Dynamic equivalence conditions and control scaling laws for ground and space manipulators

DOI编号  10.7641/CTA.2018.70852
2018,35(10):1521-1529

 作者 单位 E-mail 宗立军 西北工业大学 zonglijun@mail.nwpu.edu.cn 罗建军 西北工业大学 jjluo@nwpu.edu.cn 王明明 西北工业大学 袁建平 西北工业大学

针对如何在地面机械臂上有效验证空间机械臂控制律的问题, 本文研究空间机械臂和地面机械臂系统间 的动力学等效条件和控制相似律. 首先, 基于量纲分析研究地面机械臂和空间机械臂之间的动力学等效条件, 并基 于等效条件设计地面机械臂系统. 其次, 基于量纲分析建立空间和地面机械臂系统间的控制相似律, 设计的空间机 械臂控制律通过控制相似律将可以转化为地面机械臂相应的控制律. 最后, 考虑地面机械臂基座往往无法和空间机 械臂的基座航天器一样进行全6自由度运动, 以及地面机械臂运动时受到重力影响, 使得地面机械臂不再满足动力 学等效条件, 基于反馈线性化技术设计一种地面机械臂的动力学误差补偿策略, 使得地面机械臂和空间机械臂具有 相似的闭环动力学行为. 这样, 空间机械臂的控制律可以在设计的地面机械臂上进行验证, 仿真中以在地面机械臂 上验证空间机械臂的PID控制器为例说明所提方法的有效性.

This paper establishes the dynamic equivalence conditions and control scaling laws between ground and space manipulators, thus a ground manipulator can be designed to verify the performance of controllers that developed for space manipulators. First, the dynamic equivalence conditions between the space and ground manipulators are obtained by using the dimensional analysis, based on which, a ground manipulator can be designed for the given space manipulator leading to the dynamic equivalence between the two systems. Then, the control scaling laws between the two systems are formalized, therefore the given controller of the space manipulator can be transformed to that of the ground manipulator and verified on the ground system. Finally, unlike the space manipulator, since the ground manipulator may not have the complete six degrees of freedom for its base and it suffers from the gravity effects, the realistic dynamics of the ground manipulator may deviate from the dynamic equivalence conditions, thus a feedback linearization technique based dynamic error compensation scheme is developed for the ground manipulator to make it have the same joint movements to those of the space manipulator. As a result, controllers of the space manipulator can be verified on the ground manipulator, and it is shown how the performance of a PID controller for the space manipulator is verified using the designed ground manipulator in the simulations.