Reflective force integration method for nonautonomous mobile robot control

In this paper, a reflective force generation method of a force feedback joystick is suggested for a nonautonomous mobile robot maneuvered by a teleoperator. Three types of the reflective forces are defined such as obstacle detection, obstacle avoidance and robot posture recognition forces. To generate the reflective force for obstacle detection and avoidance, range data from ultrasonic sensors of the robot are used. Using these data, wall and center following of the robot are implemented by a fuzzy logic controller for obstacle avoidance. Next, the reflective force for robot posture recognition is generated using a gyro sensor of the robot. Thus the operator can not only maneuver the robot without collisions but also recognize the existence of obstacles and the posture of the robot by the reflective forces while driving the robot. Then, to determine the type of the reflective forces according to robot and obstacle states a state transition diagram is suggested. Finally, the experimental and simulation results with the mobile robot, ROBHAZ-DT developed by KIST show the effectiveness of the suggested method.