Development of New Optical Image Stabilization System and Implementation of Digital Logic Chip
| Autor: | Qiu, Kang-Fu, 邱康富 |
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| Rok vydání: | 2017 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 106 This study proposes design, dynamic modeling and drive system of a two degree-of-freedom (DOF) translation optical image stabilizer (OIS) in the camera embedded in the mobile devices. This OIS differs from the previous designs since it stabilizes the shift between lens and image sensor by a two-DOF translational mechanism that is actuated by voice coil motors (VCM). It can provide a solution for a fuzzy image due to the hand-shaking. Such category of technology will enable cameras-phones images reaching more clear effect by using a micro-actuator to move the lens for compensation when taking photos. Currently, the micro-actuators of the OIS system used in mobile phone cameras are mainly based on the VCM technology. In this study, the control design uses the two-axis translational OIS, Hall sensors measure the displacement, and also uses a VCM micro-actuator to control the translational position of the lens. The work can be divided into three parts: the analysis of an OIS system and building x/y axis dynamic equation of OIS, the phase lead-lag controller design, and the experimental verification. In the first part, an OIS system is taken as a controlled target for the experiment, and the frequency response analyzer is used to measure the Bode plot and the analysis system of the equations of motion. Further, the second part is to conduct the phase lead-lag controller design of the OIS system. Lastly, the third part is the simulation of the controller and the experimental verification. After verifying the effectiveness of the controller through the Matlab simulation and the experiment, the system can be built with the actual circuit. In others words, this whole proposal can divide into three parts: (1) standardized system identification for OIS system; (2)design, simulation and validation of the Lead-Integral controller for varying parameters of OIS modules; (3)the digital control system development for OIS by Field-Programmable Gate Array (FPGA) evaluation and Matlab Simulink to modify parameters. The control ability of the OIS system which have moving range realized by FPGA can make the settling time be less than 0.02 second, which is better than the settling time around 0.1 seconds in previous studies, with a steady-state error less than 2%. Moreover, the OIS system can reduce the amount of movement to within 2.5μm averagely at 1-20Hz. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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