Thread: Autonomous: Mixing Drive Distance PID's with Turn Angle PID's.
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Unread 17-11-2011, 05:46
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Re: Autonomous: Mixing Drive Distance PID's with Turn Angle PID's.
For driving curves we usually just apply a distance/speed PID and give each side of our tank drive a different target-distance/target-speed to drive.
The inside (shorter distance) target speed is reduced proportional to the difference in distance. The shape of the arc can be affected by applying a +/- constant to the inside speed (if you're into french curves).

I've also applied a drive distance PID to one side, but a drive-straight PID to the other. You can feed the drive-straight PID an encoder reading to match that has been adjusted by the ratio of the two distances. Overshoots, like if another robot is shoving you, can get jumpy though.
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Last edited by Mark McLeod : 17-11-2011 at 06:06.
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