{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,4]],"date-time":"2026-06-04T19:50:05Z","timestamp":1780602605736,"version":"3.54.1"},"reference-count":23,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2023,7,17]],"date-time":"2023-07-17T00:00:00Z","timestamp":1689552000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Korea Institute of Planning and Evaluation for Technology in Food, Agriculture, and Forestry","award":["project number 320001-4"],"award-info":[{"award-number":["project number 320001-4"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>In this study, a semi-active suspension based on a hydro-pneumatic mechanism was designed to minimize the ride vibration using a suspension control algorithm. The performance of the algorithm was critical for controlling the characteristics of the target tractor. A linear-quadratic-Gaussian (LQG) optimal control algorithm was designed as a semi-active suspension control algorithm. The plant model for developing this algorithm was based on the parameters of an actual tractor. The rear suspension deflection was represented by a Kalman-filter-based state observer feedback to estimate the state variables that were difficult to measure. The designed state observer of the LQG controller was validated in terms of an accuracy index. The estimated vertical velocity and acceleration accuracies of the cabin were 83% and 79%, respectively. The performance of the designed controller was validated in terms of a performance index by comparing the performance of a tractor equipped with a rear rubber mount with that of one equipped with a semi-active suspension. The peak and root-mean-square values of the vertical acceleration of the cabin were reduced by up to 48.97% and 47.06%, respectively. This study could serve as a basis for the application of the control algorithm to systems with similar characteristics, thereby reducing system costs.<\/jats:p>","DOI":"10.3390\/s23146474","type":"journal-article","created":{"date-parts":[[2023,7,18]],"date-time":"2023-07-18T01:46:02Z","timestamp":1689644762000},"page":"6474","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":22,"title":["Optimal Control of Semi-Active Suspension for Agricultural Tractors Using Linear Quadratic Gaussian Control"],"prefix":"10.3390","volume":"23","author":[{"given":"Da-Vin","family":"Ahn","sequence":"first","affiliation":[{"name":"Department of Biosystems Engineering, College of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea"},{"name":"Convergence Major in Global Smart Farm, College of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kyeongdae","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Biosystems Engineering, College of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jooseon","family":"Oh","sequence":"additional","affiliation":[{"name":"Department of Convergence Biosystems Engineering, Chonnam National University, Gwangju 61186, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1045-719X","authenticated-orcid":false,"given":"Jaho","family":"Seo","sequence":"additional","affiliation":[{"name":"Department of Automotive and Mechatronics Engineering, Ontario Tech University, 2000 Simcoe Street North, Oshawa, ON L1G 0C5, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jin Woong","family":"Lee","sequence":"additional","affiliation":[{"name":"Smart Agricultural Machinery R&D Group, Korea Institute of Industrial Technology, Gimje 54325, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0018-2310","authenticated-orcid":false,"given":"Young-Jun","family":"Park","sequence":"additional","affiliation":[{"name":"Department of Biosystems Engineering, College of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea"},{"name":"Convergence Major in Global Smart Farm, College of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea"},{"name":"Research Institute for Agriculture and Life Science, Seoul National University, Seoul 08826, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,7,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"205","DOI":"10.1016\/0022-4898(95)00017-8","article-title":"Tractor ride vibration\u2014A review","volume":"32","author":"Prasad","year":"1995","journal-title":"J. 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