TY - BOOK
T1 - Design rules for a MEMS gyroscope actuated by parametric resonance
AU - van Beek, H.
A2 - Nijmeijer, H.
A2 - Shaw, S.W.
N1 - Internship report. - DC 2011.022
PY - 2011
Y1 - 2011
N2 - A linear vibratory MEMS gyroscope is an angular rate sensor. The operation principle is
based on two orthogonal vibration modes, where energy from the drive mode is transferred
due to the Coriolis effect into the sense mode. The sense mode vibration amplitude is
proportional to the angular rate that is subject to the gyroscope. Mismatch between the natural
frequencies of the modes and mechanical cross coupling of the modes degrades the
performance of such a MEMS gyroscope. A novel MEMS gyroscope actuated by parametric
resonance uses nonlinear vibration phenomena to provide a design that is more robust to
frequency mismatch. The goal of this work is to determine design rules and recommendations,
that is, the selection of device and operating parameters, for a good design of such a MEMS
gyroscope actuated by parametric resonance.
An analytical nonlinear model to describe the drive and sense dynamics has been developed.
Using the method of averaging and the computer program AUTO, the influence of all the
parameters present in the equations of motion has been analysed. The observed parameter
influences can be translated into design rules for a MEMS gyroscope actuated by parametric
resonance.
First, it is advised to make the linear electrostatic excitation amplitude as low as possible; this
maximizes the unstable zero solution window that can act as an operating frequency window.
Second, the sense natural frequency should be placed in the middle of the operating frequency
window; this maximizes the robustness of the gyroscope. Third, the excitation frequency of
the gyroscope should be chosen at a frequency slightly lower than the sense natural frequency,
since the frequency response is most sensitive for changes in angular rate in this region.
Fourth, there is a trade-off between a large sense amplitude which results in a large sensitivity
and a large linear angular rate range.
Fifth, mechanical cross coupling and damping have a small negative effect on the sensitivity
of the gyroscope; it is therefore recommended to keep these as small as possible.
AB - A linear vibratory MEMS gyroscope is an angular rate sensor. The operation principle is
based on two orthogonal vibration modes, where energy from the drive mode is transferred
due to the Coriolis effect into the sense mode. The sense mode vibration amplitude is
proportional to the angular rate that is subject to the gyroscope. Mismatch between the natural
frequencies of the modes and mechanical cross coupling of the modes degrades the
performance of such a MEMS gyroscope. A novel MEMS gyroscope actuated by parametric
resonance uses nonlinear vibration phenomena to provide a design that is more robust to
frequency mismatch. The goal of this work is to determine design rules and recommendations,
that is, the selection of device and operating parameters, for a good design of such a MEMS
gyroscope actuated by parametric resonance.
An analytical nonlinear model to describe the drive and sense dynamics has been developed.
Using the method of averaging and the computer program AUTO, the influence of all the
parameters present in the equations of motion has been analysed. The observed parameter
influences can be translated into design rules for a MEMS gyroscope actuated by parametric
resonance.
First, it is advised to make the linear electrostatic excitation amplitude as low as possible; this
maximizes the unstable zero solution window that can act as an operating frequency window.
Second, the sense natural frequency should be placed in the middle of the operating frequency
window; this maximizes the robustness of the gyroscope. Third, the excitation frequency of
the gyroscope should be chosen at a frequency slightly lower than the sense natural frequency,
since the frequency response is most sensitive for changes in angular rate in this region.
Fourth, there is a trade-off between a large sense amplitude which results in a large sensitivity
and a large linear angular rate range.
Fifth, mechanical cross coupling and damping have a small negative effect on the sensitivity
of the gyroscope; it is therefore recommended to keep these as small as possible.
M3 - Report
BT - Design rules for a MEMS gyroscope actuated by parametric resonance
PB - Eindhoven University of Technology
CY - Eindhoven
ER -