一种非线性双稳态人体运动能量俘获技术  

Nonlinear Bi-Stable Energy Harvester from Human Motion

作　　者：王伟[1] 曹军义[1] 林京[1] 周生喜[1] 蔡云龙[1] 

机构地区：[1]西安交通大学机械制造系统工程国家重点实验室,西安710049

出　　处：《西安交通大学学报》2015年第8期58-63,共6页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(51421004);新世纪优秀人才支持计划资助项目(NCET-12-0453)

摘　　要：针对传统线性压电悬臂梁频带过窄且难以与人体运动相匹配的问题,考虑人体小腿的运动特点,设计了一种双稳态磁耦合压电悬臂梁应用于人体运动能量俘获,利用运动过程中小腿的摆动及其与地面间的冲击产生的加速度使悬臂梁跨越势阱提高俘能效率。以哈密顿原理及人体运动信号为基础,建立了用于人体运动能量俘获的非线性动力学模型。根据人体腿部运动的振动特征设计了一种便携式非线性振动能量俘获系统,实现了线性、非线性单稳态和双稳态等动力学特征。采用实际腿部振动信号进行的理论模型数值仿真表明:双稳态人体振动俘能技术能够产生大幅度跨越势阱运动并俘获较多的电能。人体不同运动状态的实验结果验证了非线性双稳态人体能量俘获技术的优势以及所建立的机电耦合模型的有效性。当运动速度为8km/h时,双稳态系统的平均功率达到最大值23.2μW。A nonlinear bi-stable energy harvester from the human motion is proposed to solve the problem that the frequency bandwidth of traditional linear piezoelectric energy harvesters is narrow and it is hard to match with human motions. The harvester considers the characteristics of the human leg＇s motion and improves the energy harvesting efficiency by using the acceleration caused by leg swings and their impacts on the ground. An electromechanical model of nonlinear energy harvesters is derived based on the Hamilton principle and human motion signals. A portable nonlinear energy harvesting device is designed based on the characteristics of the human motion, and dynamic characteristics of linear, nonlinear mono-stable and bi-stable oscillators are realized by adjusting the position of magnets. Numerical simulations based on real human leg＇s vibration data show that the proposed harvester achieves the large amplitude inter-well oscillation and generates more energy from the human motion. Experimental results under various motion speeds verify the great advantage of the nonlinear bi-stable energy capture technology, and the efficiency of the proposed electromechanical model. The average output power of the hi-stable system reaches a maximum value of 23.2 μW when the motion speed is 8 km/h.

关 键 词：能量俘获 非线性 双稳态 人体运动 压电悬臂梁 

分 类 号：TH39[机械工程—机械制造及自动化]