A multidirectional pendulum kinetic energy harvester system for low-power appliances in new energy buses

Wireless sensors play a crucial role in vehicle operations. The effective energy harvesting for self-powering these sensors has emerged as a critical area of interest in recent years. This paper presents a multidirectional pendulum kinetic energy harvester system (MP-KEHS) designed to power low-power sensors in vehicles. The MP-KEHS consists of four main components: an energy capture module, a motion transfer module, an energy conversion module, and an electric energy storage module. The energy capture module, comprising a mass ball and a turntable, captures omnidirectional inertial kinetic energy during vehicle acceleration, deceleration, and turning. In the motion transfer module, a one-way gear module converts the multidirectional rotations of the energy capture module into unidirectional rotations, while the planetary gear train enables speed coupling during simultaneous vehicle acceleration and turning. The energy conversion module utilizes a generator to transform rotational kinetic energy into electric energy. The electric energy storage module stores the electric energy in a supercapacitor after passing through a voltage regulator circuit, providing power to low-power devices. Using of multi-body dynamics software and Simulink, the swing angle of the mass ball was determined under four real driving cycles. Experimental results demonstrated that the average output power of the MP-KEHS reached 116.8 mW. Charging the capacitors of 220 μF, 470 μF, and 1000 μF from 0 V to 1 V takes 8 s, 24 s, and 93 s, respectively. Finally, the MP-KEHS was applied to a bus on the Liaocheng University campus, achieving an average output power of approximately 176 mW, which satisfied the power requirements of the sensors. These findings indicate that the MP-KEHS effectively harnesses the vehicle's otherwise wasted inertial energy, enabling wireless sensor self-powering.