Power from bumps in the road
A team of MIT undergraduate students has invented a shock absorber that generates electricity from small bumps in the road, while at the same time it smoothes the ride more effectively than conventional shocks. Hybrid vehicles use some of the wasted energy during breaking, so the team looked for additional places in a vehicle where energy is wasted. The suspension system was identified as a good candidate. After outfitting different cars' suspension systems with sensors and laptop computers that monitor the amount of wasted energy, the students determined that especially for heavy vehicles it will make a lot of sense to develop shock absorbers that can generate power and improve the efficiency of their operation. Senior Shakeel Avadhany and his teammates developed a prototype of a system in which shock absorbers use a hydraulic system that forces fluid through a turbine attached to a generator. The system is controlled by an active electronic system that optimizes the damping, providing a smoother ride than conventional shocks while generating electricity to recharge the batteries or operate electrical equipment. They say that using such regenerative shock absorbers can produce up to a ten percent improvement in overall vehicle fuel efficiency.
To commercialize their invention, the members of the team have established Levant Power Corp. and named their device GenShock. The tests of the prototype on a Humvee have demonstrated that each regenerative shock absorber can produce between 500 and 1000 W of power when the vehicle was driven on a standard highway. This power could be used instead of alternator power, thus improving fuel-efficiency by 3-5% and helping to drive electric equipment used on the vehicle.
Since GenShock is a fully-active system, it can dynamically adjust damping characteristics instantaneously. Damping can be stiffened or relaxed depending on the weight and/or sensitivity of the load. Simple applications allow the suspension to change damping depending on the weight of the load. Advanced algorithms allow for real-time adjustments to create a smooth ride with better handling characteristics than conventional shock absorbers. Considering the use of GenShock for military and trucking applications, Levant Power Corp. has developed the components of the system understanding that they have to be able to withstand the harshest environments while maintaining a high level of reliability. The system is designed for zero-downtime. In the unlikely case that the control system fails, the system reverts to perform like a standard (non-active) shock absorber.
Additional information is available at http://web.mit.edu/
