Absolute scale estimation for underwater monocular visual odometry based on 2-D imaging sonar. (28th February 2022)

• Record Type: Journal Article
• Authors: Yang, Disai; Ai, Haiping; Liu, Jiantao; He, Bingwei
• Is Part Of: Measurement. Volume 190(2022)
• Publication Date: 2022-02-28
• Subjects: Absolute scale estimation -- Monocular visual odometry -- Forward-looking sonar -- Multiple-view geometry -- Opti-acoustic visual system; Weights and measures -- Periodicals; Measurement -- Periodicals; Measurement; Weights and measures; Periodicals; 530.8
• DOI: 10.1016/j.measurement.2021.110665
• Languages: English
• ISSNs: 0263-2241

Abstract

Abstract: In this paper, the scale ambiguity in underwater monocular visual odometry is solved with 2-D sonar measurements obtained from three viewpoints. Each measurement value is formulated as geometrical constraint and the recovered scale can be expressed in closed-form. Different from the existing method which assumes the features being on the same plane in order to meet the pre-condition of quasi-homography transformation, our method allows the observation points to be distributed spatially (not limited to a plane), thus extending the proposed method to more general application environments. An error contribution criterion of sonar measurement is proposed to weight the constraints, which further reduces the influence of noisy input. Experiments are performed in both simulated and real environments. For nonplanar case, the proposed method gives improved accuracy after employing constraint weighting. As for planar case, our method achieves comparable accuracy to the existing method, while the time consumption is much lower. Highlights: Forward looking sonar is used to estimate translation scale for monocular visual odometry. Sonar measurements at three viewpoints are used to establish geometrical constraints. The method is applicable to both general scene and planar scene. Constraint weighting is proposed to improve the estimated results.