Design and Analysis of a Mechanical Device to Harvest Energy from Human Footstep Motion

Portable electronics is usually powered by battery,which is not sustainable not only to the longtime outdoor use but also to our living environment.There is rich kinetic energy in footstep motion during walking,so it is ideal to harvest the kinetic energy from human footstep motion as power source for portable electronic devices.In this paper,a novel mechanism based on dual-oscillating mode is designed to harvest the kinetic energy from footstep motion.The harvester contains two oscillating sub-mechanisms：one is spring-mass oscillator to absorb the vibration from external excitation,i.e.,the footstep motion,and the other is cantilever beam with tip mass for amplifying the vibration.Theoretic analysis shows that the dual-oscillating mechanism can be more effectively harness the foot step motion.The energy conversion sub-mechanism is based on the electromagnetic induction,where the wire coils fixed at the tip end of the cantilever beam serves as the slider and permanent magnets and yoke form the changing magnetic field.Simulation shows that the harvester,with total mass 70 g,can produce about 100 mW of electricity at the walking speed of 2 steps per second.

多路控制的馈能减振器的设计及实验

针对传统液压式减振器浪费车辆振动能和阻尼不可调的两个缺点,提出1种多路控制的馈能减振器。该馈能减振器包含6个发电机,通过单独控制6个发电机的电路通断及调节电路的负载,控制减振器的阻尼参数,同时收集车辆行驶的振动能。Simulink仿真结果表明,该减振器能够提供不同级别的阻尼力。使用MTS实验平台对减振器样机进行实验,实验结果表明,多路控制的馈能减振器的减振性能符合Simulink仿真结果,同时能够有效地收集振动能。