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Lapcounting

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dralphs
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Lapcounting

Post by dralphs » Sun Feb 07, 2016 10:39 pm

Hi all

This afternoon in our Scout Hut i ran a few tests on the large mat and the timing system so try and work out why we dropped laps at Curborough.

I laid out the map and checked continuity of the loops etc - no fault found.
Then tested by waving a tag over - again no fault found.

i then set up a pulley system over the mat with a loop of cord driven by a battery drill. It was about 30cm above the mat. Attached a single tag, black face forward and ran it over the mat at full speed. Tag read ok every time irrespective of direction (black or blue forward).

However if the tag was put on sideways it failed to be read no matter how slow or how low it was over the mat, so tags must have black or blue facing direction of travel.

I then tried multiple tags spaced about 5cm apart - it read all of them without problem.

Finally i added another tag taped to one of the others and the reader only read one of the pair - so is this our problem?

Going through all the appendices i have checked that we are reading the PID for multiple simultaneous reading and we don't have a aux comms board so we should be able to read two tags together.

However if the appendix its does say

1st tag read 78ms - which given our 0.5m loop width is max 15 mph so i wonder if we need to widen the loop.
secondly it states for 30mph we could need a 2.5m wide loop
finally no single side should be 4m long

so i think we definitely need to reconfigure the loop to make it wider (relatively easy to do), but to make it shorter will need to go back to the old system of having the loop each do half the track. This can still be done but can give us a failure like we had at blackbushe 2014 when one side failed.

I won't be able to re-do the loop until next weekend as i need the scout hut to lay it out in and its used every night, so can we decide what we want done by Friday please.

Mark - could you email Identec and ask them about loop sizes are we ok with 7m long by 1.5m wide and can we overlap the loops separating in cable by 5cm or so or do we have to figure 8 the loop - see attached image for details.
Attachments
proposed mat.png
cr1-ms appendices.pdf
(428.98 KiB) Downloaded 18 times
Dave
Falcon Notnray Racing
www.yarntonscouts.org.uk

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AlanGoodman
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Re: Lapcounting

Post by AlanGoodman » Sun Feb 07, 2016 10:43 pm

Many thanks for all that effort Dave!!

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Re: Lapcounting

Post by Jes@GCRE » Mon Feb 08, 2016 8:38 am

Great work, thank you very much for doing this.

I have the "suitcase" in my porch at present ready when Phil wants to have a play with it :) .

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Mark Williams
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Re: Lapcounting

Post by Mark Williams » Mon Feb 08, 2016 11:22 am

"For 50km/h the loop should extend 2.5 metres along the road"

"No dimension of the loop (length or width) should be more than 4 metres"

Is this likely to require us to have a 2.6m wide Matt with perhaps figure of eight arrangements to achieve the track width for three cars?
Mark
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Re: Lapcounting

Post by dralphs » Mon Feb 08, 2016 11:46 am

Unfortunately in the appendices there is only the one statement

"For 50km/h the loop should extend 2.5 metres along the road"

There isn't a table or a graph to work out for other speeds. The only other info was the 78ms read time for first tag.

However if you calculate 2.5m in 78ms it isn't 50kmh its 112kmh

If we ignore that 78ms first read time and assume that loop length is linear proportion to speed

0.5m wide = 8mph what we currently have 2x 0.5 loops separated by 0.5m
1.0m wide = 14mph
1.5 = 23mph - fastest car at curborough

From observation i can see that the field extends out from the loop in either direction the same distance as the loop width so our 0.5m loop appears much wider (maybe even 1.5m) hence we can read the fast cars, but its probably on its limit hence the drops.

Depending on what Identec say i think we should try increasing the loop to a 1.5m staggered overlap and see how it performs. We can always fallback to the short mat.

If however we need to have separated loops then we will need two mats which will be a pita to transport/store and still can't be wider than 1.5m (i couldn't find rubber mat any wider) unless you join them together.
Dave
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www.yarntonscouts.org.uk

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Re: Lapcounting

Post by dralphs » Mon Feb 08, 2016 11:48 am

the calculator i was using for speed/distance

http://www.machinehead-software.co.uk/b ... _calc.html
Dave
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Re: Lapcounting

Post by Mark Williams » Mon Feb 08, 2016 1:59 pm

I like the idea of two 1.2 wide loops offset to the 1.5 width of the Matt.
Given the 4+ width of the track and dropped laps sometimes happen near side, middle or far side we could be forgiven in looking at purely the loop width to begin with. Are we also running on the basis we get loop one activation loop one reading or loop one activation loop two reading ie two narrow non concurrent loops are less effective?
Mark
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Re: Lapcounting

Post by dralphs » Mon Feb 08, 2016 6:29 pm

As far as the manual states, each loop should activate/read separately and then combine result into one output
Dave
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