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Unread 14-01-2015, 16:59
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Re: Encoders on mecanum drive?

Quote:
Originally Posted by jtrv View Post
Okay, well, I seem to only have gotten one decent solution, that I get encoder values and reverse the mecanumDrive trig functions to get distance.
What you have described is called forward kinematics. If your wheel speeds are not kinematically correct*, you cannot compute a true forward kinematic solution, because there will be wheel scrubbing. You can find a least-squares solution, but there's no guarantee that will describe the vehicle's actual motion.

By the way, there are no "trig functions" required to do mec inverse kinematics.

*due to an incorrect inverse kinematic computation, or differences in motor controller calibration, or differences in performance among the 4 motors, or differences in resistance among the 4 motor wiring circuits, or differences in friction among the 4 gearboxes, or differences in friction of the rollers among the 4 wheels, etc etc etc.