Pneumatics sensors?

[Mark McLeod]

Originally Posted by Qbot2640

Still...Why?

The last time we had a pneumatic catapult we had adjustable third stage pressure to vary the shots. The operator would adjust the pressure watching feedback on the Dashboard to shoot farther or make closer shots.

Other years it told us how many times we could fire some mechanism's cylinders in succession, or when some real air hog needed time to build up reserve pressure.

[Caleb Sykes]

I have always wanted to try to keep a running approximation of pressure just using observations. Something like:

if (compressor just stopped running)
     approximate psi = 120
else if ((compressor just started running) and (approximate psi > 110))
     approximate psi = 105
else if (compressor is running)
     approximate psi = approximate psi + (1 psi/second)
else
     approximate psi = approximate psi - (0.02 psi/second)

if (piston1 is actuated)
     approximate psi = approximate psi - 10
if (piston2 is actuated)
     approximate psi = approximate psi - 30

Given, the accuracy of the approximate psi value would probably decrease over time. Although it would reset to 120 whenever the compressor stops running. It could be very useful for checking to see if working pressure is >= 60, simply by checking to see if the approximate psi is > 70 or something like that.

Has anyone done something similar to this? I am curious to know if it was successful.

[Mark McLeod]

We did that for our 2003 robot.
The drive system was dependent upon having adequate pressure at all times, so the pneumatic arms were limited if the system thought too much air had been used.
Make sure you have a big obvious indicator to the drivers as to why mechanisms may stop working mid-match.

It worked quite well except for once when we drove under the bar with the arms too high and ripped off the fittings releasing all of our air with one whoosh...