Quote:
Originally Posted by Craig Roys
This is one of the reasons we were considering looking at two pairs...we wanted to see about getting 6 CIMS to power the 4 wheels.
|
It's been a while since I've done the math, perhaps those with more recent, published models can confirm. This is all based off my intuition.
Since you have a 4 wheel drive, put 2 CIMs on modules in opposite corners, with 1 CIM in each of the other corners. The power you're supplying to your wheels should still be balanced on either side, regardless of the direction of movement which is defining said "sides" at any given time.
Adding in arbitrary rotation on top of translation complicates things a bit, since now the power available to pull off the rotation will depend on how far each "unit" of power is from the center of rotation. In particular, if you're spinning about one of your modules, if it's a 1 CIM module, you have 5 CIMs available to do the maneuver, while if it's a 2 CIM module, you only have 4 across the other 3 modules. If you spin about a point away from all the modules, you have all 6 CIMs available. A 4 CIM, 4 wheel swerve also fails to have this type of symmetry, but to a lesser extent.
In any case, a good speed control loop will ensure you still get the desired motion, but the max acceleration and force with which you can perform a maneuver may vary because of the loss of symmetry. Since a good swerve will require extensive off season testing anyway, I'd recommend trying this out so you don't have to try transferring power between modules, and seeing if the performance is acceptable.
Or go 3 wheel
