Recent Patents on Omni-Directional Wheel Applied on Wheeled Mobile Robot

Background: Wheel plays an important role in many different areas, such as the wheeled mobile robot which is now widely used in planetary exploration, industrial production, household appliances and training aid appliances. In some occasions, wheeled mobile robot is required to turn in a zero radius, thus various omnidirectional wheels including ball wheel, Mecanum wheel, orthogonal wheel and Rover wheel are proposed by researchers. Objective: To evaluate a wheeled mobile robot, mobility and loading capacity are two factors meanwhile wheel is one of the key factors that makes difference on the mobility and loading capacity of wheeled mobile robot. The purpose of this paper is to study mobility and loading capacity of different kinds of omni-directional wheels. Method: This paper reviews various representative patents, productions and papers related to omnidirectional wheels. Their structures and working principles are introduced, compared and analyzed. Results: Current and future developments of the omni-directional wheels are finally provided and discussed. Conclusion: Developing an omni-directional wheel which can be used in common at anywhere is impractical. It is effective and reasonable to develop modified omni-directional wheels based on above four kinds of wheels to satisfy different requirements for the wheeled mobile robot.