不同重力环境下间隙对机械臂末端轨迹的影响

Effect of clearance on the manipulator end trajectory under different gravity environments

以在轨服务高精度操控任务为背景,根据不同重力环境中机构的间隙界面运动特性,研究了地面装调及空间服役两种不同工况下的近似间隙等效模型。分析了不同重力环境下影响间隙形成的主要因素,并以二自由度空间机械臂为例,使用无质量轻杆法获取考虑铰间间隙的空间机械臂在重力及重力释放条件下的动力学解析解,进行了铰间间隙与重力对末端轨迹跟踪控制精度耦合影响的仿真研究。在此基础上,针对间隙等效模型造成的模型不确定性及干扰设计了间隙补偿控制器,并通过仿真验证了间隙补偿控制器的有效性。

Taking the on orbit servicing and high precision manipulation as the background, a clearance equivalent model of the mechanisms with clearance was studied for both ground alignment and spatial service according to the move- ment characteristics of mechanisms clearance interface under different gravity environments. The main factors af- fecting the formation of clearance under different gravity environments were analyzed, and then taking a 2-DOF ma- nipulator as an example, the dynamics analytical solution of the manipulator with clearance in both the gravity and the gravity release environments was obtained by using the Massless link method. What is more, the simulation re- search on the coupling effect of clearance and gravity on the precision of end trajectory tracking control was conduc- ted. Based on this, to compensate the uncertainty and the disturbance caused by the clearance equivalent model, a clearance compensation controller was designed and the simulation results showed the effectiveness of it.