Fitness Space Structure of a Neuromechanical System

This article rigorously characterizes the structure of the entire fitness space of a simple neuromechanical system consisting of a model leg in closed-loop interaction with a neural controller. Using tools from the theory of piecewise-smooth dynamical systems, we derive expressions for the location and layout of the region of high-fitness solutions in parameter space, and we show how both the boundary and the internal structure of this region arise from specific neural, mechanical, and neuromechanical properties of the walking system. In addition, we characterize the structure of the map from neural parameters to gaits to fitness.