Thread: Arc Driving
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Unread 22-01-2007, 13:48
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Re: Arc Driving

Quote:
Originally Posted by ericand View Post
I think the math works out very simply if you work in radians. If you want to follow a curve of radius R through an ARC of angle A (in radians), then the inside track of the robot will travel a distance of R*A. since the outside track of the robot is at a fixed distance from the inside (by the width of the robot W), the distance traveled by the ouside would be (R+W)*A.

Distance inside of curve : Di
Distance outside of curve : Do

Di = R*A
Do = (R+W)*A = R*A + W*A = Di + W*A

You can use simiar math to compute the robot's heading change based on the distances traveld by the right and left sides of the robot and the width of the robot.

Note that by using radians you can avoid the need for trig functions.
This would work for computing the distance traveled if you know the angle traveled and the arc radius, but an inverse trig function would still be necessary to determine what angles the wheels have to be in order to achieve that arc radius. The angle of the wheels are independent from the angle through which the vehicle travels.
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