基于蒙特卡洛方法的3-PRS并联机器人误差分析

Error Analysis of A 3-PRS Parallel Robot Based on Monte Carlo Method

针对3-PRS并联机器人误差传递关系复杂的问题,提出了用蒙特卡洛模拟抽样法计算末端位姿误差。根据设定的理想位姿,用逆向运动学求三个滑座的高度及夹角。在蒙特卡洛法的每个循环中,根据设定的概率分布及每个误差源的误差范围,随机生成误差源具体的误差数据;将三个滑座高度及机器人参数加上随机生成的误差,再用正向运动学计算末端实际位姿;进而计算理想位姿与实际位姿之间的误差。根据蒙特卡洛方法得到的末端位姿误差序列计算极限误差及特征量。最后用算例验证了方法的有效性与可行性。

Aiming at the complexity of the error propagation relation for the 3-PRS parallel robot,it proposes to analyze the end-effector position and orientation errors using Monte Carlo simulation sampling method.The inverse kinematics is used to compute highs of three sliders based on the specified ideal position-orientation.In every sampling loop of Monte Carlo method,the accrual error values for all error sources are randomly generated according to the specified error scopes and probability distribution laws.The actual end-effector position and orientation are computed using the forward kinematics based on the highs of three sliders and robot parameters that are results of adding errors to ideal highs and parameters.The position and orientation errors are computed using the actual position and orientation and ideal ones.The limiting error and characteristic can be gotten from the error sequence from Monte Carlo method.The effectiveness and feasibility are verified through computing examples finally.