考虑被动关节阻尼的液压驱动Stewart平台模态空间控制策略  

Control Strategy of Modal Space for a Hydraulically-Driven Stewart Platform Considering Passive Joint Damping

作　　者：田体先[1] 姜洪洲[1] 黄其涛[1] 何景峰[1] 佟志忠[1] 聂伯勋[1] 

机构地区：[1]哈尔滨工业大学机电工程学院,黑龙江哈尔滨150001

出　　处：《华南理工大学学报（自然科学版）》2015年第6期56-62,70,共8页Journal of South China University of Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(50975055;51175100)~~

摘　　要：针对工业应用中并联机构采用常规铰接形式导致的系统过阻尼问题,提出了带动压正反馈的模态空间控制器,该控制器将物理空间内强耦合的多输入多输出系统转化为模态空间内解耦的6个相互独立的单输入单输出系统,运用动压正反馈技术实现对存在过阻尼特性自由度的独立调节,从而将各自由度频宽扩展至固有频率附近.文中首先运用模态解耦理论分析了被动关节阻尼对液压驱动Stewart平台控制特性的影响,随后给出了带动压反馈的模态空间控制器结构及设计方法,最后对该方法进行了实验验证.试验结果表明,该模态空间控制器能够有效扩展系统频宽,从而实现降低系统各自由度耦合影响、提高响应速度的目的.In order to overcome the system over-damping caused by the conventional hinged form commonly-used in parallel manipulators in industry, a modal space controller with positive pressure feedback is presented. In this controller, the highly-coupled multiple-input multiple-output systems in the physical space are transformed into six independent single-input single-output decoupled systems in the modal space, and the positive pressure feedback technology is employed to tune each degree of freedom （DOF） with over-damping independently and to broaden the bandwidth of each DOF to the eigenfrequencies. In the investigation, first, the influence of passive joint damping on the control characteristics of a hydraulically-driven Stewart platform is analyzed based on the modal decoupling theory. Then, the structure and the design method of the modal space controller with pressure feedback are pre- sented. Finally, an experiment is carried out to testify the effectiveness of the proposed controller. The results in- dicate that the designed modal space controller effectively broadens the system bandwidth, thus reducing the cou- pling effect between each two DOFs and improving the response speed.

关 键 词：被动关节阻尼 模态空间控制 STEWART平台 动压正反馈 

分 类 号：TH113[机械工程—机械设计及理论]