Omnidirectional holonomic mobile robot using nonholonomic wheels

An omnidirectional holonomic mobile robot assembled with nonholonomic wheels has been proposed. The driving wheel axis of the nonholonomic wheel has an offset distance from the steering axis of the wheel. A wheel of this style is representative of the nonholonomic system and is conventionally used for a caster wheel. In the case of the proposed mobile robot, a wheel of this style is used as a driven wheel by actuating a wheel axle and a steering axle independently. First, we describe the modeling and control of the single nonholonomic wheel, and then describe the holonomic vehicle which has a couple of these nonholonomic wheels. To avoid the nonholonomic characteristics of the wheel, we have introduced a control method which restricts the controlled statement to only the translational velocity of the supporting point of the wheel. Computer simulations of the single wheel and of the two wheeled vehicle, and experimental results of the single wheel have shown good performances.