Finite Element Method Simulation of a New One-Chip-Style Quartz Crystal Motion Sensor with Two Functions of Gyro and Acceleration Detection

Abstract

In this study, a new one-chip-style quartz crystal motion sensor which detects one-axis angular velocity and one-axis acceleration is proposed. Some characteristics of the sensor are simulated by the finite element method, along with some simulations of vibrational characteristics. This sensor is aimed to be used as a small wristwatch-type instrumentation unit to monitor some motions of the human body. The dimensions of the prototype sensor are 16 mm in length, 6 mm in width and 0.3 mm in thickness. The sensor consists of two parts with different functions; one part is a flatly supported vibratory gyrosensor using a quartz crystal trident-type tuning fork resonator and the other is a frequency-changeable type acceleration sensor. The results of simulations show, that the gyrosensor part has a good linearity of sensitivity, although it is also sensitive to an angular velocity which could not be detected fundamentally. It also has a good linearity of sensitivity for detection of acceleration.

Design, Fabrication, and Modeling of a Novel Dual-Axis Control Input PZT Gyroscope

“…The electromechanical coupling mainly comes from the indirect relationship between the proof mass displacement and flexure deformation. Additionally, this coupling can be suppressed by a careful design of the drive and sense electrodes [ 3 , 7 , 8 ]. The cross-axis mechanical coupling is commonly called the “quadrature error” in vibratory gyroscopes [ 9 ] and can be minimized by the orthogonality between two designated resonant motions [ 7 ].…”

“…The electrostatic coupling is commonly called the “electrical feedthrough”. This coupling is ignored in most gyroscope applications [ 7 , 8 ]. Due to the miniaturized device dimensions and fabrication errors, these unnecessary couplings are two to three orders larger than the gyroscopic coupling; thus, they should be minimized for stable device operation [ 6 , 10 ].…”

Improvement of Characteristics of Frequency-Change-Type Two-Axis Acceleration Sensor

“…1,2) The one-axis acceleration sensors using the same principle of operation were proposed. [3][4][5][6] In these sensors, acceleration is detected by the change in resonance frequency. In the sensor proposed by the authors, the bending vibrator used has extremely reduced displacements at both ends before fixing and hardly produces a leakage of vibration energy from both ends after fixing.…”