Moment Method anyone?

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WilO
WilO
4
Joined: 01 Jan 2010, 15:09

Moment Method anyone?

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Wondering if anyone has any familiarity with the Milliken Moment Method, and would care to comment on it. As I found myself snowed in this past weekend, I had ample time to read a paper on the topic and thought it might be an interesting topic.

Jersey Tom
Jersey Tom
166
Joined: 29 May 2006, 20:49
Location: Huntersville, NC

Re: Moment Method anyone?

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What would you like to know? Pretty straightforward overall concept, though execution gets involved depending how accurate a vehicle model (suspension, aero, diff, etc) you want to use. Like anything, it can be as simple or as complicated as you like!

Map Ay and N as a function of delta [steering] and beta [sideslip]. Think of a grid of a variety of different steering and sideslip combinations, say from -10 to 10 degrees for each (it's somewhat arbitrary). Calculate the forces and moments at each.

With the results you can analyze anything as simple as limit grip capacity and linear understeer gradient.. to various "quasi-transient" stability and control metrics. You can even add a 3rd dimension by adding throttle, brake, or some combination.

Again, as simple or as complicated as you like.
Grip is a four letter word. All opinions are my own and not those of current or previous employers.

Mystery Steve
Mystery Steve
3
Joined: 25 Sep 2009, 07:04
Location: Cincinnati, OH, USA

Re: Moment Method anyone?

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I'm assuming you have a copy of the Millikens' book?

Race Car Vehicle Dynamics

If you don't, or if anyone else is interested, it's a good book to pick up if you really want to dive into the deep end of vehicle dynamics. And it does discuss the MMM in detail...

Flabbio Fixatore
Flabbio Fixatore
0
Joined: 02 Jan 2010, 01:54

Re: Moment Method anyone?

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Mystery Steve wrote:I'm assuming you have a copy of the Millikens' book?

Race Car Vehicle Dynamics

If you don't, or if anyone else is interested, it's a good book to pick up if you really want to dive into the deep end of vehicle dynamics. And it does discuss the MMM in detail...
eBook much cheaper!

ubrben
ubrben
29
Joined: 28 Feb 2009, 22:31

Re: Moment Method anyone?

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The original SAE Paper that Milliken et al produced in the 70s is actually much more comprehensive and a lot of the plots in RCVD are lifted straight from it.

If you go on SAE.org there are a few Moment Method papers by Milliken et al in the 70s. There was a second lot in the 90s done with Peter Wright using Lotus F1 data examples.

The first and most fundamental paper is:

760712 : The Static Directional Stability and Control of the Automobile

Ben

WilO
WilO
4
Joined: 01 Jan 2010, 15:09

Re: Moment Method anyone?

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Ben,

Thank you for the heads up on the papers; much appreciated.

Wil