Re: Full Court Target Detection
 

I didn't order the equipment, so I don't have the specifics handy. But, in general, it's just a regular infrared light designed to be used with a security camera. I think it cost around $30 or so. It's not a ring, so it is mounted next to the camera. Then we bought an infrared filter that normally would connect to a camera lens. Currently that's just taped over the Axis camera lens. So, nothing too special.

Re: Full Court Target Detection
 

Thanks for the help. I think we will give this a try.

Re: Full Court Target Detection
 

We found last year that color tracking worked wonderfully when:

1. we overexposed the image and then froze the setting

2. also froze the white balance

The first one helps to keep the camera from going into saturation because of the brightness of the reflected light. This would cause the camera to perceive a color shift.

The second is absolutely essential when it comes to changing lighting conditions. By keeping the white balance fixed, we didn't once have to calibrate the camera at an event or even at practice. We played indoors in fluorescent lights, near sodium lights and even outdoors in daylight in a covered setting and the image processing picked out the targets every time.

We ended up not using tracking in the end only because our driver was amazing (when using our patented photon cannon) and we didn't have a turret system. Creating a controller to center the whole robot proved too daunting a task. A linear system would have been much easier to control.

- Bryce

P.S. That being said, last year we used the "Tools -> Create C Code..." option in Vision Assistant after following the Vision White Paper guidelines. We then stripped out all the extra generic code that the generator created. We ended up with nice streamlined c functions that work just like the vision assistant but didn't have all the gross overhead that the code generator created.

Re: Full Court Target Detection
 

We will have to try the white balance. Is there any rule against that lights you can put on your robot

Re: Full Court Target Detection
 

Only that they can't be a laser above class 1, or so bright as to be blinding to the other team and impede their gameplay.

Re: Full Court Target Detection
 

In response to good LED lighting, FIRST recommends using this LED ring that goes around the camera lens. I prefer using a bright color like green due to the fact that it will give off a more clear reflection.
LED Angel Eye Headlight Accent Lights

Re: Full Court Target Detection
 

Hello we are having some difficulties as to how we wire the led ring for the camera into the cRio, and how to mount it on the camera itself, any help would be greatly appreciated.

Re: Full Court Target Detection
 

Why do you want to wire it to the cRIO?

You can power it directly from the battery (via a 20A circuit on the Power Distribution Board) if you want it to be on all the time. You can wire it to a Spike relay if you want to be able to turn it on and off under program control.

We used double-sided foam tape.

Re: Full Court Target Detection
 

And to add onto that, what are your current BinaryImage filters and resolutions?

Re: Full Court Target Detection
 

We are trying IR but are having some problems. How did you set your lights up

Re: Full Court Target Detection
 

Look into using the Kinect for next year if you haven't already been exploring it. The sensor capability is pretty impressive. We have been testing the Kinect with a nano-ITX form factor computer.

In outdoor full-sun tests, we were able to get approximately 60' recognition using a flashlight beamed on the reflective tape. I do not recollect if this was using the IR or electro-optical sensor. We were using a circular polarizer to cut down reflected light as well.

Our mentor lead is out this week, but I can get more information when he returns.

Last year, we used a purple (red + blue) LED light source to make a custom color for our 3D vision system. In LogoMotion, we learned that green was not a good color choice due to the field scoring projection screen had green squares behind the pegs/goal height. This green would actually cause the single-camera vision system to go off target.

Additionally, one of the major hurdles with vision processing is available field bandwidth. You may need to operate at very low framerates and resolution, so keep that in mind when designing your system. This is one of the issues that has lead us to pursue on-robot vision targeting using the Kinect.

Re: Full Court Target Detection
 

Thanks for your help. We have a system that seems to work well at short distance but are having lots of trouble getting long distance. The only way we can get good reflectivity at long distance is with a bright LED flash light. Only problem with this is we are not sure having such a bright light is legal. Does anyone know if having a very bright flashlight is legal?

Re: Full Court Target Detection
 

Don't disrupt gameplay or make an unsafe condition.


I haven't had any experience testing color photography filters on the optics of the Axis to limit the wavelength of light they can pick up. I'm also not sure if the Axis has a built-in IR filter like most CCD/CMOS cameras.

I would suggest you look at making a custom LED emitter as well.

Re: Full Court Target Detection
 

we have made are own LED emitter only problem is they are very bright and not sure if they are legal

Re: Full Court Target Detection
 

Look at it from a distance of a few feet, if it bothers your vision, you are probably in violation of R08. A lot of light is not required, just enough to overcome a set threshold.