Visual Servo Regulation of Wheeled Mobile Robots With an Uncalibrated Onboard Camera

In this paper, a visual servo regulation strategy is designed for an uncalibrated camera system mounted on a wheeled mobile robot subject to nonholonomic motion constraint, which can drive the mobile robot to the target pose with exponential convergence. Unlike existing methods, the proposed approach can work well without the camera intrinsic parameters being known in advance. Specifically, a novel fundamental matrix-based algorithm is first proposed to rotate the robot to point toward the desired position, with the camera intrinsic parameters estimated simultaneously by employing the fundamental matrix and a projection homography matrix. Subsequently, by utilizing the obtained camera intrinsic parameters, a straight-line motion controller is developed to drive the robot to the desired position, with the orientation of the robot always facing the target position. Another pure rotation controller is finally adopted to correct the orientation error. The exponentially convergent properties of the visual servo errors are proven with mathematical analysis. The performance of the proposed uncalibrated visual servo regulation method is further validated by both simulation and experimental results.