Ball wheel drive mechanism for holonomic omnidirectional vehicle

In this paper, we propose Ball Wheel Drive Mechanism for holonomic omnidirectional vehicle. Holonomici omnidirectional vehicles have high flexibility and high motion performance. Widely used omniwheels have complicated structure, because many free rollers are arranged on wheel circumference. Omniwheels cause poor motion stability and poor step overcomning ability. We solve these practical problems by using the ball wheel drive mechanism for holonomic omnidirectional vehicle. Because the ball wheel drive mechanism has only three ball wheels and three actuators, it is very simple. This mechanism do not cause over constraint, because the number of actuators agrees with the numbers of degrees of freedom. This mechanism realizes stable motions, because the rotation directions of ball wheels agree with moving directions of vehicle. Moreover, the step overcoming ability of ball wheels are higher than omniwheels. The ball wheel drive mechanism can be used under various circumstances. In this paper, we propose a ball wheel drive mechanism and evaluated its motion properties.