电液伺服试验机负载刚度自适应控制方法研究

发布时间：2018-05-13 01:23

本文选题：电液伺服试验机 + 试件刚度　；参考：《江苏科技大学》2017年硕士论文

【摘要】：电液伺服试验机可以对试件进行性能测试试验,在对其进行动静态分析、设计、控制策略及仿真研究时,由于被测试件不同,控制系统的理论模型是变化的。试验机电液伺服系统的动态特性能,根据负载情况、控制量的不同而有差别。在弹性负载的情况下,尤其是力控制系统,被测试件刚度变化对电液伺服试验机的性能影响起主导作用。本文以电液伺服试验机弹性负载加载力控制系统为研究对象,针对测试过程由于被测试件不同,控制系统的理论模型变化的问题,提出了具有最小节拍响应的模型参考自适应控制的解决方案。该控制器通过设置合适的可调参数,当被测试件发生变化时,电液伺服试验机的实际输出能很好的跟踪参考模型的输出,使得系统达到快速的响应,超调量为2%,减弱了刚度变化对系统动态性能的影响。本文的主要内容包括:(1)以电液伺服试验机为研究对象,通过系统总体分析,对由于被测试件刚度变化而系统性能变化大的弹性负载加载力控制系统进行理论建模,在此基础上定性的分析了被测试件刚度不同对系统性能产生的影响。(2)针对电液伺服试验机中变刚度问题,提出了模型参考自适应控制策略,并对利用输入-输出的模型参考自适应控制系统进行描述,基于Lyapunov稳定性理论分别对被控对象相对阶数为1和2时的自适应控制器结构、参数自适应调节规律、自适应控制规律及控制算法进行详细推导。(3)对本文中所用到的电液伺服试验机主要组成部分进行参数确定,得到了控制系统传递函数的具体结构形式,同时选取5组不同被测试件的刚度值带入,定量分析了刚度不同对系统动态性能的影响,并通过常规PID控制器对控制系统进行仿真校正。(4)基于最小节拍响应系统及严格正实函数的原则,选取具有最小超调量,快速响应的三阶最小节拍控制系统作为参考模型,并依据电液伺服试验机控制系统传递函数的结构形式,利用MATLAB/Simulik建立相对阶数为1的模型参考自适应控制系统的仿真模型,通过阶跃信号和正弦信号输入对模型实行对比仿真试验。(5)通过控制系统硬件及软件设计,搭建10KN电液伺服试验机模型参考自适应平台,并进行现场调试试验,验证所采用的基于最小节拍响应的模型参考自适应控制器解决了电液伺服试验机中变刚度问题,具有良好的有效性及可行性。
[Abstract]:The electro-hydraulic servo testing machine can test the performance of the specimen. In the dynamic and static analysis, design, control strategy and simulation research, the theoretical model of the control system is changed due to the difference of the tested parts. The dynamic characteristics of the electro-hydraulic servo system of the testing machine are different according to the load. In the case of elastic load, especially in the force control system, the stiffness change of the tested piece plays a leading role in the performance of the electro-hydraulic servo testing machine. In this paper, the elastic load control system of electro-hydraulic servo testing machine is taken as the research object, aiming at the change of the theoretical model of the control system due to the difference of the tested parts during the testing process. A model reference adaptive control scheme with minimum beat response is proposed. The controller can track the output of the reference model well when the tested parts change by setting appropriate adjustable parameters, which makes the system respond quickly. The overshoot is 2, which weakens the influence of the stiffness change on the dynamic performance of the system. The main contents of this paper are as follows: (1) taking the electro-hydraulic servo testing machine as the research object, through the overall analysis of the system, the theoretical model of the elastic load control system which has a great change in the system performance due to the stiffness change of the tested part is carried out. Based on this, the influence of different stiffness on system performance is analyzed qualitatively. Aiming at the problem of variable stiffness in electro-hydraulic servo testing machine, a model reference adaptive control strategy is proposed. The model reference adaptive control system based on input-output is described. Based on Lyapunov stability theory, the structure of adaptive controller with relative order of 1 and 2 and the law of parameter adaptive adjustment are respectively studied. The adaptive control law and control algorithm are deduced in detail. The main components of the electro-hydraulic servo testing machine used in this paper are determined, and the specific structure of the transfer function of the control system is obtained. At the same time, the effects of different stiffness on the dynamic performance of the system are quantitatively analyzed by selecting five groups of stiffness values of different tested parts. Based on the principle of minimum beat response system and strict positive real function, the third order minimum beat control system with minimum overshoot and fast response is selected as the reference model. According to the structure of the transfer function of the control system of the electro-hydraulic servo testing machine, the simulation model of the model reference adaptive control system with relative order 1 is established by using MATLAB/Simulik. Through step signal and sinusoidal signal input, the model is compared and simulated. Through the hardware and software design of the control system, the model reference adaptive platform of 10KN electro-hydraulic servo testing machine is built, and the field debugging test is carried out. It is verified that the model reference adaptive controller based on minimum beat response solves the problem of variable stiffness in electro-hydraulic servo testing machine and has good effectiveness and feasibility.
【学位授予单位】：江苏科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP273;TH137

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