一种冗余机械臂的简化运动学求解方法

A Simplified Kinematics Solution Method for Redundant Manipulator

七自由度机械臂从结构上冗余一个自由度,是为躲避障碍物和奇异点而设置。但因其冗余自由度导致运动学求解难度增加,计算耗时长,直接影响后续运动及控制效率。本文基于一款轻型仿人七自由度机械臂,提出了一种求逆解的简化方法,基于机械臂的自运动特性,将几何方法与解析方法结合,此方法在传统的利用罗德里格斯变换的方法基础上简化了求解臂型角为零时求解θ_(1)、θ_(2)、θ_(3)的过程,有效的对此机械臂进行运动学求解。并通过MATLAB中的Robotics Toolbox工具箱对所求结果进行验证,所得结果正确快速,为之后的机械臂运动控制奠定了基础。

Due to its structural characteristics,the redundant one degree of freedom is often used to avoid obstacles and singular points.However,due to its redundant degrees of freedom,the kinematics solution of the robotic arm of these degrees is more complicated and usually takes more time,directly affecting its follow⁃up movement and control efficiency.Based on a light⁃weight human⁃like seven⁃degree⁃of⁃freedom manipulator,this paper proposes a simplified method to find the inverse solution.Based on the self⁃motion characteristics of the manipulator,the self⁃motion geometric method based on the fixed arm angle is combined with the analytical method.This method simplifies the solution ofθ_(1),θ_(2) andθ_(3),when the arm angle is zero and is based on the traditional method using the Rodrigues transformation.The method effectively solves the kinematics of this manipulator.The robotics toolbox in MATLAB is used to verify the obtained results,which are correct and fast,thereby laying the foundation for the subsequent motion control of a robotic arm.