A novel mobile robot capable of changing its wheel distance and body configuration

Mobile robots have been extensively investigated since the early development of robotics and widely used in indoor and outdoor environments. However, with almost all existing wheeled robots, the distance between the wheels are constant and orientation of the wheels (except for the steering ones) are fixed with respect to the robot body, which limits their adaptability to environments. To overcome these drawbacks with conventional wheeled mobile robots, we have developed a novel mobile robot consisting of a few joint modules, two wheels and one caster. The joint modules form the arm-like body of the robot. The unique features of the robot include its strong ability to change the configuration of the body, the distance between and the orientation of the wheels, and hence the ability to run omni-directionally. The development of the system, kinematic analysis and motion planning for the robot are presented in this paper. Simulation and experiments are also provided to verify the effectiveness and illustrate the unique features of this novel robot.