FRC488 2012 -- Gojira

[Madison]

Here's a clearer pneumatic schematic.

I'm very interested in learning more about how other catapult robots regulate distance and/or arc since that was our main design challenge this season.

The system is divided into four 'zones' that each have a different working pressure.

The first zone is the high pressure storage. We have 90 cu. in. at 120 psi and are using a Rookie Kit compressor. It is highlighted in green.

The high pressure zone is separated from the remaining three zones by a regulator as required by the rules. The second zone, therefore, is the 60psi zone. This is a small zone -- really just a bridge between the remaining two zones and is orange.

The "everything else" zone is further regulated down to 30psi to conserve air and is everything at the bottom left of the schematic. This is where our pressure release valve is located and is red. This is where most of our robot functions live -- the collector deploy/lift, the collector flap rotation (for fitting into the bounding box), the elevator that loads our catapult and the brakes.

The final zone - in blue - is the catapult operation.
The firing sequence is as follows:

• Use camera to calculate distance to hoop and determine appropriate catapult settings
• Open single solenoid valve from 60psi (Orange) zone to Catapult Zone and fill until Fire Pressure Sensor reads expected value, then close the valve
• If actual value is greater than expected value, open Leak Flow Control solenoid valve to relieve pressure until expected pressure achieved.
• Repeat above two steps until system is within expected pressure tolerance -- about .5 psi
• Simultaneously, a servo is adjusting how far open the Outflow Valve is.
• Open valves to Catapult 1 and Catapult 2 cylinders
• Ball shoots, it scores! woo.
• Close Outflow Valve
• Open single solenoid valve at bottom of diagram to push air from 30psi into Catapult 1 and Catapult 2 to retract catapult arm
• Close that valve
• Ready to fire again.
  
  I think that's it. There's a lot going on there, but it only takes two or three seconds for the entire process and we're working on getting that down lower -- it's just a matter of tuning the flow control on the leak pressure valve to make hitting our target happen faster.