Hybrid Eye-to-hand and Eye-in-hand visual servo system for parallel robot conveyor object tracking and fetching

The objective of this paper is to develop conveyer object tracking and fetching system. The traditional visual servo system for parallel robot is based on Eye-to-hand method which suffers from the narrow field of view (FOV). The basic step of moving assembling is multiple objects tracking which needs broad work space and big FOV of the parallel robot. In this paper, a Hybrid Eye-to-hand and Eye-in-hand Visual Servo System for parallel robot is proposed. Via this hybrid system, the parallel robot can achieve (multiple) object tracking and fetching with priority planning we designed. The eye-to-hand visual system with low resolution camera provides the estimations of the velocities and poses of the workpieces. Also the fetching priority is planned with this system. All aforementioned information is transferred to the eye-in-hand visual servo system for further use. Once the object appeared in the FOV of eye-in-hand system in the estimated position, the high resolution camera of the system is employed to acquire the pose information of the object with high accuracy and track it frame by frame. The hybrid system is successfully demonstrated and implemented on parallel robot which not only broadens the working space of parallel robot but also achieves great efficiency and accuracy.