pre-charged Pneumatics

[Tristan Lall]

Originally Posted by Al Skierkiewicz

Peter and Howie,
This is the rule that applies...

<R90> The ROBOT will be inspected for compliance with the dimension constraints specified in Rule <R10> while in its NORMAL CONFIGURATION, by being placed within a FIRST Sizing Device that has inside surface dimensions consistent with the rule. Other than resting on the floor of the Sizing Device, no part of the ROBOT can break the plane of the sides or top of the Sizing Device during size inspection. The ROBOT must be self-supporting while in the Sizing Device.

Inspections are carried out with all systems unpressurized and unpowered for obvious safety reasons. Robot size and weight are tested with the bumpers off and the battery out. Please refer to Rule <10> and <11> as both are referenced in robot size.

The rules for stored energy govern the condition that a robot can be in at the start of a match including air stored in the Clippards. This rule allows teams to pressurize their robot with an off robot compressor but speaks to the start of a match, not to inspection. Please ask the question as we have no guidance to the contrary from the GDC. I expect the pressure vent valve to be open until the "power on" portion of the inspection takes place.

Al, I think I also need to disagree a little here. As the rules currently stand, normal configuration definitely implies a powered-on, disabled state ("the state of the ROBOT immediately before being enabled by the Field Management System, before the ROBOT takes any actions, deploys any mechanisms, or moves away from the starting location"). Although for reasons of practicality and safety it would seem valid to inspect robots in their least-energy state, if doing so would inaccurately simulate the normal configuration during sizing, the rules would seem to demand that it be tested in the normal configuration (per <R88> and <R90>).

Of course, there are not many mechanisms for which this is a valid concern, because with control system outputs disabled, control of most actuators and other devices is not practical. One possibility that comes to mind is an electromagnet that receives power directly from the PDB, through a mechanical switch, and which holds down some component until that switch is triggered, cutting power. (This is a custom circuit, and by using a non-relay switch, avoids being controlled by the cRIO.)

Now, it is certainly within an inspector's authority—and indeed, responsibility—to take steps to minimize the risk to themself and others during inspection. In the above case, if the team were to argue that they needed that component to be held back, but the inspector was uncomfortable with the presence of an armed mechanism in the sizing box, perhaps a compromise could be reached where the mechanism is fixed in the appropriate position, but in a locked-out state.

But in other cases, if the inspector considers the hazard relatively minor, I don't think that the rules would prevent a team from asking to be sized in a powered-on, disabled state.