Visual control of integrated mobile robot-pan tilt-camera system for tracking a moving target

Abstract

In this paper, in order to track a moving target, we propose a new control law for an integrated mobile robot- pan tilt-camera system. Our controller consists of two control loops, i.e., a kinematic and dynamic control loop, respectively. The kinematic control loop performs three tasks, i.e., allowing an image feature of the target to converge to the center of the image plane asymptotically, designing a trajectory for the mobile robot, and allowing the mobile robot to track the desired position and direction. In the dynamic control loop, the torques are determined; the actual angular velocities of the system, i.e., angular velocities of pan and tilt axis, angular velocities of right and left wheels, track the desired angular velocities which are the outputs of the kinematic controller of the kinematic control loop. According to the Lyapunov theory and Barbalat's theorem, the asymptotic stability of the whole system is proven. Simulation results achieved by using Matlab - Simulink are introduced.