Regeneration no longer just about braking

Gizmag.com ^ | 01/02/09 | Paul Evans

[Reaganesque]

January 2, 2008 Recent developments in regeneration technology are almost ready for prime time. Both Hydraulic Hybrid Vehicles http://en.wikipedia.org/wiki/Hybrid_vehicle and Power Generating Shock Absorbers http://en.wikipedia.org/wiki/Shock_absorber are both being field tested and may be soon headed for mass production. Transport company UPS has committed to purchasing seven "series" hydraulic hybrid delivery vehicles while Electric Truck, LLC has exclusively optioned commercial rights to a technology from Tufts University that uses Regenerative Shock Absorbers to recharge the batteries of any hybrid electric and electric-powered vehicle while it is driven.

Regenerative shock absorbers

The regenerative electromagnetic shock absorber uses an electromagnetic linear generator to convert variable frequency, repetitive intermittent linear displacement motion to useful electrical power. The regenerative electromagnetic shock absorber technology was developed by Tufts University http://en.wikipedia.org/wiki/Tufts_University engineering professor emeritus Ronald Goldner and colleague Peter Zerigian within the School of Engineering and received additional support in subsequent years from Argonne National Laboratory. While Goldner and Zerigian have patented the idea, it also appears that an almost identical concept was developed in the same period by David Oxenreider of Boiling Springs, PA, a design which took out Second Prize in the 2005 Emhart "Create the Future" Design Contest.

How it works

A conventional automotive shock absorber dampens suspension movement to produce a controlled action that keeps the tire firmly on the road. This is done by converting the kinetic energy http://en.wikipedia.org/wiki/Kinetic_energy into heat energy, which is then absorbed by the shock’s oil. The Power-Generating Shock Absorber converts this kinetic energy into electricity instead of heat through the use of a linear electric motor http://en.wikipedia.org/wiki/Electric_motor . The electricity generated by each PGSA can then be combined with electricity from other power generation systems (e.g. regenerative braking) and stored in the vehicle’s batteries.

The motor is usually a cylindrical 3-phase brushless permanent magnet linear electric motor that is sometimes referred to as a ServoRam. Early ServoRams were developed in the 1990s to replace hydraulic rams in entertainment motion simulators. Bose have also developed an Active Suspension System that uses linear stepper motors http://en.wikipedia.org/wiki/Stepper_motor to replace standard shocks/springs. Bose claim they have been working on the software (algorithm as they call it) for 24 years (since 1980). The difference between the Bose system and power generating or regenerative shock absorbers is that the later retain standard coil springs to suspend the static load of the vehicle while Bose have deleted springs altogether.

Linear motors as replacement ‘shock absorbers’ are a much cheaper solution with more regenerative potential and have enormous potential in motorsport, where shock absorbers could be constantly variable. An electromagnetic shock absorber could be tuned to respond to virtually any input. With regenerative shock absorbers connected to a microprocessor system with any number of inputs such as on-chip gyro, accelerometer, ride height and steering angle a 4-shock system can actively control a vehicles pitch, roll and yaw.

Since the technology actively uses the weight of a vehicle for energy recovery, it could help speed the expansion of the hybrid and battery electric vehicle market from cars to vehicles of greater size, weight and payloads, such as SUVs http://en.wikipedia.org/wiki/Sport_utility_vehicle , pickup and delivery trucks, mail trucks, school and city buses and other light and medium duty trucks

Hydraulic hybrid regeneration

The UPS "series" hydraulic hybrid delivery vehicles have a diesel engine combined with a unique hydraulic propulsion system, replacing the conventional drivetrain and transmission. The vehicle uses hydraulic pumps and hydraulic storage tanks to capture and store energy, similar to what is done with electric motors and batteries in a hybrid electric vehicle. In this case, the diesel engine is used to periodically recharge pressure in the hydraulic propulsion system. Fuel economy is increased in three ways: vehicle braking energy is recovered that normally is wasted; the engine is operated more efficiently, and the engine can be shut off when stopped or decelerating. The hydraulic series hybrid, originally developed in a laboratory of the US Environmental Protection Agency (EPA), uses a diesel engine/pump to pressurize and transfer hydraulic fluid to the rear drive pump/motor and/or high pressure accumulator. The hydraulic drivetrain replaces the conventional drivetrain and eliminates the need for a conventional transmission. UPS and the US Environmental Protection Agency (EPA) said the prototype vehicle had achieved a 45-50% improvement in fuel economy compared to conventional diesel delivery trucks.

Eaton Corporation began working with the EPA in October 2001 under a Cooperative Research and Development Agreement involving hydraulic hybrid systems and components. As part of Eaton’s role in designing and developing hybrid technologies, the company’s engineers were co-located at the EPA’s Ann Arbor facility. Eaton also earned a number of hybrid power system patents and continues to work on a number of other hybrid vehicles initiatives with UPS and others.

The EPA believes the technology can perform equally well in other applications such as shuttle and transit buses and refuse pick-up trucks. In 2007, the agency launched a project to develop hydraulic series hybrid systems for Class 6 port yard hostlers—the heavy-duty diesels that move goods and products from ships to trucks at ports.

Paul Evans

[Reaganesque]

A picture of the shock absorber:

Makes sense to me. Combine these shocks with regenerative brakes, solar cells on the exposed surfaces of the vehicle, fuel cells and what have you and we might have something that could compete with a gas fueled car. We'll see. It is getting interesting out there, though.

[Paladin2]

Won’t work on a smooth road.

[optiguy]

Good post. Thanks!

[thackney]

BTTT

[TC Rider]

With some of the washboard dirt roads around here, I could sell power back to the grid.

[texas booster]

If you could apply this concept to stereo systems, my neighbor could recapture most of the energy he puts into his low rider.

[Popman]

Looks pretty expensive

Sir, we replaced all four shocks and rotated your tires for free!!!

Here's your bill:
$ 2,500 plus your 25 % carbon tax, 10 % state tax, 15 % federal tax
Total is $3,750

(Tips are appreciated)

[TheThinker]

What about wind energy that could be captured by turbines as the car is driven?

[Reaganesque]

The road doesn’t have to be rough. Turning, braking, accelerating and just the normal vibration from any road surface would generate electricity. Heck, you could park the vehicle and jump up and down on the bumper and it would generate electricity. If the vehicle is moving, such a system could recover some energy from that movement.

[reg45]

Just another excuse for the government not to repair potholes.

[thackney]

LOL!

[Mark was here]

Won’t work on a smooth road.

A smooth road is more energy efficient, now that you mention it.

[Pearls Before Swine]

Any quantitative estimate of how much would be generated? Also, the more you try to recover, the firmer the ride. The more power you try to extract from a generator, the harder you have to turn it (or in this case, push it).

[freebilly]

I’m for anything that will allow us to say F*** Y** to OPEC....

[Red Badger]

Shocking! Ping!.........

[Reaganesque]

Me too, buddy. Me too. So long as it works.

[Red Badger]

I am shocked........

[WOBBLY BOB]

then it should sell well here in Minnesota.

[o_zarkman44]

This is very interesting. I can see how a hydraulic drive would be much smoother and economical than a mechanical drive with more moving parts.
Approaching shocks is interesting also. I have been involved in racing and know how hot a working shock gets on a rough track. shocks are a very important part of the set up. Thats why NASCAR has shock engineers.

Harnessing the kinetic energy from shocks has a lot of potential. I find it a fascinating approach.

[Reaganesque]

You could add piezo-electic materials to the speakers. Vibration causes them to produce electricity. Someone has already proposed putting such materials underneath roads so that everyday traffic would generate electricity for cities. They would lay it down as part of the road building/repairing process so, it wouldn’t cost all that much more.