Gait generation for a six-legged walking machine through graph search

Abstract

A walking machine must plan its footsteps in such a way that it is able to follow the desired route without stepping over the bad patches on the ground. A good way of doing this is to search through a graph of possible moves. We have previously done that for a four-legged machine (1990, 1991). For a six-legged machine, however, there are too many ways of choosing a stable support pattern. So, strong heuristics are needed to reduce the search. In this paper, a novel heuristic rule, based on the support state transitions of the wave gait, has been presented. This rule helps in converging to and maintaining the wave gait through a limited search, while retaining adequate options to deviate from the wave gait, as and when needed, to adapt to the terrain, or to execute a generalised motion. Thus, we have a gait generation mechanism that combines the efficiency of the wave gait with the terrain adaptivity of the free gait. >