{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,13]],"date-time":"2025-12-13T23:01:11Z","timestamp":1765666871324,"version":"build-2065373602"},"reference-count":20,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2009,11,30]],"date-time":"2009-11-30T00:00:00Z","timestamp":1259539200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Horizontal axis washing machines are water and energy efficient and becoming popular in the USA. Unlike a vertical axis washer, these do not have an agitator and depend solely on tumbling for the agitation of laundry during the wash cycle. However, due to the constant shifting of laundry during washing, the load distribution is often unbalanced during the high speed spin cycle. We present a displacement-based sensing method to detect unbalance early while the spin rate (rpm) is well below the resonance frequency so that corrective actions may be taken prior to the high speed spin cycle. Experimental and analytical characterizations of the sensor configuration are presented. Results show that the displacement sensor is more appropriate than an accelerometer for this application and offer the potential for a simple, reliable, low cost detection of unbalance.<\/jats:p>","DOI":"10.3390\/s91209559","type":"journal-article","created":{"date-parts":[[2009,11,30]],"date-time":"2009-11-30T11:14:33Z","timestamp":1259579673000},"page":"9559-9571","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["A Capacitive Displacement Sensing Technique for Early Detection of Unbalanced Loads in a Washing Machine"],"prefix":"10.3390","volume":"9","author":[{"given":"Melur  K.","family":"Ramasubramanian","sequence":"first","affiliation":[{"name":"Mechanical and Aerospace Engineering, North Carolina State University, Broughton Hall 1217, Box 7910, NCSU Campus, Raleigh, NC 27695, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Karthik","family":"Tiruthani","sequence":"additional","affiliation":[{"name":"Mechanical and Aerospace Engineering, North Carolina State University, Box 7910, NCSU Campus, Raleigh, NC 27695, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2009,11,30]]},"reference":[{"key":"ref_1","unstructured":"Dienes, M., Fett, J., and Scharf, L. (1984). Dynamic simulation of the initial start-up of a washing machine using the programs CADDS4X and ADAMS. Phillips Appliance."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"301","DOI":"10.1006\/jsvi.1995.0595","article-title":"On the problem of oscillatory walk of automatic washing machines","volume":"188","author":"Conrad","year":"1995","journal-title":"J. Sound Vib."},{"key":"ref_3","unstructured":"Adolfsson, J. (2001). Passive control of mechanical systems: bipedal walking and autobalancing. [PhD thesis, Department of Mechanics, Royal Institute of Technology]."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"705","DOI":"10.1098\/rsta.2007.2123","article-title":"Investigation of a multi-ball, automatic dynamic balancing mechanism for eccentric rotors","volume":"366","author":"Green","year":"2008","journal-title":"Phil. Trans. R. Soc A."},{"key":"ref_5","unstructured":"Haberl, I., and Trangoni, M. (1999). Dynamic Balancing Method for a Washing Machine. (US Patent 5,862,553)."},{"key":"ref_6","unstructured":"Ryan, K.F., and Sribar, R. (2000). Horizontal Axis Clothes Washing Machine with Balance Rings. (US Patent 6,158,257)."},{"key":"ref_7","unstructured":"Cummings, S. (2006). Washing Machine with Pumping Damper for Automatic Balancing. (US Patent 0,230,543 A1)."},{"key":"ref_8","unstructured":"Kim, J.Y., and Ryu, D.Y. (2008). Washing Machine having Ball Balancers. (US Patent 2008\/0110212 A1)."},{"key":"ref_9","unstructured":"Murray, P., Henderson, M.I., Marcetic, D., Marcinkiewicz, J.G., Sadasivam, V., and Rajarathnam, A.V. (2004). Method and System for Determining Washing Machine Load Unbalance. (US Patent 0,211,009 A1)."},{"key":"ref_10","unstructured":"Lee, D.S., and Kim, D.W. (2007). Apparatus for Sensing Type of Unbalance of Washing Machine and Method Thereof. (US Patent 0,039,104 A1)."},{"key":"ref_11","unstructured":"Park, C.J., Kim, C.H., and Kim, M.C. (2007). Unbalance Detection Method and Washing Machine Using the Same. (US Patent 0,044,247 A1)."},{"key":"ref_12","unstructured":"Zhang, Z., Xu, H., Conrad, D.C., and Slabbekoorn, S.D. (2007). Method and Apparatus for Monitoring Load Imbalance in a Washing Machine. (US Patent 7,296,445 B2)."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"410","DOI":"10.1016\/j.mechatronics.2008.09.006","article-title":"Control of magnetorheological dampers for vibration reduction in a washing machine","volume":"19","author":"Spelta","year":"2009","journal-title":"Mechatronics"},{"key":"ref_14","unstructured":"Chrzan, M.J., and Carlson, D.J. MR fluid sponge devices and their use in vibration control of washing machines. Newport Beach, CA, USA."},{"key":"ref_15","unstructured":"Analog Devices Available online: http:\/\/www.analog.com\/en\/sensors\/inertial-sensors\/adxl202\/products\/product.html\/ (accessed on November 3, 2009)."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"359","DOI":"10.1006\/mssp.1995.0029","article-title":"Formulation and implementation of parametric optimization of a washing machine suspension system","volume":"9","author":"Kiray","year":"1995","journal-title":"Mech. Syst. Signal Process"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"534","DOI":"10.1115\/1.2893862","article-title":"Modeling and Experimental Assessment of Suspension Dynamics of a Horizontal-Axis Washing Machine","volume":"120","author":"Kiray","year":"1998","journal-title":"J. Vib. Acoust. (Trans. ASME)"},{"key":"ref_18","unstructured":"Papadopoulos, E., and Papadimitriou, I. (, January July). Modeling, Design and Control of a Portable Washing Machine during the Spinning Cycle. Como, Italy."},{"key":"ref_19","unstructured":"Marsh, C., Taylor, S., Milliken, P., and Senaratne, G. Australian and New Zealand Mathematics in Industry Study Group, MISG. [23rd ed.]. 30 January 2006\u20133 February 2006."},{"key":"ref_20","unstructured":"Kelly, G.S. (1996). Schaum's Outline of Theory and Problems of Mechanical Vibrations, McGraw-Hill."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/9\/12\/9559\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T22:11:49Z","timestamp":1760220709000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/9\/12\/9559"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2009,11,30]]},"references-count":20,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2009,12]]}},"alternative-id":["s91209559"],"URL":"https:\/\/doi.org\/10.3390\/s91209559","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2009,11,30]]}}}