【作者】 孙衍石；

【导师】 熊晓燕； 靳宝全；

【作者基本信息】 太原理工大学 ， 机械电子， 2009， 硕士

【摘要】 电液位置伺服系统作为控制领域中一个重要的组成部分,具有控制精度高,响应速度快,便于调节的特点,同时又能控制大惯性实现大功率输出,因而在工业控制领域得到广泛的应用。随着电液伺服技术的发展和应用领域的逐步推广,对电液伺服系统的控制要求越来越高,在诸多影响电液伺服系统的控制精度的因素中,控制策略的选择非常关键。因此研究性能良好且算法不太复杂的控制方法是提高电液位置伺服系统控制精度的一项重要措施。由于实际电液位置伺服系统中,存在外界干扰力、液压油泄漏、油液品质、油温等不确定因素,使得电液位置伺服系统是一种典型的非线性系统,动态特性十分复杂,很难建立系统的精确数学模型,因而采用传统的基于线性系统的的控制方法设计的控制器的适应性和抗干扰能力差,难以得到好的控制效果。而实际系统要求稳态误差小、快速性好、鲁棒性强,这就给控制系统的设计带来了很大的困难。为了克服这些不利因素,满足系统要求,本文将滑模变结构控制策略应用于电液伺服控制系统中,来消除非线性对系统控制性能的影响,并采用指数趋近律的抖动消除法,有效减弱了系统的抖振现象,并改善了趋近阶段的运动品质。本文以阀控缸位置伺服系统为研究对象,通过对电液伺服系统的理论分析,建立了液压系统的数学模型,计算出了系统的有关参数。利用Matlab软件中的动态仿真工具Simulink,构造了电液伺服系统仿真模型,采用s函数来描述控制器和被控对象。分别采用了PID与滑模变结构控制方法对电液位置伺服控制系统进行了对比仿真和结果分析。利用AMEsim和Simulink各自优点的联合仿真技术能更加准确的模拟实际系统的工作状态,因而本文对系统又进行了AMEsim和Matlab/Simulink联合仿真分析。仿真实验结果证明,不管是Matlab环境下的Simulink仿真还是AMEsim/Simulink联合仿真,在系统参数变化和施加外干扰力的情况下,与PID控制相比,滑模变结构控制具有更好的动态特性,对被控对象的结构和参数变化以及外干扰力,具有很强的鲁棒性和自适应能力,取得了较高的位置伺服控制精度。本文还分析了指数趋近律的参数和滑模控制器的参数变化对系统性能的影响。Simulink仿真和AMEsim/Simulink联合仿真均证明采用滑模变结构控制策略,系统具有抗参数摄动能力强,动态特性良好,鲁棒性强以及算法简单易于微机实现等优点。因此趋近律滑模变结构控制在电液伺服系统中的应用可以有效提高系统的抗干扰能力,提高控制精度,在实际工程中有广泛的应有价值。更多还原

【Abstract】 Electro-hydraulic position servo control system as an important component of the control and high precision, fast response, easy to adjust the characteristics of large inertia control at the same time to achieve high power output, which has been in the field of industrial control a wide range of applications. With the electro-hydraulic servo technology applications development and the gradual promotion of electro-hydraulic servo control systems have become increasingly demanding in a lot of impact on the control precision electro-hydraulic servo system of the factors, the choice of control strategy is critical. The study not too good and complex control algorithm is to improve the electro-hydraulic position servo system to control an important measure for accuracy.As the actual electro-hydraulic position servo system, the existence of outside interference, and hydraulic oil leakage, oil quality, oil and other uncertainties, the electro-hydraulic position servo system is a typical nonlinear system, the complexity of the dynamic characteristics , it is difficult to establish a precise mathematical model of the system, thus using the traditional system based on linear control method of adaptive controller design and poor anti-interference ability, it is difficult to get good control.The actual system requirements for steady-state error small, fast and good robustness, which to the control system design has led to great difficulties. In order to overcome these negative factors, to meet the system requirements, this article will be sliding mode variable structure control strategy applied to the electro-hydraulic servo control system to control the elimination of non-linear properties of the system, and the use of index reaching law to eliminate the jitter, effectively weaken the system chattering phenomenon, and to improve the quality of the convergence phase of the campaign.In this paper valve control oil hydraulic cylinder position servo system for the study, through the theoretical analysis of electro-hydraulic servo system, the establishment of a mathematical model of the hydraulic system to calculate the relevant parameters of the system. The use of Matlab software, the dynamic simulation tool Simulink, structural simulation model of the electro-hydraulic servo system used to describe the functions controller and controlled object.Using the PID and sliding mode variable structure control method of electro-hydraulic position servo control system and compared the results of simulation analysis. AMEsim and Simulink to use the advantages of their more accurate co-simulation technology to simulate the actual system state, and therefore this paper carried out on the system AMEsim and Matlab / Simulink co-simulation analysis.The simulation results show that, regardless of Matlab’s Simulink simulation environment or AMEsim/Simulink co-simulation, changes in system parameters and external disturbance force imposed circumstances, compared with PID control, sliding mode variable structure control has better dynamic characteristics of the object changes the structure and parameters as well as outside interference, and has strong robustness and adaptive capacity, and achieved high precision position servo control.This article also analyzes the parameters of exponential approach law and sliding mode controller parameters on system performance. Simulink simulation and AMEsim/Simulink co-simulation have proved the use of sliding mode variable structure control strategy, the system is good with fast, smooth control, good dynamic performance, robustness and the algorithm is simple and easy to achieve the advantages of computer. Sliding mode variable structure control is therefore in the electro-hydraulic servo system can effectively improve the system of anti-interference ability to improve the control precision, in practice there are a wide range of projects to be valuable.更多还原