Energy Harvesting Vehicle Suspension System

Background

• Ride comfort, road handling and fuel efficiency of a vehicle have always been crucial factors for vehicle shock absorber design.

• The MMR converts the bidirectional linear motion to unidirectional rotational motion to harvest the energy from the road surface vibrations. Avg power harvested 24.7 W at 40 mph. Reduced chassis vibration by 8 %.

• The energy harvesting hydraulically interconnected suspension similarly harvests this vibrational energy using hydraulic circuits. Road test exhibit 70% improvement in roll angle with 6 W harvested at 20 mph speed.

Innovation

• This project proposes and studies a novel energy harvesting hydraulically interconnected shock absorber (EH-HISA) system to improve efficiency of energy harvesting, ride comfort and road handling performance.

• The novel hydraulic circuit design consists of a unique diagonal energy harvesting approach which improves the energy harvesting ability significantly as compared to the previous designs while maintaining the ride comfort and handling ability of the vehicle.

Approach

• A simulation model is setup in AMESim software to simulation the dynamic response and energy harvesting ability of EH-HISA.

• EH-HISA is prototyped, and bench tests are conducted to validate the simulation results.

Achievement

• A 7 DOF vehicle model is setup and an SUV vehicle equipped with EH-HISA is simulated over C class road surface while performing the double lane change test maneuver at 50 kmph constant speed.

• The car body COG acceleration during double lane change test is found out to be 11% lower and power harvested increases by 222% (230 W average power harvested as compared to previous design).

• Overall, the EH-HISA performs better than the previous design in energy harvesting and ride comfort while reducing the overall cost and weight of the system (reduced number of hydraulic components).