based on the actual structure, and uses the centralized parameters to represent the role of the subsystems abstractly as a resistive element R, a perceptual element I, and a capacitive element. Three kinds of role of C. Using this method, the physical concept of modeling is clear, and combined with the state-space analysis method, the linear system can be described and analyzed more accurately. This method is an effective method to study the dynamic characteristics of complex nonlinear systems in the time domain. According to the main characteristics of each component of the self-adjusting back pressure control system and the modeling rules [1], the power bond diagram of the system is obtained. The upper half of each key in the figure represents the power flow. The two variables that makeup the power are the force variables (oil pressure P and force F) and the flow variables (flow q and velocity v). The O node indicates that the system is connected in parallel, and the force variables on each key are equal and the sum of the flow variables is zero; 1 The nodes represent the series connection in the system, the flow variables on each key are equal and the sum of the force variables is Zero. TF denotes a transformer between different energy forms. The TF subscripted letter represents the conversion ratio of the flow variable or the force variable. The short bar on the key indicates the causal relationship between the two variables on the key. The full arrow indicates the control relationship. There are integral or differential relationships between the force and flow variables of the capacitive and perceptual elements in the three types of action elements. Therefore, a complex nonlinear equation of state with nine state variables can be derived from Fig. 3 . In this paper, the research on the dynamic characteristics of the sliding table starts from the two aspects of the slide's hedging and the smoothness of the motion. The fourth-order fixed-length Runge-Kutta is used for digital simulation on the IBM-PC microcomputer.(3) Slide advanceThe swaying phenomenon of the slide table is caused by the sudden disappearance of the load acting on the slide table (such as drilling work conditions). In this process, the table load F, the moving speed V, and thepressure in the two chambers of the cylinder P3 and P4 can be seen from the simulation results in Fig. 4. When the sliding table moves at a uniform speed under the load, the oil pressure in the rodless cavity of the oil cylinder is high, and a large amount of energy is accumulated in the oil. When the load suddenly disappears, the oil pressure of the cavity is rapidly reduced, and the oil is rapidly reduced. When the high-pressure state is transferred to the low-pressure state, a lot of energy is released to the system, resulting in a high-speed forward impact of the slide. However, the front slide of the sliding table causes the pressure in the rod cavity of the oil cylinder to cause the back pressure to rise, thereby consuming part of the energy in the system, which has a certain effect on the kicking of the slide table. We should see that in the studied system, the inlet pressure of the self-adjusting back pressure valve is subject to the comprehensive effect of the two-chamber oil pressure of the oil cylinder. When the load suddenly disappears, the pressure of the self-adjusting back pressure valve rapidly rises and stably exceeds the initial back pressure value. It can be seen from the figure that self-adjusting back pressure in the speed control system when the load disappears, the back pressure of the cylinder rises more than the traditional speed control system, so the oil in the rod cavity of the cylinder absorbs more energy, resulting in the amount of forward momentum of the slide It will be about 20% smaller than traditionalspeed control systems. It can be seen from this that the use of self-adjusting back-gear speed control system as a drive system slider has good characteristics in suppressing the forward punch, in which the self-adjusting back pressure valve plays a very large role.(4) The smoothness of the slideWhen the load acting on the slide changes periodically (such as in the case of milling), the speed of the slide will have to fluctuate. In order to ensure the processing quality requirements, it must reduce its speed fluctuation range as much as possible. From the perspective of the convenience of the discussion of the problem, assume that the load changes according to a sine wave law, and the resulting digital simulation results are shown in Figure 5. From this we can see that this system has the same variation rules and very close numerical values as the conventional speed control system. The reason is that when the change of the load is not large, the pressure in the two chambers of the fuel tank will not have a large change, which will eventually lead to the self-regulating back pressure valve not showing its effect clearly.(5) Improvement measuresThe results of the research show that the dynamic performance of a sliding table with self-regulating back pressure control system as a drive system is better than that of a traditional speed control system. To reduce the amount of kick in the slide, it is necessary to rapidly increase the backpressure of the rod cavity when the load disappears. To increase the smoothness of the sliding table, it is necessary to increase the rigidity of the system. The main measure is to reduce the volume of oil. From the system structure, it is known that the cylinder has a large volume between the rod cavity and the oil discharge pipe, as shown in Fig. 6a. Its existence in terms of delay and attenuation of the self-regulating back pressure valve function, on the other hand, also reduces the rigidity of the system, it will limit the further improvement of the propulsion characteristics and the smoothness of the motion. Thus, improving the dynamic characteristics of the sliding table can be handled by two methods: changing the cylinder volume or changing the size of the self-regulating back pressure valve. Through the simulation calculation of the structural parameters of the system and the comparison of the results, it can be concluded that the ratio of the volume V4 between the rod cavity and the oil discharge pipe to the volume V3 between the rodless cavity and the oil inlet pipe is changed from 5.5 to 5.5. At 1 oclock, as shown in the figure, the diameter of the bottom end of the self-adjusting back pressure valve is increased from the original 10mm to 13mm, and the length of the damper triangle groove is reduced from the original lmm to 0.7mm, which will enable the front of the slide table. The impulse is reduced by 30%, the transition time is obviously shortened, and the smoothness of the slide motion will also be greatly improved.中文译文液压系统W Arnold1. 绪论液压站称液压泵站,是独立的液压装置。

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附录A 译文随车液压起重机的控制摘要：本文主要是描述随车液压起重机的控制过程。

这篇论文分为五个部分：需求分析，液压系统以及存在的问题的分析，不同结构产生不同问题的分析，基于更加先进复杂电液比例控制阀的新技术的发展趋势的分析。

本文的研究工作是和实际的工业相结合的，比纯粹的研究理论更有意义。

关键字：随车液压起重机，控制策略，电液比例控制阀1.引言本文主要叙述的是对随车起重机控制系统的改进方法随车汽车起重机可以看成是一种大型柔性控制机械结构。

这种控制系统把操作人员的命令由机械结构变为执行动作。

这样定义这种控制系统是为了避免在设计它事产生模糊的思想这是一种通过人的命令把能量转化成机械动作的控制系统。

本文所写的就是这种控制系统。

以这个目标为指导方针来分析怎样设计出新的控制系统。

文章分为五个部分：1.分析这种控制系统必须据有易操作性，高强度，高效性，稳定性，安全性。

2.分析目前这种操作系统所存在的问题。

3.从不同的方面分析这种控制系统：不同的操作方式，不同的控制方法，不同的组织结构。

4.介绍一种适合于未来工业的比较经济的新的控制系统。

5.分析一种据有高性能，高效率，易控制等的比较好的控制系统。

它将成为今后研究的比较经济高效的一种方案。

2. 论文部分2.1 对控制系统必备条件的分析在一种新的操作系统开始正式投入工作之前，对这种控制系统据有严格的要求。

对控制系统的影响有很多因素。

例如：机械结构的可实行性因素，可操作性因素，效率因素，符合工业标准。

工业需求必须放在第一位。

这与在控制系统中导管破裂保护和超载保护有同等的地位。

其次稳定性要求也很重要；系统不稳定就没法正常工作。

一旦稳定性要求得以确定，控制系统性能要求就可以进一步确定。

机械结构决定了起重机的可操作性。

机械机构是随车起重机中可以往复转动固有频率低的大型柔性结构。

为了防止起重机振动，必须使起重机在固有频率下工作，或者提高起重机的固有频率。

如果它的固有频率太低或者太高，操作人员将无法给它进行操作。

最后传动效率可以在工业标准，稳定性，执行机构确定的基础上得到最优的方案。

2.2 对目前这种控制系统的分析在设计一种新的起重机之前，研究目前起重机存在的问题是很有必要的。

当前液压随车起重机主要存在以下三个问题：1.不稳定性2.不经济性3.低效性2.2.1 不稳定性不稳定性是一个严重问题，他可能会损伤操作人员或者会是设备受到毁坏。

当一个系统不稳定时通常产生严重振动。

为了消除当前系统的不稳定性，设计人员既花费了很多时间来研究又花费了很多财力设计出更加复杂的机构。

如图1所示为一种起重机，它适合于在高速下工作。

但是为了可以安全的工作必须合理控制其运行速度。

要提高它的控制速度又必须增加更加昂贵复杂的机械系统。

液压系统的参数，如温度或压力同样影响系统的稳定性。

一个参数合理的液压系统比一个设计参数不合理的液压系统稳定，为了使整个系统运行稳定，有时必须降低次要的参数值。

2.2.2 不经济性目前的液压系统是纯液压的机械系统，因此如果用户想实现一个功能，他就必须买一个能使现这个功能的液压机械组件。

因为大多数用户又不同的使用要求，要求同一个设备可以进行升级。

这就意味着这些标准设备可以人为的改造，这就增加了组件升级费用。

2.2.3 低效性液体在液压系统的两个液压缸之间流动时效率较低。

这是因为大多数液压阀都是用一个阀心来控制两个节流口，由于这个链接不可能使阀芯两侧的压力相等，因此在流出端就产生一个与液流方向相反的背压力，同时也增加了流入端的压力。

由激励源产生的这个背压力与阀芯两端的压力差成正比的，给油缸的实际压力没有被有效的作用在油缸上。

例如，给液压缸的压力为1000psi/1600psi传到液压缸时就只有0psi/600 psi了。

无论如何，这样的话，提供的电量必须高于有效电量，这些额外的电量就被白白的浪费了2.3 控制系统不同的控制方法目前主要用电液比例控制阀来控制液压阀的运动。

然而对控制筒有不同的控制方法。

电液比例控制阀对阀的关/开，公共汽车系统，电源的智能激励，泵的调节方案控制精度都较高。

必须对这种系统的优缺点进行分析，找出合理的方案。

2.4 近期方案即使这种十分新的系统最佳外形的布局已经得以证明是可行的，但是起重机制造商和配件商还不能立刻就接受这种技术。

这是一个渐进的过程，所以提出了一种临时解决的方案。

这种方案是由微型计算机和升缩机构组成。

这种离合阀可使这种更加高效稳定的执行控制机构得以实现。

微型计算机可以对阀进行柔性控制。

可以把这些变量编入软件。

这样就消除了制造商许许多多不同的变量问题。

起重机制造厂家可以根据产品功能选择不同型号的液压阀。

配件商也将不得不生产这种型号的阀，这样不仅降低了制造成本，而且使起重机的性能得到提高。

2.5 更高效方案的分析这种分析依赖于不同布局结果，液压泵控制的区域决定将要用的控制方法，再依次对这个区域进行分析。

不同的区域将用不同的方法探讨，用不同的刀具位置控制。

3. 实验设备本文的中心是研究发展中的经济型机械控制方案的可实现问题，更多重点是先进的实验结果。

实验结果由两种方法获得。

第一种是通过研究单自由起重机实验台获得，第二种是通过研究一台由丹麦一家起重机厂送给英国的一所军校的起重机获得。

如图1所示图1系统实验台左：单自由度起重机模型右：随车起重机实物虽然目前这种升缩分离机构在生产商中没有被普遍接受，但是两分离阀将会被逐渐取代。

如图2所示是一种幅度-脉冲变换液压缸，它是通过数字信息处理器/奔腾双信息处理器运行程序来控制液压阀的。

由数字信号处理器运行控制代码，奔腾处理器来判断并提供图形用户界面。

4. 当前工作4.1 直线轴流控法当今市场常见的直线流控器都需要压力补偿。

压力补偿器可以使阀芯突然受压时保持恒定的压力。

但是新增加的压力补偿器会使阀的结构比简单的随动阀更加复杂。

另一种解决方法是用流控器测量阀的压力降来调整阀芯的位置来实现。

这种想法虽然简单，但是由于压力传感器和微控器的费用比较高，想普遍运用于商品上是很难的。

然而目前这种利用微控器和压力传感器的思想对于生产商来说是可以接受的。

虽然依据方程来看很简单，但是要实现却很难。

流控器的位置精度取决于位置传感器的精度压力传感器的精度。

噪声会影响位置传感器和压力传感器的稳定性。

采用延时控制可以消除影响稳定性的噪声，这样，超过阀的运行范围的特征值用就不能用柏努力方程计算，应用更复杂的方程来计算。

图2升缩分离机构4.2 液压缸控制方法根据不同的受力方向和速度方向这种液压缸有四种工作情形。

如图3所示：多数是普通的随动液压阀，它这种控制方法已经在文献中可以找到，依靠一般的测量法测液压缸的速度位移相当复杂。

它们也需要相当复杂的运算法则来控制。

本文主要分析基于简单的PI控制器和没有严格速度位移要求的液压缸的控制方法。

这种系统的控制方法比复杂的控制方法简单得多，由于它不需要特殊的传感器而且容易被大多数工程师理解所以比较容易被厂商采用。

在设计一种控制方法时另一种特别的控制方法也需要了解，它也是液控中常用的一种方法。

移动液压阀要求低泄漏，以前的液压阀大们通常有很大的交迭。

然而，使生产商能够接受的这种线轴式液压缸的驱动性能相当慢。

这种具有很大交迭的重合以及激发很慢的液压阀很难满足现在的要求。

交迭和较慢的驱动使压力控制变得相当困难。

新的控制方法可以用一个例子清楚简单的描述出来。

从入口端实行流控制，出口端就实现液压力。

流控制符合柏努力方程。

液压控制过程中PI控制器图3起重机工作的不同情形图4减压控制器维持较小的压力来提高效率并且可以防止气穴现象。

这些都是为了解决大交迭和较低的驱动所做的工作，压力控制器仅仅能排除控制中的一点问题。

这就意味着如果控制人员想提高压力，却不能使液压缸移动，只能够降低控制口的开口量。

这样做的作用只能使操作人员想改变活塞的方向时使它准时脱离零位。

这种情况下外力方向和活塞运动仍然不能改变，这种方式需要改进。

既然这样，需要压力控制器在出口变大时提供与外力方向相反的有用压力，当已知入口端的压力下降的时候，它可以增加与外力相反的压力。

这个压力也受PI 控制器控制，如图4所示就是是一个这种控制系统的控制模型结构。

在写本文的时候这种控制的实验已经在图1所示的实验台上完成了，由于起重机上安装了载荷单向阀，所以稳定性没有达到要求。

然而，用液压单向阀取代这种载荷单向阀，可以使系统的稳定。

在液压系统中，载荷闭式阀可以实现超载保护和卸载保护两种功能。

由于在这种控制方法中使用伸缩阀机构对卸载保护很起作用，因此在起升机构中很有必要使用有这种功能的单向阀。

一个操作单向阀的驾驶员可以做这一点，没有增加复杂的动力来阻止起重机的倾。

安装了这种单向阀，起重机操作人员不需要再增加更复杂的外力来防止起重机产生倾翻。

5. 结束语即使没有大量的实验设施，但是实验还是完成了，一个好的开始是成功的一半。

这个论文题的大轮阔已经确定，它是有意义而且合理的。

这个工作分为需求分析、目前的系统分析、不同布局分析、近期的解决办法的分析和最优解决方案的发展趋势分析五个部分。

在本论题的最后，液压随车起重机的控制模将会被修改。

6.感谢语感谢Danfoss Fluid Power A/S为这个研究提供了部分基金。

也感谢Højbjerg Maskinfabrik (HMF) A/S愿意为这种起重机的测试提供技术上的支持随车液压起重机的轨迹控制问题描述这项方案是根据如图1所示的多自由度随车液压起重机控制问题提出来的。

控制随车起重机要求操作人员技术相当高，它的操作机动范围很小。

如果可以让现代的起重机实现遥控控制的话，操作人员只需要控制他手中的遥控器就可以控制起重机把重物放在他要求的任何地方。

一个按钮控制一个自由度方向上的转动。

因此只需要让操作人员得到熟练的训练他就可以每次控制更多的按钮来实现多个自由度的转动。

图1所示为一台随车液压装载起重机部分液压系统控制图实例这项工程的目标是设计一台非熟练操作人员都能够控制的移动式液压起重机。

操作人员根据吊具总成的合成轨迹控制一根操纵杆。

这样不同的自由度就可以同时被控制。

多数随车液压起重机的结构就像图1所示的那样，大多数都是非常柔性化的，因此当受载时它们就会弯曲。

这样做可以使起重机吊重比最低。

事实上吊重顶端位置也是制约控制系统结构偏差的因素。

这种问题可以通过一个好的位置偏差补偿控制系统解决，这个系统还可以消除操作初期结构上发生的摆动。

继续使结构轨迹偏差补偿控制系统在起重机上进一步发展，起重机的装载能力将可以大大得到提高。

当这种在起重机里的摆动可以被控制系统抑制的方法能够得到充分证明，在一个长的期限里可能有一个降低动力学安全系数的机会。

这将使起重机生产商和用户节省一大笔费用。

吊具总成 图2测试起重机图片方案内容现以一台如图2所示的HMF 680-4型随车液压起重机来分析这些问题。

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