Newsgroups: rec.autos.simulators
Path: news.jprc.com!dca1-feed2.news.digex.net!dca1-hub1.news.digex.net!digex!howland.erols.net!news-peer.gip.net!news.gsl.net!gip.net!den-news-01.qwest.net!news.acsu.buffalo.edu!freenet.buffalo.edu!bd427
From: Doug Milliken <bd427@freenet.buffalo.edu>
Subject: Re: G-Force indicaters in racing simulations
In-Reply-To: <4HiA2.2352$tk.3050566@news2.atl>
Content-Type: TEXT/PLAIN; charset=US-ASCII
Message-ID: <F7nxwy.B75@freenet.buffalo.edu>
Sender: nntp@freenet.buffalo.edu
NNTP-Posting-Host: freenet.buffalo.edu
Organization: Buffalo Free-Net
References: <36d0caf4.18294410@news.mindspring.com> <4HiA2.2352$tk.3050566@news2.atl>
Mime-Version: 1.0
Date: Wed, 24 Feb 1999 14:36:05 GMT
Lines: 48
Xref: news.jprc.com rec.autos.simulators:76871


*Real* race car drivers would kill(!) for this display, to be used during
practice & setup (probably not too easy to use it during a race<grin>).

Kind of like the pictures on pp 338-9 in our book, "Race Car Vehicle
Dynamics".  We've been using the friction circle presentation for a long
time -- earliest reference to the technique is from the late 1950's... 

Some recent work we've seen (not by us) says that realtime friction
circles may actually be measurable on real tires.  Isn't science
wonderful?

-- Doug
		Douglas Milliken  <bd427@freenet.buffalo.edu>
		Milliken Research Associates Inc.


On Mon, 22 Feb 1999, Jack wrote:

> What I think would be *really* useful is to have four pairs of concentric
> circles (i.e. friction circles) on the screen.
> 
> Each inner circle would enclose a force vector that would grow in size in
> proportion to the magnitude of the force acting at each respective corner of
> the car. Each enclosed vector arrow would point in the direction of the
> resultant force acting at each corner of the car, so you could get a clear
> indication of how the forces at each corner were being consumed: braking,
> cornering, traction, or some combination of these forces.
> 
> The outer circle in each concentric pair would change in diameter also and
> would be proportional to the adhesive force available at each respective
> corner based on current wheel loading. When the diameter of the inner circle
> grew to match the diameter of the outer circle, you'd know that you had
> reached the limit of adhesion. Powerful stuff!
> 
> These vector circles could be displayed in the Replay view and would be
> incredibly valuable in analyzing both your own, as well as other driver's,
> setups and driving styles. Seems that I've heard rumors that some of this
> data is in fact retained in the replay files.
> 
> Graphically, it would be relatively easy to implement. Heck, I might even
> consider doing it myself, if Papy chose to make the data available. Randy?
> 
> 
> 
> 
> 

