Identification of Anisoelasticity and Nonproportional Damping in MEMS Gyroscopes
A.S. Phani and A.A. Seshia
University of Cambridge, UK
Keywords: MEMS gyroscopes, nonproportional damping, anisoelasticity, modal coupling
A novel approach to identify nonproportional damping and structural anisoelasticities in vibratory MEMS gyroscopes is proposed in this paper. The proposed identification method is based on measured vibration data in the form of frequency response functions (FRFs.) A new identification method, called the matrix perturbation method, is proposed to identify nonproportional damping from the measured FRFs. This method is based on a perturbation expansion of the FRF matrix of the nonproportionally damped system in terms of the FRF matrix of the proportionally damped system. A closed form expression for the off-diagonal modal damping matrix is obtained based on the perturbation theory. The mass and stiffness matrices required by this method are obtained using the instrumental variable (IV) method, proposed by Fritzen, which is also used to identify the structural anisoelasticities.
Nanotech 2004 Conference Technical Program Abstract