Sonar-based wall-following control of mobile robots

In this paper, the wall-following problem for low-velocity mobile robots, e quipped with incremental encoders and one sonar sensor, is considered. A ro bust observer-based controller, which takes into account explicit constrain ts on the orientation of the sonar sensor with respect to the wall and the velocity of the wheels, is designed. The feedback controller provides conve rgence and fulfillment of the constraints, once an estimate of the position of the mobile robot, is available. Such an estimate is given by an Extende d Kalman Filter (EKF), which is designed via a sensor fusion approach mergi ng the velocity signals from the encoders and the distance measurements fro m the sonar. Some experimental tests are reported to discuss the robustness of the control scheme. [S0022-0434(00)01101-1].