基于粒子群算法的空间机械臂关节驱动力矩优化设计

采用绝对节点坐标方法对空间柔性机械臂臂杆进行动力学建模，采用自然坐标法对机械臂关节进行建模，最终得到刚柔耦合的空间机械臂动力学模型.对冗余自由度机械臂进行逆运动学分析，由规划的末端轨迹得到了含自运动项的关节转角轨迹.利用动力学方程中Lagrange乘子的物理意义，对机械臂系统进行逆动力学分析，推导了关节轴瓦与轴颈在运动过程中受到的关节驱动力/力矩.利用粒子群算法优化机械臂的自运动项，得到了最小化的关节驱动力矩能耗，从而形成了一种冗余空间机械臂关节驱动力矩优化设计新方法.在平面三连杆柔性机械臂进行了数值仿真，仿真结果表明:所提出的方法在实现末端轨迹跟踪的同时，能有效降低关节力矩能耗；得到的关节力矩连续性好，能够满足工程实际需要. 

Joint Actuated Torque Optimization Technique Applied to Space Manipulators via PSO Algorithm

In this paper absolute nodal coordinate formulation (ANCF) was utilized to model space manipulator links and natural coordinate formulation (NCF) was adopted to model manipulator joints to develop the dynamic equations of a rigid-flexible coupling space manipulator system. Joint rotation trajectories containing the self-movement term were deduced from the predetermined end-point trajectory by inverse kinematics theory. Inverse dynamics of the manipulator system based on Lagrange multiplier in dynamic equations leads to joint actuated forces/torques applied to bearing shells and journals during the movement. Thus particle swarm optimization (PSO) algorithm with constriction factor can be employed to optimize the redundant self-movement term to obtain the minimum energy consumption of actuated torques, which forms a new joint actuated torque optimization technique applied to redundant space manipulators. The three-link planar manipulator was used to evaluate this method. Simulation results show that the proposed method is effective in the end-point trajectory tracking and in reducing energy consumption; the computed joint torques obtained are well continuous and suitable for practical engineering.