Assessment of Vehicle Performances with Energy-Harvesting Shock Absorbers

Energy-harvesting from vehicle suspensions has attracted a lot of attention recently due to its potential to recover large amount of kinetic energy which is traditionally wasted in oil shock absorbers, besides it can improve the ride comfort and road handling at the same time. Rotary electromagnetic mechanism has been a popular solution in the design of energy-harvesting shock absorbers and recently an innovative energy-harvesting shock absorber based on so-called mechanical motion rectifier (MMR) has been proposed, which converts the irregular bi-directional suspension vibration into unidirectional motion of the generator. Though it may offer advantages of higher mechanical reliability and harvesting efficiency, its influence on the whole vehicle dynamics is not known yet due to the nonlinearity of the MMR shock absorber. This paper presents an integrated model of a quarter car with a conventional or MMR-based rotary electromagnetic energy-harvesting shock absorber, and assesses the vehicle dynamics and energy-harvesting potential under various road conditions.