International Journal of Advanced Robotic Systems
Visual Odometry for Planetary
Exploration Rovers in Sandy Terrains
Regular Paper
Linhui Li
1
, Jing Lian
1,*
, Lie Guo
1
and Rongben Wang
2
1 State Key Laboratory of Structural Analysis for Industrial Equipment,
School of Automotive Engineering, Dalian University of Technology, Dalian, China
2 Transportation College, Jilin University, Changchun, China
* Corresponding author E-mail: lianjing80@126.com
Received 4 Jun 2012; Accepted 2 Jan 2013
DOI: 10.5772/56342
© 2013 Li et al.; licensee InTech. This is an open access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,
distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract Visual odometry p rovides planetary
exploration rovers with accurate knowledge of their
position and orientat ion, which needs eff ective feature
tracking resul ts, especially i n barren sandy terrains. In
this paper, a stereovisi on based od ometry algori thm is
proposed for a lunar rover, whi ch is composed of
corner extraction, feature tracking and mot ion
estimation. First, a morpholog y base d image
enhancement method is studied to guarantee enough
corners are extra cted. Second, a Rand om Sampl e
Consensus(RANSAC)algorithmisproposedtoma kea
robust estimation of the fundamental matrix, which is
the basic and critical part of fea ture mat ching and
tracking.Then,the6degreesoffreedomroverposition
and orientation is estimated by the RANSAC
algorithm . Finally, experiments are performed in a
simulated lunar surfa ce environment using a
prototype rover, which have confirmed
the feasibility and eff ectiveness of the proposed
method.
Keywords Visual Odometry, Sandy Terrain, Feature
Tracking,MotionEstimation
1.Introduction
Visual odometry is the process of determining the
position and orientation of an autonomous ve h i c l e by
analysingtheassociatedcameraimages.It has beenused
in a
wide variety of robotic applications. In 1987, visual
odometry was developed by L. Matthies [1] for indoor
robotse lf‐positioning.Inrecentyears,themostsuccessful
applications of visual odometry are the Spirit and
Opportunity MERs (MERs, Mars Exploration Rovers) [2]
landed on Mars, in addition to the application in UGVs
(UGV,UnmannedGroundVehicle)[3,4].Comparedwith
traditional local positioning sensors (e.g., w h e e l
odometry, inertial navigation sensors), visual odometry
hasthefollowingadvantages:
1. Positioning accuracy only relies on visual inputs, so
is independent of slip, slope, sinkage and other
factors. In a soft outdoor environment, visual
odometry has higher relative positioning accuracy
andmotionestimationresults.
2. Slip rate can be estimated by comparing wheel
odometry information [5]. On one hand, it c an
obtain the soil parameters. On the other hand, it
1
Linhui Li, Jing Lian, Lie Guo and Rongben Wang:
Visual Odometry for Planetary Exploration Rovers in Sandy Terrains
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Int J Adv Robotic Sy, 2013, Vol. 10, 2013