Experimental investigation on converting commercial shock absorber into regenerative shock absorber

• a regenerative shock absorber is designed based on conventional shock absorber. • The developed regenerative shock absorber utilizes a mechanical motion rectifier to provide a one-way rotational motion. • the equivalent damping coefficient of both classical and developed regenerative shock absorbers are comparable at very low input speeds. • The study validates a practical method to convert vibrational energy into electricity to improve energy efficiency without sacrificing ride quality. Commercial shock absorbers dissipate vibration energy induced by road roughness in order to maintain ride quality. However, an appropriate regenerative shock absorber can recover a portion of input energy without changing the initial performance of commercial shock absorber. While most existing energy harvesting prototypes require complex custom-made structures, in this research a regenerative shock absorber is designed based on converting a conventional shock absorber of Peugeot 405 by maintaining its initial structure through a retrofit design. The developed regenerative shock absorber utilizes a rack-pinion mechanism and a mechanical motion rectifier to provide a one-way rotational motion for the permanent magnetic DC generator. The proposed mechanical motion rectifier as the principal part of rectifier uses one-way ball bearings instead of complex clutches to decrease number of components used in conversion of up and down motion into one-way rotational motion. The system was evaluated using a custom-built pneumatic test rig capable of simulating various road profiles. Results show that the damping coefficients of classical and developed regenerative shock absorbers are comparable in very low input speeds, validating that the proposed design preserves the primary function of the suspension system. Furthermore, the displacement amplitude was identified as a key parameter influencing the harvested power. The harvested power from regenerative shock absorber in very low frequency of 0.041Hz with speed of 300mm/min is 45.70 mW which can be increased by increasing input energy. This study presents a practical, cost-effective approach to equip existing commercial vehicles with energy harvesting capabilities.