Page 165 - Autonomous Mobile Robots
P. 165
4 Landmarks and
Triangulation in
Navigation
Huosheng Hu, Julian Ryde, and Jiali Shen
CONTENTS
4.1 Introduction ............................................................ 150
4.2 Landmark-Based Navigation .......................................... 152
4.3 Laser Scanner and Retro-Reflective Landmarks ..................... 154
4.3.1 Laser Scanner and Angle Observation ....................... 154
4.3.2 Triangulation Algorithm ...................................... 155
4.3.3 KF-Based Navigation Algorithm ............................. 157
4.3.4 Implementation and Results .................................. 159
4.4 Vision and Digital Landmarks ........................................ 160
4.4.1 Landmark Recognition........................................ 161
4.4.1.1 Region finding module ............................. 161
4.4.1.2 Digits finding module .............................. 163
4.4.1.3 Digits recognition module ......................... 163
4.4.2 Position Estimation ........................................... 165
4.4.2.1 Triangulation method .............................. 166
4.4.3 Least Square Estimator (LSE) ................................ 168
4.4.3.1 Single-landmark LSE (SLSE) ..................... 169
4.4.3.2 Dual-landmark LSE (DLSE)....................... 169
4.4.4 Implementation and Results .................................. 170
4.5 SICK Laser Scanner and Geometric Landmarks ..................... 173
4.5.1 Circular Hough Transform.................................... 174
4.5.2 Least Squares Fitting of Circles .............................. 175
4.5.3 Cooperative Position Estimation ............................. 179
4.5.4 Implementation and Results .................................. 180
4.6 Conclusions ............................................................ 183
References .................................................................... 184
149
© 2006 by Taylor & Francis Group, LLC
FRANKL: “dk6033_c004” — 2006/3/31 — 16:42 — page 149 — #1
