Testing the Effects of Evolved Central Pattern Generators in an Articulated Robot Animat Ecosystem

Abstract

This study added central pattern generators (CPGs) to 3D artificial animal (i.e., animat) articulated robots contained in a simulated ecosystem. Specifically, Hopf and Matsuoka CPG equations were added to the hidden neuron calculations, and the effects of these augmentations on robot behavior were analyzed. The results indicated that robots utilizing sum-and-squash neurons with the CPG equations in the hidden neuron equation performed better than robots using only sum-and-squash neurons without CPGs. The rhythmic motor patterns generated by the CPG dynamics helped the articulated robots to move around the environment, as well as to better accomplish survival and reproduction. The robots equipped with CPGs were able to reproduce more often and with higher energy efficiency than the No CPG robots. The performance advantage in birthrates of robots with CPGs over robots without CPGs increased as the simulation progressed. Overall, the addition of CPGs to the neurons of 3D articulated robots provided useful rhythmic movement that proved beneficial for movement, survival, and reproduction.

Received: 13 September 2025 | Revised: 11 November 2025 | Accepted: 28 November 2025

Conflicts of Interest

C.H. is a maintainer of the ERAIASON simulator used in this study, which is distributed free and open-source on GitHub. A paid executable version is also offered as an option. This potential financial interest is disclosed; no other competing interests are declared.

Data Availability Statement

The data that support the findings of this study are openly available in Zenodo at https://doi.org/10.5281/zenodo.17110785.

Author Contribution Statement

Christian Hahm: Conceptualization, Conceptualization, Methodology, Software, Validation, Formal analysis, Investigation, Resources, Data curation, Writing – original draft, Writing – review & editing, Visualization, Supervision, Project administration. Rohan Jay: Conceptualization, Methodology, Software, Validation, Formal analysis, Investigation, Resources, Data curation, Writing – original draft, Writing – review & editing, Visualization.