Quote:
Originally Posted by iyportne
This thread contains many excellent perspectives. And yes, swerve is not easy to employ but worth the journey. We tend to look at swerve as our development infrastructure and learning bed. We are currently on version 4.0 and have successfully used swerve to our satisfaction in the last two seasons. Code is rock solid and and basically a library object so scalability is not an issue. We have a solid working encoder and have now figured out a robust position and mount to survive an entire competition. We use our technology to develop relationships with local machine shops off season so we have that covered (though the last two seasons we used the Team 221 Revolution Pro modules). We have working robots to practice with so driver training is also covered. I would suggest that if you are interested in any advanced drive train(s) that you make it a multi-season effort and manage your competition risk as you go. And also, you don't have to re-invent the wheel (ha-I just saw the pun there) since FIRST rules dictate that if any of us develop off-season hardware or logic, we must provide design and code to the FIRST community prior to kickoff in order for us to use it that season. We post links to our Swerve design models and JAVA code here on CD.
A few more benefits to swerve added to those already mentioned are:
1. You are no longer limited to a two sided functional robot (front-back). Programming wise any side can be designated as front, and can be switched on the fly.
2. You can easily switch between or mix field-centric and robot-centric movements with vector math.
3. Your center of rotation is now virtual rather than mechanical, so it can exist anywhere - even outside the robot perimeter - great for object acquisition or placement.
4. Sure we use 8 motors, but the entire robot is now a very predictable 360° continuous turret while static or in field-centric motion - that means you have a turret for object acquisition and launch/placement.
5. With a full 150 lbs. competition weight on 4 swerve wheels pointed to the center of the robot, you have a pretty awesome brake for resisting defense or for ramps and it remains active at power-off.
6. You have full 4-wheel positive traction 100% of the time (obviously on flat surfaces) during any movement and don't suffer the movement control loss when not all four wheel are in weighted contact with some surface.
7. Our current development has gotten the net drive train weight near or below the standard KOP drive train.
8. If the game requires obstacle negotiations, you don't have to abandon the benefits of swerve, think of other add-on motion devices like belts, cogs or tank treads...remember Swank Drive?
We should have our Strange Swerve 4.0 designs posted before kickoff. Good luck with the development path you choose!
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Having watched these guys develop their swerve system as well as borrowed their lessons learned as well as those from Anthony at 221, this is all really good info.
I'm not 100% convinced about mixing other drive types with swerve (swank) but these guys made it work and it was impressive to watch.
Swerve is hard to get right.