Configuration and readhesion control for a mobile robot with external sensors

Since a wheeled mobile robot is subject to nonholonomic constraints, the position and the configuration of the robot cannot be derived directly from only the rotation angle of its wheels. In other words, the position and the configuration of a mobile robot cannot be calculated correctly if its wheels skid. For the purpose of the position estimation of a mobile robot, some external sensors are used, in general. This paper uses position information from a position-sensitive detector camera that is a high-speed visual sensor to correct the errors that are due to skid and so on. Also, we estimate a skid of wheels by using its visual information. In this paper, the authors propose a control system that enables control of both the configuration of the robot and the skid of wheels simultaneously by including these estimated values in the control loop of a mobile manipulator.