基于激光扫描测量臂的工业机器人运动学标定

Kinematics Calibration Method for Six-axis Industrial Robot based on Laser Scanning Measuring Arm

提出一种基于激光扫描测量臂测量系统的6轴工业机器人运动学标定方法。分析了机器人本身的运动偏差和综合考虑测量系统构造的机器人坐标系与真实基座标系之间的不重合问题;建立机器人末端位置与各连杆参数相关的绝对定位误差方程,基于该误差方程,利用便携式激光扫描测量臂测量系统对不同空间位置姿态下机器人的法兰中心点进行测量,并用最小二乘法对误差方程进行解算,利用计算出的参数误差修正机器人模型中的各名义参数值,可以提高机器人运动的准确度。将该方法应用在Staubli TX90工业机器人上,实验结果表明,机器人的绝对定位精度由标定前的均值/标准差0. 742 5 mm/0. 191 0 mm减少到标定后的0. 242 8 mm/0. 098 1 mm,提高了近50%,表明该标定方法的有效性和准确性。

A six-axis industrial robot kinematics calibration method based on laser scanning measurement arm measurement system is proposed.Firstly,the motion deviation of the robot itself is analyzed and the problem of non-coincidence between the robot coordinate system constructed by the measurement system and the real base calibration system is comprehensively considered.The absolute positioning error equation related to the parameters of each end of the robot is established,based on the error equation,using the portable laser scanning measurement arm measurement system,the flange center point of the robot in different spatial position posture is measured,and the error equation is solved by least square method.By using the calculated parameter error,the nominal parameters in the robot model are corrected,the accuracy of the robot movement can be improved.By applying the method to the Staubli TX90 industrial robot,the experimental results show that the absolute positioning accuracy of the robot is reduced from the mean/standard deviation of 0.742 5 mm/0.191 0 mm before calibration to 0.242 8 mm/0.098 1 mm after calibration,which is increased by nearly 50%,indicating the validity and accuracy of the calibration method.