Illegal?

[Gdeaver]

The output of most ccf's under most circumstances and most people would cause an unpleasant shock. However, under the right circumstances and the right person, that level of current and voltage could kill. Yes, it is dangerous. If First bans them then there is no risk. If they are allowed then what is the probability or risk of a serious incident. What would be the cost and impact of an incident. CCF's are not necessary to the primary purpose of the robot. Does allowing them present acceptable risk? With the American legal system it's easy to just say no.
UV light does affect the camera. We noticed in 2006 with our tests that the camera had problems with HID lighting but was fine with fluorescents. A UV blocking sun glass lens helped allot. If UV LED's are allowed then a bank of UV LED's could be a great defensive tactic but then there is the GP aspect of First.

[Dave Flowerday]

If the CCF lamps pose as much danger as everyone here is claiming, then you all should be petitioning FIRST to disallow them and remove them from the KOP.

I don't understand how anyone can claim that they are disallowed for robot use due to safety concerns when FIRST provides them in the KOP and even asks teams to wire them up themselves.

I'm not trying to argue whether they're dangerous or not - all I'm saying is that if people think they are dangerous then there needs to be a rule about it (and that's what you should be working on). Having individual inspectors decide on their own that they don't like CCFs and therefore disallowing them is not the appropriate way to handle this. Think about it in government terms - inspectors are the law enforcement. They are not supposed to make up rules (bad things happen when the police make up their own laws). The GDC is the legislative and judicial branch, so if you think something needs to be a rule then go to them. A quick look at the past year or two with all the complaints of inconsistent reffing and inspecting shows us why it's important to have rule decisions originating from the top (the GDC) rather than the middle or bottom.

Nothing in the 2007 rules that I can see rules out the use of CCFs. The inverter for the CCFs is not a power source (it does not generate power - unplug it from the battery and tell me if you can keep the lights on). Stepping up voltage is not the same as a power source. Many, perhaps most, custom circuits do indeed step up voltage, as nearly every custom circuit I've seen uses an RS-232 driver chip which derives a higher voltage from a 5v supply.

Frankly I think the green lamps used by the camera are a more dangerous situation than CCFs on a robot. Walk through the pits sometime and tell me how many people you see standing on their toes holding up the green lights. Sometimes they're not even covered by the plastic lens. If a CCF breaks on a robot it's more likely to be when the robot is driving, and people usually aren't right next to the robot when it's driving. Again, my point is not that they aren't dangerous, but simply that if they are then a blanket rule should be made and the green lamps should go.

[Kingofl337]

I can't seem to find the exact company that we used this year but this is another company that carries the same products. We used 36" strips they are very bright and we definitely had to white material them to keep them legal as you would need sunglasses without it. The LED's are great as they take allot of abuse and keep working.

http://www.superbrightleds.com/light_bars.htm

We didn't use cold cathode tubes because we were worried about them breaking.

[dtengineering]

Excellent suggestion on the LED light bars. Our secret plan this year... if we had time... was to do a Canadian Flag in IR Leds.

No one would see it until it showed up in photos and on the big screen.

(If you want to see what I'm talking about, use your camera phone/digital camera/video camera to take a look at the LED on the IR remote control for your TV when you hold down a button on the remote. Its pretty cool...)

We ran into reality when we couldn't find a good source for cheap IR LED's, though. So if you know a good place to get 1,000 or so IR LEDs for less than 10 cents each, let me know.

Jason

P.S. This would not be likely to jam either the camera (at least not any more than the very bright lights that form part of the field set up, or the red and blue lights over the player stations) or other IR sensors, which tend to be tightly focussed and/or modulated.

[Al Skierkiewicz]

Originally Posted by Daniel_LaFleur

I guess we are just going to have to agree to disagree
TBH, First does a rather poor job of electronics safety on the robot. A cold cathode lamp should be fused (or non-resetable breaker,not a resetable breaker) with a 2 amp 12 volt (24 watt) or under fuse. The fact that any custom electronics must use at least a 20 amp resetable breaker (even if it's just driving an LED) leaves too much chance for injury.

Agreed and working on it.

Originally Posted by Daniel_LaFleur

Again, teams should design in safety and be able to explain the 'safety' features of their robot, not be dictated a 'one size fits all' answer.

There are some things that do need to fit under an umbrella. I have discussed certain items with a few people I know at UL and in order for this device to be considered safe it must be contained inside a housing, like the enclosure specified for the light source in the KOP and be electrically protected (fused as you have pointed out). My concern is that power supplied by the main battery and fuse panel is on until the main breaker is opened. Often this does not occur until after the robot is carried off the field.

Originally Posted by Daniel_LaFleur

What you are saying is absolutely true, but there are 2 things that you are missing.

1> The 'super bright' LED averages around 2000-3000mcd in it's wavelength. At a distance beyond 6" (due to exponential energy loss for didtance) this does not have the luminecence to saturate most CCD arrays.
2> CCD color cameras (like the CMU camera) have 3 CCD elements per pixel. Each element is for 1 of the primary (Red, Green, Blue) color bands of light. Since the target lamp is fairly close to (#00FF00) process green, as long as you avoid LEDs that emit a large portion of their energy in that wavelength you should not affect the Camera. Red (628 nm) and Blue (472 nm) LEDs are good, while White (broad spectrum) and Green (525 nm) would be bad.

Daniel, don't forget that the luminent intensity specification is measured at 1 meter in the center of the eye's normal range (about 550 nM). White LEDs do have a broad peak in this range that is less than half as intense as the sharp peak at 470 nM. So even accounting for the inverse square law at 2 meters, the source at 470nM is still very bright. Obviously the further away the object is from the camera, the less effect it will have on the camera system as a smaller region of the pickup is illuminated. Remember that the pixel size for this camera is 8x9 micro meters and the entire image area is only 3x2.5 mm.
Now for further discussion...Dave, I expressed an opinion on custom circuit voltage convertors earlier in this thread. +/- 15 volt power supplies are very different than 1200 volt unloaded power supplies. Although the GDC has stated that fluorescent light sources are allowable, the implementation, type and use of any light source is subject to inspection. I am stating a general opinion of CCFL light sources based on the device questioned at the beginning of this post. As to the use of any light source on a robot that might interfere with the camera vision system, the decision is generally a consensus of opinions from the head ref, Lead Inspector, FTA and any FIRST official present. The height of the light source in 2006 and 2007 was less likely to be influenced by robot color or lighting due to the height of the target. (robot vision design should have prevented the camera from seeking a light source below 6 feet.) In 2005, the vision system was looking at the floor and that made inspections for interference a much more difficult task. As to good electrical design in this case, a 20 amp breaker to protect the wiring between the breaker panel and the insulated enclosure followed by a 1 amp, fast blow, non-resettable, fuse inside the enclosure would, in my opinion, be an appropriate method of safe CCFL/Inverter implementation.

[Jessica Boucher]

[quote=dtengineering;630971]Excellent suggestion on the LED light bars. Our secret plan this year... if we had time... was to do a Canadian Flag in IR Leds.

No one would see it until it showed up in photos and on the big screen.
/QUOTE]

We still get people oohing and ahhing over it. Moe from 88, after seeing it for the first time, put it best:
Me: "So when it lights up, we know we can get the tube..."
Moe: "And everyone knows you have a tube!"
Me: "Yeah. We didn't think of that until later."

We really scoured the aftermarket car decoration market for possibilities. Our runner up was electroluminescent wire, or EL wire, bunched within a clear lexan tube four bar linkage. However, the weight of the claw forced the tubes to bend to a point where the linkage couldn't reliably hold a position. Thus, the LEDs won out in the end.

[benhulett]

Alright....so I'll take the UV lamps out for sure, and I'll reconsider the CCFLs and maybe replace them with those LED light bars (not green or white). I'll leave the fans up to the inspectors....We're also putting a switch on the lights...so if they really don't want us to have LEDs in the match, we can just turn them off before the match correct? Or would they have to be completely removed? I also redesigned our box, and it will allow the indicators on the victors and RC to be completely visible.

[AV_guy007]

Originally Posted by dtengineering

Excellent suggestion on the LED light bars. Our secret plan this year... if we had time... was to do a Canadian Flag in IR Leds.

No one would see it until it showed up in photos and on the big screen.

(If you want to see what I'm talking about, use your camera phone/digital camera/video camera to take a look at the LED on the IR remote control for your TV when you hold down a button on the remote. Its pretty cool...)

We ran into reality when we couldn't find a good source for cheap IR LED's, though. So if you know a good place to get 1,000 or so IR LEDs for less than 10 cents each, let me know.

Jason

P.S. This would not be likely to jam either the camera (at least not any more than the very bright lights that form part of the field set up, or the red and blue lights over the player stations) or other IR sensors, which tend to be tightly focussed and/or modulated.

I am not 100% sure this would work properly, while many inexpensive consumer cameras do no block UV light most higher end consumer and professional cameras have a UV filter that will block out UV rays. I know this is true for my digital camera as well as many others.

very cool idea though

[FourPenguins]

Since the Original Poster's intent is to put his lights on the inside of a closed box, isn't CCD interference irrelevant?
Also, I agree that, for various reasons (mostly the broken glass/plastic from the tube) Cold Cathode Lights would not be a good idea on a competition bot. After the end of the year, soup it up for summer demos

[Cuog]

One thing with CCFLs breaking is that the small filament inside the tube is what is glass, the tube itself is acrylic and designed to contain the glass and electrical elements inside in the event of damage. As long as the CCFL is positioned securly and in a place that it will not take strong enough impacts to break the acrylic tube, and didn't interfere with other CMUcams, then its use on a competition bot would likely be legal*


*As I tell everyone I give advice on legality, I'm not an inspector nor am I am member of the GDC, so I would recommend strongly that next year you look at the rules then ask in the official Q&A to be sure of the legality of anything.

[popo308]

I know that the heat shrink is legal, we use it every year. The inspectors never have a problem, they just complain that we have sharp plastic edges and wiring mounts. As far as the lights if they aren't green or bright enough to irritate the drivers in the control station then they are legal. For more info on the legality of the lights go to the FRC sight and see the rules and specs area you should find anything you are looking for in that area. I like the electric box idea that people have brought up... Next year we are going to make extension for the tether and the program connectors on the RC that way we don't need to worry about the accessibility of the ports then we are going to mount a piece of lexan towards the outside of the robot so its easy to tether the robot or program it. We have found that to be the best way.

[benhulett]

1 more quick question! Are false floors illegal? I want to hide some of the wires with a false floor, do the wires have to be visible to the inspectors? Or just the contacts?

[Cuog]

I think that they are legal to have but if an inspector wants to get to the wires it needs to be easily accessible for them otherwise they may think that you are up to something other than just hiding your wiring and may not pass your bot at inspection.

[Billfred]

Originally Posted by benhulett

1 more quick question! Are false floors illegal? I want to hide some of the wires with a false floor, do the wires have to be visible to the inspectors? Or just the contacts?

I would be hesitant to pass a robot whose wiring I couldn't see. Now, if you can remove a panel for inspection (and repair, don't forget repair), you'll generally be fine.