Manual override of compressor software control

[willross]

Is it acceptable for an operator to manually override the software control of the compressor on/off sequence? We would like to be able to have the software automatically turn the compressor on at some low pressure state and kick off at full pressure but we also would like to be able to use a joystick button to turn the compressor on manually rather than waiting for the pressure to drop to that low state.

[pras870]

I'm somewhat confused by your question. The pressure switch that FIRST supplys us with automatically turns the compressor off when the system reaches 120 psi, but turns it on when it drops below that or reaches 60 (might be off on that #) psi in the system. Possibly if you re-word your question I can give a better answer/explanation.

[steven114]

FIRST does not specify when the compressor must be on or off - you could run it for all 2 minutes as far as they care. It's all about saving the motor in it and the battery. So, yes that would be acceptable.

[Joe Ross]

He wants to know if he can manually turn the compressor on, or can the compressor only come on when the pressure sensor senses low pressure.

Based on my reading of the rules, my first inclination would be to say no based on <R54>. However, why would FIRST give you a second pressure sensor if it couldn't be used for making decisions about the compressor? You should ask in the FIRST Q/A.

[dez250]

Originally Posted by Joe Ross

He wants to know if he can manually turn the compressor on, or can the compressor only come on when the pressure sensor senses low pressure.

Based on my reading of the rules, my first inclination would be to say no based on <R54>. However, why would FIRST give you a second pressure sensor if it couldn't be used for making decisions about the compressor? You should ask in the FIRST Q/A.

The pressure switch is made to turn on at any pressure below 90psi and off at 120psi. You still need to program it and i think that there is a way to code the switch to have a second state in which if a secondary switch (controlled by you) is on, the pump goes on and shuts off still @ 120psi.

[pras870]

That's what I thought he meant when he asked his question. I just find it odd that someone would want to manually turn a compressor on when the pressure switch does it for you. Experience has shown my team, that having the compressor constantly running will dramatically drain the battery, which is why FIRST supplies the pressure switch. Just make sure that there is no leaks so the compressor isn't on all the time.

P.S.- It's also a good idea to charge your system before a match. Have an extra battery for turning the compressor on to charge up your system, so the compressor doesn't run during autonomous

[Joe Ross]

If you have a 2" bore, 24" stroke piston, you are going to want to make sure there is more then 90 PSI in the system before you fire. That is why you would want to run the pump before the sensor normally would.

There are many ways you "could" program the system, but my question is whether <R54> allows that.

[sanddrag]

I would also like to know if it is acceptable to manually turn the compressor off.

[Ryan Cumings]

I entirely missed <R54>
The wording makes it a bit tricky from a strictly legeal stand point. However with the whole spirit of the game, I think the rule is trying to make sure that you do not hook the pressure sensor directly inline with the compressor.

The pneumatics manual hints at this under the section they designate for the pressure switch. It also says that there is no control in the default program to control the relay so I suppose it goes to say that you can control the relay however you want, just as long as it is done entirely in the code.

[Rickertsen2]

I would think it would be legal. I don'st see any rules against it. I saw a team that did it alst year. There anrn't ant rules against it. and overpressure isn't an issue bc there is a mechanical overpressure valve o n the compressor.

[KevinB]

Yeah I don't think they care when or how the compressor turns on or off as long as the pressure in the system never exceeds 120PSI.

They give you an analog pressure sensor for this reason -- to customize the control of the pump.

[dlavery]

You can insert a manual override option to turn the compressor "Off" whenever you want to. You can insert a manual override option to turn the compressor "On" whenever you want to, as long as it does not disable the automatic shut-off at 120psi. E.g. you can turn the compressor "On" at any time, through manual or autonomous means, but the existing software that turns the compressor "Off" at 120psi must always take priority over all other functions.

-dvae

[steven114]

Originally Posted by dlavery

but the existing software that turns the compressor "Off" at 120psi must always take priority over all other functions.

-dvae

The 120 psi is a hardware limit - the compressor has a relief valve. Keeping it running will not charge it above 120psi unless you modify the compressor.

[dlavery]

Originally Posted by steven114

The 120 psi is a hardware limit - the compressor has a relief valve. Keeping it running will not charge it above 120psi unless you modify the compressor.

And the existing software code provides a redundant safety feature that provides two-fault tolerance. In the event that the relief valve should fail (not an unheard-of occurrence), the software limits the pressure output of the compressor to a safe level well below the burst pressure ratings of any of the pneumatic components provided in the FIRST kit. For that reason, the existing software that turns the compressor "Off" at 120psi must always take priority over all other functions.

(and yes, it also works the other way around - the relief valve acts as a backup for the software, in case you accidentally do something to mess with the software-commanded shut off)

-dave

[steven114]

I never saw any such control thing in the code - where is it? And doesn't this require that the compressor and switch be wired up in a very specific way? I fail to see how this works...