Design and optimization strategies for muscle-like direct-drive linear permanent-magnet motors

Abstract

We report a new approach to the design of direct-drive linear permanent-magnet motors for use in general-purpose robotic actuation, with particular attention to applications in bird-scale flapping-wing robots. We show a simple, quantitative analytical modeling framework for this class of actuators, and demonstrate inherent scaling properties that allow the production of motors with force densities and efficiencies comparable to those of biological muscles. We illustrate the effectiveness of our model with finite-element analysis and a comparison with commercially available motors, and discuss future plans for experimental validation. We show how this model leads to a set of practical design specifications for muscle-like motors, and examine the resulting trade-off between thermal management and motor fabrication complexity.