空间双臂机器人机械臂最优轨迹规划仿真

Simulation of Trajectory Planning for Minimizing Base Reaction and Manipulators Jerk of Dual-arm Space Robot

空间机器人工作过程中,因机械臂与基座之间的动力学耦合,造成平台姿态扰动及机械臂振动,使得空间机器人操作精度降低。针对空间双臂机器人在轨服务过程中平台姿态保持与机械臂震颤抑制问题,提出一种基于多目标混沌粒子群优化的机械臂轨迹规划方法。为获得机械臂运动对基座的反作用力矩,首先建立了双臂机器人动力学方程,并且利用正弦函数参数化机械臂的运动轨迹。定义最小化基座反作用力矩与机械臂震颤抑制参数为适应函数,并考虑了机械臂关节角、关节角速度、角加速度约束条件,采用多目标混沌粒子群算法求全局最优解,实现关节空间的机械臂路径规划。通过仿真对规划方法的正确性和有效性开展验证,结果表明,利用提出的轨迹规划方法减小了机械臂运动对平台姿态的扰动,降低了控制力矩峰值,规划出的机械臂轨迹平滑连续,可应用于多自由度空间机械臂。

During the operation process of space robot, base disturbance and manipulators vibration are induced because the dynamics coupling of base and manipulators, it decreased the capable of accurately performing autonomous manipulation tasks within an acceptable execution time. To deal with the base attitude stability and manipulators jerk during service on orbit by dual - arm space robot, we propose a novel trajectory planning approach for manipulators based on Multi - objective Chaotic Particle Swarm Optimization （ MCPSO ） at joint space. The dynamic model of the dual - arm space robot is established to get the reaction torque at first. Then, the joint trajectory is parameterized by using a sinusoidal function, and an adaptive function is defined by minimizing the base reaction and manipulators jerk. Finally, with bounded joint angel, joint velocity and joint acceleration, the constrained nonlinear multivariables trajectory optimization problem is solved by MCPSO. Simulation results for a simple dual -arm space robot with 2 degree of freedom （DOF） demonstrate that this proposed minimum base reaction and minimum - jerk trajectory planning algorithm is effective and feasible. Furthermore, the method can be applied to space manipulator with any DOFs and the trajectory is smooth.