Omni-wheel accuracy

[Andrew Schreiber]

Originally Posted by Nemo

Our team has built 4 wheel omni drives like OP is describing on several occasions, and our experience is that they drive pretty nicely without encoder feedback. Maybe the 3 wheel version is touchier.

Encoders could solve the problem described by the OP. Setting the motors to brake instead of coast can solve it faster and cheaper. Adding encoders has additional benefits such as making the robot drive in a straight line and enabling more accurate autonomous driving.

I like instrument feedback. I just don't think it's worth $200 in this case.

I'm not sure whether the 3WD platform is touchier. My gut feeling tells me that it would spin a little easier and would show this problem a little more but I do not have data to back this up. I'm open for suggestions on how to collect this data.

I would disagree that simply placing it in brake mode would fix the core problem of motors moving at different speeds. It may fix the majority of it but for our team it was worth the $150 it cost to actually address the issue and to give us accurate autonomous navigation. It was also worth it to teach the lesson of the importance of feedback systems to my students.

I guess, my suggestion to OP would be to try the cheap and fast solution and if it meets your needs cool if not move on to using feedback.