13 replies to this topic

[JForce]

Assistance required from the tech gurus!

Please see this thread in Readers Comments, with some unusual information on traction control, pit to car telemetry, and Scott Speed and Red Bull cheating (ok maybe I'm kidding about the cheating thing)

Can you come give us a hand?

[desmo]

Perhaps a D-GPS beacon to help the car locate itself more accurately on the course? Better location data could help the differential or TC (what else?) know which maps to call up.

[JForce]

Originally posted by desmo
Perhaps a D-GPS beacon to help the car locate itself more accurately on the course? Better location data could help the differential or TC (what else?) know which maps to call up.

I suppose that wouldn't violate the telemetry rules, because the car would be reading the beacons, not the other way.

I am so surprised to have never heard anything about this before. You would think that if it was legal, and it gave an advantage, they'd all be doing it. I've never heard anyone mention it in any article, or anything

[scarbs]

All the teams do it, hang around the barriers at a race or test and you'll see the small beacons on mini tripods and an external battery. Its not illegal and its no secret.
Teams have been developing GPS to negate the need the beacons and even provide soem element of slip angle sensing.

[Fat Boy]

What Scott was talking about was the infra-red beacon that spits out an encoded beam across the track. There is a beacon reciever on the car. People put them at start/finish and often a couple other points around the track. When the reciever 'sees' the infra-red beam, then the ECU knows that the car is at start/finish. Distance is measured by wheel rotations, not necessarily GPS. This allows the car to calculate where it is on the track and alter the diff/TC/ECU/etc. accordingly. It's completely legal, and in no way a secret. There is no pit-to-car communication involved.

This is hardly high tech stuff, you'll find it on 90% of the go-karts at your local racetrack. You folks need to get out more.

[Ross Stonefeld]

Im the last person to scream about driver aids, but at what point do we actually make them think about what they're doing? Im worried the next step is visor HUDs with left and right arrows that change from green to yellow to red, arcade style, to recommend the appropriate speed through that corner.

Though powerups would be cool.

[JForce]

Originally posted by scarbs
All the teams do it, hang around the barriers at a race or test and you'll see the small beacons on mini tripods and an external battery. Its not illegal and its no secret.
Teams have been developing GPS to negate the need the beacons and even provide soem element of slip angle sensing.

How is it not illegal? I thought they'd (again) banned pit-to-car telemetry? Or am I wrong?

[alexbiker]

It's not telemetry, as the beacon carries no data apart from its existence.

Alex

[phantom II]

Most times the markers are NDBs (non directional beacons) transmitting at one Watt at different frequencies and their signals are attenuated by other cars or rain as an IR beam is. How do you encode a IR beam? Each frequency triggers the next pre programed settings.
Alanso last year spun out in practice at Imola because the marker was not working and the diff was set for the previous corner.
A transponder on the car is a different aninimal which interrigates radio signals from the ground at various points and transmits to the pit in code for lap times and speed.

Originally posted by Fat Boy
What Scott was talking about was the infra-red beacon that spits out an encoded beam across the track. There is a beacon reciever on the car. People put them at start/finish and often a couple other points around the track. When the reciever 'sees' the infra-red beam, then the ECU knows that the car is at start/finish. Distance is measured by wheel rotations, not necessarily GPS. This allows the car to calculate where it is on the track and alter the diff/TC/ECU/etc. accordingly. It's completely legal, and in no way a secret. There is no pit-to-car communication involved.

This is hardly high tech stuff, you'll find it on 90% of the go-karts at your local racetrack. You folks need to get out more.

[phantom II]

Oops, read not attenuated.


QUOTE]Originally posted by phantom II
Most times the markers are NDBs (non directional beacons) transmitting at one Watt at different frequencies and their signals are not attenuated by other cars or rain as an IR beam is. How do you encode a IR beam? Each frequency triggers the next pre programed settings.
Alanso last year spun out in practice at Imola because the marker was not working and the diff was set for the previous corner.
A transponder on the car is a different aninimal which interrigates radio signals from the ground at various points and transmits to the pit in code for lap times and speed.

[/QUOTE]

[Christiaan]

So what about track conditions, like if you are lapping another driver or overtaking or avoiding a collision. What aboput changing track conditions, temperature, rain etc. If the software is loaded for each corner how does it deal with that?

I am quite disappointed that driver aids have reached that point. Its a pity but I actually miss the no TC days.

[ivanalesi]

Last year, in their official press release BMW Williams, Theissen said that they have been focused on launch control developments. I dont remember the test, I think that I even posted a new thread about it. So, get used to it:) They have it all!

[Lukin]

Didn't want to post in the RC forum, but this quote is from there.

Originally posted by F3000
Every F1 team has a beacon transmitter on the pit wall. It transmitts either an infra-red or microwave signal and tells the car's on-board data logger that it has just completed another lap. This is marked in the data set and is used for viewing the data, especially overlaying one lap with another, so the start of the laps line up both in time and distance.

F1 teams use multiple beacons around a circuit to increase the accuracy of the data and to tell the car where it is. If the distance is calculated from the front wheel speed sensors errors can add up when a driver locks a brake. So if the driver locks up a few times in a lap the total distance will be less than if he doesn't lock up. Multiple beacons 'reset' the car's distance reference.

As for programming diffs and gearboxes, the car needs to know where it is so it can be at its correct setting at the correct place. For example, a diff may be set tight from 0m(start line) to 1200m track distance, then loosened for the next 500m (tight series of corners possibly). Then tightened again, and so on.

I hope this helps.

PS: The FOM split beacons do not transmit and nor does the driver receive these splits on their dash. The splits they receive are either from their own team beacons or generated at pre-determined track distances.

Exactly right, except for the distance calculation.

All telemetry/logging software can tell the difference between a lock up and a 'proper' deceleration and all take it into account so that won't actually effect the lap distance calculation. If you have two front wheel speed sensors (one left and one right) you can take the max of the two and then correct it from there. For example, if a wheel locks up the wheel speed sensors will see it go from, say, 200 to 120 in a short space of time. But unless the longitudinal acceleration picks up a similar speed change (the integral of it's signal) it knows it's just simply a lock up and will return vehicle speed as a function of any other wheel speed sensors it has or simply by the longitudinal acceleration signal. You can fool a wheel speed sensor, but it's harder to fool a g sensor.

What effects the distance is driving line. If you take the lapdistance from each lap during a race there will be differences. Hopefully not much; anymore than .1% would be a concern unless there was a good reason such as traffic or overtaking.

It's pretty amazing they use this for control though, I agree with Christian that it's become a control engineers wet dream and a fan's nightmare.

Also, unless the driver does spin early in the lap, I can't imagine they would need a beacon unless they want vastly different characteristics for corners close together. After all, after each beacon it's possible to have a non-accurate measure of lapdistance, if you get my drift. Also, it's not hard to use a basic lapdistance number and the other sensors available to tell the car it's in a corner. Any number of the sensors available (lateral g, slip angle, steering) will tell you that.


Most series use a standard beacon trasmitter (Australia is mostly Dorian, don't know about everywhere else) and the teams must use their own system, which is mostly MoTeC here. Go to any race meeting and there will be a flurry of beacons along the pitwall. Important thing is to get thm in the right spot every time you go to that track otherwise you have to offset the data to overlay between years, whcih is never fun.

On another note, Pi Rules!

[Greg Locock]

Here's a war story.

On our first ABS car we did an FMEA (failure modes and effects analysis) and someone asked, what would happen if a dealer fitted a non abs (ie no tone wheel) rotor to an ABS car?

So, teh brake development driver got told to do a test.

He started at (say) 30 kph, full stop, seemed OK

40 kph

OK

50 kph

OK

60 kph

OK

70 kph

OK

80 kph.

Car spins round, he needs clean jocks.

There are 5 wheel studs. The pickup could pick them up instead of teh tone wheel. Due to a programming error/decision we used the slowest wheel as the vehicle speed. So the vehicle thought it was travelling at about 1/8 of the real speed. At 10 kph (or so) the ABS cuts out, so he'd actually been braking without ABS until 80 kph, (I must have the numbers wrong a bit).