Design, Development, and Mobility Test of an Omnidirectional Mobile Robot for Rough Terrain

Omnidirectional vehicles have been developed and widely applied in several areas, but most of them are designed for the case of motion on flat, smooth terrain, and are not feasible for outdoor usage. This paper presents an omnidirectional mobile robot that possesses high mobility in rough terrain. The omnidirectional robot employs four sets of modules called active split offset caster (ASOC). The ASOC module has two independently-driven wheels that produce arbitrary planar translational velocity, enabling the robot to achieve its omnidirectional mobility. Each module is connected to the main body of the robot via a parallel link with shock absorbers, allowing the robot to conform to uneven terrain. In this paper, a design and development for the ASOC-driven omnidirectional mobile robot in rough terrain are described. Also, a control scheme that takes into account a kinematics of the omnidirectional mobile robot is presented. The omnidirectional mobility of the robot regardless of ifs heading direction is experimentally evaluated based on a metric called omnidirectional mobility index.