A Central Pattern Generator Network for Simple Control of Gait Transitions in Hexapod Robots based on Phase Reduction

TL;DR

This paper introduces a simplified phase reduction-based CPG network model for controlling gait transitions in hexapod robots, demonstrating its effectiveness through numerical simulations of various gait changes.

Contribution

It develops a phase reduction approach to design a CPG network that simplifies gait control in hexapod robots, enabling desired gait transitions with minimal complexity.

Findings

Successful gait transitions demonstrated in simulations

Phase equations effectively describe synchronization dynamics

Coupling functions enable control over gait patterns

Abstract

We present a model of the central pattern generator (CPG) network that can control gait transitions in hexapod robots in a simple manner based on phase reduction. The CPG network consists of six weakly coupled limit-cycle oscillators, whose synchronization dynamics can be described by six phase equations through phase reduction. Focusing on the transitions between the hexapod gaits with specific symmetries, the six phase equations of the CPG network can further be reduced to two independent equations for the phase differences. By choosing appropriate coupling functions for the network, we can achieve desired synchronization dynamics regardless of the detailed properties of the limit-cycle oscillators used for the CPG. The effectiveness of our CPG network is demonstrated by numerical simulations of gait transitions between the wave, tetrapod, and tripod gaits, using the FitzHugh-Nagumo oscillator as the CPG unit.