Design of novel energy-harvesting regenerative shock absorber using barrel cam follower mechanism to power the auxiliaries of a driverless electric bus

Abstract This paper presents a novel energy-harvesting shock absorber using a barrel cam follower mechanism to harvests energy from the vehicle suspension system. The proposed system comprises an input module, transmission module, generator module, and power storage module. The input module converts the low-frequency irregular vibration caused by the road roughness into bi-directional rotary motion with a barrel cam and follower mechanism. The transmission module changes the bi-directional rotary motion into unidirectional rotary motion. The power produced by the generator is stored in a supercapacitor for power supply to auxiliaries when the vehicle is stationary. The simulation and experimental investigation techniques were performed using MATLAB and Mechanical Testing and Sensing system, respectively. Furthermore, the unpredictable variations in the experimental condition were evaluated by uncertainty analysis. The experimental and simulation results were compared under similar loading conditions and found a maximum relative error of 5.5% at 2.5 mm and 1 Hz. Finally, the highest output power of 3.85 W was harvested at 7.5 mm sinusoidal amplitude and 2 Hz input frequency with a maximum efficiency of 51.4%. The harvested energy can power the sensors of driverless electric buses to reduce battery consumption.