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AustinShalit 06-02-2015 22:30

2015 FRC Inspection Checklist
 
As part of the 2/6/15 Team Update the Inspection Checklist was posted.

I have a few questions that I am hoping will be addressed in a new revision of the list.

Regarding Wire Colors, can green be added as an appropriate color for the return wires? This is the color of the return wire built into the Talon SRX and Victor SP. (This should also be added to the rules)

For Compressor Power, the inspection checklist says “under control of the robotRIO”. Is this different from the rules, “must still be controlled and powered by the ROBOT”?

During the Power On Check, Confirm Pneumatics Operation - Does this mean that we have to have the compressor start when the robot is first enabled? What if we do not want it to?

cgmv123 06-02-2015 22:41

Re: 2015 FRC Inspection Checklist
 
Quote:

Originally Posted by AustinShalit (Post 1439562)
Regarding Wire Colors, can green be added as an appropriate color for the return wires? This is the color of the return wire built into the Talon SRX and Victor SP.

R40 doesn't apply to wiring that doesn't have a constant polarity, like the outputs of speed controllers.

Quote:

For Compressor Power, the inspection checklist says “under control of the robotRIO”. Is this different from the rules, “must still be controlled and powered by the ROBOT”?
It's a combination of "must still be controlled and powered by the ROBOT", "The two wires from the pressure switch must be connected directly the pressure switch input of the PCM controlling the compressor or, if controlled using the roboRIO and a Spike relay, to the roboRIO." (R77-C), and "If connected to the roboRIO, the roboRIO must be programmed to sense the state of the switch and operate the relay module that powers the compressor to prevent over-pressuring the system." (R77-D).

Quote:

During the Power On Check, Confirm Pneumatics Operation - Does this mean that we have to have the compressor start when the robot is first enabled? What if we do not want it to?
Not sure about that one.

Jon Stratis 06-02-2015 23:09

Re: 2015 FRC Inspection Checklist
 
cgmv123 is right on with the first items.

Quote:

Originally Posted by AustinShalit (Post 1439562)
During the Power On Check, Confirm Pneumatics Operation - Does this mean that we have to have the compressor start when the robot is first enabled? What if we do not want it to?

For this one, please ask the Q&A. Something like "Can we have an operator-controlled stop for the compressor, so long as the compressor will only turn on in accordance with the normal operation of the pressure switch?"

This is something that is NOT at all clear in the rules. A few years ago, I came across a similar situation with a team at champs, and pulled one of the division LRI's over (I can't remember if it was Jeff or Al...). At that time, it was ruled legal as the pressure switch did still control the compressor from a safety perspective. You may not get this same ruling from every inspector or even LRI, though, as it's a very uncommon situation.

I will say, however, that I think the rules, as they are currently written, are probably leaning in your favor. R77-D states "If connected to the roboRIO, the roboRIO must be programmed to sense the state of the switch and operate the relay module that powers the compressor to prevent over-pressuring the system." It says nothing about turning the compressor on at any point, just about turning it off to prevent over pressuring the system. However, as I am not the LRI at your event, my opinion won't mean anything without an answer from the GDC on the Q&A!

EricH 06-02-2015 23:14

Re: 2015 FRC Inspection Checklist
 
Quote:

Originally Posted by AustinShalit (Post 1439562)
During the Power On Check, Confirm Pneumatics Operation - Does this mean that we have to have the compressor start when the robot is first enabled? What if we do not want it to?

That's a good one for Q&A. However, further reading of the checklist indicates that this is with no pressure in the system (AKA, empty pneumatics, which is a really really bad way to start the match in most cases). Starting with full tanks will keep the compressor from running. (There is also no rule stating that the compressor must be running when the robot is enabled--and for good reason, considering offboard compressors.)

Tristan Lall 07-02-2015 02:03

Re: 2015 FRC Inspection Checklist
 
Quote:

Originally Posted by Jon Stratis (Post 1439573)
For this one, please ask the Q&A. Something like "Can we have an operator-controlled stop for the compressor, so long as the compressor will only turn on in accordance with the normal operation of the pressure switch?"

This is something that is NOT at all clear in the rules. A few years ago, I came across a similar situation with a team at champs, and pulled one of the division LRI's over (I can't remember if it was Jeff or Al...). At that time, it was ruled legal as the pressure switch did still control the compressor from a safety perspective. You may not get this same ruling from every inspector or even LRI, though, as it's a very uncommon situation.

I will say, however, that I think the rules, as they are currently written, are probably leaning in your favor. R77-D states "If connected to the roboRIO, the roboRIO must be programmed to sense the state of the switch and operate the relay module that powers the compressor to prevent over-pressuring the system." It says nothing about turning the compressor on at any point, just about turning it off to prevent over pressuring the system. However, as I am not the LRI at your event, my opinion won't mean anything without an answer from the GDC on the Q&A!

Quote:

Originally Posted by EricH (Post 1439575)
That's a good one for Q&A. However, further reading of the checklist indicates that this is with no pressure in the system (AKA, empty pneumatics, which is a really really bad way to start the match in most cases). Starting with full tanks will keep the compressor from running. (There is also no rule stating that the compressor must be running when the robot is enabled--and for good reason, considering offboard compressors.)

I don't think that's a question that requires the Q&A—though if you think it would elicit more widespread understanding, go ahead. The past and present rules say nothing specific about when the compressor may or must start, only when it must not start (when at risk of "over-pressuring the system" or language to that effect).

The robot code libraries even provide a standard method for doing this that gives you the option to either run it under pressure switch control, or not run it.

Jon Stratis 07-02-2015 07:26

Re: 2015 FRC Inspection Checklist
 
Quote:

Originally Posted by Tristan Lall (Post 1439609)
I don't think that's a question that requires the Q&A—though if you think it would elicit more widespread understanding, go ahead. The past and present rules say nothing specific about when the compressor may or must start, only when it must not start (when at risk of "over-pressuring the system" or language to that effect).

The robot code libraries even provide a standard method for doing this that gives you the option to either run it under pressure switch control, or not run it.

While I agree with that interpretation (which I think is clear in my post), that sort of behavior is not common. A majority of inspectors out there will see an unusual control scheme of the compressor and ask for the LRI, and most LRI's who haven't seen it before will sit there and scratch their heads... Their final ruling may or may not be correct in that situation as a result. The best way to ensure 0 problems at the event is to ask the question and make it absolutely clear for everyone that it's legal. With Q&A in hand, the team can help to educate their local inspection crew about a situation that, I think, we might see more and more of in future years (due to the "drive train arms race" and a desire to get as much pushing power as possible).

rich2202 07-02-2015 07:33

Re: 2015 FRC Inspection Checklist
 
Quote:

Originally Posted by AustinShalit (Post 1439562)
During the Power On Check, Confirm Pneumatics Operation - Does this mean that we have to have the compressor start when the robot is first enabled?

At first reading: Yes

Quote:

What if we do not want it to?
Explain why? What's the purpose of pneumatics if you don't have any pressure?

Let's say that you don't want to activate the compressor during autonomous because you need the power for your lifter/moving. I remember our team having code to disable the compressor during times when more power is needed.

I'd be willing to let you get the robot into a state where the compressor turns on. It seems to me that the purpose of the rule is to test the entire operational aspect of the pneumatics system.

The wording is: " ... compressor should start when robot is enabled.". To me, that means:
1) Compressor does NOT run when robot is NOT enabled
2) At some point during the time when the "robot is enabled", and not necessarily when the robot is FIRST enabled, the compressor turns on and goes through the normal operational cycle, and safety systems are working.

MrForbes 17-02-2015 12:52

Re: 2015 FRC Inspection Checklist
 
We have one day to make sure our robots are ready to go for the competitions!

You might want to print the Inspection Checklist

http://www.usfirst.org/sites/default...ecklist1.1.pdf

and go over it line by line, to make sure your robot adheres to the rules. If you find any discrepancies, there is still time to order the correct parts, or make minor changes...or at least figure out what changes you'll need to make on the first day of your regional or district event.


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