Development of omni-directional vehicle with step-climbing ability

In this study, we propose a new holonomic mobile mechanism which is capable of step-climbing. This mechanism realizes to move in any direction on the flat floor and pass over steps and slopes in one (fore and hind) direction. The vehicle equips with seven omni-directional wheels with cylindrical free rollers and a passive body axis that provides to change the shape of the body on the rough terrain. There is no need for additional actuators or sensors for the passive body axis. In our previous work, we constructed a prototype mobile mechanism and analyzed its kinematic characteristics. In this paper, we design a new control scheme and improve the mechanism for passing over the steps more stably. The performance of the prototype system is verified through experiments and computer simulations.