How are lap timings done?

[anonymous-user]

Occasionally two cars will qualify within a few milliseconds of each other.

But how are such tiny measurements made when there are so many variables present?

I wondered if the cars break some beam of light across the track but that would be fine for a single car but not when it is all neck and neck.

I wondered if the car has some "beacon" on it that passes a "loop" in the road but radio type beacons would have differing ranges and some team that happened to get one with a slightly longer range than a competitor would have an advantage.

Any one know how the lap timings are done to be accurate and fair ?

TIA

[PHuzzy]

Same as most racing, they use transponders.

Basically radio waves emitted and in to a feedback loop buried in the track.
Also as far as I'm aware, each transponder transmits a different frequency to eliminate interference.

[Exige77]

PHuzzy said:

Same as most racing, they use transponders.

Basically radio waves emitted and in to a feedback loop buried in the track.
Also as far as I'm aware, each transponder transmits a different frequency to eliminate interference.

The transponders have the be fitted in a particular place on the car so they are all exactly the same distance from the front of the car.

There are usually several loops in the track, hence the sector times.

[andrewcliffe]

Each car has two transponders for timing purposes.

One is mounted in the nose of the car, on the centreline of the front wheel axis, and the other is mounted in the cockpit in line with the drivers head.

See page 104 of the 2020 of the technical regulations for a location diagram. https://www.fia.com/file/112562/download/29875

The transponders will have a unique identifaction so the timing systems can place them accurately, and with two units on each car in exactly the same place, errors can be minimalised.

FIA regulations (https://www.fia.com/file/74363/download) require corresponding induction loops are fitted at the finish line, pit entry and exit, at least two intermediate points (sectors) and possibly safety car lines with

Additionally there is an optical beam across the track and high speed video cameras capable of recording to 1/1000th second.

[anonymous-user]

Thank you AndrewCliffe for the detailed information.

I am still curious how results of ms can be measured and what is to prevent teams cheating. Imagine I find a transponder that has a range of 1Metre and yours has a range of only 10cm then my car can be up to 90cm behind yours and still register first??

TIA

[carl_w]

MikeStroud said:

I am still curious how results of ms can be measured and what is to prevent teams cheating. Imagine I find a transponder that has a range of 1Metre and yours has a range of only 10cm then my car can be up to 90cm behind yours and still register first??

TIA

The transponders are provided by the official timekeepers. I suspect if you're found to have mucked about with them the consequences will be serious.

[TheDeuce]

MikeStroud said:

Thank you AndrewCliffe for the detailed information.

I am still curious how results of ms can be measured and what is to prevent teams cheating. Imagine I find a transponder that has a range of 1Metre and yours has a range of only 10cm then my car can be up to 90cm behind yours and still register first??

TIA

Surely the transponder is configured to report upon the point is passes the centre of the loop, ie where the signal peaks as it passes over. Same principal as using a cable/pipe decector, where regardless of range, the signal is strongest across the centre line.

[anonymous-user]

TheDeuce said:

MikeStroud said:

Thank you AndrewCliffe for the detailed information.

I am still curious how results of ms can be measured and what is to prevent teams cheating. Imagine I find a transponder that has a range of 1Metre and yours has a range of only 10cm then my car can be up to 90cm behind yours and still register first??

TIA

Surely the transponder is configured to report upon the point is passes the centre of the loop, ie where the signal peaks as it passes over. Same principal as using a cable/pipe decector, where regardless of range, the signal is strongest across the centre line.

That may be it. At 200kmph a car will travel 6cm in 1ms. I guess that the transponder signal at the loop peaks and falls in a smaller distance than that hence the high level of accuracy they can get.

Thanks all.

[andrewcliffe]

With two transponders on the car maybe they are able to resolve out some potential inaccuracies, as the exact distance between the two are known.

[Gary29]

When I used to race RC cars, we always used to try and locate the transponder as near to the front of the car as possible.

If yours was at the back of the car and your competitors was at the front, it would be possible to be first across the line (marginally) but still finish second on the timing screen.

Wouldn't be an issue in qualifying though.

Edited by Gary29 on Tuesday 7th January 08:36

[kambites]

TheDeuce said:

Surely the transponder is configured to report upon the point is passes the centre of the loop, ie where the signal peaks as it passes over. Same principal as using a cable/pipe decector, where regardless of range, the signal is strongest across the centre line.

I believe (I could be wrong!) the RFID chip transmits continuously while energised by the loop. The actual point of measurement is deemed to be the chronological mid-point between the transponder signal first being picked up and the signal vanishing as it moves out of the field and powers down again. Obviously this isn't strictly speaking 100% accurate unless the car is travelling at constant velocity, but it'll be bloody close and the same for all cars.

In terms of who actually wins a race (as opposed to fastest lap and qualifying times), if two transponders are picked up and disappear on the same polling cycle they will resort to high speed cameras to determine who crossed the line first.

ETA: Another interesting point. People use the term "transponder" but it's as far as I know it's incorrect. I think F1 cars use RFID chips (which are dumb and powered by the coil embedded in the track) not transponders (which are active and require a local power source).

Edited by kambites on Tuesday 7th January 09:01

[TheDeuce]

kambites said:

I believe (I could be wrong!) the RFID chip transmits continuously while energised by the loop. The actual point of measurement is deemed to be the chronological mid-point between the transponder signal first being picked up and the signal vanishing as it moves out of the field and powers down again. Obviously this isn't strictly speaking 100% accurate unless the car is travelling at constant velocity, but it'll be bloody close and the same for all cars.

ETA: Another interesting point. People use the term "transponder" but it's as far as I know it's incorrect. I think F1 cars use RFID chips (which are dumb and powered by the coil embedded in the track) not transponders (which are active and require a local power source).

Edited by kambites on Tuesday 7th January 09:01

The induction loop in the track will be fairly narrow too, so as you say, the midpoint is established in a fairly basic but really pretty accurate way, and in any case the entire field of measurement itself is very small to begin with.

An RFID actually is a type of transponder, the term transponder itself is very broad and covers endless transmit-respond technologies and levels of functionality. I only know that because I work in automation sometimes and the signal engineers tend to roll their eyes if we refer to such things by a generic catch all name 'transponder'... But without their depth of knowledge I'd probably use the wrong term half the time if I tried to be any more specific

[kambites]

Maybe the bredth of the definition depends on the exact field. Or just the engineer in quesiton. Where I've seen it used it explicitly refers to a device which actively monitors for an external signal to be transmitted to it, then responds with a code of its own rather than a device which continuously transmits when powered. Kind of irrelevant anyway.

Bit off-topic anyway.

[anonymous-user]

kambites said:

I believe (I could be wrong!) the RFID chip transmits continuously while energised by the loop. The actual point of measurement is deemed to be the chronological mid-point between the transponder signal first being picked up and the signal vanishing as it moves out of the field and powers down again. Obviously this isn't strictly speaking 100% accurate unless the car is travelling at constant velocity, but it'll be bloody close and the same for all cars.

In terms of who actually wins a race (as opposed to fastest lap and qualifying times), if two transponders are picked up and disappear on the same polling cycle they will resort to high speed cameras to determine who crossed the line first.

ETA: Another interesting point. People use the term "transponder" but it's as far as I know it's incorrect. I think F1 cars use RFID chips (which are dumb and powered by the coil embedded in the track) not transponders (which are active and require a local power source).

Edited by kambites on Tuesday 7th January 09:01

OK thanks. I liked the "peak" idea someone suggested but this "mid-point" idea also makes sense as even if the "transponders" have different ranges so one is picked up first, the mid point will remove that advantage.

[mcdjl]

Gary29 said:

When I used to race RC cars, we always used to try and locate the transponder as near to the front of the car as possible.

If yours was at the back of the car and your competitors was at the front, it would be possible to be first across the line (marginally) but still finish second on the timing screen.

Wouldn't be an issue in qualifying though.

Edited by Gary29 on Tuesday 7th January 08:36

In qualifying you'd have to move the transponders from the back of the car to the front for it to be an issue. Or make it so that as you start a fying lap the range is short and then long as you finish it.....Mandating where transponders its eliminates that though.

[Mr Pointy]

Back in the old days Bernie brought in MST (if I recall correctly) in to take over the F1 timing & then Borged some of them into his organisation so he could have complete control. Just another element he found a way to charge someone for!

They used to have manual timing for every session as well in case the electronics went down & it's quite an art: there were a little flock of timekeepers who would be employed to attend each race. I'm not sure if they still run the manual timing these days or if they just rely on backup electronic systems.