Quote:
Originally Posted by apalrd
IMHO, the requirement to control the compressor via the cRio at all (on or off-board) is meaningless.
You can start the match with 120psi of air in the tanks. You can change the battery after you charge the tanks. You don't even have to have the compressor on your robot. And there isn't even a requirement for a specific pressure switch or compressor. There is no competitive advantage to running the compressor when the robot is not enabled, as long as the valves cannot be actuated (which is true now).
A simple pressure switch and relay would suffice, but instead we need to use a control system programmed by the teams (which IMHO is less safe than a simple relay), which has a significant boot time and requires a laptop just to fill up the robot in the queue line.
I also don't see how preventing a shop type compressor from being used to fill the robot is any less safe than a team using the same compressor for an air riveter in their pit. The compressor is running, the commercially made tank is full of air, and the pits are fine.
In the same way, we currently use a 50a rated battery connector which has proven itself unfit for the hundreds of amps a modern FRC robot is capable of drawing. It will (and has, in several cases) melted before the main breaker trips. The manufacturer even makes larger connectors which are perfect for us, but we can't legally use them.
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This is, at it's core, a safety issue. The compressor must be controlled by the Crio so it can be disabled by the FMS, just like every other robot mechanism. A simple commercial solution may well work to put air in the tanks to the right pressure, but it would not be something that could be remotely disabled through the FMS or if the control system loses comms or whatever.
The programing related to safe operation of the compressor is verified by a specific set of tests conducted during inspection (pressure switch set point, vent plug setpoint and compressor shutdown on robot disable). If a robot fails any of these, the programming is fixed till it can pass.
Shop compressors in the pits have been unwelcomed for a long time. They're loud, trip breakers and encourage the use of tools that probably shouldn't be used in a pit. Yes, there are valid uses for one and I'm sure teams will continue to bring them and some venues will be inclined to allow them. That doesn't make it a great idea, though, and teams that want to use one should be prepared to be told to put it away. I'm really apprehensive about using them to pre-charge storage tanks on the robot. Again, it's a safety thing. The safe operation of the robots pneumatics is verified by the inspectors, whereas it would be impossible for inspectors to verify the safety of every robot/shop compressor combination, and the implications of failed pneumatics storage are incredibly serious.
I agree that the current Anderson connector is probably underrated for our needs. While the manufacturers rating and it's application specific rating aren't necessarily the same, and the majority of melted connectors are probably due to poor maintenance and other issues, a larger capacity connector would be reasonable. But rules is rules.