Impact of Energy Efficiency on the Morphology and Behaviour of Evolved Robots

TL;DR

This study explores how incorporating energy efficiency into evolutionary robotics influences robot morphology and behavior, revealing that energy-aware evolution tends to produce smaller, slower robots without compromising speed.

Contribution

It introduces a simulator extension with energy modeling and investigates its effects on evolving robot morphologies and behaviors.

Findings

Energy-aware evolution reduces robot size.

Energy-aware evolution results in slower robots.

Speed can be maintained without size reduction.

Abstract

Most evolutionary robotics studies focus on evolving some targeted behavior without taking the energy usage into account. This limits the practical value of such systems because energy efficiency is an important property for real-world autonomous robots. In this paper, we mitigate this problem by extending our simulator with a battery model and taking energy consumption into account during fitness evaluations. Using this system we investigate how energy awareness affects the evolution of robots. Since our system is to evolve morphologies as well as controllers, the main research question is twofold: (i) what is the impact on the morphologies of the evolved robots, and (ii) what is the impact on the behavior of the evolved robots if energy consumption is included in the fitness evaluation? The results show that including the energy consumption in the fitness in a multi-objective fashion (by NSGA-II) reduces the average size of robot bodies while at the same time reducing their speed. However, robots generated without size reduction can achieve speeds comparable to robots from the baseline set.