重载夹持装置双马达消隙传动系统的建模与控制

【作者】 易达云；

【导师】 邓华；

【作者基本信息】 中南大学 ， 机械电子工程， 2009， 硕士

【摘要】 本文以250吨锻造操作机夹钳传动系统为研究对象,对夹钳传动系统与控制策略进行了研究。由于系统惯性大、负载变化大,液压元件的非线性、控制阀死区、齿隙、摩擦力矩非线性等特点,很难满足系统的快速启动制动平稳性和精确定位的要求。本文结合锻造操作机夹钳传动系统的要求和特点,提出了一种消除齿轮齿隙的双马达功能互换的传动系统,达到平稳换向和精确定位要求,主要研究如下:1、提出了一种消除齿轮齿隙冲击影响的双马达传动系统。为分析齿轮齿隙对系统的影响程度,采用未消除齿轮齿隙的单马达传动系统进行比较,建立了液压传动系统中核心控制元件—插装式比例节流阀的数学模型,建立了夹钳传动系统的非线性模型。2、根据频响特性和阶跃响应曲线,利用最小二乘法对插装阀的参数进行了辨识;结合液压马达实验,建立了马达的摩擦力矩模型,并利用逐步回归的方法对马达模型中的相关参数进行了辨识。3、将模糊自适应参数整定PID控制算法应用于锻造操作机夹钳传动系统控制,对系统存在控制阀死区、齿轮齿隙和摩擦的非线性等影响因素的控制效果对比表明,常规PID控制器中加入模糊参数自整定后,改善了系统的控制性能,消除了累积误差,满足了规定的精度要求。4、对消除了齿轮齿隙影响的夹钳传动系统和存在齿轮齿隙影响的夹钳传动系统进行了仿真对比,结果表明,齿轮齿隙对系统的性能影响较大,双马达功能互换传动的液压系统能很好地消除齿轮齿隙对系统的影响。通过仿真分析结果表明所提出的夹钳双马达消隙传动控制系统的响应速度和控制精度能够满足要求,且系统具有启停平稳、抗干扰能力强的特点。更多还原

【Abstract】 The design and control strategies of the rotational driving system for the grippers of 250 Ton forging manipulators were studied in this thesis. The system has the features such as large inertia, large variation of load, nonlinearities of hydraulic part, dead zone of control valve, gear backlash and nonlinear of friction torque. It is difficult to meet the requirement of fast accelerating, fast retarding and precise positioning. A function exchangeable driving system with two motors was proposed in combination with the requirements and features of forging manipulator gripper driving system to eliminate the effect of gear backlash. The main studies are as follows:1、A two motors driving system was proposed for eliminating the effect of backlash. A single motor driving system which can not eliminate the effect of gear backlash was also built to compare with the double motor driving system. The nonlinear models of the driving systems were established.2、The parameters of the cartridge valve were identified by the least square method based on the frequency responses and step responses. The frictional torque model of the motors was also set up based on experimental data.3、The fuzzy adaptive tuning PID controller was applied to the control of the driving system. The comparison between conventional PID and fuzzy PID shows that fuzzy PID has better control performance for systems with dead-zone of control valve, gear backlash and friction nonlinearities. The accumulated error of the gripper driving system can be eliminated and requirement of precision can be met.4、The comparison between gripper rotational driving systems with and without gear backlash shows that gear backlash affects the performance of system significantly and the driving system with double motors can eliminate the effect of gear backlash on the system.The analysis of simulation results indicates that the proposed double motor driving system can meet the requirement of response speed and control precision. Moreover, the system has the features such as smoothness of fast response and strong anti-interference capability.更多还原