基于运动学分析的工业机器人轨迹精度补偿方法

Trajectory precision compensation method for industrial robot based on kinematics analysis

运动轨迹精度是工业机器人重要的性能评价指标,从机器人运动学角度研究工业机器人轨迹精度提高补偿方法。以SR4C六自由度工业机器人为研究对象,基于国标中对机器人轨迹精度的评定标准,提出一种基于运动学分析的工业机器人轨迹精度补偿方法,并建立了曲线运动轨迹偏差与运动学模型参数误差映射的机器人运动轨迹误差数学模型。在实现激光跟踪仪和机器人坐标系统一的快速有效的坐标系转化方法的基础上,采用改进最小二乘算法选择轨迹偏差最小时的最优运动学参数,对构建的机器人轨迹测试与补偿实验系统进行了轨迹补偿实验,验证了该方法的有效性。结果表明,经该方法补偿后机器人平均位置误差由3.65%提高至0.79%,直线、圆弧轨迹精度分别提高了38.75%、25%。

Motion trajectory accuracy of industrial robot is an important performance evaluation index. The compensation method for trajectory accuracy improvement of industrial robot is studied from the perspective of robot kinematics. Taking a SR4 C industrial robot with six degrees of freedom as the study object, based on the evaluation criterion of national standard for robot trajectory accuracy, an industrial robot trajectory accuracy compensation method based on kinematics analysis is proposed. The mathematical model of robot motion trajectory error is established, which maps the curve motion trajectory deviation to kinematic model parameter error. On the basis of realizing the unified, fast and effective coordinate system transformation method of laser tracker and robot coordinate systems, the improved least square algorithm is adopted to select the optimal kinematic parameters for the smallest trajectory deviation, The trajectory compensation experiment on the constructed robot trajectory test and compensation experiment system was conducted, which verifies the effectiveness of the proposed method. The results show that the average position error of the robot is improved from 3.65% to 0.79% after the compensation with the proposed method, and the accuracies of the straight and circular trajectories are improved by 38.75% and 25%, respectively.