针对用于物流仓储领域的平面四索并联机器人,提出一种基于视觉定位的自标定方法。通过相机和货架上的AprilTag获取末端动平台的位置,进行模型参数辨识和误差补偿,实现平面四索并联机器人的几何参数快速标定。首先,建立该四索并联机器人的运动学模型；然后,提出基于该机器人构型的运动学参数标定方法及位姿测量方法；最后,通过计算机仿真和实验验证该标定方法的有效性。实验结果表明,该标定方法能够快速实现末端动平台的运动学标定,达到小于1 mm的定位精度,满足仓储堆垛任务的定位误差要求。
An auto-calibration method was developed for planar four-cable parallel robots based on visual measurements. The end-effector pose is obtained using a camera fixed on the end-effector that measures the pose of AprilTags on storage racks. Geometric parameter identification and error compensation are then used for rapid calibration of the planar four-cable parallel robot. The system model is based on a kinematics model of the planar four-cable parallel robot for storage and logistics tasks. Then, the kinematics calibration method is used with the pose measuring method to calibrate the robot. The calibration accuracy was verified using both computer simulations and tests. The results show that this rapid calibration method provides positioning accuracy of less than 1 mm, which meets the accuracy requirement for the storage and stacking tasks.
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