Energy harvester for vehicle tires: Nonlinear dynamics and experimental outcomes

Abstract

This article presents a very compact electromechanical wideband energy harvester optimized for tire applications. The device exploits an asymmetric magnetic spring to be adaptive and effective at almost any vehicle speed. The device has been simulated through an experimentally validated SIMULINK block-oriented model. The simulation takes into account nonlinear dynamic and adaptive resonant behavior of the seismic mass, electromagnetic, and magnetostatic coupling between floating magnetic mass and coils, and the transfer of the generated power to an external load by means of a nonlinear circuit interface. A particular focus on the pneumatic effect on the floating magnet has been made. A convenient choice of clearance between moving and fixed parts can be used to create an effective air brake preventing or softening shocks with end stops and to modify system dynamic. A nonlinear equivalent spring dashpot model of the pneumatic effect and a method to estimate its parameters from geometry have been proposed. An analysis of different nonlinearities of the system at different vehicle speed and a study on the combined effect of softening and hardening behavior of the device have been performed and discussed.

A Comprehensive Study on Technologies of Tyre Monitoring Systems and Possible Energy Solutions

“…A similar frequency spectrum pattern was obtained by Roundy [20,49] and Löhndorf et al [21]. Vibration based piezoelectric, electrostatic and electromagnetic micro generators for tyre pressure monitoring have been developed by several researchers and companies [69–79], but in most cases, micro generator performance highly depends on the applied frequency in such a way that it has a quite narrow band width of the efficient power generation level around its resonance frequency which makes it not suitable for the variable excitation frequency environment, such as in land vehicle tyres. However, vibration energy harvesters can be a good option when applied on constant speed machinery by toning their resonance frequencies with the machines' operation speeds.…”

Energy Harvesting Technologies for Tire Pressure Monitoring Systems

“…To overcome some of these difficulties, systems with adjustable natural frequencies and designs having multiple oscillators have been proposed to improve the performance by encouraging resonance. The use of nonlinear behavior has also been exploited to harvest energy efficiently over a wider frequency range. Gu and Livermore also proposed a harvester whose natural frequency can passively track the rotational speed of a spinning rotor.…”

“…One approach is to use inertial devices, wherein a levitated magnet is driven past stationary coils in a device that is mounted on the wheel rim . Inertial harvesters that are embedded in the inner liner of the tire have also been proposed . Efforts to use electromagnetic coupling for energy harvesting have been reported by Visityre .…”

“…A novel inertial harvesting device has been reported, which is mounted on the inner liner of a tire. The frequency spectrum and amplitudes of the resulting vibrations vary with time according to the vehicle speed and road terrain, see Figure 9 a and share similarities with the schematic in Figure .…”

Efficiency Enhancement of a Cantilever-Based Vibration Energy Harvester

“…A similar frequency spectrum pattern was obtained by Roundy [ 15 , 16 ] and Löhndorf et al [ 6 ]. Vibration based piezoelectric, electrostatic and electromagnetic micro generators for tyre pressure monitoring have been developed by several researchers and companies [ 9 – 11 , 17 – 24 ], but in most cases, micro generator performance highly depends on the applied frequency in such a way that it has a quite narrow band width of the efficient power generation level around its resonance frequency which makes it not suitable for the variable excitation frequency environment, such as in land vehicle tyres. However, vibration energy harvesters can be a good option when applied on constant speed machinery by toning their resonance frequencies with the machines' operation speeds.…”