Turrets and cameras

[Luke Pike]

I have been able to get the camera working pretty well in two locations by adjusting the brightness.

At our playing field there are long fluorescent lights attached directly to the white ceiling. As you can imagine, this lighting is very bad, it causes whatever is in the foreground to bleed into the ceiling where a light is. However, I was able to get it working by setting the camera's brightness to 25. It was here that we shot our promotional video.

At our shop, there isn't as much light, so a brightness of 30 works well. Towards the end of build season I would work all day in the shop and around 3:00 PM the sunlight would shine through a window and blind the camera. A piece of cardboard over the window was enough to get it working again, but once the sun was low enough, the light was to low and I would have to take the cardboard off to make the camera work again! In other words, variable light is bad for the camera.

Good luck to all teams with their camera calibration!

[Paul Gehman]

Originally Posted by Rich Kressly

Attached are the cam values we used from calibrating with Greg from NI at lunch on Thurs. to score in autonomous in DC...the lunchtime calibration on Thursday is what allowed us to consistently track and score on targets in auto.

I am going to expand on comments from Team 1712 Mentor Rick Kressly, Sean Lavery, and National Instrument's Greg McKaskle, as posted above.

Greg/NI was available during lunch on Thursday, at the DC Regional, to assist Teams who wanted to calibrate their cameras, and adjust parameters in their softwares. We jumped at the opportunity to field test our camera settings and vision VIs (LabView). For Team 1712, that meant varying key settings in our implementation of the "two-color camera servo" example code. Read Greg's reply carefully and take a good look at his posted images and masks.

The field's lighting at DC was much brighter than the lighting back at Lower Merion High School, or in the DC Regional pit areas or on the practice field. For an extreme example of what the bright lights could do to a target, as viewed by the camera and software, look at Greg's image labeled "Default West" - read front glare.

On a related point, the DC field's lighting consisted of 2 high-mounted banks of can lights aligned with the long sides of the Arena, aka the Crater. This could create bright sides on the pink/green target - read side-glare - leaving a "shadow" down the center. For a somewhat similar mask to what we were experiencing in DC initially, albeit a more extreme example, look at Greg's image labeled "Default SW Corner mask."

Prior to lunch on Thursday - Team 1712's first autonomous run indicated that the camera/two-color tracking software locked on nothing - even when targets were directly in front. On analysis = green was never recognized - in essence, our hue settings were too high. With Greg's general guidance, and the sample pictures similar to what was posted above, Team 1712's coding crew talked over our proposed adjustments, played with lowering the brightness value, lowering the green hue's upper and lower range values, adjusted the lower red saturation value, and adjusted the servo speed/ranges. All this activity took one busy lunch hour. Part of Team 1712 then spent the rest of Thursday watching the Dawgma Team's robot "Alice" begin to hone in during the next several matches, as we tested and refined our approach. Tom Line, also in this thread, lists the key tuning steps that Team 1712 also utilized to refine "Alice's" vision.

I can definitely agree with Greg and Rich on a couple of interesting issues. When "Alice's" camera stared at the black background behind the big-screen TV - we believe the camera adjusted enough to void out one Thursday match. And what eventually worked for "Alice" in autonomous mode on Friday and Saturday might not apply elsewhere. Best advice -- grab a hold of any available time to test on the real field. Using Greg's/NI's snapshots of targets and masks for ideas, and understanding how the brighter lights, the darker backgrounds, and the software settings were interacting and affecting "Alice" in DC -- we eventually developed better and better masks for "Alice" to use in tracking and scoring in autonomous mode.

[Doug Leppard]

Originally Posted by Paul Gehman

we eventually developed better and better masks for "Alice" to use in tracking and scoring in autonomous mode.

Did you score int autonomous mode in official games? If so how often and what precentage of the balls went in?

[Vikesrock]

Originally Posted by Doug Leppard

Did you score int autonomous mode in official games? If so how often and what precentage of the balls went in?

They did, quite a few times.

Here's a quote from Sean in another thread

Originally Posted by Lil' Lavery

1712 scored four times in auto in DC. Three times it was 7/7, and the fourth it was 3/7. Two or three other occasions the bot would line up but not score, and 1712 would dump in the first second or two of tele-op.

[Greg McKaskle]

I saw a handful of video posts on the general forum about autonomous scoring. The attached video will give you an idea of the glare and how much the camera is shifting the exposure to keep colors from over saturating. It also shows why it is good to not overreact when a frame doesn't contain the target. Glare, a hit, all sorts of things can cause small glitches.

http://www.youtube.com/watch?v=xJnq-...eature=channel

Greg McKaskle

[Phil Ross]

Originally Posted by Michael Corsetto

Are they allowing teams to go on the field during breaks (primarily lunch) to calibrate their camera with field conditions? I remember doing that at a number of regionals in 2006 and 2007, it was very helpful.

yes, they are allowing team to do that during lunch break on thursday. My main concern is for teams using the camera in ATL. Since the Georgia dome has partially naturally lighting the camera may need to be calibrated more than once. Im concerned that there wont be enough time with all the matches being run in each devision.

Then, if a team in the Einstein division is using a camera they will need to recalibrate again. Einstein has different track lighting on it than all the others have. Hopefully the NI people and the other teams in ATL will figure something out.

[Flyin' Axe]

What we did was we got on the field, took some screen shots and determined an acceptable range of the HSL values using Paint.

But then our operator says he barely uses our camera track. So I can't really say that it works.

Good luck!