Abstract
This paper proposes an omnidirectional vehicle with multiple steerable drive wheels. The wheels are modularized on their mechanisms and controllers, so that we can tailor the vehicle to many transfer applications. A hierarchical control system composed of a vehicle level controller and the wheel module controllers enables the wheel modules to precisely execute omnidirectional motions of the vehicle by their coordination. An odometric dead-reckoning system, which fuses the redundant odometry information of the wheel modules in a decentralized manner, can identify the vehicle position reliably in the environment with fewer external landmarks. The simulation results of a vehicle with four wheel modules justify the proposed method.