MoTeC FSAE seminar: Australia

[MoTeC]

Ok Gentlemen/Ladies,
I have Claude Rouelle here for the next week or so. I have been talking to him about the FSAE seminar and working out times, topics etc. As the Aussies will know I do the first day on MoTeC equipment and Claude does the second two days on Vehicle Dynamics.

Ok, I would like to know what you guys want to know. One thing I am going to give more detail on is traction control because that was the most common question at this years event. I will ask Claude if he can explain the ins and outs from his point of view as well.

What else do you want to know?

Mark McCoy/Donna Arbuckle

[MoTeC]

Ok Gentlemen/Ladies,
I have Claude Rouelle here for the next week or so. I have been talking to him about the FSAE seminar and working out times, topics etc. As the Aussies will know I do the first day on MoTeC equipment and Claude does the second two days on Vehicle Dynamics.

Ok, I would like to know what you guys want to know. One thing I am going to give more detail on is traction control because that was the most common question at this years event. I will ask Claude if he can explain the ins and outs from his point of view as well.

What else do you want to know?

Mark McCoy/Donna Arbuckle

[Frank]

http://www.msnusers.com/mypicture?user=4263~5AADAAAAAE!cSAgOqC0p83T7uEpptb yj0iIyK9cGC07Tu3nJ!M1ikZCQ$$~5AAEAAAAAG*uhzwpb52i6 ngYt9Y!eJRPQRfvZn80Zm1M0$

I'd like to see...

1 A bit more about using shock histograms, and tuning dampers WRT transient cornering behaviours.

2 More information about tyre temperatures, and the practicalities of using IR tyre pyrometers.


Mark

These were the final TC settings I was using last weekend

I found it really important that you use LESS than 75% maximum available cut, and that 50% was more appropriate.

At 50%, it still had easilly enough cut to "catch it" during high speed, high rpm, power on oversteer. In future i think i will start by setting the maximum cut to a value JUST high enough to catch the car in this sinario.

I must say that setting up the launch control on a number of different surfaces is quite important.

For instance, the FSAE-A track was really hot and sticky, and we needed to raise launch RPM about 1000 RPM to suit.

I still havn't tested on a wet track yet, but hopefully will get to experiment soon.

I also still think that it's best not to give drivers too much time practicing driving with slip control. They get cheeky, and start to drive poorly.

I also think that expressing the above TC parameters graphically is a very good idea, and logging slip at greater than 20 Hz would be prefereable (M4 not so good).


Launch Change Speed 26
Launch Rpm 6,800
Launch Control Range RPM 700
Launch Aim RPM 6,100
Tyre Rolling Dia 1640 mm
Maximum Cut 50%
No Cut RPM 6,000
Cut Mode 2
Full Cut RPM 6,750
Desired % Slip 10 (for all throttle positions)
Slip Control Range % 12

About suggesting improvments to the TC_MUX box... I think the launch control settings are better set by an engineer watching the vehicle. But I believe setting the slip control should be done whilst driving. I'd use three varible dials attached to the TC_Mux box.

I know this is really "OLD SCHOOL" attitude, but it's hellishly long process from the sideline, I'd guess it'd still be hard with remote and real time setting control.

Dial 1= Maximum percent cut 0% - 100%

Dial 2= Desired Slip 0% - 30%

I found the car easier to drive when the desired slip was a constant, as opposed to the linear interpolation table settings suggested in the help files. I'd be interested to see what it's like when driving on an icy (or very slipery) surface though. Perhaps a 4th dial to change the gradient of the throttle position interpolation table.

Dial 3= Slip Control Range 0% - 30%

Thanks for your help so far about all this Mark !!!

Regards

Frank

ps We're still wondering if our gearbox failure on the Saturday was caused by the 0 msec gear change ignition cut recovery time (this was applied accidentally)

I'm still thinking that a 30 - 50 msec recovery time should be enough to avoid gearbox carnage, i think i remember you saying that we should use more? (i guess it is an expensive type of "on-track" destructive testing that tells the required value http://fsae.com/groupee_common/emoticons/icon_smile.gif )

The slip control takes care of the "2nd gear chirpies" quite easilly once the recovery time is above 30msec.

(Sorry, i just had to say "chirpies".. a product of growing up in Caboolture Qld http://fsae.com/groupee_common/emoticons/icon_wink.gif )

[This message was edited by Frank on December 15, 2003 at 04:09 AM.]

[MoTeC]

Thanks for your reply Frank,
This is the type of feed back Claude and Myself need.

Traction control is one of those things that is always going to be a time consuming thing to set up. Obviously the amount of cut is relative to how easily the engine can over come the traction of the tyres, it is one thing that I hope to have a lot more detail on.

Any reports from testing you would like to forward to me are most welcome. I find that in this industry the best thing to do is ask ten experienced people and make sure you understand what they are saying, also make damn sure they are a reliable source of info there is obviously a lot of B.S. flying around.

I do like your graphical representation but I feel with out a torque curve and a simple tyre model or information it is only part of the setup. Not the easiest thing to get spot on is it?

Chirpies....I am a QLD'er as well I know this word. http://fsae.com/groupee_common/emoticons/icon_wink.gif

If anyone id doing any traction control testing (in Melbourne) feel free to let me know I am more than happy to come along and help.

The actual background reasoning if Gear Change Ignition Cut is that the cut is only to get the box out of gear, the RPM limit will let you get into the next gear and the recovery time softens the shock on the drive train. Recovery time is again based on the power of the engine and how much your drive train will hack...and this is based on your budget. http://fsae.com/groupee_common/emoticons/icon_smile.gif

Come on everyone else I need some more ideas otherwise I decide what I want to teach and so does Claude.

Mark McCoy/Donna Arbuckle

[me]

Do a thing on CRIP and then send them over to Detroit where they can teach me!! http://fsae.com/groupee_common/emoticons/icon_smile.gif

Damn its confusing!!! http://fsae.com/groupee_common/emoticons/icon_frown.gif

Why o why did i want to be in electrical? Oh well, at least we should have a decent car in Detroit... to take on u ozzies!!

[MoTeC]

Hi Me,
The crip is not that confusing if you think of it like this: For an ECU to know where the engine is in a 720 degree cycle it must have a reference point, we use TDC compression on number one cylinder (pretty logical). Now you need tooth pattern which is exclusive to 720 degrees. The easiest way is to have a number of teeth on the crank, evenly spaced is fairly common but an extra or missing tooth is quite normal on factory set ups. The one problem with doing this on the crank is that it turns twice in one engine cycle. If you have a singhle tooth on the cam that only comes around once in 720 dergrees. We use this single tooth to "Choose" the next tooth on the crank (or next missing or additional tooth). Now you have an arm point to choose a certain tooth once in 720 degrees. The crip is how many crank degrees it takes to get from this chosen tooth back to TDC compression number one (forwards that is not backwards).

If you download the latest interpreter software from the net it will instal a program which is a little animation of how to work out CRIP. It will be under "start", "programs", "motec", "utilities", and is called MoTeC Trigger modes. It is a big help.

CRIP is one thing I make sure everyone understands. Email me at mark.mccoy@motec.com.au if you need any further info. BTW I will be on holidays as of Saturday this week and will not be back till the 5th of January.

Mark McCoy/Donna Arbuckle

[MoTeC]

Opps,
Sorry it is not in Utilities it is just in "MoTeC". http://fsae.com/groupee_common/emoticons/icon_smile.gif

Mark McCoy/Donna Arbuckle