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#31
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Re: Separate Powered Flashlights?
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A few years ago, in a non-FIRST competition, the organizers were asked multiple times if "all power must turn off when Big Red Button is pressed" meant that "no electrons are flowing at all including in computing devices". The answer, multiple times, was "yes, that's what it means". My team spent a lot of time getting our onboard laptop to run off one of the two onboard 12V batteries (IIRC, that was our method for complying with the rule--meant removing the battery). Anybody want to guess why the rule was changed at competition to allow the computers to run after the button press? At least FIRST doesn't do that very often... |
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#32
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Re: Separate Powered Flashlights?
As a referee, I've seen several robots with light rings that made it uncomfortable to look at the robot. Is this something that should be sent back for re-inspection even if it doesn't fall under the "military grade or self-defense" rubric?
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#33
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Re: Separate Powered Flashlights?
R07M. e.g. means "for example" (as opposed to i.e., "that is"). So if they're illuminated when they're not targeting something, you probably want to talk to your Head Ref about talking to the LRI.
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#34
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Re: Separate Powered Flashlights?
I'm guessing most rookies doing vision are going to have a problem if that becomes a requirement given that spikes aren't made anymore.
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#35
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Re: Separate Powered Flashlights?
Sorry I haven't had time to check in on CD for a few days. Work got in the way...
In no particular order, FRC chose the wording "one battery" as a engineering challenge. I started in FRC when we were still using battery powered drills for drive and each drill used it's own battery. When FRC moved to the current battery (which BTW has a very good energy density) laptops were prohibitively expensive items to put on robots as well as video cameras. As the cost of these items fell, FRC changed rules to allow these devices with integral batteries to be used if the battery was not also connected to robot systems like drive or control. They still needed to be included in robot weight as they are now. LED rings can be "super bright" or my term "mini-sun" and be objectionable. However, the majority of teams using LEDs control them so they are only illuminated when needed. "Self defense" flashlights are by definition "blinding" illumination. We had a lot of feedback from mentors and from UL that these devices put our teams and volunteers at risk of temporary and/or permanent eye damage. And many of those people pointed at a rather lengthy document highlighting the risks, recommendations and support for not using these devices in certain applications. The rule is a response to those who helped point us in the direction of safety. Many people who simply read about "super capacitors" and think they are a way to circumnavigate the rules are surprised when the capacitor doesn't perform as expected. Large capacitors have an internal resistance that does not allow them to supply large amounts of current over even a few seconds. They take significant energy and time to charge and are meant to supply energy for short duration dips in voltage or to supply a voltage to a circuit that requires very little current. (in the nano-ampere range) The equations for charge and discharge of capacitors are all that is needed to analyze if a super cap will work in your application. |
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#36
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Re: Separate Powered Flashlights?
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But hey instead of clarifying the ambiguous wording, they've said that if the COTS computing device is designed to use a battery then it's fair game so we'll see about that ![]() And I agree about super capacitors. They aren't any different than regular capacitors really. Our robot was described as a literal "bomb" last year because of our temporary use of them but I don't think it posed any more of a threat than anything else I've seen on robots. I have hopes that FIRST will see the light and clarify the ruling next year or sometime soon but until then we'll keep trying new stuff. They fixed the scanning LIDAR stuff after a couple years: http://www.firstinspires.org/sites/d...0_09_24_41.pdf Q71 was asked by Team 900 that year. As usual, we were told to scram. They are now legal though... speaking of... have an announcement to make later. |
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#37
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Re: Separate Powered Flashlights?
Marshall,
Can you please specify what you think is ambiguous in the rule so we can speak from a common position? |
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#38
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Re: Separate Powered Flashlights?
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So what characteristic or characteristics make a battery "essential to completeness" for a COTS computing device? Is it enough to have a device that is merely designed to accept a battery and has a battery slot/containment/attachment area? Does it have to be sold with the battery? If I can replace the battery for a laptop then why can't I add a battery to a raspberry pi? What's the difference in engineering terms? What about a circuit board with some inputs labeled "battery"? Does that count as having a COTS device that has an integral battery? What engineering challenge is FIRST proposing teams solve by making a team with a raspberry pi engineer a bulletproof system to keep their pi from needing to be reflashed from corruption but yet a team who can put a laptop on the robot doesn't have to worry about any of that? What is the point in this? They want teams with better vision systems and better autonomous (I had a nice chat about it with Don and some folks from IBM last year) so why not allow USB battery packs for COTS devices? EDIT: Also want to point out that while you can't use a USB battery pack for your Pi, you can gut a laptop down to nothing and use it to power a USB port that you can run your Pi off of. WTF?!?! (Where's The Flashlight?) Last edited by marshall : 24-01-2017 at 12:03. |
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#39
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Re: Separate Powered Flashlights?
Marshall,
I agree with you. I think that those questions need answering and that the definition of when non-robot batteries is something that needs to be revised, specified, and re-thought. But for now, I think that the solution FIRST will be going with is relying on LRIs to make the distinction. Yes, this can lead to a robot being legal at one event and not at the next. Yes, this is not a good solution. Yes, something should be done to remedy this. But I have trouble believing that those upstairs will make this distinction this season. My interpretation of the rule on whether it is integral or not are to ask the following questions: Can I power this device without using it's battery and without plugging it into the wall? A cellphone that requires the battery to be inserted to run would be allowed to use its battery. A drill where you can just power the terminals with a motor controller would not. If it is possible to power without it's battery or plugging it into a wall, is it safe to do so? I cannot think of any examples where it would not be safe but still possible off the top of my head but I'm sure one exists. A Raspberry Pi can be powered without a battery pack very easily and it is perfectly safe. So in this case you would have to power it with the robot battery. I know, it doesn't solve everything. Even though the manual does not use these words here, it appears that they expect a "reasonably astute observer" to be able to say whether or not it is integral. |
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#40
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Re: Separate Powered Flashlights?
That was a good reminder for me, I forgot they stopped making those. Even so, you are allowed to hook an LED ring up to a Spark, right? Or an I wrong?
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#41
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Re: Separate Powered Flashlights?
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Sorry for going off-topic. |
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#42
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Re: Separate Powered Flashlights?
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#43
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Re: Separate Powered Flashlights?
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What you could do is put a resistor in series with the LED ring to abate the current issue. |
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#44
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Re: Separate Powered Flashlights?
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Last edited by pilleya : 25-01-2017 at 08:38. |
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#45
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Re: Separate Powered Flashlights?
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