具有初始动量的空间机械臂零反作用轨迹跟踪

对具有初始动量的自由漂浮空间机械臂系统进行了研究，考虑其执行在轨任务时便已经具有的动量，根据系统的构型参数建立运动学模型，再采用拉格朗日第二类方程建立动力学模型。利用空间机械臂系统具有冗余自由度这一特性，推导运动学和动力学方程，得到了零反作用运动方程，消除了基座和机械臂之间的角速度耦合作用。末端运动轨迹用多项式插值函数来逼近，根据给定的机械臂末端初始和终止状态来规划其运动轨迹，并将机械臂末端的工作空间转换到关节空间中。根据已知的动力学模型，设计合适的比例-微分（PD）控制率。仿真结果表明，通过选择合适的增益反馈矩阵，机械臂末端能平稳地跟踪目标轨迹，同时，机械臂的运动不会对基座的姿态产生扰动，保证了基座姿态的稳定性及航天器的正常运行。

Zero Reaction Motion Trajectory Tracking for Space Manipulator with Non-zero Initial Momentum

The free-floating manipulator system with non-zero initial momentum was studied.The configuration parameters of the manipulator system and the Lagrange equations were used to build the dynamic model. In order to eliminate the coupling effects between the base and the manipulators in angular velocity,the zero reaction motion equation was derived by using the manipulator system redundancy. A polynomial interpolation method was used to approach the trajectory of end-effector and the trajectory was planned due to the initial and final position of end-effector which could turn workspace of end effector into joints space. A suitable proportion-differentiation (PD) control algorithm was designed to drive manipulators movement. Simulation results demonstrate that the end-effector can smoothly track the target and the movement of the manipulator doesn′t make any disturbance to the base′s attitude at the same time and the spacecraft also can work normally because of the stability of base.