A Planar Symmetric Walking Cancellation Algorithm for a Foot—Platform Locomotion Interface

Abstract

In this paper we describe a planar symmetric walking cancellation algorithm for generating smooth and collision-free turning motions on the foot—platform locomotion interface, the Virtual Walking Machine that has two three-degree-of-freedom (DOF) planar and three-DOF footpad parallel manipulators connected in series. This solves the problem of the asymmetric walking velocity profile of the swing and stance feet in the existing constant-velocity walking cancellation method. The proposed symmetric walking cancellation method cancels the stance foot motion with the opposite swing foot motion. In addition, the proposed walking cancellation method was extended to a planar walking algorithm that uses constraint motions of curvatures to avoid mechanical collisions between the two foot platforms. Walking simulations, experiments, and user evaluations showed that the proposed symmetric walking cancellation algorithm is better than the previous constant-velocity algorithm in terms of smoothness, absence of delay, and walking stability. For planar motions, the device can generate a maximum turning angle of 20 ^° and a maximum turning velocity of 45 ^° per second for one step with a minimum available curvature of 1 m. Navigation experiments in a virtual environment were performed to show the effectiveness of the suggested planar walking algorithm.