弹性负载电液发生器的设计与分析

发布时间：2018-03-16 02:19

本文选题：弹性负载　切入点：负刚度负载　出处：《武汉科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：一般的弹性负载指正刚度弹性负载，有一类变刚度弹性负载既有正刚度也有负刚度。对于与位置有关的加载系统，当加载对象含有变刚度弹性负载时，系统因负的负载刚度属于本质不稳定系统，这类变刚度弹性负载对系统的影响随其刚度值的大小变化以及刚度值的正负变化而产生变化。这些影响使系统不能够保持一致的响应速度和精度，甚至不能稳定工作。本文以实验研究中对含有变刚度弹性负载的位置控制系统加载的弹性负载电液发生器为研究对象。对变刚度弹性负载对加载系统的稳定性与响应特性的影响以及前馈控制对消除这些影响进行研究。具体工作归纳如下： (1)概述力控制系统的基本理论，分析了与位置有关的加载系统的控制原理。 (2)根据实验要求的加载系统物理模型，建立了弹性负载电液发生器的数学模型，并通过设计计算获取了系统的主要参数。 (3)根据系统数学模型建立其仿真模型，，并利用MATLAB的Simulink工具箱进行数字仿真，分析了不同位置不同负载刚度对系统控制精度、响应速度及稳定性的影响，通过仿真值验证了数学模型的准确性。 (4)针对负刚度负载使加载系统失稳的问题，在满足系统响应时间一致的目标下，借助BP神经网络提出前馈控制与PID控制相结合的综合校正策略，并通过仿真分析，得出了校正后的系统稳定以及响应速度与控制精度均能达到要求的结论。本文针对加载系统负载刚度可能为正也可能为负的特点，侧重探讨了系统在负载刚度为负的时失稳的问题，以提高系统响应速度与控制精度并保证系统稳定为目标，采用前馈控制与PID控制结合的综合校正策略，为解决负负载使控制系统失稳的问题提供了一种新方案。
[Abstract]:A class of variable stiffness elastic loads have both positive and negative stiffness. For a location-dependent loading system, when the loading object contains a variable stiffness elastic load, The system is essentially unstable because of its negative load stiffness. The influence of this kind of variable stiffness elastic load on the system varies with the magnitude of the stiffness value and the positive and negative changes of the stiffness value, which makes the system unable to maintain a consistent response speed and accuracy, or even work stably. In this paper, the electro-hydraulic generator of elastic load loaded by position control system with variable stiffness in the experimental study is studied. The effect of the elastic load with variable stiffness on the stability and response characteristics of the loading system is studied. And feedforward control to eliminate these effects. The specific work is summarized as follows:. 1) the basic theory of force control system is summarized, and the control principle of loading system related to position is analyzed. 2) according to the physical model of the loading system required by the experiment, the mathematical model of the elastic load electrohydraulic generator is established, and the main parameters of the system are obtained by design and calculation. The simulation model is established according to the mathematical model of the system, and the digital simulation is carried out by using the Simulink toolbox of MATLAB. The influence of different position and different load stiffness on the control precision, response speed and stability of the system is analyzed. The accuracy of the mathematical model is verified by the simulation results. 4) aiming at the problem that the load with negative stiffness causes the instability of the loading system, a comprehensive correction strategy combining feedforward control and PID control is put forward with the help of BP neural network under the goal of consistent response time of the system, and the simulation analysis is carried out. It is concluded that the system stability after correction and the response speed and control precision can meet the requirements. In view of the fact that the load stiffness of the loading system may be positive or negative, this paper focuses on the problem of system instability when the load stiffness is negative. The aim of this paper is to improve the system response speed and control accuracy and to ensure the stability of the system. A new scheme is proposed to solve the problem that the negative load makes the control system unstable by adopting a comprehensive correction strategy which combines feedforward control with PID control.
【学位授予单位】：武汉科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TH137;TP273

【共引文献】