In this chapter, we describe a homography approach to vision based feedback for nonholonomic mobile robots control. Differently than other approaches based on homography or fundamental matrix, our method has been developed to be robust to reference features loss, during the robot movement. This allows us to implement an arbitrary control law without the need of a teach-by-showing stage. In the chapter, the use of a stereo camera system to improve the observer accuracy and to perform an auto-calibration of the stereo-head pose is investigated. Experimental results are provided to show the performances of the proposed system state estimation, using an eye-in-hand mobile robotic platform.
Output Tracking of Nonholonomic Mobile Robots with a Model-free Fractional-order Visual Feedback