基于激光视觉传感器的机器人实时焊缝跟踪方法

为实现变姿态焊接过程的实时焊缝跟踪,提出基于机器人坐标系下绝对焊缝轨迹的实时跟踪算法.将线式激光传感器安装在机器人的法兰盘上,且位于焊枪运行的前方.焊接过程中,激光传感器连续采集焊缝位置信息,并结合手眼标定矩阵以及机器人实时姿态,将传感器采集的焊缝坐标转换到机器人基础坐标系下,从而形成空间绝对焊缝轨迹;再根据焊枪的当前...

The method of real time seam tracking for robotic welding system based on laser vision sensor

In order to realize real-time seam tracking while changing welding torch′s gesture,a novel tracking strategy based on absolute seam trajectory is proposed.The line structured laser sensor is mounted on the flange of robot in the front of the welding torch.During the welding process,the laser sensor continuously collects the seam position in sensor coordinate system.Using hand-eye matrix and robot position and gesture matrix,the homogeneous coordinate value can be transformed from sensor coordinate system into robot base coordinate system,which formed the absolute seam trajectory;the position deviation can be computed according to the current position of the welding torch and the absolute seam trajectory.In order to improve the accuracy of the calculation,a method of interpolation based on cubic non-uniform rational B-splines is addressed;finally,the position deviation is transformed to the coordinate system of welding torch tool for real-time position correction.The experimental results show that the novel strategy can realize the continuous smoothly tracking while changing torch′s gesture in welding process,and its tracking error is better than 0.5 mm which satisfies the requirements of automatic welding.