Kinematics and Moving Properties of a Four-Wheel-Drive, Omnidirectional Mobile Robot.

Abstract

An omnidirectional vehicle (ODV), which can move in any direction without changing its body direction, was investigated. The principal driving motion involves four wheels equipped with rollers on their circumference. These rollers rotate along the axle direction of the wheels. The wheels are installed on all four sides of the vehicle. Moving properties of this vehicle were investigated through computer simulations and experiments. The simulation tests confirmed that the ODV can move to arbitrary places in arbitrary directions. Spinning motions and turning motions are also possible in addition to the omnidirectional motion. A variety of movements were examined in the ODV experiments. To analyze these results, an omnidirectional robot (ODR) called "calligraphy robot" was constructed, which drew a cursive style Chinese character with a writing brush on a sheet of Japanese writing paper. Movements and control of the ODR were evaluated, and satisfactory movement and control performances were confirmed.