无反作用力矩空间机器人轨迹跟踪控制

摘要

针对目前关节驱动方式的不足，提出一种采用无反作用力矩驱动方式的空间机器人设计概念。系统平台与各节机械臂上均安装一组金字塔构型的控制力矩陀螺（CMGs）作为力矩执行机构，各臂间由自由球铰连接。采用Rodriguez 参数描述平台姿态和机械臂角位移，利用Kane方程建立系统动力学模型。在此基础上，设计了渐近稳定的轨迹跟踪控制律，使得平台姿态和机械臂角位移跟踪期望运动轨迹；并设计了CM Gs操纵律，使之准确输出期望控制力矩。此外，研究了机械臂工作空间到关节空间的轨迹规划算法，使得所设计的控制律也可应用于工作空间的轨迹跟踪控制。由三关节系统的仿真结果，验证了无反作用力矩设计概念的可行性和轨迹规划算法的有效性。%A new reactionless space robot design concept was put forward to overcome the shortcomings of the current drive types . Control moment gyros (CMGs) were mounted on each part mechanical arm and system platform as movement actuators . Mechanical arms were connected with spherical hinges . Platform attitude and angular displacement were measured by the Rodrigues parameters (RPs) .Based on system dynamics model built with Kane method ,a gradually stable trajectory tracking control law was designed to track the platform attitude and mechanical arm angular displacement ,and a CMGs steering law was designed to output exact expected control torque .Moreover ,the designed control laws can be further extended to track and control the workspace trajectory by studying the trajectory planning algorithms between the mechanical arms workspace and joints space . The simulation results from the three joints systems have verified the feasibility of design and effectiveness of the proposed trajectory algorithms .