The spreadsheet the @Zook posted in the above thread was mind blowing to me.
A summary:
121/192 - 63% of the robots in the playoffs used swerve
102/144 - 71% of the Captains/1st/2nd robots in the playoffs used swerve
22/24 - 92% robots on Einstein used swerve
I knew going into this season that there was going to be an explosion of swerve drives because of the confluence of multiple factors, but I never thought it was going to be this dramatic. Obviously this sample is only looking at the highest levels of play for this season, but the numbers are still way higher than I expected. Welcome to the swerve revolution, folks.
My question -
We’ve seen with the emergence of COTS swerve that a lot of field carpets are getting destroyed from modules dragging across the carpet. The carpet isn’t cheap… will FIRST do something about this?
I don’t think they would ever do such a thing, but perhaps they design the game to make swerve less useful (i.e. Stronghold), find a different field carpet that holds up to the abuse, or find a cheaper carpet that is less of a financial burden to replace.
There’s a few reasons why swerve drives are doing this to the carpet. Malfunctioning modules, unoptimized controls, defense robots pushing others across the carpet. There’s not much you can do to mitigate these things.
Actually, there is something you can do about it. Make sure that your robot is not traction limited at motor stall. If, instead, you are current limited or torque limited (or both) then the wheels will be less likely to skid and destroy the carpet. Maybe this is what you meant when you said “unoptimized controls”?
Many of the complaints that were discussed here and that I saw at local competitions were not about the swerve bot being pushed around but about the swerve bot itself pushing up against an immovable object (i.e. the fender on the hub or the field perimeter walls) and their wheels had so much torque that they overcame the traction of the wheel against the carpet and started to spin. The “worst” damage was the result of this spinning continuing long enough to actually melt through the carpet. A module that was misaligned and being dragged sideways across the carpet, or the entire robot being pushed against locked-off wheels will do relatively little damage, simply because the wheels don’t stay in the same spot on the carpet and therefore don’t have a chance to melt it.
In FTC, they used to have an inspection test where you drove your robot against the field perimeter wall and pushed as hard as you could to prove that you did not damage the field. A simple test like that in FRC would also reveal teams that had not properly implemented current limiting or other traction control limits to prevent the field damage.
Bottom line, if you have elected to use wheels that are capable of damaging the fields (i.e. Nitrile treads), then it does not seem like a stretch to also require your team to do so in a way that prevents field damage. And it is something that can be tested at inspection.
