This could be an excellent way to reduce fuel (imported oil) consumption on hybrids and extend e-range of PHEVs and BEVs. With a potential energy saving of 10% to 15% a subsidy would be justified to offset part of the upgrade cost.

Our very rough badly maintained street and roads would offer even more pentential energy savings.

Americans have the knowhow and creativity to develop more efficient machines. What is needed is appropriate leadership for mass production and diffusion.

HarveyD, bad roads aren't so great, and here's why: The efficiency of the regeneration may be higher, but it is the efficiency of the power needed to move forward *and* the power needed to overcome the bumps. On a bumpier road you'll recover more but you'll also expend more. So accourding to their own table, for the relatively smooth road you get ~1900 W out of ~9,600 invested, and in the bumpier road you get 17,400 out of 25,000 invested (approx.), which means you still wasted the same 7600 W.

You can't beat the 2nd law of common sense*: Energy can't be generated by wasting it.

Still, getting back all that energy is even better than regenerative breaking, as it's a constant increase in efficiency - wasting the same 7600 W is obviously better than wasting the full 25,000. It only remains to be seen if it can be made economically.

---
* derived from the second law of thermodynamics, of course:
http://en.wikipedia.org/wiki/Second_law_of_thermodynamics

I'm sceptic about the figures quoted. If 16 kW of power is absorbed by the shock absorbers - worst case - in a 2500 lb (1130 kg) car they would burn and fall off. That's a very small car, if you include some luggage and passengers in the weight. Imagine the size of the shocks.

"It seems that in order to maintain proper response (equal response times and forces both in the upward and downward direction) this system would actually operate at net energy loss."

Could you explain that? Why wouldn't they just generate power in both directions?

That was me, sorry.

Some comments - a: it sounds too good to be true.

b: If we really are loosing that much energy in shock absorbing, why not try to optimize the shocks for fuel economy (rather than ride comfort [ or whatever they are optimized for now] ), or at least put fuel economy in as a parameter (or make it switchable) - sport, comfort - economy.

c: It sounds like it needs independent verification - just how much can you save on normal roads in normal driving.
They may have slanted the figures for the benefit of investors.

Nonetheless, it is an interesting problem to look at, and it can be applied to any drivetrain, so it could be useful.

It would be interesting to see a full "energy diagram" for a typical car to show all the losses.

The part of this that I have a problem with is that these and many professors, most likely with government money, created a widgit and then sell an exclusive license to a private party. What ever happened to the tax payers having at least a partial ownership in the things they funded? Why not make that widgit available to anyone and everyone? I believe this would increase the likelihood that it becomes available at a reasonable, non monopolistic price.

>>anon

I will bet that these same professors have a plan up their sleves to create long stretches of washboard and pot-holed roads just to charge batteries.

:>)
Rikiki

Listen to all these rocket scientist!
Regen shock are so logical I've been tempted to experiment myself. A common garden variety hydraulic shock absorber simply converts resisting spring movement into heat. Rally cars have remote reservoirs to help dissipate some of this heat to prevent shock failure. As all the above rocket scientists know heat and energy are directly related so there is power there to be harvested.
This has ENORMOUS potential in motorsport where shock absorbers could be constantly variable. An electromagnetic shock could be tuned to respond to virtually any input. Hook the system up to an on-chip gyro and a 4 shock system can be variable via a microprocessor according vehicle to pitch and yaw.
Bose have been working on a similar system of linear motor shocks since the mid 80s but I think they went too far in deleted the springs making it a fully active suspension system. Linear motors as just ‘shock absorbers’ are a much cheaper idea with more regenerative potential.

We love pot holes.

The regenerative magnetic shock absorber sounds to me like an electromechanical active suspension. If you feed energy into this device in the right manner, it can counter unwanted body motion. But then, energy can flow in either direction so you can use it as a shock absorber, which regenerates body motion energy rather than just converting it into heat like a conventional shock absorber.

But I would rather have a smooth road than a bumpy one. Its better not to set the sprung mass into up-and-down motion in the first place, than regenerate body motion once it starts. Unfortunately, perfectly smooth roads are not always possible.

@Jim from Virginia (Although I'm only a mech. eng., not a metalurgist):
To answer your first question, the relevant mass in that matter is that of the entire vehicle sitting on the suspension, so the coils' mass is negligible.

The second question is more a question of economics: the cost of energy vs. the cost of materials. This changes over time, so you might see tomorrow's cars having copper-windings, and the cars of 2050 having aluminum-powder or any other cheap and efficient tech of the day. Let the producers worry about that :)