Visual servo control and parameter calibration for mobile multi-robot cooperative assembly tasks

In the recent years visual servo control has become a popular research topic in robotics. Usually, it is applied to fixed-base robotic manipulators working in a structured industrial environment. This paper focuses on developing a visual servo control system for a mobile robot, which operates in an unstructured environment. First, the system hardware and control objective are introduced. Second, the system kinematic model and the coordinate transformation issues are studied. Finally, a visual servo controller is derived based on the Lypunov method, which guarantees asymptotic stability of the closed-loop system. In addition, the issue of camera calibration of the visual servo control system is discussed in the paper. Through manually measuring some sample points in the real world and their corresponding pixel coordinates in the image, the extrinsic and intrinsic camera parameters are identified and calibrated. The developed mobile visual servo control system is intended for use in a multi-robot cooperative assembly task.