A novel hardware-efficient CPG based on ergodic sequential logic for controlling six-legged robot

Abstract

In this study, a novel ergodic sequential logic (SL) central pattern generator (CPG) for the realization of multiple gaits of a six-legged robot is presented. First, a novel generalized ergodic SL oscillator and its theoretical analysis method are presented. Using the theoretical analysis method, it is shown that the ergodic SL oscillator can realize oscillations with various amplitudes by adjusting its parameters. Second, a novel ergodic SL CPG consisting of a network of the ergodic SL oscillators is presented. The SL CPG can be classified into four classes (i.e., ergodic CPG of ergodic SL oscillators, ergodic CPG of regular SL oscillators, regular CPG of ergodic SL oscillators, and regular CPG of regular SL oscillators) depending on properties of their driving signals. Detailed analyses show that the ergodic CPG of ergodic SL oscillators is most suited to be used as the CPG for controlling the six-legged robot. Third, the presented CPG is implemented by a filed programmable gate array. Experiments validate that the presented CPG can realize six-legged and four-legged gaits of the six-legged robot. Furthermore, it is shown that the presented CPG is much more hardware-efficient compared to some commonly used conventional CPGs.