motions affect SSL estimation. Based on the insights gained,
we developed a motion planning algorithm for mobile robots
that optimizes movement to improve SSL accuracy. This
approach was then implemented on a robotic dog to assess
its effectiveness in real-world mobile robot applications. The
results demonstrate that, by combining just two microphones
with the proposed motion planning framework, the robot sig-
nificantly improves its SSL estimation.
Future work will aim to fully automate the gas leak detec-
tion framework within the robotic system. This includes
enhancing its ability to determine whether a sound source is
positioned in front of or behind the robot and enabling the
distinction between leakage sources and environmental noise.
Additionally, the integration of multiple sensing modalities
will be prioritized to improve gas leakage source localiza-
tion, ensuring reliability even under varying environmental
conditions.
REFERENCES
Abadi, N. R., A. W. Bahman, H. Peel, M. Nancekievill, C. Ballard, B.
Lennox, O. Marjanovic, and K. Groves. 2023. “CARMA II: A Ground
Vehicle for Autonomous Surveying of Alpha, Beta and Gamma Radia-
tion.” Frontiers in Robotics and AI 10:1137750. https://doi.org/10.3389/
frobt.2023.1137750.
Almadhoun, R., T. Taha, L. Seneviratne, J. Dias, and G. Cai. 2016. “A
Survey on Inspecting Structures Using Robotic Systems.” International
Journal of Advanced Robotic Systems 13 (6): 1729881416663664. https://doi.
org/10.1177/1729881416663664.
Ambati, P., K. M. Raj, and A. Joshuva. 2020. “A Review on Pipeline Inspec-
tion Robot.” In AIP Conference Proceedings Vol. 2311 (1): 060002. AIP
Publishing. https://doi.org/10.1063/5.0033998.
Brandstein, M. S., and H. F. Silverman. 1997. “A robust method for speech
signal time-delay estimation in reverberant rooms.” 1997 IEEE Interna-
tional Conference on Acoustics, Speech, and Signal Processing (Vol. 1):
375–378.
Carter, G. C. 1987. “Coherence and time delay estimation.” Proceedings of
the IEEE 75 (2): 236–255.
Carter, G. C., A. H. Nuttall, and P. G. Cable. 1973. “The smoothed coher-
ence transform.” Proceedings of the IEEE 61 (10): 1497–1498.
Coleman, T. F., and Y. Li. 1996. “An Interior Trust Region Approach for
Nonlinear Minimization Subject to Bounds.” SIAM Journal on Optimiza-
tion 6 (2): 418–45. https://doi.org/10.1137/0806023.
Delic, U. 2019. “Cavity Cooling by Coherent Scattering of a Levitated Nano-
sphere in Vacuum.” PhD diss., PhD thesis, University of Vienna.
Doshmanziari, R., H. Khaloozadeh, and A. Nikoofard. 2020. “Gas Pipeline
Leakage Detection Based on Sensor Fusion under Model-Based Fault
Detection Framework.” Journal of Petroleum Science and Engineering 184:
106581. https://doi.org/10.1016/j.petrol.2019.106581.
Drives &Controls. 14 July 2021. “Robot Dog Carries Acoustic Imager to
Inspect Plants Safely.” Drives &Controls: Automation for Manufacturing.
https://drivesncontrols.com/robot-dog-carries-acoustic-imager-to
-inspect-plants-safely/.
Eret, P., and C. Meskell. 2012. “Microphone Arrays as a Leakage Detection
Tool in Industrial Compressed Air Systems.” Advances in Acoustics and
Vibration 2012 (November): 1–10. https://doi.org/10.1155/2012/689379.
Fischer, B. 2016. “Optical Microphone Hears Ultrasound.” Nature Photonics
10 (6): 356–58. https://doi.org/10.1038/nphoton.2016.95.
Fischer, G. K. J., M. Bergau, D. A. Gómez-Rosal, A. Wachaja, J. Graeter, M.
Odenweller, U. Piechottka, F. Höflinger, N. Gosala, N. Wetzel, D. Büscher,
A. Valada, and W. Burgard. 2024. “Evaluation of a Smart Mobile Robotic
System for Industrial Plant Inspection and Supervision.” IEEE Sensors
Journal 24 (12): 19684–97. https://doi.org/10.1109/JSEN.2024.3390622.
Fletcher, N. H. 2014. “Animal Bioacoustics,” in Springer Handbook of Acous-
tics, pp. 821–41 (ed. T. D. Rossing). Springer Handbooks. New York, NY:
Springer New York. https://doi.org/10.1007/978-1-4939-0755-7_19.
Fluke. “Fluke ii900 Industrial Acoustic Imager.” 2021. https://www.fluke.
com/en-us/product/industrial-imaging/sonic-industrial-imager-ii900.
Francis, A., S. Li, C. Griffiths, and J. Sienz. 2022. “Gas Source Localization
and Mapping with Mobile Robots: A Review.” Journal of Field Robotics 39
(8): 1341–73. https://doi.org/10.1002/rob.22109.
Fu, X. G., G. Z. Yan, B. Yan, and H. Liu. 2006. “A New Robot System for
Auto-Inspection of Intersected Welds of Pipes Used in Nuclear Power
Stations.” International Journal of Advanced Manufacturing Technology 28
(5-6): 596–601. https://doi.org/10.1007/s00170-004-2384-0.
Guizzo, E. 2019. “By Leaps and Bounds: An Exclusive Look at How Boston
Dynamics Is Redefining Robot Agility.” IEEE Spectrum 56 (12): 34–39.
https://doi.org/10.1109/MSPEC.2019.8913831.
Ilyas, M., H. Y. Khaw, N. M. Selvaraj, Y. Jin, X. Zhao, and C. C. Cheah. 2021.
“Robot-Assisted Object Detection for Construction Automation: Data and
Information-Driven Approach.” IEEE/ASME Transactions on Mechatronics
26 (6): 2845–56. https://doi.org/10.1109/TMECH.2021.3100306.
Jiang, B., A. P. Sample, R. M. Wistort, and A. V. Mamishev. 2005. “Autono-
mous Robotic Monitoring of Underground Cable Systems.” Proceedings of
the 12th International Conference on Advanced Robotics: 673–79. https://
doi.org/10.1109/ICAR.2005.1507481.
Knapp, C., and G. Carter. 1976. “The generalized correlation method for
estimation of time delay.” IEEE Transactions on Acoustics, Speech, and
Signal Processing 24 (4): 320–327.
Kwon, B., Y. Park, and Y.-S. Park. 2010. “Analysis of the GCC-PHAT tech-
nique for multiple sources.” ICCAS 2010: 2070–2073. Gyeonggi-do, South
Korea.
Levenberg, K. 1944. “A Method for the Solution of Certain Non-Linear
Problems in Least Squares.” Quarterly of Applied Mathematics 2 (2):
164–68. https://doi.org/10.1090/qam/10666.
Li, J., Y. Li, X. Huang, J. Ren, H. Feng, Y. Zhang, and X. Yang. 2021.
“High-Sensitivity Gas Leak Detection Sensor Based on a Compact Micro-
phone Array.” Measurement 174 (April): 109017. https://doi.org/10.1016/j.
measurement.2021.109017.
Liang, W., L. Zhang, Q. Xu, and C. Yan. 2013. “Gas Pipeline Leakage Detec-
tion Based on Acoustic Technology.” Engineering Failure Analysis 31 (July):
1–7. https://doi.org/10.1016/j.engfailanal.2012.10.020.
Liao, P., M. Cai, Y. Shi, and Z. Fan. 2013. “Compressed Air Leak Detection
Based on Time Delay Estimation Using a Portable Multi-Sensor Ultrasonic
Detector.” Measurement Science &Technology 24 (5): 055102. https://doi.
org/10.1088/0957-0233/24/5/055102.
Liu, C., Y. Li, L. Fang, and M. Xu. 2017. “Experimental Study on a
De-Noising System for Gas and Oil Pipelines Based on an Acoustic Leak
Detection and Location Method.” International Journal of Pressure Vessels
and Piping 151 (March): 20–34. https://doi.org/10.1016/j.ijpvp.2017.02.001.
Ma, T., S. Liu, and H. Xiao. 2020. “Location of Natural Gas Leakage Sources
on Offshore Platform by a Multi-Robot System Using Particle Swarm Opti-
mization Algorithm.” Journal of Natural Gas Science and Engineering 84:
103636. https://doi.org/10.1016/j.jngse.2020.103636.
Mitchell, D., P. D. E. Baniqued, A. Zahid, A. West, B. N. R. Abadi, B.
Lennox, B. Liu, B. Kizilkaya, D. Flynn, and D. J. Francis et al. 2023.
“Lessons Learned: Symbiotic Autonomous Robot Ecosystem for Nuclear
Environments.” IET Cyber-Systems and Robotics 5 (4): e12103. https://doi
.org/10.1049/csy2.12103.
ME
|
LEAKLOCALIZATION
60
M AT E R I A L S E V A L U AT I O N • A P R I L 2 0 2 5

Munoz, N. E., and D. T. Blumstein. 2020. “Optimal Multisensory Integra-
tion” (ed. L. Simmons). Behavioral Ecology 31 (1): 184–93. https://doi
.org/10.1093/beheco/arz175.
Populin, L. C., and T. C. T. Yin. 1998. “Pinna Movements of the Cat during
Sound Localization.” Journal of Neuroscience: The Official Journal of the
Society for Neuroscience 18 (11): 4233–43. https://doi.org/10.1523/
JNEUROSCI.18-11-04233.1998.
Purohit, H., R. Tanabe, T. Ichige, T. Endo, Y. Nikaido, K. Suefusa, and Y.
Kawaguchi. 2019. “MIMII Dataset: Sound Dataset for Malfunctioning
Industrial Machine Investigation and Inspection.” Proceedings of the
Detection and Classification of Acoustic Scenes and Events 2019 Workshop
(DCASE 2019): 209-213. https://doi.org/10.33682/m76f-d618.
Rascon, C., and I. Meza. 2017. “Localization of Sound Sources in Robotics:
A Review.” Robotics and Autonomous Systems 96:184–210. https://doi.
org/10.1016/j.robot.2017.07.011.
Ruhland, J. L., A. E. Jones, and T. C. T. Yin. 2015. “Dynamic Sound Local-
ization in Cats.” Journal of Neurophysiology 114 (2): 958–68. https://doi.
org/10.1152/jn.00105.2015.
Schenck, A., W. Daems, and J. Steckel. 2019. “AirleakSlam: Detec-
tion of Pressurized Air Leaks Using Passive Ultrasonic Sensors.”
2019 IEEE SENSORS: 1–4. Montreal: IEEE. https://doi.org/10.1109/
SENSORS43011.2019.8956631.
Thewissen, J. G. M. H., and S. Nummela. 2008. Sensory Evolution on the
Threshold: Adaptations in Secondarily Aquatic Vertebrates. Univ. of Cali-
fornia Press.
Wang, F., W. Lin, Z. Liu, S. Wu, and X. Qiu. 2017. “Pipeline Leak Detection
by Using Time-Domain Statistical Features.” IEEE Sensors Journal 17 (19):
6431–42. https://doi.org/10.1109/JSEN.2017.2740220.
Wang, S., and X. Yao. 2020. “Aeroacoustics Measurement of the Gas
Leakage Rate for Single Hole.” Review of Scientific Instruments 91 (4):
045102. https://doi.org/10.1063/1.5132999.
Wang, X., T. Luo, and Y. Lei. 2022. “Inspection Robot Design for Under-
water Structure in Complex Flow Environment.” 2022 International
Conference on Service Robots (ICoSR): 193–197. https://doi.org/10.1109/
ICoSR57188.2022.00043.
Yamamoto, S. 1992. “Development of Inspection Robot for Nuclear
Power Plant.” Proceedings of the 1992 IEEE International Conference
on Robotics and Automation (Vol. 2): 1559–60. https://doi.org/10.1109/
ROBOT.1992.220030.
Yan, Y., Y. Shen, X. Cui, and Y. Hu. 2018. “Localization of Multiple Leak
Sources Using Acoustic Emission Sensors Based on MUSIC Algorithm and
Wavelet Packet Analysis.” IEEE Sensors Journal 18 (23): 9812–20. https://doi.
org/10.1109/JSEN.2018.2871720.
Ye, W., B. Zhou, Z. Tu, X. Xiao, J. Yan, T. Wu, F. Wu, C. Zheng, and F. K.
Tittel. 2020. “Leakage Source Location Based on Gaussian Plume Diffusion
Model Using a Near-Infrared Sensor.” Infrared Physics &Technology 109:
103411. https://doi.org/10.1016/j.infrared.2020.103411.
Young, E. D., J. J. Rice, and S. C. Tong. 1996. “Effects of Pinna Position on
Head-Related Transfer Functions in the Cat.” Journal of the Acoustical
Society of America 99 (5): 3064–76. https://doi.org/10.1121/1.414883.
Zhang, X. 2022. “VideoGasNet: Deep Learning for Natural Gas Methane
Leak Classification Using an Infrared Camera.” Energy 238 (Part B): 121516.
https://doi.org/10.1016/j.energy.2021.121516.
Zhao, M., T. Huang, C. Liu, M. Chen, S. Ji, D. M. Christopher, and X. Li.
2021. “Leak Localization Using Distributed Sensors and Machine Learning
for Hydrogen Releases from a Fuel Cell Vehicle in a Parking Garage.”
International Journal of Hydrogen Energy 46 (1): 1420–1433. https://doi.
org/10.1016/j.ijhydene.2020.09.218.
Zheng, X., Q. Wang, S. Xue, and C. Zheng. 2021. “A Beamforming-Based
Joint Estimation Method for Gas Pipeline Leak Localization.” Measurement
177: 109264. https://doi.org/10.1016/j.measurement.2021.109264.
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