基于误差分布特性的机器人闭链协调轨迹规划

Trajectory planning for robot with closed-chain coordinated operation based on error distribution characteristics

针对机器人关节柔性误差提出利用误差分布空间描述操作精度的方法,耦合各关节的操作误差得到真实操作点在空间中可能存在的区域,进而得到机器人沿各个方向上的操作精度.给出了误差分布空间的计算方法,通过对低维误差空间的分段升维,解决了计算难度随维数指数倍增长的问题.研究了闭链协调操作过程中的误差分布特性,并基于误差分布空间分析了冗余度机器人关节自运动特性对闭链协调操作精度的影响.研究结果表明:同一操作精度对应的关节构型不唯一,且操作空间中误差最小值对应的关节角度并不连续.为此提出了一种基于最小二乘的误差极小化机器人轨迹规划方法,并通过仿真验证了该方法的有效性.

An error distribution space method to describe the operation precision caused by flexible joint errors was proposed.The operating errors of each joint were coupled to obtain the possible regions of the real operating points in space,and the operating accuracy of the robot along all directions was obtained.The algorithm for error distribution space was given,and the problem of exponential multiplication with dimension was solved by increasing dimension of low-dimensional error space.The error distribution characteristics in the process of closed-chain coordinated operation was studied,and the influence of the self-motion characteristics of redundant robot joints on the precision of closed-chain coordinated operation was analyzed based on the error distribution space method.Research result shows that the joint configuration corresponding to the same operating precision is not unique and the joint angle corresponding to the minimum error in the operating space is not continuous.Therefore,a method of trajectory planning with minimum error based on the least square method was proposed,and its validity was verified by simulation.