Dynamics, stability, and energy efficiency of an energy-recycling rimless wheel with spring-clutch legs

Unknown Date

AI Summary

This study proposes an energy-regenerative rimless wheel integrated with a spring-clutch mechanism to enhance the energy efficiency of passive dynamic walkers while preserving gait stability. The design employs a lockable clutch to capture impact-induced elastic energy during ground contact and actively releases it in the subsequent step to assist propulsion. Through hybrid dynamic modeling, numerical simulations, and prototype experiments, the approach is shown to maintain locally stable periodic gaits while substantially reducing the cost of transport: simulations demonstrate reductions of up to 16.13% compared to a viscoelastic leg model and over 50% relative to a rigid leg model. The physical prototype achieves passive walking on a 1° slope with a remarkably low cost of transport of approximately 0.02.

Abstract

This paper proposes an energy-recycling rimless wheel with spring-clutch legs. The proposed mechanism uses a lockable clutch to store part of the impact-induced elastic energy after foot contact and reinject it in the next gait cycle. First, we develop a hybrid dynamic model of the energy-recycling rimless wheel. Second, numerical simulations are used to examine the dynamics, local stability of periodic gaits, and the Cost of Transport (CoT) of the proposed mechanism. The simulation results show that the proposed mechanism reduces the CoT by up to 16.13% compared with a benchmark viscoelastic-legged rimless wheel with telescopic spring-damper legs. Compared with the rigid rimless wheel, the viscoelastic-legged and energy-recycling models reduce the CoT by more than 50%. The energy-recycling model also maintains locally stable periodic gaits over the tested slope and stiffness ranges. Finally, prototype experiments on an inclined plane are conducted to examine the feasibility of the proposed mechanism. The experimental results show that the proposed rimless wheel achieves passive walking on a shallow 1° slope, corresponding to a CoT of approximately 0.02. These results suggest that the proposed spring-clutch mechanism can improve the simulated walking efficiency of the energy-recycling rimless wheel, while the prototype experiments support the feasibility of passive walking with the mechanism.

Problem

• energy efficiency
• passive walking
• rimless wheel
• dynamic stability
• Cost of Transport

Innovation

• energy-recycling
• spring-clutch mechanism
• rimless wheel
• Cost of Transport
• passive walking