So as you know, FIRST changed the rules starting in 2019 to require all pneumatic mechanisms to be filled only by the onboard compressor. As it is, the only way I know of to power the compressor is to enable the robot. But I don’t feel this is a safe thing to do. The team is changing bumpers and fixing any broken parts in the robot while the robot is powered on and enabled. The joysticks controlling the machine are balanced on top of a toolbox in the corner.
How do we do this safely? Is it enough to simply unplug the joysticks, or is the hazard of having people working on a robot while it is on serious enough to warrant
a) rewiring the compressor with a cable to connect it directly to the battery (is this legal, and are the voltages correct)
or
b) requiring all team members to not touch the robot while the compressor is filling, and thus shortening our repair and bumper changing times?
How does your team handle doing this safely in the pits?
Edit to people reading this later: the post above was based in large part on a major misunderstanding of how the off board compressor worked. However, the issue with being safe while refilling the air is still important, but simply moving back to an off-board compressor will not solve this issue; it is up to teams to be safe with how they handle the robot.
My apologies for any confusion.
We’ve always just run the compressor and filled the tank as part of the pre-match check, before leaving the pit. The robot cart holds the robot so the wheels are not touching anything so the robot won’t move, and the mechanisms are all checked for operation, which means everyone around the robot has to be aware of what’s going on (no extra people in the pit, either).
But we also design the robot to use only as much air as can be stored in one smallish tank. Air has it’s uses, they don’t include things that require doing lots of work.
Maybe you could tell us how long it takes to fill your air tank(s)?
You absolutely can not power the compressor directly from the battery. Please read the pneumatic rules to find the applicable rule. The compressor has to be powered from the pneumatic hub so that power can be turned off once it reaches the proper pressure.
With regards to not being safe - you need to clear out the ‘danger zone’ around the robot you are powering the robot and it has the potential for motion. People absolutely should not have their hands in a live robot, ever.
No, this is not legal. Please see the very first line in Section 9.8 Pneumatics Rules and couple that with R812. The intent is for all the air in the storage tanks on the robot to be sourced from the one and only one on board compressor that is controlled by the robot control system at all times.
What aspects of requiring on board air compressors only (post 2019) do you feel are less safe than pre-2019 that allowed either on board or off board? Do you perceive an off board compressor is inherently safer for some reason?
Arguably, having a pressurized pneumatics system creates a condition where it isn’t really safe to be doing most types of work on your robot. Some teams normally charge in the queue, and swap batteries before going onto the field. Testing the robot and this sort of thing in the pits is different, presumably this is as part of getting ready for a match?
We’re planning on having 4 of the black clippard tanks and two tanks that are about 2/3 the size of those. We’re going to be using it both for our intake extension/retraction and for some parts of the climber, so we will need to refill most of the tanks at the end of the match. How much will depend on defense, which would cause us to be extending and retracting the intake more than in an undefended match.
As I recall, the offboard compressor had to be connected to–and controlled by–the robot’s controller. So you still had to turn the robot on and enable it.
This is a team safety protocol issue not a robot rules issue. As has been made very clear here on CD in other threads, “safety” is subjective and dependent on exercising good judgement by the parties involved. There are lots of “unsafe” things teams can do with a legal robot.
Please expand upon this further for my clarity. I don’t understand what you mean by “the offboard compressor doesn’t require the robot to be enabled while operating”. How would you legally have been doing this (pre-2019) with an off board compressor that now post-2019 is different other than the physical location of the compressor?
I am confused by this as well. We have not used Pneumatics since 2019, and have not finished implementing ours yet this year, but I thought I remembered the (onboard) compressor filled the tanks while the robot was disabled. Am I wrong? I know the Compressor object changed a bit this year (it is automatic), but I thought as long as a valve was instantiated, the compressor would charge when you turned the robot on.
I must have remembered wrong. Thank you for that. It helps us plan.
This year’s game may not require that much air early on for those devices. So, if that is the case (you do not need that much air that early), auto could be an option.
Have you looked in to ways to reduce air consumption? Using gas springs or other type of elastic device on the intake lifting mechanism can let you use small cylinders. Using single ended cylinders or leaving one end open, and having gravity “drop” the intake, can also save half the air use. Using air to lift the robot for a climb is usually an iffy way to do it, you can get a lot more power out of a motor or two, pulling a cable or similar.
I’ve just seen too much that can go wrong with having lots of stored air, that is needed to play a match. The long filling time, using the legal method for filling tank(s), is one of those things.
I apologize, my facts were wrong about what using the offboard compressor was like, as my rookie year was in 2019. All I know is that our offboard compressor that we still use sometimes in driver practice to shorten time between matches has a battery connector, not some sort of wire to plug into the robot. I’m not sure if this is how we used it in competitions as I was not there. Thank you very much for your recommendations about changing the team’s safety culture instead of changing the design, I will discuss this with the team.
We are primarily using motors in the climber, but as we intend to articulate the hooks to get around the bar there are pneumatics involved in moving between those two positions.
As it is, we are probably overestimating our air needs; we want to be prepared to have to extend and retract the intake every time we pick up a ball, but most matches will not need to do this, so filling our tanks fully every match will probably be unusual. The idea of using one way cylinders is interesting; I will have to see if our climber rests in the up position such that this might work, or put springs on it if it needs a little pull.
In Infinite Recharge we had an air tank that took almost 4 minutes to charge. We started charging it as soon as we got to the pits with the last matches battery and then did our robot checks. This worked pretty well. If your compressor is fast enough you can also fill it part way and let it charge during the match if it doesn’t need to be at full charge at the start.
There’s a good chance you will have the weight to be able to mount a compressor onboard. That’s not a bad way to go, in most scenarios. You may not want to have to run it at all during a match, but you have the option this way. Also, you can set things up with an analog pressure gauge and/or add logic so you can control when any compressor runs. This way, you can make it a manually controlled option to enable it to run, if the pressure is low.
Our rookie year, weight was a problem…and we ended up with an off board compressor. It was powered by the robot, as required by the rules even then. What a pain. They’ve always been onboard since then. The compressor weight was part of the weight budget from the start, if it was a pneumatics year.
