Variable Ride Height Solutions

[RostimusPrime]

I'm looking for a way to adjust the ride height of my car without having to break out any tools. I'm planning to use a laptop to control it on the fly. (i study automation and thought this would be a good project)

My instincts said to use an air suspension, i was thinking airbags, but from some of the threads here it seems that it'll kill the handling on my stock G2.

Ideally i want something that offers the same handling as my stock setup but i need it to be highly reactive. I'm going to use some lasers that measure linear distance to control the individual ride height of each wheel so that when i'm coming up on a pothole it'll compensate quickly and will minimize the bump. It's a simple enough task but if air bags are not quick enough and/or crappify the ride of my car i need some suggestions here.

And noone say hydraulics, they are messing, heavy and noisey.

Also, does anyone know how much the truck hatch weighs?

 

[DG-FNR]

You're biting off quite a mouthful here.

If you want the suspension to be truely reactive, the control problem is a couple of orders of magnitude more difficult than you suspect. Even when F1 allowed fully active suspensions (no springs, just actuators) they were never closed-loop feedback systems. Most of their programming was geographic in nature (when you run laps on a closed course, you know where all the bumps are)

Lately there have been some advances that suggest that closed-loop, self-programming active suspensions may be doable (Bose has one) but this is serious black magic.

The only actuators that work quickly enough are indeed hydraulic - don't think "construction equipment" hydraulic, think "aircraft control surface actuator" hydraulic. Something like surplus F16 elevon actuators might work, if they can be packaged.

You can use certain types of pnumatic - they're fast enough - but you will need a sizeable resevoir of compressed air, and keeping it full may prove challenging. Actuators fast enough tend to be non-return, so you'll consume air as it operates.

If the aim is cockpit-adjustable ride height, then air bags work. You'll lose some handling, as airbags make for crappy springs, but they do work, and they're cheap - just not quick. Certainly not fast enough to do semi-active or fully-active suspension.

You control system is going to need to operate in the 500-1000 Hz range, and is going to need to be sensitive to travel changes on the order of 0.0625". This ain't going to be cheap.

DG

Learn: http://autocross.dsm.org/books.html

 

[Omega]

I have also heard that air systems have been bashed in terms of ride quality and handling.

That said, I watched a show on Speed a few weeks ago about it. Some big company invited a whole bunch of people out to a track for some testing. They Even would do back to back runs with a car that had a stock suspension then the air... and it handled better with the air. I can't remember the name though!

Sounds like for what you are looking for, that would be the way to go.