| Volume 26 Issue 2 - Publication Date: 1 February 2007 |
| Special Issue on the Fifth International Conference on Field
and Service Robotics, 2005 |
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| 3D Position Tracking in Challenging
Terrain |
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| P. Lamon and R. Siegwart
Eidgenössische Technische Hochschule (ETH), 8092 Zürich, CH |
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| The intent of this paper is
to demonstrate how the accuracy of 3D position tracking can be improved
by considering rover locomotion in rough terrain as a holistic problem.
Although the selection of good sensors is crucial to accurately track the
rover’s position, it is not the only aspect to consider. Indeed, the
use of an unadapted locomotion concept severely affects the signal to noise
ratio of the sensors, which leads to poor motion estimates. In this work,
a mechanical structure allowing smooth motion across obstacles with limited
wheel slip is used. In particular, this enables the use of odometry and
inertial sensors to improve the position estimation in rough terrain. A
method for computing 3D motion increments based on the wheel encoders and
chassis state sensors is developed. Because it accounts for the kinematics
of the rover, this method provides better results than the standard approach.
To further improve the accuracy of the position tracking and the rover’s
climbing performance, a controller minimizing wheel slip has been developed.
The algorithm runs online and can be adapted to any kind of passive wheeled
rover. Finally, sensor fusion using 3D-Odometry, inertial sensors and visual
motion estimation based on stereovision is presented. The experimental results
demonstrate how each sensor contributes to increase the accuracy and robustness
of the 3D position estimation. |
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| Multimedia Key |
= Video |
 = Data |
= Code |
= Image |
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Extension |
Type |
Description |
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Example
1: Sensor fusion results (3DOdometry, VME, Inertial sensors).
(1.9 MB) avi |
| 2 |
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Example
2: Slip minimization controller (video A). (3.7 MB) avi |
| 3 |
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Example
3: Slip minimization controller (video B). (3.1 MB) avi |
| 4 |
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Example
4: SOLERO performance in rough terrain. (1.4 MB) avi |
| 5 |
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Example
5: SOLERO climbing a large rock. (6.4 MB) mpg |
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