An autonomous docking method based on ultrasonic sensors for self-reconfigurable mobile robot

Autonomous docking is an essential capability for self-reconfigurable robots. In this paper, a measurement system based on ultrasonic sensors for measuring distance between two mobile modules is firstly introduced. Then, triangle localization arithmetic for measuring the relative position/orientation between two mobile modules to implement docking is analyzed. Considering inherent drawbacks of triangle localization arithmetic by experiments, a novel arithmetic of centering alignment based on the concept that the received ultrasonic signal intensity should be balanced when the two modules are centered and faced each other is proposed, and involved parameters are discussed and optimized. Following experiments indicate that the centering alignment arithmetic is high-efficiency and good-reliability and can implement the docking of JL-2 modules accurately. The centering alignment arithmetic proposed in this paper can be generally applied to other planar docking process.