Adaptive Stabilization for Uncertain Nonholonomic Dynamic Mobile Robots Based on Visual Servoing Feedback

The stabilization problem of nonholonomic dynamic mobile robots with a fixed (ceiling-mounted) camera is addressed in this paper. First, a camera-object visual servoing kinematic model is introduced by utilizing the pin-hole camera model and a kinematic stabilizing controller is given for the kinematic model. Then, an adaptive sliding mode controller is designed to stabilize uncertain dynamic mobile robot in the presence of parametric uncertainties associated with the camera system. The proposed controller is robust not only to structured uncertainty such as mass variation but also to unstructured one such as disturbances. The stability of the proposed control system and the boundedness of estimated parameters are rigorously proved by Lyapunov method. Simulation results are presented to illustrate the performance of the control law.