Robust capsule-robot positioning with limited magnetic observations: An inertial-enhanced approach

ABSTRACT

The capsule robot has become an important tool in covering the entire spectrum of digestive tract disease diagnosis. To achieve magnetic capsule-robot localization, the Levenberg-Marquardt (LM) algorithm has become a mainstream approach that provides accurate solutions in the general case. In practice, however, to meet the requirements of wearability, fewer sensors and lower power consumption are required. When the number of sensor observations becomes smaller, local convergences and outliers may occur in positioning results. To mitigate this issue, this paper makes two contributions to enhance the robustness of capsule-endoscope positioning, especially when the quality of magnetic observations is low. First, it proposes a two-step approach that initializes the capsule attitude by using inertial measurements before estimating the position. Second, it presents an improved LM-based positioning algorithm based on vest-type magnetic sensor arrays. Furthermore, to verify the proposed approach, a vest-type wearable device with two low-cost magnetometer arrays is designed. Test results have shown the effectiveness of the proposed LM method in enhancing positioning when there is a lack of observations.

KEYWORDS:

• Capsule-robot
• Levenberg-Marquardt (LM)
• wearable
• positioning

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Additional information

Funding

This work was supported in part by the National Natural Science Foundation of China [grant number 42104038].

Notes on contributors

Peng Zhang

Peng Zhang received the PhD degree from the Wuhan University in 2016 and is now an associate researcher at the State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University. He is mainly engaged in indoor positioning, wearable devices and mobile health research. He presided over and participated in 6 projects including the National Natural Science Foundation of China, the Natural Foundation of Hubei Province, the National Key Research and Development Program, and the Canadian Association for Scientific and Engineering Research Foundation projects. He has co-published over 20 academic papers and has 3 patents pending and received over 4 academic awards.

Ruizhi Chen

Ruizhi Chen received the PhD degree in Geophysics from University of Helsinki, Finland, in 1991. He is currently a Professor and Director of the State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing at Wuhan University. He used to work as an Endowed Chair Professor at Texas A&M University Corpus Christi, US; Head and Professor of the Department of Navigation and Positioning at Finnish Geodetic Institute, Finland, and Engineering Manager in Nokia, Finland. He has published two books and more than 260 scientific papers. His current research interests include indoor positioning, satellite navigation and location-based services.

Weiguo Dong

Weiguo Dong is a professor, archiater and doctoral tutor of the Department of Gastroenterology, Renmin Hospital of Wuhan University. Recently, he is a member of Chinese Society of Gastroenterology, a member of the General Practitioner Branch of Chinese Medical Doctor Association and a Chairman-designate of Digestive Disease Branch of Hubei Medical Association. His research interests include gastrointestinal tumor and inflammatory bowel disease. He has been awarded 6 items for the National Natural Science Fund and 16 scientific research items at the provincial and ministerial levels. Besides, he has won one second prize for scientific and technological progress in Hubei province, two third prize for natural science (all ranked first).

You Li

You Li is a Professor at the State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing (LIESMARS), Wuhan University, China. He received PhD degrees from Wuhan University and University of Calgary in 2015 and 2016, respectively, and a BEng degree from China University of Geoscience (Beijing) in 2009. His research focuses on positioning and motion-tracking techniques and applications. He has co-published over 80 academic papers and has over 20 patents pending. He serves as an Associate Editor for the IEEE Sensors Journal, a committee member at the IAG unmanned navigation system and ISPRS mobile mapping sessions.

Yan Xu

Yan Xu received her Bachelor’s degree in Surveying and Mapping Engineering from Liaoning Technical University in 2015 and her Master’s degree in Photogrammetry and Remote Sensing from Liaoning Technical University in 2018. She is currently studying for a doctorate degree in Geodesy and Surveying Engineering in the State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing in Wuhan University. She is mainly engaged in the research of remote sensing image processing algorithm, medical image interpretation and visual positioning technology of medical application engineering.

Jian Kuang

Jian Kuang received the PhD degree in Geodesy and Survey Engineering from Wuhan University in 2019. He is currently an Associate Researcher with the GNSS Research Center in Wuhan University, China. His research interests focus on inertial navigation, pedestrian navigation and indoor positioning.

Yuan Zhuang

Yuan Zhuang is a professor and the founder of the Sensing, Navigation & Artificial Intelligence Lab (SNAIL) at the State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, China. He received the PhD degree in geomatics engineering from the University of Calgary, Canada in 2015. His current research interests include multi-sensors integration, realtime location system, wireless localization, Internet of Things (IoT), and machine learning for navigation applications. To date, he has co-authored over 100 academic papers and over 20 patents and has received over 10 academic awards. He is on the editorial board of Satellite Navigation and IEEE Access, the guest editor of the IEEE Internet of Things Journal, and a reviewer of over 20 IEEE journals.

Rong Yu

Rong Yu received the Bachelor of Medicine in 2019. she is currently pursuing the master’s degree Gastroenterology at Renmin Hospital of Wuhan University. Her research interests include the Basic and clinical research of gastrointestinal tumors and diagnosis and treatment of digestive endoscope.

Mingyue Dong

Mingyue Dong received the BS degree in School of Remote Sensing and Information Engineering from Wuhan University, China, in 2021. She is currently pursuing the PhD degree at State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing (LIESMARS), Wuhan University. Her research interests include 3D reconstruction, indoor and outdoor scene parsing.

Xiaoji Niu

Xiaoji Niu is a Professor of GNSS Research Center at Wuhan University in China. He got his PhD and bachelor degrees (with honor) from the Department of Precision Instruments at Tsinghua University in 2002 and 1997 respectively. He did post-doctoral research at the University of Calgary and worked as a senior scientist in SiRF Technology Inc.He is currently leading the integrated & intelligent navigation group (i2Nav). His research focuses on GNSS/INS integrations, low-cost navigation sensor fusion, and the relevant new applications. He has published 100+ academic papers and own 30+ patents.