{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,10]],"date-time":"2026-05-10T16:23:00Z","timestamp":1778430180422,"version":"3.51.4"},"reference-count":18,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2019,6,4]],"date-time":"2019-06-04T00:00:00Z","timestamp":1559606400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["No. 51777151"],"award-info":[{"award-number":["No. 51777151"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"name":"National Key R&amp;D Program of China","award":["No. 2016YFB0901200"],"award-info":[{"award-number":["No. 2016YFB0901200"]}]},{"name":"Shaanxi Provincial Key Technologies R&amp;D Programme","award":["2016GY-001"],"award-info":[{"award-number":["2016GY-001"]}]},{"name":"Open Research Fund of State Key Laboratory of Rail Traffic Control and Safety","award":["RCS2017K006"],"award-info":[{"award-number":["RCS2017K006"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>In industrial production processes, rotational speed is a key parameter for equipment condition monitoring and fault diagnosis. To achieve rotational speed measurement of rotational equipment under a condition of high temperature and heavy dust, this article proposes a digital approach using an electrostatic sensor. The proposed method utilizes a strip of a predetermined material stuck on the rotational shaft which will accumulate a charge because of the relative motion with the air. Then an electrostatic sensor mounted near the strip is employed to obtain the fluctuating signal related to the rotation of the charged strip. Via a signal conversion circuit, a square wave, the frequency of which equals that of the rotation shaft can be obtained. Having the square wave, the M\/T method and T method are adopted to work out the rotational speed. Experiments were conducted on a laboratory-scale test rig to compare the proposed method with the auto-correlation method. The largest relative errors of the auto-correlation method with the sampling rate of 2 ksps, 5 ksps are 3.2% and 1.3%, respectively. The relative errors using digital approaches are both within \u00b14\u2030. The linearity of the digital approach combined with the M\/T method or T method is also superior to that of the auto-correlation method. The performance of the standard deviations and response speed was also compared and analyzed to show the priority of the digital approach.<\/jats:p>","DOI":"10.3390\/s19112540","type":"journal-article","created":{"date-parts":[[2019,6,4]],"date-time":"2019-06-04T04:26:40Z","timestamp":1559622400000},"page":"2540","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":31,"title":["Digital Approach to Rotational Speed Measurement Using an Electrostatic Sensor"],"prefix":"10.3390","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9272-3104","authenticated-orcid":false,"given":"Lin","family":"Li","sequence":"first","affiliation":[{"name":"State Key Laboratory of Power Equipment and Electrical Insulation, Xi\u2019an Jiaotong University, Xi\u2019an 710049, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hongli","family":"Hu","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Power Equipment and Electrical Insulation, Xi\u2019an Jiaotong University, Xi\u2019an 710049, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yong","family":"Qin","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Rail Traffic Control and Safety, Beijing Jiaotong University, Beijing 100044, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kaihao","family":"Tang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Power Equipment and Electrical Insulation, Xi\u2019an Jiaotong University, Xi\u2019an 710049, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2019,6,4]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"3068","DOI":"10.1063\/1.1149057","article-title":"High resolution optical shaft encoder for motor speed control based on an optical disk pick-up","volume":"69","author":"Yeh","year":"1998","journal-title":"Rev. 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