Trapped-energy vibratory gyroscopes using a partially-polarized piezoelectric ceramic plate with plano-mesa structure

A new trapped-energy Vibratory gyroscope which uses the thickness-shear vibrations in a partially-polarized piezoelectric ceramic plate with plano-mesa structure is proposed. A resonator for the gyroscope has three electrodes for excitation and detection of the vibrations and the electrodes are deposited in the central region of the plate. By choosing the electrode dimensions appropriately, the resonant frequencies of two orthogonal thickness-shear vibrations almost coincide with each other. The trapped-energy gyroscope consists of the resonator and a driving and detecting circuit. A trapped-energy gyroscope on a PZT plate of 25 mm-square and 2 mm-thick is constructed, and its experimental results are presented. The result show that high reliable gyroscopes of easy support can be realized because of the energy trapping effect and the detection sensitivity of 16 mV/deg/sec, which the driving voltage is 2 Vp-p and the total gain of the detecting circuit is about 80 dB.