A Strategy of Wave Gait for a Walking Machine Traversing a Rough Planar Terrain

Abstract

The performance of a legged system is closely related to the adopted gait. Among the many available gaits, the wave gait possesses the optimum stability [1–3] and has been applied to walking on perfectly smooth terrain. The follow-the-leader (FTL) gait has the least demands for foothold selection and is the most suitable for walking on rough terrain [14]. In this paper, a strategy of wave gait which enables a hexapod to traverse two-dimensional, rough terrain is developed. This strategy applies a quasi FTL mode in walking and hence it has the advantages of both wave gait (optimum stability) and FTL gait (easy control on rough terrain). During walking, the legs move according to the wave gait and the two forelegs are adjusted to avoid forbidden areas. The maximum foot adjustment is determined by the current foot positions and the foot positions in the following one or two step(s). In order to improve the stability, different methods of foot adjustments and body adjustments are evaluated and integrated into the strategy. Finally, this strategy is verified by using computer graphics simulations.