Electrical and Electronics Engineering PhD Thesis Defense by Abasin Ulasyar

KOÇ UNIVERSITY

GRADUATE SCHOOL OF SCIENCES & ENGINEERING

ELECTRICAL AND ELECTRONICS ENGINEERING

PhD THESIS DEFENSE BY ABASIN ULASYAR

Title: Design and Adaptive Control of Magnetorhelogical Damper for Washing Machine.

Speaker: Abasin Ulasyar

Time: August 29, 2018, 13:00

Place: MARC Lab, ENG B203

Koç University

Rumeli Feneri Yolu

Sariyer, Istanbul

Thesis Committee Members:

Prof. Dr. Hakan Ürey (Advisor, Koç University)

Prof. Dr. İsmail Lazoğlu (Co-Advisor, Koç University)

Asst. Prof. Dr. Sedat Nizamoğlu (Koç University)

Assoc. Prof. Dr. Funda Acar Yağci (Koç University)

Asst. Prof. Dr. Ali Fuat Ercenç (Istanbul Technical University)

Asst. Prof. Dr. Seyed Ehsan Layegh Khavidaki (MEF University)

Abstract:

This thesis primarily focuses on the design, analysis, active and adaptive control of a new magneto rheological damper for the vibration attenuation of washing machine. The MR damper provides variable and controlled damper for all the frequency ranges of washing machine. The damping force of MR damper is selected according to the desired value of force required inside washing machine. The design of MR damper is made by using finite element analysis and reluctance method. This research has worked on three different prototypes of MR damper. Furthermore, a special experimental test-bed is established for testing all the prototypes of MR damper.  The MR damper is tested with commercially available MR fluid. The performance of MR damper is also evaluated using different samples of MR fluid synthesized by the Koç University chemistry lab.

This thesis introduces a novel design of adaptive controller for the MR damper inside the washing machine, which is not available in the literature and in any commercial washing machine yet. A sliding mode control theory is used to develop a controller for the MR damper. In the sliding mode control, a sliding surface is defined in terms of the state error and convergence parameter. A nonlinear terminal sliding surface is proposed for the whole system in order to counter any nonlinearities, disturbances and unmodeled dynamics. All the three prototypes of MR dampers are tested in the washing machine with significant reduction of vibrations. Initially, the first prototype of MR damper is tested and observed that the MR damper attenuate 75 % vibrations in terms of displacement as compared to the passive dampers in washing machine. However after using second prototype of MR dampers and the designed adaptive control, it is seen that the MR dampers have reduced 85 % vibrations of washing machine in terms of displacement with fast response time. Besides this, the temperature of MR dampers are also measured successfully at inside and outside surfaces of MR damper for its full cycle.