自由度冗余蛇形臂机器人手眼标定研究

Research on Hand-eye Calibration of Freedom Redundancy Snake-like Arm Robot

摘要:

针对自由度冗余蛇形臂机器人的手眼标定问题,提出一种不依赖蛇形臂机构运动参数求解视觉系统与末端法兰盘手眼关系的方法；借助外部辅助双目相机系统,通过构造外部相机、末端法兰盘、视觉导航相机三者坐标系的闭环转换得到待求手眼关系；首先根据立体视觉原理得到标志点在对应相机坐标系下的3D坐标；然后利用四元数法分别求得外部相机坐标系与法兰盘坐标系、外部相机坐标系与视觉导航相机坐标系间的转换关系；最后构建坐标系转换关系闭环求得手眼关系；实验结果表明,该标定法避免了蛇形臂自由度冗余导致运动控制精度差带来的干扰,标定精度满足设计要求。

Abstract:

Aiming at problem of hand-eye calibration of a freedom redundancy snake-like arm robot, a method that independent of serpentine arm’s motion parameters to calculate the hand-eye relationship between vision system and the end-flange was presented. With the assist of external binocular camera system, the hand-eye relationship was obtained by establishing closed-loop transformation of external camera, end-flange and visual navigation system. Firstly, 3D coordinates of marked points was calculted based on the principle of stereoscopic vision. Secondly, by using of quaternion method, the transformations between external camera system and end-flange, external camera system and visual navigating system were obtained. Finally, the hand-eye transformation was calculated by creating closed loop. Experimental results indicate that the jamming originated from poor motion control precision caused by freedom redundant of snake-like arm robot was avoided, and the calibration precision meet the designed requirements.