基于双目视觉和距离误差模型的工业机器人运动学参数标定方法

基于距离误差模型的标定技术,建立机器人末端距离误差与机器人运动学参数误差间的模型关系,避免了标定过程中坐标系的转换误差,能显著提高标定精度。视觉测量技术具有测量精度高、非接触性、实时性强等特点,与传统的机器人末端测量手段相比,具有成本低、操作简单等优势。研究一种将距离误差模型与视觉测量技术相结合的机器人标定方法,用于提高工业机器人特定工作空间的精度。采用双目视觉系统,将相机外置于机器人进行测量。基于距离误差模型进行机器人参数标定,利用标定结果进行运动学参数补偿。结果表明:特定标定工作空间内的距离误差都有所改善;在标定轨迹上,绝对距离误差的平均值从0.279 9 mm减少为0.104 4 mm,非标定轨迹的误差降幅高达50%以上,验证了该方法的可行性。

Kinematics Parameter Calibration Method of Industrial Robot Based on Binocular Vision and Distance Error Model

Based on the calibration technology of the distance error model, the model relationship between the distance error of the robot end and the kinematics parameter error of the robot was established, the transformation error of the coordinate system in the calibration process was avoided, and the calibration accuracy could be improved significantly. The vision measurement technology has the advantages of high precision, non contact and real time, compared with traditional methods, it has the advantages of low cost, easy operation. A robot calibration method which combined distance error model with vision measurement technology was proposed to improve the accuracy of industrial robots in specific workspace. A binocular vision system was adopted, and the camera was placed outside the robot for measurement. The robot parameters were calibrated based on the distance error model, and the kinematics parameters were compensated by using the calibration results. The results show that the distance errors are improved in a given calibration workspace; on the calibration trajectory, the average error of the absolute distance is reduced from 0.279 9 mm to 0.104 4 mm, and the error of the uncalibrated trajectory is decreased by more than 50%, by which the correctness and feasibility of the method are proved.