Dissertation Defense - Hakan Çetin (PHDEE)

Hakan Çetin – Ph.D. Electrical and Electronics Engineering

Asst. Prof. Polat Şendur – Advisor

Asst. Prof. Göksenin Yaralıoğlu – Co-Advisor

Date: 18.06.2021

Time: 17:00-18:00

Location: This meeting will be held ONLINE. Please send an e-mail to gizem.bakir@ozyegin.edu.tr in order to participate in this defense.

ANALYSIS OF MODE MATCHED GYROSCOPES

Thesis Committee:

Asst. Prof. Polat  Şendur, Özyeğin University

Assoc. Prof.  Cenk Demiroğlu, Özyeğin University

Asst. Prof.  Özgür Ertunç, Özyeğin University

Assoc.  Prof.  Ayhan Bozkurt, Sabancı University

Asst.  Prof.  Birkan Tunç, Yeditepe University

Abstract:

The aim of this thesis is to characterize the mode-matched vibratory gyroscopes in terms of noise and stability. Furthermore, the mode-matched wave coupling in rotating rod systems due to the Coriolis Effect is explored in order to provide a basis for novel gyroscope structures. This thesis is composed of two parts. In the first part, the noise analysis of the mode-matched vibratory gyroscope is discussed with emphasis on MEMS gyroscope. Various mode-matched gyroscope architectures have been proposed and their noise performances have been analyzed in the literature. However, in most of these analyses, zero-rate output was considered and the noise analysis for dynamic cases was ignored. In the first part, we demonstrate the noise analysis of mode-matched vibratory gyroscope using the power spectral density (PSD) and the Allan deviation methods while a non-zero rate is applied to the gyroscope. We show that ARW (Angle Random Walk) increases proportionally with the rotation rate for the open-loop and the force to rebalance operation modes.

In the second part, vibration analysis of rods that are subjected to rotation is presented. It is shown that flexural-flexural, longitudinal-flexural and torsional-flexural wave coupling occurs due to the Coriolis Effect. We also show that for different drive frequency (ω) and rotation rate (Ω), wave couplings exhibit different characteristics. Based on the several case studies, it is found that the sizes of the rod structures are not suitable enough for the sensor applications, except for the case of flexural-flexural wave coupling. Thus, the flexural wave that couples with its conjugate flexural mode can be used to measure the rotation rate applied about the direction of propagation, where the gyro structure can be miniaturized in small scales by the MEMS technology. Based on this observation, we proposed a novel cylindrical rod gyroscope using the coupled flexural-flexural wave propagation.

Bio: 

Hakan Cetin received the B.Sc. and M.Sc.    degrees in electrical engineering from Özyeğin University,  Istanbul,  Turkey,  in  2014  and  2016,  respectively. He is currently pursuing a Ph.D. degree in electrical engineering from Özyeğin University, Istanbul, Turkey. His research interest includes vibration, acoustics, acoustofluidics, MEMS sensors and inertial sensors.