A Simple Robotic Eye-In-Hand Camera Positioning and Alignment Control Method Based on Parallelogram Features.

A simple and effective method for camera positioning and alignment control for robotic pick-and-place tasks is described here. A parallelogram feature is encoded into each 3D object or target location. To determine the pose of each part and guide the robot precisely, a camera is mounted on the robot end-flange to determine and measure the location and pose of the part. The robot then adjusts the camera to align it with the located part so that it can be grasped. The overall robot control system follows a continuous look-and-move control strategy. After a position-based coarse alignment, a sequence of image-based fine alignment steps is carried out, and the part is then picked and placed by the robot arm gripper. Experimental results showed an excellent applicability of the proposed approach for pick-and-place tasks, and the overall errors were 1.2 mm for positioning and 1.0 degrees for orientation angle.