Transponders

[Fromafar]

  On 4/6/2024 at 2:08 PM, eric i said:

I can't see any infastructure by the track, is it it buried under the track?

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All I know is they are being used,not sure of the technical details.

[IanBrannan]

  On 4/6/2024 at 2:08 PM, eric i said:

I can't see any infastructure by the track, is it it buried under the track?

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The sensors are buried under the track, the only thing to see is the transponder itself on the bikes mounted on the handlebars I think 

[Dickie Head]

My understanding is that whilst the tracks have installed the equipment, there remains a technical difficulty whereby the individual transponders fitted to bikes are not yet able to fully communicate with the recording hub.

Similarly the automated tape release system that was supposed to be introduced this year is not yet operational.

A reliable source indicated that, rather than invest in the tried and tested GP system, the BSPL bought a cheaper alternative that has proved unreliable and negotiations between both parties to find a solution are ongoing.

[IainB]

  On 4/6/2024 at 5:01 PM, Dickie Head said:

My understanding is that whilst the tracks have installed the equipment, there remains a technical difficulty whereby the individual transponders fitted to bikes are not yet able to fully communicate with the recording hub.

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That makes sense based on heat 5 at Scunny last night where to me at least (and Lambert) it seemed that he got 2nd only for it to be given to Jason Edwards 

Schlein made a good point though saying he hoped the riders involved had remembered to attach their transponders to their bikes... who checks this before each race? The machine examiner?

[IainB]

  On 4/6/2024 at 5:01 PM, Dickie Head said:

A reliable source indicated that, rather than invest in the tried and tested GP system, the BSPL bought a cheaper alternative that has proved unreliable

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Believably unbelievable... chuck them on the scrap heap along with the GTR's and the Anals () tyres 

[eric i]

  On 4/6/2024 at 6:44 PM, iainb said:

That makes sense based on heat 5 at Scunny last night where to me at least (and Lambert) it seemed that he got 2nd only for it to be given to Jason Edwards 

Schlein made a good point though saying he hoped the riders involved had remembered to attach their transponders to their bikes... who checks this before each race? The machine examiner?

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Same here I thought Lambert got it, it seemed to take the ref a while to decide, I am not sure if he was watching a replay.

  On 4/6/2024 at 6:47 PM, iainb said:

Believably unbelievable... chuck them on the scrap heap along with the GTR's and the Anals () tyres 

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There was an inevitability about them not working, Britsh speedway struggles to get a set of tapes and microphone to work never mind transponders.

[Chris116]

How speedway can fail with transponders when many of the tracks run stock cars who have been using transponders for many years with very few problems. System works for 20 plus cars but can't manage 4 bikes. It must be a totally rubbish system or the transponders are fixed too high on the bikes. On the cars they have strict rules about where they are fixed including how high above the track.

[Humphrey Appleby]

  On 4/6/2024 at 10:22 PM, Chris116 said:

How speedway can fail with transponders when many of the tracks run stock cars who have been using transponders for many years with very few problems. System works for 20 plus cars but can't manage 4 bikes. It must be a totally rubbish system or the transponders are fixed too high on the bikes. On the cars they have strict rules about where they are fixed including how high above the track.

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Looking at the SCB website, they look to be using the MyLaps TR2 car/bike transponder which is generally reliable and widely used in motorsport. However, they appear to advise to mount them horizontally on the handlebars when in fact they should mounted in an upright orientation as the magnetic wave travels downwards. 

The transponders are also detected by a wiring loop in the track, which is normally no more than 2 or 3 cms under the surface. I'd guess with dirt tracks you need to put them a fair bit deeper as the top surface will gradually wear or be graded away over the course of a meeting and expose the loop (which will then get caught on something).

For motocross it's recommended to put them in a plastic pipe about a 30 cms down, but the maximum recommended range of a MyLaps bike transponder is about 1.2 metres, so if the transponder is not pointed in an optimal position, then I'd imagine this will be beyond the limit of the transponder range and why they're not working reliably. 

It's a problem that should be very easy to identify as the timekeeping system should record the number of transponder hits as it crosses the timing loop in the track. If you're seeing little or no hits, then either the transponders are 1) badly positioned or 2) low on charge (or more rarely faulty), 3) there's a break somewhere in the timing loop, 4) excessive noise on the loop (often due to poor shielding), or 5) the timing loop is simply too far below the surface. My money would be on a combination of 1) and 5). 

Edited April 8, 2024 by Humphrey Appleby

[Humphrey Appleby]

  On 4/6/2024 at 3:27 PM, IanBrannan said:

The sensors are buried under the track, the only thing to see is the transponder itself on the bikes mounted on the handlebars I think 

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A co-axial loop will be running under the finish line of the track which is connected back to a decoder (which could be trackside or up in race control). The transponder sends out an magnetic wave with an encoded ID number, which is picked up by the loop through induction as it passes over it, and sent to the decoder which records and timestamps each passing. The decoder passes that to timekeeping software running on a PC, which translates that data into the competitors names, race position and times and can relay that to live timing. 

In fact, you can have multiple loops around a track (often 3 + pit-in/out in car racing) - each connected to a separate decoder - which all send the data back to the timekeeping computer (via a dedicated server that aggregates the data) 

 

Edited April 8, 2024 by Humphrey Appleby

[Humphrey Appleby]

  On 4/6/2024 at 6:44 PM, iainb said:

That makes sense based on heat 5 at Scunny last night where to me at least (and Lambert) it seemed that he got 2nd only for it to be given to Jason Edwards 

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Transponders should really be supplemented with an optical timing beam which is broken when the front wheel of the bike crosses the line. There will often some slight difference in the positioning and orientation of each transponder, so they're not infallible when it comes to close finishes. 

Speedway only involves four bikes so you can probably do without the optical beam provided someone is watching the finish line with their own eyes and can overrule the transponder system. Happens all the time and it's perfectly legitimate to adjust transponder times by the odd hundredth of a second where you can clearly judge the result by eye. In fact, we also use a finish line camera so can roll back and review the footage if it's a close finish.

Edited April 8, 2024 by Humphrey Appleby

[IainB]

Is there anywhere we can view the data from these transponders?

[Fortythirtyeight]

  On 4/8/2024 at 6:48 PM, iainb said:

Is there anywhere we can view the data from these transponders?

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No.

[Chris116]

  On 4/8/2024 at 6:48 PM, iainb said:

Is there anywhere we can view the data from these transponders?

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The stock car promotions, as well as many kart and Motocross tracks post the results on Speedhive but to date speedway has not done so.