Uncalibrated Dynamic Visual Tracking of Manipulators

This paper presents a new controller for controlling a number of feature points on a robot manipulator to trace desired trajectories specified on the image plane of a fixed camera. The controller is designed to cope with the case when the intrinsic and extrinsic parameters of the camera as well as the robot parameters are not calibrated. The controller employs the depth-independent image Jacobian to map the errors on the image plane onto the joint space. By using the depth-independent image Jacobian, it is possible to linearly parameterize the unknown camera parameters in the closed loop dynamics of the system. A new algorithm is developed to estimate unknown parameters on-line. We have proved asymptotic convergence of the image errors by Lyapunov method with a full consideration of dynamic responses of the robot manipulator and demonstrated the performance by experiments.