基于相机空间点约束的机器人工具标定方法

工具标定就是确定工具坐标系相对于机器人末端坐标系的变换矩阵,但传统的解决方案是通过人工示教点约束的方法,为此提出一种基于视觉相机空间的自动工具标定方法。在末端工具上增加特征点如圆环标志,利用相机建立机器人三维空间与相机二维空间之间的关系,通过自动的三维空间视觉定位,实现对圆环标志的中心点的点约束,视觉定位不需要相机的标定等繁琐过程。基于机器人的正运动学和相机空间点约束完成工具中心点(TCP)求解。重复实验的标定误差小于0.05 mm,实验的绝对定位误差小于0.1 mm,验证了基于相机空间定位的工具标定具有较高的可重复性以及可靠性。

Robot tool calibration method based on camera space point constraint

The tool calibration means calculating the transformation matrix of the tool coordinate system relative to the end of the robot coordinate system. Traditional solution realizes point constraint by manual teaching. A calibration method based on visual camera space positioning was proposed. It used the camera to build the relation between the 3D space of the robot and the 2D space of camera to achieve the point constraints of the center point of the rings marks which were used as feature points and stuck on the edge factor. Visual positioning did not need camera calibration and other tedious process. The Tool Center Point (TCP) was figured out based on the forward kinematics derivation process of the robot and camera space point constraint. The calibration error of repeated experiments was less than 0.05 mm, and the absolute positioning error was less than 0.1 mm. The experimental results verify that the tool calibration based on camera space positioning has high repeatability and reliability.