Regenerative Suspension System Research etc Links.

[Logic]

The ease with which one can stick magnets to a shock absorber and surround that field with copper wire windings makes Regenerative Suspensions/shocks enticing.

Rectify each coil's output and feed that to a MPPT and you're golden.

Well...
While accelerating: Only if your system has a higher power to weight ratio than the std car, truck etc, improving the performance of the vehicle as a whole.

Once cruise speed is reached; power to weight ratio becomes a non-issue and the added weight increases the power generated by a slight amount.

Due to time constraints.
here, in no particular order, is the (full paper) research i have found so far on the subject

In a nutshell: The heavier the vehicle and the worse the road; the better.
(off road)

https://www.researchgate.net/publica...y_Technologies

https://www.sunysb.edu/commcms/aertc...Zuo%202011.pdf

https://dspace.mist.ac.bd/xmlui/bits...=1&isAllowed=y

https://www.researchgate.net/publica...tion_rectifier

https://sci-hub.ru/10.1007/s12206-015-0331-7

https://www.diva-portal.org/smash/ge...FULLTEXT01.pdf

[Isaac Zachary]

Back when hydraulic hybrids were being considered, I wondered why a simple check valve with an appropiately sized cylinder in each shock assorber that feed into the hydraulic accumulator of the hydraulic hybrid system wouldn't work.

[Hersbird]

In my opinion if there is a bunch of wasted energy there will be heat buildup. So the springs don't waste any energy, they store some briefly and then immediately return it to where it needs to be. So the shocks do take in energy and don't return it by slowing the spring travel down. In something like off road Baha 1000 racing they do get very hot and have remote reservoirs but on a street car there is very little heat which to me would mean very little energy to gain.

I would think if you are adding some kind of generator to capture wasted energy, look at where there is heat. The brakes have been figured out with regen braking. On an ICE there is much more to be gained in the cooling system and exhaust, but even an EV there is a battery cooling system that is wasting heat and I bet the motors make more heat than the shocks too.

[freebeard]

There's still the opportunity for magnetorheological shock absorbers.

[Isaac Zachary]

Originally Posted by Hersbird

I would think if you are adding some kind of generator to capture wasted energy, look at where there is heat.

The dash comes to mind.

On the highway, most energy is lost to aerodynamic drag. So the biggest gain would be fixing the aerodynamic drag.

However, especially in modern cars, the extreme weight creates sigificant rolling resistance.

If you could lower considerably the aerodynamic drag and/or rolling resistance you'd get a lot better fuel mileage.

[Logic]

Originally Posted by Isaac Zachary

The dash comes to mind.

On the highway, most energy is lost to aerodynamic drag. So the biggest gain would be fixing the aerodynamic drag.

However, especially in modern cars, the extreme weight creates sigificant rolling resistance.

If you could lower considerably the aerodynamic drag and/or rolling resistance you'd get a lot better fuel mileage.

Yep

Build a tandem Aptera!
ie: The fuselage of a modern sailplane.

But as we cant use thermals down here we still need to move it down the road somehow.
That somehow is Serial Hybrid IMHO.

[Logic]

Originally Posted by Hersbird

In my opinion if there is a bunch of wasted energy there will be heat buildup. So the springs don't waste any energy, they store some briefly and then immediately return it to where it needs to be. So the shocks do take in energy and don't return it by slowing the spring travel down. In something like off road Baha 1000 racing they do get very hot and have remote reservoirs but on a street car there is very little heat which to me would mean very little energy to gain.

I would think if you are adding some kind of generator to capture wasted energy, look at where there is heat. The brakes have been figured out with regen braking. On an ICE there is much more to be gained in the cooling system and exhaust, but even an EV there is a battery cooling system that is wasting heat and I bet the motors make more heat than the shocks too.

Yes it isn't much Hersbird.
But it is a theoretical 7 to 10% improvement in fuel consumption according to the papers you didn't bother to look at.

BUT, most importantly;
It's linear mechanical motion, making it easy for DIYers to experiment with.
And, thanks to todays powerful magnets, one of the only places where doing so may well result in an improvement in the power to weight ratio of the vehicle IMHO.
ie; a real gain rather than just added complexity.

TECs on the exhaust is a wash as they are hugely inefficient, adding more weight and cost than they are worth.
(The solder melts if you move them up to the hotter end)

BMW's Turbo Steamer got 15% for the added complexity of dual high pressure steam engines.
(This works well on ships where there is a competent crew to monitor and maintain such systems.
It would work well on stationary engines and slow moving vehicles like Bulldozers etc too, until the inevitable deadly explosion caused by a Monkey Wrencher!)

Regen for EV's doesn't do much better % wise because of the low Power Density (as apposed to Energy Density) of batteries.
ie: For a given voltage battery pack they just cant be charged as fast as they need to be able to, to absorb more of the braking power.
Combining Super/Ultra Capacitors (high Power Density) with Batteries (high Energy Density) would go a very long way to improving matters, but it seems that somehow there just isn't a human alive today capable of producing a control system for said combo!?

[freebeard]

If the tires had an automatic inflation system, would adding a one-way check valve and an accumulator harvest compressed air from hitting bumps?

[jjackstone]

Looked into this many years ago and at the time the following was the only paper I found on the subject.

https://www.semanticscholar.org/pape...2be7891fb7aa97

JJ