Central pattern generator model with periodic perturbation of state transition timing: synchronization analysis and efficient hardware implementation

A ring of unidirectionally coupled phase oscillators, which are straightforward to implement in digital circuits, is unsuitable for central pattern generators (CPGs) because of the coexistence of stable equilibria. This study proposes a novel CPG model based on a ring of unidirectionally coupled phase oscillators, enhanced with additional circuitry to perturb state transition timing periodically. This enhancement includes a counter and comparator, enabling the model to address the coexistence of stable equilibria problem. Numerical analyses demonstrated that the proposed model robustly generates a typical hexapod gait pattern and identified appropriate parameters for the additional circuitry. Furthermore, comparisons with implementations of conventional models demonstrated that the proposed model is highly suitable for implementing CPGs for controlling hexapod robots.