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Instantaneous Center of Rotation for a Differential Drive Robot

  1. Jun 2, 2013 #1
    I want to find the instantaneous center of rotation of a differential drive robot. Assuming I know that the robot will travel with a particular linear and angular velocity (v,w) I can use the equations (given here http://rossum.sourceforge.net/papers/CalculationsForRobotics/CirclePath.htm ).

    which come out to be

    x_c = x_0 - abs(v/w) sin(\theta_0) y_c = y_0 - abs(v/w) cos(\theta_0)

    I'm using the webots simulator and I dumped gps points for the robot moving in a circle (constant v,w (1,1)) and instead of a single x_c and y_c I get a center point for every point. if I plot it out in matlab it does not look nice.

    Here's an image ...

    the red points in the image are the perceived centers


    they just seem to trace the curve itself.

    is there some detail I am missing ? I'm really really confused as to whats happening.

    help please

    I'm trying to figure out the center so I can check whether an obstacle is on this circle or not and whether collision will occur.
  2. jcsd
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