Design and performance analysis of human walking induced energy recovery system by means of hydraulic energy conversion and storage. (1st August 2020)

• Record Type: Journal Article
• Authors: Shi, Hu; Yue, Yinyun; Wang, Haitao; Xu, Jun; Mei, Xuesong
• Is Part Of: Energy conversion and management. Volume 217(2020)
• Publication Date: 2020-08-01
• Subjects: Human walking -- Energy recovery -- Dynamic modeling -- Gait analysis -- Hydraulic system -- Accumulator; Direct energy conversion -- Periodicals; Energy storage -- Periodicals; Energy transfer -- Periodicals; Énergie -- Conversion directe -- Périodiques; Direct energy conversion; Periodicals; 621.3105
• DOI: 10.1016/j.enconman.2020.113008
• Languages: English
• ISSNs: 0196-8904

Abstract

Highlights: Force interactions between foot and ground within a gait cycle are changing in a dynamic manner. Capturing the vertical component of force and motion generated by foot can maximize the energy harvested from human walking. Energy induced by footstep motion can be converted into hydraulic energy directly and stored simultaneously. Hydraulic energy recovery system is superior in power density and storage to those aimed at generating electricity. Abstract: Human walking induces a lot of mechanical energy available for harvesting. It is promising to use such energy to reduce the energy supply of wearable electronics and robotic equipment such as exoskeleton. This paper mainly deals with the design and performance analysis of the energy recovery system based on fluid power transmission principle. Firstly, modeling and simulation of single foot walking motion were carried out to investigate the human walking dynamics to explore the variation of energy produced by human walking within a gait cycle. Together with gait characteristics measurement, the foot-ground interaction force in the horizontal and vertical directions is obtained. Then, the energy recovery system based on the working principle of volumetric pump was designed to convert the human walking induced mechanical energy into hydraulic energy directly and achieve energy storage with accumulator in the meantime. The energy recovery results obtained under different conditions of walking speed and load carrying are considered by numerical simulation and experimental verification. It is shown that the output power in average of the recovery mechanism by single foot walking at 5.56 km/h is around 3.2 W, and the captured power can be increased with higher precharge pressure of accumulator. Comparisons indicate that power and its density of the system proposed in this paper are far greater than that achieved by electric generation, providing a potential solution for hydraulically actuated walking mechatronic systems.