【作者】 陈亮；

【导师】 李维嘉；

【作者基本信息】 华中科技大学 ， 轮机工程， 2007， 硕士

【摘要】 六自由度平台的动态性能是其重要的技术指标之一。本文通过研究液压伺服系统的控制方法,进而改善基于液压驱动的六自由度平台的动态性能,为研制高水平的模拟器奠定基础。论文首先分析了六自由度平台的结构及运动特点,推导出了平台单回路的数学模型及控制器模型,并利用AMESim液压系统仿真软件建立了单回路运动控制系统的仿真模型,为平台控制策略的研究提供了保证。通过对PID控制、带有压力反馈补偿的PID控制以及鲁棒H∞三种控制方法的仿真分析和实验分析,可以得出:1)第一种控制方法具有简单、可靠性高、易于实现的特点,但是无法满足平台作高频(>1Hz)运动时动态指标的要求,且抗负载扰动能力差;2)第二种控制方法可以提高液压系统的阻尼比和固有频率,增加系统的运动平滑性与响应快速性,却同样存在着抗负载扰动能力差的弱点;3)第三种控制方法在试验中表现了很好的抗负载扰动能力,其不足在于无法显著地提高系统的动态响应速度。因此,单纯地采用任何一种控制方法,难以理想地提高系统的动态性能。最后,论文提出一种带有压力反馈补偿的鲁棒H∞控制方法。仿真与试验表明,此种控制方法可以使平台系统具有较好的响应速度、运动精度及鲁棒性,并且平台系统的位姿响应频宽从1Hz提升到了5Hz。更多还原

【Abstract】 The dynamic performance of Six-DOF platform is most important qualification among the rest. Through studying the control strategy of electro-hydraulics servo system, advance the dynamic performance of Six-DOF platform and lie the foundation of a high- performance simulator.Based on the structural and movement characteristic of Six-DOF platform,the mathmatic model of the platform and the controller were deduced.With the combination of AMESim simulation software ,it provided clearly reliable guarantee for study.PID algorithm,PID with pressure feedback compensation and Robust H∞have been discussed in the paper. PID algorithmis is simple,steady and easy to implement ,but in the control system of Six-DOF platform ,this method can not meet the need of control effect especially under quick movement and be poor in resisting load disturbance.PID with pressure feedback compensation can advance systemic movement flatness and response speed,but also be poor in the ability of resistance to load disturbance.The Robust H∞control method incarnates the good performance in stabilization.From the low speed to the high speed ,the Robust H∞control method can make the sytem quickly response to the input and keep the whole sytem steady,but the Robust control method can not obviously advance the response speed of whole system.To conclude ,using any one control method among three only can not make the dynamic performance of system best.In conclusion,a control strategy of Robust H∞with pressure feedback compensation is put forward. Experiment study is made on the prototype , and the results indicate that , with this control strategy , the response time,movement accuracy and the ability of resistance to load disturbance can be greatly improved.更多还原