CVT control of an omnidirectional mobile robot with steerable omnidirectional wheels for energy efficient drive

In a previous research, a new class of an omnidirectional mobile robot was proposed. Since it has synchronously steerable omnidirectional wheels, it is called an omnidirectional mobile robot with steerable omnidirectional wheels (OMR-SOW). It has 3 DOFs in motion and one DOF in steering. One steering DOF can function as a continuously variable transmission (CVT). CVT of the OMR-SOW increases the range of velocity ratio from the wheel velocities to robot velocity, which may improve performance of a mobile robot. In this paper, kinematics and dynamics of this robot are analyzed. A control algorithm for CVT mounted on the OMR-SOW, which considered motor efficiency in its operation, is discussed in detail. Various tests have been conducted to demonstrate validity and feasibility of the proposed mechanism and the steering algorithm. Experimental results show the OMR-SOW can be driven more efficiently with the proposed steering algorithm and a CVT mechanism.