Quote from Töki (HUN) :

A pic.

/me runs.

Appologize Indonesians... or rivierans from Monaco

Quote from Mysho :

Yes it does, if I died tomorrow noone would notice it and it would mean nothing to my country, but if I was a president and died with other important persons it would mean a lot of consequences...

President, several representatives, chairmans of several institutions (ie. central bank), 4 commanders of 4 types of armed forces, many politicians - effects are like inverted coup d'etat - most of them were opposition. That means unexpected changes...

Quote from obsolum :

I understand they were all very important people but still... ~3000 vs. 132? I also understand that for you this is a lot worse than 9/11 as it's much closer to where you live. I'm just sayin'... most Americans will probably not agree with your statement

I dont think we should compare it with 9/11. But to show you all non-Poles our perception I posted historical example we had.

Quote from obsolum :

Don't you think you may be slightly exaggerating here? ~3000 people killed vs. 132 people killed...

Some differences there: we know about 90 peolpe on the flight list and probably 2 or 3 that didnt go on that plane. Reuters, Euronews and Novosti say about 132 people.

Quote :

@AndRand, that's why I thought this was a bit "fishy" as well but it's no good speculating about this kind of stuff. It may very well have been "just" a plane crash and if there was more to it we probably will never know for sure

No - I am not speculating. I just show how we perceive that loss.

Quote from obsolum :

That was my first thought You can't be sure of anything these days.

We had in WWII two reminding tragedies: Commander in Chief died in plane crash in Gibraltar. It is said that because of his knowledge on more than 20,000 officers (which meant - doctors, engieneers, lawyers) captured and killed in Katyn, Russia. This one looks like both for us, and it happened near Katyn, just before mourning celebrations of this.

I read there that LFS cars are default cars and I wonder if results are the same in VHPA and LFS using the same input data.

Quote from Bob Smith :

Here's the graphs: http://www.vehicle-analyser.com/

I wonder if your (?) VHPA with up to 6% accuracy on calculations gets the same results as LFS when using LFS cars: http://www.vehicle-analyser.com/download.html?

Quote from EQ Worry :

Indeed, that is why LFS EI was created in the 1st place. Of course all depends on the particular server admins and the way they choose to do things, but both IHR and cargame are currently using EI to enable faster cars based on rank (points) OR past experience (EI).

Latest Airio (2.3.9) can even assign initial safety rating based on EI, meaning e.g. people with experience of 700 can drive GT2 and all slower cars (GTL, TBO, STD, ...) straight away and they also get say 80% of safety rating on 1st connect. But SR is another limiting factor and if it goes down car classes may become unavailable regardless of EI.

Good to hear because for now I just dropped even checking multiclass servers

OK, I scaled the units, scaled change of longitudinal force according to the Figure 6.
And comparing to simple scaling to Fxmax (so Fx*Fy doesnt go over Fxmax) it looks bit different still . If anybody wants I attach .xls also.

Last edited by AndRand, Thu, 8 Apr 2010 22:14.

Quote from jtw62074 :

Vector addition should gives us (792*792+506*506)^0.5 = 1371 which is what we should see in your bottom graph. (This would change the curves dramatically but they'd still be wrong).

Your bottom graph shows 940 for this cell.

Don't tell me Excel calculates it wrong as 939,84

@Nikn: I think you should zoom it in to get the feel of one quater 'cos it is symmetrical

BTW: I perceived those graphs as geometrical and forgot about units. In fact it doesnt matter if I use %, degrees or rads but the numbers should be used in the proper places for chosen units if taken from other charts

Last edited by AndRand, Thu, 8 Apr 2010 21:38.

If you want I can send you .xls

But if you want numbers: here you go (this is also the saddle but bit different as I dont have previous one and had to figure out again). And I know what you are pointing out - this is because I used linear or exponential proportion instead of hyperbolic for changing of force curve along the opposite coordinate because I didnt bother for big values (more than 8-10%and 8-10 degrees) of SR and SA.

edit: F*ck it - comma. For me it was all scalable but I was changing Fx 10x too fast

Last edited by AndRand, Thu, 8 Apr 2010 21:21.

Quote from jtw62074 :

Figure 6 is mostly below the limit of traction except in the areas where they hook back to the left as they go down. The rest of it is near the origin where your graphs start at 0 and climb extremely quickly and then go off and do goofy things.

Fx - Slip Ratio from 0 to 90%, Slip Angle for 2, 5, 8 and 12 degrees on Figure 6.
Fy - Slip Angle from 0 to 30 degrees and SR 10, 20, 40 and 80% on Figure 7.

You say they dont match?

Quote from jtw62074 :

And your graphs don't reflect this data at all like you thought they did, per my last post. I agree with Android in that it looks like you aren't really understanding what your own graphs are saying and how they relate to the ones in the paper

top 3d chart is result (vector sum) of charts below.

Quote from jtw62074 :

Obviously not because your data is showing something quite different from mine. One of us made an error in our math. Quite sure it wasn't me

Did you use Figure 7 or Figure 7 and Figure 6?

Quote from AndroidXP :

Sorry for putting this a bit bluntly, I just can't help myself sometimes :o

Sorry to put it bluntly... but here it IS MEASURED (for both Fx and Fy). And it sure doesnt look like turning that slip ratio 0 curve 360°.

Quote from jtw62074 :

I just whipped up a quick little proggy to take the data in the top graph of figure 7 and add it all together vectorially.

Well, I took data from Figure 7 for lateral force and for Figure 6 for longitudinal and then combined them vectorially (which result is shown on my 3d graphs)

Quote :

It doesn't mean I know everything, but I'm not a noob to this stuff and do know what I'm talking about on this one

I can see and appreciate your understanding and answers.

Quote from EQ Worry :

What a thread... Just a few comments from me:

1) Why not ban people causing crashes in T1? Problem is you get crashed in T1, you say "idi*ts", but that is so simple! But who in fact is the idi*t responsible? When you check replay (which obviously no one ever bothers), in 75 percents (or even more) of cases there's no one specific to blame, it is simply small lags or small mistakes leading to HUGE crashes because of LFS collision detection.

2) InSims like Airio can help to get rid of laggy cars, but what would need to be changed is the collision system itself. Here I completely agree with cargame.nl and others - new car/track/physics may be nice, but collision detection needs substantial correction NOW. Cars flying 60 meters high when before hitting a barrier they were moving at 30 kmph? Huh! That says it all.

Well, I dont know if it is actually attainable without filtering all racers lagging even a little. Any lag makes it inevitable when car "appears" to be in the barrier thus creating burst of energy (in fact it should be only possible between cars not car and barrier, because car/barrier hit happens on local PC). Maybe it would be achieved if collision detection took into account lag: so it not only calculated vehicle dynamic between packets but also solved situation of big difference between not only position of the car but also enormous difference between ie. speed calculated and received. That doesn't change the fact of cars in collision position after synchronizing packets.

Quote :

5) LFSEI is to a large extent an experimental thing. Because it is based purely on LFSW data the best thing possible would be when it is calculated and available right at the LFSW. If Victor wants to add such a thing, I'd gladly submit/discuss the way it is calculated (and which looks very reasonably). But recently I was sending some other ideas to both main developers (direct support of some restricted cars like GT2s or UFBs, both in game and stats, time-limited demo but with REV BL tracks, completely open sites for custom tracks) and I got no response. So...

Does it mmean that with my stats since 2004 I dont have to climb on ladders with your insim?

REV BL? no way online drifting for free!

Quote from jtw62074 :

Forgive the goofy artwork. If those combined force graphs looked like that (saddle shape) you'd wind up with not a friction ellipse theory, but something more like the shape in my attachment. Here, along some combination of slip angle/slip ratio you couldn't make as much force as you could along pure slip or any other combination of slip angle/ratio. Sorry to say, but this is complete nonsense

Well, I have to disagree - I cant show diagram of Fx vs. Fy right now but I think, looking at Bob's charts (Fx for different SA and Fy for SR) that combined would look alike.

Quote from jtw62074 :

AndRand, I still haven't found the time/inclination to get fully into this with all the details of what's wrong. Maybe I will later today.

For now, if you are to plot lateral or longitudinal force by itself rather than the combined force magnitude, what you should get is a shape like one quadrant of this:

http://img215.imageshack.us/img215/6734/lateralforce23.jpg

Here the peak is outrageously high compared to the rest of it (garbage in/garbage out), but in essence this is what you ought to get. Again, you'd only be plotting one quadrant of this, but the point is the worst that ought to happen is at the origin you'd have 0 force which then climbs to a peak roughly some distance away from the origin (which you could trace with an ellipse) which then fans out into a fairly level surface. Unless I'm having a brain fart right now, both lateral and longitudinal ought to look something like this in terms of basic shape with the lateral being rotated 90 degrees to this one.

The combined/resultant force graphs you've been posting are just the vector sums of the other two graphs, which ought to have the same basic shape rather than something where you've got a bump above either of the pure slip force peaks and then a huge dip at some combination out in the combined slip area.

The small diagrams I showed beneath those plateaus show the same - just a quadrant and 2d instead of 3d (XMR ). But I noticed how important is not only pure one force view but also the way it changes along with opposite coordinate.

I can make charts using Pacejka model using those data:

But without data on how separate forces behave in regards to opposite coordinate (if I call it correctly) I would be just speculating. The shape (not onl peak and sliding values) of the forces is also very important.

Like on this next diagram - where in order to avoid "miraculous" traction regaining with tyre of difference and sharp change between peak and sliding value big drop of traction along with opposite coordinate is needed. Also a table if someone likes it colorful.

Quote from Bob Smith :

Funny, I have graphed those coefficients and there is indeed fall off (far more longitudinally than laterally, as you would expect).

Indeed, the paper with empirical survey shows somewhat different - the drop is bigger there on lateral force but there could be many issues regarding tyre type.

But nevertheless diagrams you showed (are you Ben or Bob? :tilt look more alike those empirical than those derived from Pacejka's model and Friction Circle, which I attached (for me Fx vs. Fy diagrams are somewhat non-intuitive and the differences between characteristics are not so clear).

Quote from Nikn :

that seems odd.

here is a picture of what a pacejka combined force plot looks like. (some of the params might be a tiny bit off) for some random 195/65/15 tyre

the quality is a bit bad.


Red = greater magnitude, Green = less magnitude, used blue to show band lines. an interesting note is that it's not symmetrical over braking and acceleration.

where are the axis? what are the segment views for Fx (fn to SA) and Fy (fn to SR)? What empirical data was that based on? I just wanted to know so I could tell - should you just tweak some inputs or you have plainly wrong model?

And did you measured it? guestimated? or just guessed? if first - great! if second - not bad! if the last - wish you luck!

Last edited by AndRand, Wed, 7 Apr 2010 21:33.

OK, so here you go with the perfect saddle I have mentioned earlier. You can see how do segment views look in this situation. In fact this is the graphical representation of Grip Circle (although there should be some kind of one level area). Furthermore, you can see the nose-dive when going off the circle, which without empirical data was in fact guessing.

In extreme situation it looks like on the second diagram I named "rain".

Last edited by AndRand, Wed, 7 Apr 2010 20:51.

Quote from bosbrandje :

yes, but if you are constantly involved in crashes and ramming others, on purpose or not, maybe it's then time to protect other drivers, and send you to a server that is more noob oriented. remember it's the car that wrecks that's being removed/spectated/whatever not the car that is being wrecked.
sudden movements on straights, towards the side, are mostly always crashers.

heh, "Extreme waving warning" for Hamilton in Sepang

But in fact, such an index per km driven would be an indicator (damn banger racers )

Last edited by AndRand, Wed, 7 Apr 2010 11:39.

Quote from jtw62074 :

Maybe what you could do when you get access to the file is check the max combined force in pure slip in either direction, then see if there are any values off either axis that are higher than this maximum value. In the exaggerated diagram this is clearly not the case, but perhaps for the other it is. If so, there is a point to be made about something that I'll get to.

According to those diagrams for separate force component for opposite coordinate... it always is when the off-grip part of curve doesn't drop much if at all (with change of opposite coordinate).
I will post today a graph with Lateral Force characteristic more like this one (dotted line on the higher diagram): http://www.lfsforum.net/attach ... d=103386&d=1270299972 - these measures were taken for, as I remember, normal threadded tyre with high sidewalls, so for low slicks it would look different.

Nevertheless, before I step into fiddling data to represent reality I think this approach is viable, more viable than Friction Circle approach which is in fact only one of the states for given coefficients. While using Friction Circle leads to sheer guess what happens beyond that and in fact as you stated Todd, it is based on fake assumption that forces for opposite coordinate equaling zero can be summed as vectors to get combined force (so in fact that is also sheer guess).

Last edited by AndRand, Wed, 7 Apr 2010 12:32.