空间机械臂关节失效瞬时力矩突变抑制

针对空间机械臂执行负载操作任务突发关节失效引起的关节负载补偿力矩突变问题，建立了关节负载补偿力矩突变优化模型及求解方法。首先分析关节负载补偿力矩突变原因，以故障瞬间力矩突变量最小为目标，考虑突发关节故障，建立关节负载补偿力矩突变优化模型；其次构造含有抑制系数及静力学可操作度梯度的关节力矩修正项，并构造最优抑制系数函数，求解关节力矩突变优化问题；最后通过仿真对关节负载补偿力矩突变优化方法的正确性和有效性展开验证。结果表明：通过搜索最优抑制系数，突发关节失效引起的关节负载补偿力矩突变可被有效抑制，平均抑制率高达89.26%，且末端操作力精度不受影响，保证了空间机械臂负载操作任务安全可靠完成。

Joint Torque Jump Inhibition at Failure Moment for a Space Manipulator

For inhibiting the joint load compensation torque jump caused by an unexpected joint failure when space manipulator executes the load carrying tasks, the optimization model and its solving process are proposed in this paper. The load compensation torque jump caused by the locked-joint failure is analyzed at first, and to minimize the torque jump at failure moment, the optimization model of the joint load compensation torque jump in the presence of the unexpected joint failure is established. The correction item of the joint torque containing the compensation coefficient and statics manipulability gradient is constructed and the optimal inhibition of the joint load compensation torque jump can be realized by fitting the optimal compensation coefficient function. Finally, the effectiveness of the proposed inhibition method is verified by the numerical simulation. The results show that the joint load compensation torque jump caused by the unexpected joint failure can be effectively inhibited by the proposed method, and the average inhibition ratio can reach up to 89.26%. Meanwhile, the accuracy of the operating force on the end-effector will not be affected, thus the space manipulator can finish the load carrying tasks stably and safely.