A new fully mobile omnidirectional vehicle with improved kinematic, dynamic and dead reckoning performance is presented. The vehicle has a unique ball wheel mechanism which has no kinematic singularity and, moreover, possesses configuration-invariant kinematics and dynamics. Uniform kinematic and dynamic characteristics allow smooth motion and precise motion control.
First, the ball wheel mechanism, with a unique ring bearing to hold a spherical tire, is presented. Second, we generalize upon this particular design and look for solutions within a wider class of mechanisms. Analysis reveals essential kinematic requirements and we show theoretically why spherical tires are difficult to hold. The ring bearing arrangement is developed as a solution to this problem. Third, incorporation of the ball wheels into vehicles is analyzed and optimized with respect to traction and anti-slip control. A prototype vehicle is designed, built and tested, and smooth motion and precision dead reckoning are accomplished.