Quote:
Originally Posted by biojae
Could all be integrated into the PDB.
A brownout detector circuit that would switch the 24 boost converter and 12v radio power regulator inputs to the backup battery.
How did the IFI backup work?
Was it in parallel with the 12v main power?
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The IFI backup was a 9V straight to the controller. If the main voltage coming in dropped too far, the backup kicked in to keep the controller alive and responding. It was required from 2004-2008; before then, robots that had low voltage could wander all over the field and not respond to the E-stop.
The cRIO responds by having a monopoly on power after a certain low voltage is reached. The IFI system did not.
If something like this were to be implemented, I could see something like this:
Each team gets one or two "pit crew" members and a temporary disable switch (like the pressure pads in 2003 and 2005, only less finicky). They have to be in a box the whole time. Each alliance gets one pull-through lane, ideally with a barrier (and a DQ for entering while an opponent was in there, penalty if nobody's inside). Each robot gets one main battery and a "staying alive" battery. The "staying alive" battery has a dedicated PDB section, or similar way to distribute power, and a breaker of its own. (This to allow for full shutdown, because the battery obviously wouldn't go through the 120A main.) NOTHING can connect to that section except the cRIO and the radio (Connection type TBD by the EE types).
Robot pulls into the lane, and the pit crew runs/steps out with the fresh battery, hitting the disable as they go. Battery is replaced, minor "loose ends" get tied up, and the pit crew runs/steps for their waiting area, hitting the disable again to re-enable the robot. Robot pulls out the other side. Legal repairs include pulling off trailing items, checking cables, and changing batteries. No loading game pieces (unless that's part of the game--pull in and do some work, and you can load up with X game pieces). NO working on an enabled robot (DQ--safety violation). Think a NASCAR pit stop for a quick example--tires, fuel, tweak suspension/air inlet, get rolling again, except that in this case full shutdown of the engine (disable) happens.
Biggest problem: How cramped are the arenas the fields get set up in? You'd want decent space for the crew away from the field. Lane could be built into the field design, with a decently-high barrier.