Purely Image-Based Pose Stabilization of Nonholonomic Mobile Robots With a Truly Uncalibrated Overhead Camera

Although many vision-based control methods have been proposed for nonholonomic mobile robots, in their implementation, it is usually necessary to calibrate the camera intrinsic and/or extrinsic parameters using offline/online parameter estimation algorithms or online adaptation laws. To avoid the tediousness of camera calibration and to make the system performance highly robust to camera parameter uncertainties, in this article, we propose novel image-based pose stabilization control approaches for nonholonomic mobile robots with a truly uncalibrated overhead fixed camera. In the proposed approaches, only image position information of three feature points from an overhead camera is used for controller design, while information from other sensors (such as wheel encoders) is not required. Furthermore, either offline or online camera calibration is not necessary, and no knowledge about the camera intrinsic and extrinsic parameters is needed, which also can greatly simplify the controller implementation. Simulation and experimental results are given to demonstrate the feasibility and effectiveness of the proposed purely image-based pose stabilization approaches.