Boosting the fuel efficiency of motor vehicles by “harvesting” the energy generated by their shock absorbers and feeding it back into batteries or electrical systems such as air conditioning has become a major goal in automotive engineering. Now, a University of Huddersfield researcher has designed a system and built a prototype that is ready for real-world testing.

Ruichen Wang focused on the suspension rather than braking systems, which have been previously studied.

Ruichen Wang focused on vehicle suspension systems in his work.Ruichen Wang focused on vehicle suspension systems in his work.In an abstract of the published paper, the authors say that their regenerative hydraulic shock absorber system converts the oscillatory motion of a vehicle suspension into unidirectional rotary motion of a generator.

They say that a system using piston-rod dimensions of 50–30 mm achieves recoverable power of 260 W with an efficiency of around 40% under sinusoidal excitation of 1 Hz frequency and 25 mm amplitude when the accumulator capacity is set to 0.32 L with the load resistance 20 Ω.

They go on to show that the appropriate damping characteristics required from a shock absorber in a heavy-haulage vehicle can be met by using variable load resistances and accumulator capacities in a device similar to the prototype. The validated model paves the way for further system optimization towards maximizing the performance of regeneration, ride comfort, and handling.

The authors say that harvested energy can be used for any auxiliary purpose in a vehicle, and in hybrids it could recharge the electric motor.

The next stage is to work with an industrial partner to install and test Wang’s system in a road-going vehicle.

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