{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,19]],"date-time":"2026-04-19T15:45:11Z","timestamp":1776613511784,"version":"3.51.2"},"reference-count":24,"publisher":"Fuji Technology Press Ltd.","issue":"2","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JRM","J. Robot. Mechatron."],"published-print":{"date-parts":[[2026,4,20]]},"abstract":"<jats:p>In this study, we present a novel autonomous excavation method that achieves high efficiency under varying soil conditions.   This method consists of two main steps, including first estimating the density of the soil and then generating an optimal excavation path based on the estimated density.   The proposed method estimates soil density by taking advantage of the bulking phenomenon, which refers to an increase in the volume of excavated soil.   This estimation relies solely on 3D point-cloud data obtained before and after excavation.   Using the estimated soil density, an optimal excavation path is generated by applying a genetic algorithm in a physics simulator that replicates both the hydraulic excavator and the target ground.   The algorithm explores a range of paths over multiple generations to find one that maximizes efficiency.   The effectiveness of the proposed method was verified through simulations and field experiments.   In particular, field experiments conducted in soft soil showed that the proposed method improved excavation efficiency by 27.7% compared with a baseline method using fixed parameters.<\/jats:p>","DOI":"10.20965\/jrm.2026.p0672","type":"journal-article","created":{"date-parts":[[2026,4,19]],"date-time":"2026-04-19T15:02:06Z","timestamp":1776610926000},"page":"672-684","source":"Crossref","is-referenced-by-count":0,"title":["Soil-Adaptive Autonomous Excavation: Bulking Factor-Based Soil Density Estimation and Excavation Path Optimization with a Genetic Algorithm"],"prefix":"10.20965","volume":"38","author":[{"given":"Ryosuke","family":"Yajima","sequence":"first","affiliation":[{"name":"Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shinya","family":"Katsuma","sequence":"additional","affiliation":[{"name":"Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shunsuke","family":"Hamasaki","sequence":"additional","affiliation":[{"name":"Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9755-8435","authenticated-orcid":true,"given":"Pang-jo","family":"Chun","sequence":"additional","affiliation":[{"name":"Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2147-2712","authenticated-orcid":true,"given":"Keiji","family":"Nagatani","sequence":"additional","affiliation":[{"name":"Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan"},{"name":"Faculty of Systems and Information Engineering, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6419-5535","authenticated-orcid":true,"given":"Genki","family":"Yamauchi","sequence":"additional","affiliation":[{"name":"Public Works Research Institute, 1-6 Minamihara, Tsukuba, Ibaraki 305-8516, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6367-4833","authenticated-orcid":true,"given":"Takeshi","family":"Hashimoto","sequence":"additional","affiliation":[{"name":"Public Works Research Institute, 1-6 Minamihara, Tsukuba, Ibaraki 305-8516, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1280-069X","authenticated-orcid":true,"given":"Atsushi","family":"Yamashita","sequence":"additional","affiliation":[{"name":"Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9482-497X","authenticated-orcid":true,"given":"Hajime","family":"Asama","sequence":"additional","affiliation":[{"name":"Tokyo College, Institutes for Advanced Study, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"8550","published-online":{"date-parts":[[2026,4,20]]},"reference":[{"key":"key-10.20965\/jrm.2026.p0672-1","unstructured":"B. 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Cheng, J. Pan, and R. Yang, \u201cCompact Reachability Map for Excavator Motion Planning,\u201d Proc. of the 2019 IEEE\/RSJ Int. Conf. on Intelligent Robots and Systems (IROS), pp. 2308-2313, 2019. https:\/\/doi.org\/10.1109\/IROS40897.2019.8968050","DOI":"10.1109\/IROS40897.2019.8968050"},{"key":"key-10.20965\/jrm.2026.p0672-5","doi-asserted-by":"crossref","unstructured":"S. Yoo, C.-G. Parks, S. H. You, and B. Lim, \u201cA Dynamics-based Optimal Trajectory Generation for Controlling an Automated Excavator,\u201d Proc. of the Institution of Mechanical Engineers, Part C: J. of Mechanical Engineering Science, Vol.224, Issue 10, pp. 2109-2119, 2010. https:\/\/doi.org\/10.1243\/09544062JMES2032","DOI":"10.1243\/09544062JMES2032"},{"key":"key-10.20965\/jrm.2026.p0672-6","doi-asserted-by":"crossref","unstructured":"H. Yamamoto, M. Moteki, H. Shao, K. Ootuki, Y. Yanagisawa, Y. Sakaida, A. Nozue, T. Yamaguchi, and S. 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Reece, \u201cPaper 2: The Fundamental Equation of Earth-Moving Mechanics,\u201d Proc. of the Institution of Mechanical Engineers, Vol.179, Issue 6, pp. 16-22, 1964. https:\/\/doi.org\/10.1243\/PIME_CONF_1964_179_134_02","DOI":"10.1243\/PIME_CONF_1964_179_134_02"},{"key":"key-10.20965\/jrm.2026.p0672-11","doi-asserted-by":"crossref","unstructured":"O. Luengo, S. Singh, and H. Cannon, \u201cModeling and Identification of Soil-tool Interaction in Automated Excavation,\u201d Proc. of the 1998 IEEE\/RSJ Int. Conf. on Intelligent Robots and Systems, pp. 1900-1906, 1998. https:\/\/doi.org\/10.1109\/IROS.1998.724873","DOI":"10.1109\/IROS.1998.724873"},{"key":"key-10.20965\/jrm.2026.p0672-12","doi-asserted-by":"crossref","unstructured":"O. M. U. Eraliev, K.-H. Lee, D.-Y. Shin, and C.-H. 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Rostek, \u201cEffect of Repeated Tractor Wheeling on Stress\/strain Properties and Consequences on Physical Properties in Structured Arable Soils,\u201d Soil & Tillage Research, Vol.73, Nos.1-2, pp. 101-106, 2003. https:\/\/doi.org\/10.1016\/S0167-1987(03)00103-X","DOI":"10.1016\/S0167-1987(03)00103-X"},{"key":"key-10.20965\/jrm.2026.p0672-15","doi-asserted-by":"crossref","unstructured":"A. A. G. Al-shammary, A. Z. Kouzani, A. Kaynak, S. Y. Khoo, M. Norton, and W. Gates, \u201cSoil Bulk Density Estimation Methods: A Review,\u201d Pedosphere, Vol.28, Issue 4, pp. 581-596, 2018. https:\/\/doi.org\/10.1016\/S1002-0160(18)60034-7","DOI":"10.1016\/S1002-0160(18)60034-7"},{"key":"key-10.20965\/jrm.2026.p0672-16","unstructured":"A. Nelson, \u201cDictionary of Mining,\u201d George Newnes, 1965."},{"key":"key-10.20965\/jrm.2026.p0672-17","unstructured":"A. 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Golparvar-Fard, \u201cConstruction Performance Monitoring via Still Images, Time-lapse Photos, and Video Streams: Now, Tomorrow, and the Future,\u201d Advanced Engineering Informatics, Vol.29, Issue 2, pp. 211-224, 2015. https:\/\/doi.org\/10.1016\/j.aei.2015.01.011","DOI":"10.1016\/j.aei.2015.01.011"},{"key":"key-10.20965\/jrm.2026.p0672-20","doi-asserted-by":"crossref","unstructured":"C. Yuan, S. Li, and H. Cai, \u201cVision-Based Excavator Detection and Tracking Using Hybrid Kinematic Shapes and Key Nodes,\u201d J. of Computing in Civil Engineering, Vol.31, Issue 1, Article No.04016038, 2016. https:\/\/doi.org\/10.1061\/(ASCE)CP.1943-5487.0000602","DOI":"10.1061\/(ASCE)CP.1943-5487.0000602"},{"key":"key-10.20965\/jrm.2026.p0672-21","doi-asserted-by":"crossref","unstructured":"Y. Sakaida, D. Chugo, H. Yamamoto, and H. 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