Evolved embodied phase coordination enables robust quadruped robot locomotion

TL;DR

This paper presents an evolutionary approach to designing embodied phase coordination control systems for quadruped robots, improving real-world robustness and reducing simulation-to-reality performance gaps.

Contribution

It introduces sensor-feedback influenced phase coordination in evolutionary control design, enabling more complex and robust quadruped robot locomotion in real environments.

Findings

Enhanced transferability of control systems from simulation to real robot

Improved robustness in diverse real-world environments

Evolutionary design yields more complex coordination patterns

Abstract

Overcoming robotics challenges in the real world requires resilient control systems capable of handling a multitude of environments and unforeseen events. Evolutionary optimization using simulations is a promising way to automatically design such control systems, however, if the disparity between simulation and the real world becomes too large, the optimization process may result in dysfunctional real-world behaviors. In this paper, we address this challenge by considering embodied phase coordination in the evolutionary optimization of a quadruped robot controller based on central pattern generators. With this method, leg phases, and indirectly also inter-leg coordination, are influenced by sensor feedback.By comparing two very similar control systems we gain insight into how the sensory feedback approach affects the evolved parameters of the control system, and how the performances differs in simulation, in transferal to the real world, and to different real-world environments. We show that evolution enables the design of a control system with embodied phase coordination which is more complex than previously seen approaches, and that this system is capable of controlling a real-world multi-jointed quadruped robot.The approach reduces the performance discrepancy between simulation and the real world, and displays robustness towards new environments.