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Learning Occupancy Grid Maps with Forward Sensor Models

Authors: Sebastian Thrun

Published: 2003 (Journal Paper)

Source: Autonomous Robots

Algorithm: Occupancy Grid Mapping

DOI: 10.1023/A:1025584807625

Summary

Abstract

This article describes a new algorithm for acquiring occupancy grid maps with mobile robots. Existing occupancy grid mapping algorithms decompose the high-dimensional mapping problem into a collection of one-dimensional problems, where the occupancy of each grid cell is estimated independently. This induces conflicts that may lead to inconsistent maps, even for noise-free sensors. This article shows how to solve the mapping problem in the original, high-dimensional space, thereby maintaining all dependencies between neighboring cells. As a result, maps generated by our approach are often more accurate than those generated using traditional techniques. Our approach relies on a statistical formulation of the mapping problem using forward models. It employs the expectation maximization algorithm for searching maps that maximize the likelihood of the sensor measurements.