环卫机械手的电液伺服系统研究与仿真

发布时间：2018-10-10 16:52

【摘要】：本文以液压机械手作为实体控制对象,完成了机械及液压系统的整体设计,阐述了环卫液压机械手的电液伺服阀控系统的结构组成及理论。主要针对机械手液压驱动系统的电液伺服闭环控制系统进行研究,在AMESim平台下建立阀控非对称液压缸的液压-机械系统模型,通过AMESim/Simulink进行联合仿真分析,解决了电液伺服控制系统在AMESim平台下难以建模的问题;针对电液伺服阀控系统存在的非线型性、参数时变性及液压系统振荡等问题,提出模糊PID控制算法进行系统性能优化,重点对电液伺服闭环控制系统进行研究。首先,根据工况要求完成了环卫液压机械手的机械本体结构,分析其动作要求所需的自由度及运动空间,确定机械手为5自由度关节型液压机械手。选取多路阀控系统作为机械手液压驱动,同时,将闭环位置控制系统作为液压机械手的核心研究部分,并在AMESim平台下进行仿真分析。其次,研究开发了电液伺服系统的位置闭环控制系统,在AMESim平台下建立阀控非对称缸液压系统模型。根据特定参数,计算了液压机械手的电液伺服系统传递函数,并在MATLAB平台下绘制bode图,验证系统的动态稳定性。根据仿真结果,有针对性的提出对电液伺服系统性能的改善和研究方向。另外,分析伺服阀的主要性能指标,针对电液伺服阀阀控系统存在的非线型性、参数时变性和液压系统振荡以及外在扰动,研究模糊、PID控制器的控制原理和结构,通过分析比较各自的控制优、缺点,提出了基于模糊PID控制的阀芯位置闭环控制系统优化算法。最后,以机械大臂的阀控系统为研究对像,在AMESim环境下建立大臂的液压控制系统模型,并进行系统稳定性仿真分析;针对电液伺服控制系统难以在AMESim下建模的问题,在MALAB/Simulnk模块下,建立大臂电液位置伺服控制系统的模糊PID控制器模型,结合AMESim软件进行联合仿真,并对实验结果进行分析校对。实验结果表明,控制优化效果明显,系统响应速度显著加快,位移误差小于10%.,满足预期效果。
[Abstract]:This paper takes the hydraulic manipulator as the entity control object, completes the whole design of the machinery and the hydraulic system, and expounds the structure composition and theory of the electro-hydraulic servo valve control system of the sanitation hydraulic manipulator. The electro-hydraulic servo closed-loop control system of manipulator hydraulic drive system is studied. The hydraulic mechanical system model of valve-controlled asymmetric hydraulic cylinder is established under the AMESim platform, and the joint simulation analysis is carried out through AMESim/Simulink. This paper solves the problem that it is difficult to model the electro-hydraulic servo control system under the AMESim platform, and puts forward a fuzzy PID control algorithm to optimize the performance of the electro-hydraulic servo valve control system, aiming at the problems of non-linearity, parameter time-varying and hydraulic system oscillation, etc. Emphasis is placed on the study of electro-hydraulic servo closed loop control system. Firstly, according to the requirements of the working conditions, the mechanical body structure of the sanitation hydraulic manipulator is completed, and the degree of freedom and motion space required for its movement are analyzed, and the manipulator is determined to be a 5-DOF joint type hydraulic manipulator. The multi-way valve control system is selected as the hydraulic drive of the manipulator. At the same time, the closed-loop position control system is taken as the core research part of the hydraulic manipulator, and the simulation analysis is carried out under the AMESim platform. Secondly, the position closed loop control system of electro-hydraulic servo system is developed, and the hydraulic system model of valve controlled asymmetric cylinder based on AMESim is established. According to the specific parameters, the transfer function of the electro-hydraulic servo system of the hydraulic manipulator is calculated, and the bode diagram is drawn under the MATLAB platform to verify the dynamic stability of the system. According to the simulation results, the performance improvement and research direction of electro-hydraulic servo system are put forward. In addition, the main performance indexes of servo valve are analyzed, and the control principle and structure of PID controller are studied, aiming at the nonlinearity, parameter time variation, hydraulic system oscillation and external disturbance of electro-hydraulic servo valve control system. By analyzing and comparing the advantages and disadvantages of each control, an optimization algorithm for the closed loop control system of valve core position based on fuzzy PID control is proposed. Finally, taking the valve control system of the mechanical arm as the research object, the hydraulic control system model of the arm is established under the AMESim environment, and the system stability is simulated and analyzed, aiming at the problem that the electro-hydraulic servo control system is difficult to model under AMESim. In the MALAB/Simulnk module, the fuzzy PID controller model of the electro-hydraulic position servo control system is established, and the simulation is carried out with the AMESim software, and the experimental results are analyzed and proofread. The experimental results show that the control optimization effect is obvious, the system response speed is accelerated significantly, and the displacement error is less than 10%, which satisfies the expected effect.
【学位授予单位】：湖北工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TP241

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