A novel omni-directional perturbation platform

The study of human, upright-balance is often performed by perturbing a base on which a subject is standing. Once a perturbation is initiated, data describing a subject´s ability to balance is recorded and analyzed. We introduce a novel perturbation device that can translate and rotate its base in any direction within a 2D plane. This robust perturbation envelope will expand researchers´ abilities in the study of upright balance and balance recovery. The heart of the design is the use of four powered casters as the platform´s transmission system. The casters´ offset insures that the Jacobian matrix describing the system´s planar motion is non-singular. A rapid embedded programming method is used to develop the control system. By controlling the orientation and speed of each caster, translation, rotation, or combined perturbations can be easily implemented.