Fault detection for mobile robots using redundant positioning systems
Paul Sundvall and
Patric Jensfelt
Abstract:
Reliable navigation is a very important part of an autonomous mobile
robot system. This means for instance that the robot should not lose track of its
position, even if unexpected events like wheel slip and collisions
occur. The standard approach to this problem is to construct a
navigation system that is robust in itself. This paper proposes that
detecting faults can also be made outside the normal navigation system, as
an additional fault detector.
Besides increasing the robustness, a means for detecting
deviations is obtained, which can be important for the rest of the
robot system, for instance the top level planner.
The method uses two or more sources of robot position
estimates, and compares them to detect unexpected deviation without
getting deceived by drift or different characteristics in the position
systems it gets information from. Both relative and absolute position sources
can be used, meaning that existing positioning systems already implemented can
be used in the detector.
For detection purposes, an extended Kalman filter is used in
conjunction with a CUSUM test. The detector is able to not only detect faults,
but also give an estimate of when the fault occurred, which is useful for doing
fault recovery. The detector is easy to implement, as it requires no
modification of existing systems. Also the computational demands are very low.
The approach is implemented and demonstrated on
a mobile robot, using odometry and a scan matcher as sources of
position information. It is shown that the system is able to detect
wheel slip in real time.
BibTeX Entry:
@InProceedings{Sundvall06a,
author = {Paul Sundvall and Patric Jensfelt},
title = {Fault detection for mobile robots using redundant positioning systems},
booktitle = {Proc.~of the IEEE International Conference on Robotics and Automation (ICRA'06)},
year = 2006
}
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