Self-powered and self-sensing triboelectric electromagnetic hybrid generator with dual motion amplification mechanism for application in floating slab track system

Abstract

To ensure the safe operation of the floating slab rail transit, it is necessary to achieve stable and long-term monitoring of the health status of the floating slab track side. Based on the low amplitude characteristics of the track, this paper proposes a self-powered and self-sensing triboelectric-electromagnetic hybrid generator (SS-TEHG) with displacement amplification and rotational speed amplification. The main function of the triboelectric nanogenerator (TENG) is to serve as a signal combined with deep learning to monitor the damage of the floating slab track system, including steel spring failure, fastening failure, and vibration failure. The electromagnetic generator (EMG) utilizes the lever principle to amplify the vibration displacement of the floating slab track. After passing through the screw and bevel gear rectification mechanism, the linear vibration displacement of the track is converted into unidirectional rotational motion and transmitted to the planetary gearbox for speed amplification and then generates electrical energy in the generator. On this basis, a coupled dynamics model of vehicle-rail-floating slab-harvester is constructed in Simpack software to obtain the vibration state of the floating slab track at different speeds to evaluate the performance of SS-TEHG. The deep learning model consists of four modules: Spatial Feature Extraction Module (SFEM), Temporal Feature Extraction Module (TFEM), and Attention Module (AM). The experimental results show that the test accuracy of the 2TFEM group and the SFEM (64) +2TFEM group can reach 99.81% and 99.97%, respectively. The time taken by 2TFEM and SFEM (64) +2TFEM is 7938.6 s and 4654.9 s, respectively. As the speed increases from 20 km/h to 100 km/h, the RMS voltage of the EMG increases from 2.04 V to 3.55 V. The combination of EMG and LTC3588 power management circuit only requires 10 s of power supply to a 1000 μF capacitor, which can provide stable power supply for temperature and humidity sensors for 80 s. The above results provide an effective solution for the dual function integration of energy harvesting and state self-monitoring to the floating slab rail transit.