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The Action Model


To update the belief when the robot moves, we have to specify the action model tex2html_wrap_inline2959 . Based on the assumption of normally distributed errors in translation and rotation, we use a mixture of two independent, zero-centered Gaussian distributions whose tails are cut off [Burgard et al. 1996]. The variances of these distributions are proportional to the length of the measured motion.


Figure 3 illustrates the resulting densities for two example paths if the robot's belief starts with a Dirac distribution. Both distributions are three-dimensional (in tex2html_wrap_inline2961 -space) and Figure 3 shows their 2D projections into tex2html_wrap_inline2963 -space.

Dieter Fox
Fri Nov 19 14:29:33 MET 1999