工业机器人接触式标定技术分析与研究

Analysis and Researchon Contact Calibration Technology of Industrial Robot

工业机器人标定技术是提高机器人绝对定位精度、实现机器人离线编程及快速故障恢复的有效途径。本文提出一种通用的面向六自由度工业机器人的接触式标定计算流程。针对机器人基坐标系与测量坐标系的转换关系不固定、传统位置误差模型不适用的问题,将测量坐标系、标定板坐标系与机器人的转换矩阵作为未知参数,推导了测量坐标系下的位置误差模型。并在修正的MDH模型下,给定不同的几何参数误差范围,比较位置误差模型以及距离平方差模型下的参数辨识的效果。实物验证结果表明,误差补偿后机器人的绝对定位精度整体提高了50%。

Industrial robot calibration technology is an effective way to improve absolute robot positioning accuracy,achieve off-line robot programming and fast fault recovery.This paper proposes a generalized contact calibration calculation process for six-degree-of-freedom industrial robots.For the problem that the conversion relationship between the robot base coordinate syst em and the measurement coordinate system is not fixed and the traditional position error model is not applicable,the position error model under the measurement coordinate system is derived by taking the conversion matrix of the measurement coordinate system,the calibration plate coordinate system and the robot as the unknown parameters.And given different error ranges of geometric parameters under the modified MDH model,the effects of the position error model and the parameter identification under the distance squared difference model are compared.The experimental results show that the overall absolute positioning accuracy of the robot is improved by 50%after error compensation.