Recovering Energy from Shock Absorber Motion on Heavy Duty Commercial Vehicles

As commercial vehicles are propelled forward, their suspensions encounter road irregularities that deflect suspensions up and down. GenShock® was created to convert linear motion from suspension oscillations into usable electricity while actively controlling damping force. This paper investigates the available energy in the suspension of a Class 8 truck, characterizes the damper dynamics in a truck suspension system, and demonstrates the fuel efficiency gains from reducing electrical load on the alternator. Two generations of GenShock prototypes were built and tested, and the resulting power regeneration and adaptive damping control were demonstrated. By reducing alternator load on a Class 8 test truck, fuel consumption was correspondingly reduced. To investigate real-world benefits, suspension displacements were sampled during actual on-road travel to characterize a representative highway (I-75 between Detroit and Toledo) and were subsequently used as input for a system model. In parallel, real-world data was collected for a typical long haul trucking application to measure vehicle electric power requirements and regenerated suspension energy.