Do Intermediate Gaits Matter When Rapidly Accelerating?

Published in IEEE Robotics and Automation Letters, 2019

Recommended citation: C. Fisher, C. Hubicki and A. Patel, "Do Intermediate Gaits Matter When Rapidly Accelerating?," in IEEE Robotics and Automation Letters, vol. 4, no. 4, pp. 3418-3424, Oct. 2019, doi: 10.1109/LRA.2019.2927952. https://ieeexplore.ieee.org/document/8758791

Abstract: Transient locomotion is still poorly understood in terms of planning and implementation on robotic platforms, with most research concentrated on steady-state motion. In this letter, we investigate optimal rapid acceleration (positive and negative) maneuvers of a planar numerical quadruped and biped robot. The question we ask is whether legged robots should transition through discrete, intermediate gaits (walking to trot to bound) or plan a direct transition to the top-speed gait. We present numerical evidence supporting the energetic optimality of transitioning to a desired gait without intermediate gait transitions. Trajectories were generated from rest to steady state and vice versa. Two cost functions (cost of transport and a heat-based cost function) were analyzed and compared to observations made in nature. A full 30-m trajectory was generated and compared to the acceleration and deceleration results, which further supported transitioning directly to the desired gait. All the trajectories were observed to follow a sliding mass template model which, in future, can be used as a heuristic to plan these transient maneuvers.

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