基于大景深三维扫描仪的机器人“手-眼”标定

Calibration Method for the Eye-in-hand Relationship of the Robot Vision Based on Large Depth-of-field Portable 3-D Scanner

针对机器人视觉对便携式三维扫描系统的大景深要求,利用Scheimpflug条件对像平面进行偏转,扩大了扫描系统的景深,并采用了一种将系统整个景深范围分段及进行分段校准的方法,提高了大景深三维扫描系统的测量精度;利用半径已知的球体作为参照工具,提出了一种新的机器人视觉“手-眼”关系标定方法,将姿态关系Rs与位置关系Ts解耦,使用线激光与球体的交线拟合圆恢复球心以及扫描球面拟合球心的方法,分别标定了扫描系统与机器人的旋转和平移关系,从而使机器人能够与扫描仪一起完成扫描任务,扫描精度可以达到0.2 mm。实验结果表明,该方法具有精度高及稳定性好的特点。

To satisfy the request of robot vision, the depth-of-view of a portable 3-D laser scanner is successfully extended by tilting the image plane according to the Scheimpflug condition. The depth-of-view of the scanner is divided into two parts and calibrated respectively to improve the measurement accuracy. The laser 3-D scanner is used by a 6-DOF robot to extend the scanning range. Using a sphere with a known diameter as calibration tool,a new method is proposed to decompose the transformation matrix and determine the rotation matrix and translation vector of the laser scanner＇s coordinates relative to the robot respectively. Experimental results show that this calibration algorithm is robust and the measurement accuracy is 0.2 mm. The application of scanning a tap and a lamina is also given to demonstrate the effectiveness and high precision of our system.