Using Sensors to detect Auto/Align Line

[Bucephalus]

Hi All,

We are a rookie FRC team from Australia. We attempted to search for the answer to this question, but were not successful! (Apologies if we missed something)

We would like to detect crossing the Auto-Line or Alignment-Line during the Autonomous period. We are currently planning to purchase sensors that detect reflected IR light - the gaffer taper being different to the carpet.

Can anyone confirm that we are on the right track? Are there any better approaches?

Thanks for the help,

Regards,
Team 5985

[cgmv123]

I think you're on the right track. Just note that:

1. The tape that marks the AUTO LINE and the ALIGNMENT LINE is green in color. There may not be enough contrast with the carpet (also green in color) to reliably detect.
2. Lighting on the field will vary from event to event which may throw off your readings. There is an opportunity at each event to calibrate sensors to account for different lighting conditions.

[Bob Steele]

Does anyone know which green gaffer's tape we are to use? Or have a source for some of the new green carpet?

I would think it would be this:
http://www.amazon.com/Polyken-510-Ru...n+gaffers+tape

But there is also this color:

http://www.amazon.com/Pro-FLGRN250-G...n+gaffers+tape
I would think that this would be Neon Green but it is not specified as such.

It would be nice to get a piece of the carpet too... I don't believe we have used this before...

someone correct me if I am wrong please.
I don't remember green carpet..

[Bucephalus]

Thanks for the response!

We were aware of the line/field colour similarities, but weren't sure if these were "usual" conditions or something new for 2016.

Are teams supposed to be able to track the auto/align line, or are the lines just meant to be used for field setup?

We realise these are rookie questions, so we thank you for your patience!

Regards,
5985

[sraque]

Originally Posted by Bucephalus

We realise these are rookie questions, so we thank you for your patience!

Don't worry, not just a rookie question. We have had similar questions for this year. Game video says line in the courtyard is for alignment, but it is the same color as the carpet? I don't get it. To me that is just a mess-up in the field design. We came to the conclusion to ignore it rather than hunt down an actual carpet sample, get the tape, and then do some testing to determine what sensor values work...and all this with the risk that it would be dodgy at best.

I'll add it to the choice of boulder. If they had chosen the 8 inch diameter one, we could get them easily and cheaply, and US teams could have walked into Wal-Mart and bought them.

[The Doctor]

Our idea was to use an infrared reflection sensor. We're not sure if the lines are shiny though, does anyone know?

[wt200999]

A similar discussion here http://www.chiefdelphi.com/forums/sh....php?p=1542906

[maxnz]

Originally Posted by Bob Steele

Or have a source for some of the new green carpet?

It would be nice to get a piece of the carpet too... I don't believe we have used this before...

According to the manual, this is the carpet they are using: https://shawfloors.com/flooring/carp...10/scotch-pine