一种基座姿态可控空间机器人的通用避奇异算法

针对基座姿态可控空间机器人笛卡儿路径规划中的奇异问题，提出了一种通用的运动学奇异回避算法。通过虚拟机械臂的方法建立空间机械臂的雅可比矩阵，实时判断雅可比矩阵行列式的值与角速度的关系确定奇异区，采用Newton-Raphson迭代法进行逆运动学求解，并设计了一种“微分项提取+二次拟合”的分段路径规划算法应用于奇异回避，直至关节角脱离奇异区。仿真结果表明:所提算法能够有效回避奇异，适应各种自由度与构型机械臂，调节计算时间与跟踪精度之间的关系，具备较好的通用性。 

A general singularity avoidance algorithm for pedestal-controllable space manipulator

A general singularity avoidance algorithm is proposed to solve the kinematic singularity problem of pedestal-controllable space manipulator in Cartesian path planning. First, we establish Jacobian matrix of the space manipulator by the method of virtual mechanical arm, and determine singular area by judging the relationship between the determinant of Jacobian matrix and angular velocity in real time. Then, Newton-Raphson iterative method is used to solve inverse kinematics of manipulator. Finally, we design a segmental path planning algorithm of "differential term extraction + refitting" for singularity avoidance, until the joint angle breaks away from the singular area. Simulation results show that the proposed algorithm can accomplish the singular avoidance task effectively. The proposed algorithm can be adapted to various degrees of freedom and configurations of mechanical arm. Moreover, it is convenient for users to adjust the relationship between calculation time and tracking accuracy, and has good universality.