【作者】 程俊兰；

【导师】 吴晓明；

【作者基本信息】 燕山大学 ， 机械电子工程， 2004， 硕士

【摘要】 本文的主要目的是对液压位置伺服系统低速运行时的摩擦力进行研究并实现摩擦负载补偿。在对国内外研究现状进行深入分析的基础上，提出了系统低速运行时摩擦力的动态补偿方法，并针对常见的电液位置伺服系统建立摩擦模型、设计摩擦观测器。通过仿真及实验验证了该摩擦模型及动态补偿方法的有效性。首先，本文从分析电液伺服系统各个组成环节来分析提高系统低速性能的方法。从分析结果得知影响伺服系统低速性能的主要因素是摩擦力。因此，要提高电液伺服系统的低速性能，必须对摩擦力进行补偿。本文在对摩擦机理深入了解的基础上，吸收了国内外在该领域的先进研究成果，总结了传统摩擦补偿方法的优点及不足，提出了基于新型摩擦模型(即LuGre摩擦模型)的动态补偿方法。其次，本文重点放在如何将新型摩擦模型应用到实际的电液位置伺服系统中，以实现对阀控液压缸电液位置伺服系统的摩擦力进行动态补偿，并应用MATLAB的Simulink仿真工具进行仿真，通过调节摩擦补偿环节的参数可得到良好的补偿效果。由于摩擦力主要影响电液位置伺服系统的低速跟踪精度和定位精度(即稳态误差)，所以要考虑补偿前后这两个指标的变化情况，仿真测试信号选为低速斜坡信号和单位阶跃信号。仿真结果表明该新型摩擦模型和补偿技术具有良好的补偿效果，能够动态、适时的补偿摩擦力，为设计高精度、超低速电液伺服系统提供了有效的途径。最后，为实现实时控制设计了计算机数据采集及监控程序。本文是以Windows 98为操作平台，用Visual C++编程语言开发了可视化控制软件。使用证明，该软件人机交互性能好，操作简单，实用性强。实验研究结果表明，该控制补偿方法可以有效的补偿系统低速运行时的摩擦力，大大提高系统低速性能。更多还原

【Abstract】 The main purpose of this paper is to study the friction force in hydraulic position servo system, especially when it is running at low velocity state, and to make effort to compensate it. According to the elaborate analysis on friction at home and abroad, a dynamic friction compensation method is proposed to compensate the system’s friction force at low velocity. A dynamic friction model is build and a friction observer is designed for ordinary position servo system. This friction model and compensation measure is effective, which is testified by doing experiment and simulation. Firstly, this paper studies every component of the servo system to improve the performance at low speed. From the analysis results, we learned that the main influence factor is friction force. Therefore, in order to improve the system low speed performance, it is necessary to compensate the friction force. Based on well knowing the friction mechanism, this paper absorbs advanced research results in this field, summarizes the strongpoint and insufficiency of traditional friction compensation methods, and proposes a dynamic friction compensation method according to a new friction model (LuGre friction model).Secondly, this paper emphasizes how to apply this new friction model to practical valve controlled cylinder position servo system and realize the dynamic friction compensation. The paper designs the compensation law and uses the MATLAB/Simulink tools to testify the compensation effect. Because the friction force mainly influences the track precision and the orientation precision of the servo system, it should consider these two targets changes between before and after compensation. Low-velocity ramp signal and step signal were chosen as simulation test signal. The simulation results indicate this new friction model has good compensation effects and can compensate friction force dynamically. This method provides an efficient way to design high precision, low speed electro-hydraulic servo system.Finally, in order to realize real time control, computer data acquisition and <WP=6>control program are designed. Using Windows 98 as its O.S., the control software is developed by using Visual C++ language. The results show that the software has strong application value and its interface is interactive and easy to operate. The experiment results indicate this friction compensation method can effectively compensate the friction and greatly improve the system character.更多还原