RIP batteries.
2 Likes
Diffy swerve with suspension for terrain or tri motor Diffy swerve but that pushes the batteries to the extreme limits
2 Likes
I personally don’t see this happening at all. A crucial attribute of the KOP chassis is that it allows even a rookie team with very little mechanical/programming knowledge to have a fully functioning drivetrain for competition. Unless there can be a way to drastically simplify the mechanical/programmatic complexity of a swerve drive, it won’t make sense to have the KOP chassis be exclusively swerve.
5 Likes
With diffy swerve would you really need 3 motors?
I do think diffy swerve with a suspension would be top tier though. Now if you add in easily changeable wheel sizes and some traction control software I am not sure there would be a better drivetrain option.
2 Likes
3 motors isn’t required it’s more of just the limit you can have without murdering a battery, but suspensions and easily swappable wheel sizes would make it interchangeable year to year for any game.
three motor diffy is kinda sorta mechanically impossible tho, so like
1 Like
If you’re doing both, you might want to consider octocanum. It gives you the omnidirectional drive, the beastly tank pushing machine, and you can do it with only four motors (and more if you hate your batteries). By using different sized wheels and/or different sized sprockets, you can integrate shifting gears into the action of shifting drive modes as well, and your code is just the libraries for differential drive and for mecanum drive on a button toggle.
I realize that it’s probably unpopular to say anything positive about mecanum these days, but four motors and either two or (more likely) four pneumatic cylinders (on a single solenoid) is a much, much smaller investment in terms of money, controls complexity, and weight than a swerve cobbled (however expertly) to a tank–except, perhaps, in a situation like Stronghold, where 1533’s Swank was really a fantastic option.
Edit: please note that I did not say “octocanum > shifting swerve,” I only said “octocanum probably > swank”.
4 Likes
I think we are going to need lithium batteries to provide the current needed for any of these drivetrain concepts, 4 falcons can already brownout a robot if you don’t current limit them.
1 Like
That’s definitely true battery technology needs to evolve with the rest of the system, but you can do some very fancy software limitations of current draw and if you use a prediction model running barely ahead of the main Rio loop 5-10ms and send the data over a websocket you could create a kinematics system which only ever produces safe to apply commands by predicting the entire system draw and adjusting current limits every cycle but I’m not sure how much that would impact the CAN bus.
1 Like
Come on! Swankanum is the future, if you put one of these each on four swerve modules, you would be unstoppable!!!
22 Likes
twerve
3 Likes
I would love to see lithium being used in FRC, but that adds lots of safety concerns especially in the pits.
2 Likes
Alex the old battery won’t save you from being smashed by a pneumatic arm, they’re pretty low on the safety concern compared to pressurized systems and spring loaded or tensioned mechanical parts.
1 Like
No, but the old battery also isn’t likely to explode/combust when put in the hands of inexperienced highschool students (plus they’re relatively affordable).
Edit: After posting this, I fear we’re about to derail this thread and start yet another “Should We Use Lithium Batteries in FRC” discussion… Guess its time to break out my beach chair and popcorn as we wait for summer CD to start🍿
4 Likes
Such a fun derailment, but really drivetrains are being limited by the batteries, they do t have to be lipos but there is some innovation needed to keep up with the power of the brushless motors in use now, CATL new sodium batteries coming out could be an option for safety in the future, that’s the end of my minor derailment.
2 Likes
See the concerns around Battle bot batteries. 2 years ago at Mi States Greg was telling the FUN crew about how battery safety inspections go… Long story short: ANY damage and that pack is done. No appeals. Gets expensive quickly.
1 Like
After seeing a dead robot in many of the Einstein matches, including the finals, and seeing many more robots go out in division elims, I see absolutely no reason why we need to bring more battery power into FRC. If we allowed lithium batteries into the competition, we would need motor power or quantity limits to make efforts to slow robots down. That, or consistently rocky fields that don’t allow anyone a 10ft stretch to get up to speed. We can’t expect a high school competition to be even more obsessed with wiring quality than it already is, when even top teams can’t handle the stresses this year. I mean really, champs was getting pretty ridiculous towards the end.
The future of FRC drivetrains should, hopefully, be 4-motor drives with the power of 4 NEO motors on the ground.
9 Likes
This got me thinking - when we eventually get another game with 2016 style terrain that doesn’t allow for swerve, will we see top teams with octocanum drives? You’d think it’s a better solution than building turrets, seeing as everyone’s already used to moving sideways, and a lot of powerhouse teams show up at shooting games with both swerve and turrets.
Take it from someone who tried it. Its not worth it.
1 Like