Browsing by Author "Chang, Cheng-Yang"

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Design and Simulation of a New Dual-Axis Control Input Piezoelectric Gyroscope
(2016)
Chang, Cheng-Yang
;
Chen, Tsung-Lin
;
機械工程學系
;
Department of Mechanical Engineering
This paper proposed a new design of the dual-axis control input, dual-axis position measurement piezoelectric gyroscope. Using piezoelectric actuation/sensing to implement this gyroscope can be much more difficult than the conventional gyroscope, which equips only single-axis control input and dual-axis position measurement. This is because multiple mode shapes may exist in the flexure deformation, which complicates the relation between flexure deformation and the proof mass position. This paper solves this multiple-mode-shape problem by designing the location and dimensions of the electrodes such that the piezoelectric force would not excite multiple mode shapes and the voltage output of the sensing electrodes responds only to specific mode shapes. The proposed design achieves a sensitivity of 8 mu v/deg/sec for the angular rate sensing and a quadrature error of 0.007%. The low quadrature error could be one of the advantages of sensing the position of the proof mass via sensing the specific deformed shape of the flexure.
Design, Fabrication, and Modeling of a Novel Dual-Axis Control Input PZT Gyroscope
(2017-11-01)
Chang, Cheng-Yang
;
Chen, Tsung-Lin
;
機械工程學系
;
Department of Mechanical Engineering
Conventional gyroscopes are equipped with a single-axis control input, limiting their performance. Although researchers have proposed control algorithms with dual-axis control inputs to improve gyroscope performance, most have verified the control algorithms through numerical simulations because they lacked practical devices with dual-axis control inputs. The aim of this study was to design a piezoelectric gyroscope equipped with a dual-axis control input so that researchers may experimentally verify those control algorithms in future. Designing a piezoelectric gyroscope with a dual-axis control input is more difficult than designing a conventional gyroscope because the control input must be effective over a broad frequency range to compensate for imperfections, and the multiple mode shapes in flexural deformations complicate the relation between flexural deformation and the proof mass position. This study solved these problems by using a lead zirconate titanate (PZT) material, introducing additional electrodes for shielding, developing an optimal electrode pattern, and performing calibrations of undesired couplings. The results indicated that the fabricated device could be operated at 5.5 +/- 1 kHz to perform dual-axis actuations and position measurements. The calibration of the fabricated device was completed by system identifications of a new dynamic model including gyroscopic motions, electromechanical coupling, mechanical coupling, electrostatic coupling, and capacitive output impedance. Finally, without the assistance of control algorithms, the open loop sensitivity of the fabricated gyroscope was 1.82 V/deg/s with a nonlinearity of 9.5% full-scale output. This sensitivity is comparable with those of other PZT gyroscopes with single-axis control inputs.