关节柔性的漂浮基空间机器人基于奇异摄动法的轨迹跟踪非奇异模糊Terminal滑模控制及柔性振动抑制  

Nonsingular fuzzy terminal sliding mode control and elastic vibration suppressing of a free-floating space robot with flexible joints based on trajectory tracking of the singular perturbation method

作　　者：梁捷[1,2] 陈力[1] 

机构地区：[1]福州大学机械工程及自动化学院,福州350108 [2]中国空气动力研究与发展中心,绵阳621000

出　　处：《振动与冲击》2013年第23期6-12,共7页Journal of Vibration and Shock

基　　金：国家自然科学基金(11072061、10672040);福建省自然科学基金(2010J01003)资助项目

摘　　要：如果在漂浮基空间机器人系统动力学建模和控制方法设计过程中忽略关节柔性的存在,其控制系统的精度和稳定性将受到极大影响。以考虑关节柔性、系统参数不确定的漂浮基空间机器人系统为研究对象,讨论了其动力学建模过程、运动轨迹跟踪控制方案设计及柔性振动振动抑制。结合拉格朗日第二类方法并结合系统动量、动量矩守恒关系,分析、建立了系统动力学方程。以此为基础,为了同时实现空间机器人运动轨迹的渐近跟踪和抑制由关节柔性引起的系统弹性振动,采用奇异摄动理论的双时间刻度分解,将系统分解为表示系统刚性运动部分的慢时标子系统和表示系统柔性运动部分的快时标子系统。针对慢时标子系统设计了非奇异模糊Terminal滑模控制方案。该控制方案采用非奇异Terminal滑模面,并基于模糊逻辑系统自适应调整控制律的切换项,不但克服了在设计中需要知道系统不确定性的上界的限制,又消除了滑模变结构控制器抖振的缺点。针对快时标子系统,采用速度差值反馈控制律来抑制关节柔性引起的系统弹性振动,保证系统的稳定性。仿真时以平面两刚性臂、两柔性关节的漂浮基空间机器人系统为例证明了所提出方法的有效性。If flexible joints were ignored in dynamic modeling and control method design of a free-floating space robot,the precision and stability of its control system would be influenced seriously. Here,the dynamic modeling,motion trajectory tracking control design and flexible vibration suppression of a free-floating space robot with flexible joints uncertain parameters were discussed. The system's dynamic equations were established by using the linear momentum conservation,angular momentum conservation and Lagrangian equations. Based on the above results,in order to realize the motion trajectory's asymptotic tracking of the space robot and to suppress its elastic vibration caused by flexible-joints, the system was decomposed into a slow-subsystem and a fast-subsystem using the double-time scale decomposition of the singular perturbation theory. For the slow-subsystem,the fuzzy adaptive nonsingular terminal sliding mode control scheme was designed to achieve the desired motion trajectory's asymptotic tracking. For the fast-subsystem,a velocity difference feedback controller was proposed to suppress the elastic vibration caused by flexible-joints and to guarantee the stability of the system. In simulations,a free-floating space robot system with two rigid arms and two flexible joints was taken as an example. The simulation results verified the efficiency of the proposed method.

关 键 词：漂浮基空间机器人 关节柔性 模糊逻辑 参数不确定 柔性振动控制 

分 类 号：TP241[自动化与计算机技术—检测技术与自动化装置]