Best static representation of ride quality

[mistertate]

What do you guys think is the best way to quantify ride quality on a luxury car or SUV?
I'm looking for something I can show on paper that one damper is better than another.
Would accelerometer data from the cabin be of any use or would it get too complicated?
A little out of my element here, thanks

[gordner]

On top gear they suspended a colander of eggs over the drivers head and drove a rough course, that was a very visual representation of ride quality, though probably not the answer you were looking for!

[Flieger]

It's not that hard if you've got the software to do a transmissibility plot where you show how much the sprung mass accelerates or displaces, etc. for a given road input, but to rate that acceleration or displacement as a ride quality is actually quite complicated. To make things worse the transmissibility changes with vehicle speed so a German sedan may feel great on the autobahn but be too stiff on an interstate. It also gets more complex if you want to move away from a simple quarter car model and then move into pitch and roll inputs.

Maurice Olley has some good tips, and the Army has some correlations between fatigue and the RMS shaking that a solider gets in an APC or jeep.

http://www.millikenresearch.com/MauriceOlleybyWFMilliken.pdf

Are you trying to sell the dampers or spec the dampers for your car?

[VFR750]

An accelerometer would be useful if you could record consistent data, over the exact same path and speed for each car/SUV. Placement of the accelerometer would be important too. If you think about it, the drivers head might be the best, since long trip fatigue comes from fighting your head-bob over rough pavement.

The comparison might show less acceleration for soft cars and higher for stiff ones. The duration, rebound, and decay would be visible in the time vs g trace. The more accelerometers the better too.

This is a reasonable thing to quantify, and play around with. I'm sure all the auto manufacturers record this data. And do exactly what you suggest; quantify the competition.

But you may find the qualitative feel is as important as the data. Hence you might record a video as you drive over your "proving ground course" and comment on what you liked and did not.

Comparing both quantitative and qualitative would be interesting.

[island911]

Originally Posted by mistertate

...I'm looking for something I can show on paper that one damper is better than another....

Dampers are part of a system.

You may as well say, I'm looking for something I can show on paper that one spring is better than another.

Anyway, dampers are part of a classic mechanical engineering problem – mass, spring, damper. Where mass (unsprung weight) is the inertial force, the spring is the deflection dependent force, and the damper is the speed dependent force. It is the combination of those values which will give you your over damped, under damped, or critically damped System.

[john70t]

Originally Posted by mistertate

Would accelerometer data from the cabin be of any use or would it get too complicated?

Everything you might need is probably in a smartphone: Sensors on Your Smartphones | Blue Bugle
a). Mount it reliably to a chassis surface which will transfer best for collecting whole car data.
b). Mount it to the steering wheel for collecting steering feedback.
c). An interior video camera (on headrest?) with angles plotted in tape on the windshield and steering wheel to show input vs. result. FPS between set points on the road can be clipped and counted up to show timing.

Find and create a road course with all the necessary variables(slalom, long curves, brake dive, bump and double bump and multibumps, etc) and test using the same environmental conditions. Run through the course multiple times. More data is better.

Download the data, plot and graph the multiple overlays to show average results.

Materials required: Phone, tape, vid camera, mounts, pc and graphing software.

[scottmandue]

Originally Posted by john70t

Everything you might need is probably in a smartphone: [url=http://www.bluebugle.org/2013/01/smartphone-sensors.html]Sensors on Your

Seemed like not too long ago most of the car magazines had a gadget that registered and recorded horizontal G's... don't know if they sensed vertical G's too.

[Noah930]

My dog, when I was a kid, was prone to motion sickness. We joked that when my dad bought his Lexus (the original LS400) the dog suddenly didn't yuke in the car any longer. That was a graphic (and universally understood ) demonstration of ride quality.

[mistertate]

Haha, yes, that and Gordners post about the eggs are appealing. I will be reporting data to an automotive but non-technical audience so examples such as these are relevant.
Thanks for the paper on Olley, Flieger, that was a fun one.

[VincentVega]

They used tofu in Initial D, seems to have worked great.