iCART: Intelligent Cooperative Autonomous Robot Transporters

Mechanical parking systems, such as elevator/tower parking systems, convey parking systems, shuttle parking systems, etc., are very popular in Japan especially inside of a crowded city. These systems are used to park automobiles efficiently for department stores, hotels, etc., although users are required to maneuver their cars skillfully and locate their cars at a specified narrow place. iCART (Intelligent Cooperative Autonomous Robot Transporters) is a robot system which maneuvers a car in a narrow space instead of its driver. Coordination of multiple mobile robots for handling a vehicle is a challenging task for multiple mobile robots. The slippage between a mobile base and the ground is inevitable and its odometry could not be used for the coordination of the multiple robots having physical interaction. The estimation error of robot pose caused by the slippage could damage the automobile carried by the system. A new coordinated motion control scheme has been designed inspired by a “caster” mechanism and implemented in the robots to overcome the problem. Through the development of iCART, we will discuss issues relating to robotics as systems integration.