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Unread 23-01-2011, 03:03
efoote868 efoote868 is offline
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Re: Calibrating Mecanum Drive

Imagine your robot has four mecanum wheels, with two dead motors on opposite corners, and two live motors on the different corners.

You use the joystick to try and go straight in an axis. Because there are only the opposite two motors powering the robot, the robot will spin as it moves. Since the gyro is compensating for the spin, the robot will still be attempting to move in that same direction. The two live motors will begin to output less and less.

The robot will continue to spin until the two dead motors are perpendicular to the axis that you're trying to move the robot on, and the two motors that work will be lined on that axis. The robot will no longer move, because the gyro in field centric drive will tell the working motors not to move, and tell the dead motors to go full power.


Now, imagine that instead of two dead motors, they only work at 90%. The same process will occur, except an equilibrium will be found sooner. This equilibrium requires no extra code to compensate for the biased motors.


I hope that makes sense? Otherwise I might have to try some of my mad paint skills.
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