Next Article in Journal
Modeling and Compensation of Random Drift of MEMS Gyroscopes Based on Least Squares Support Vector Machine Optimized by Chaotic Particle Swarm Optimization
Previous Article in Journal
Comparing the Performance of Indoor Localization Systems through the EvAAL Framework
Article Menu
Issue 10 (October) cover image

Export Article

Open AccessArticle
Sensors 2017, 17(10), 2333; https://doi.org/10.3390/s17102333

Control Design and Digital Implementation of a Fast 2-Degree-of-Freedom Translational Optical Image Stabilizer for Image Sensors in Mobile Camera Phones

Institute of Electrical and Control Engineering, National Chaio Tung University, Hsinchu City 300, Taiwan
*
Author to whom correspondence should be addressed.
Received: 1 August 2017 / Revised: 29 September 2017 / Accepted: 10 October 2017 / Published: 13 October 2017
(This article belongs to the Section Physical Sensors)
View Full-Text   |   Download PDF [10231 KB, uploaded 24 October 2017]   |  

Abstract

This study presents design, digital implementation and performance validation of a lead-lag controller for a 2-degree-of-freedom (DOF) translational optical image stabilizer (OIS) installed with a digital image sensor in mobile camera phones. Nowadays, OIS is an important feature of modern commercial mobile camera phones, which aims to mechanically reduce the image blur caused by hand shaking while shooting photos. The OIS developed in this study is able to move the imaging lens by actuating its voice coil motors (VCMs) at the required speed to the position that significantly compensates for imaging blurs by hand shaking. The compensation proposed is made possible by first establishing the exact, nonlinear equations of motion (EOMs) for the OIS, which is followed by designing a simple lead-lag controller based on established nonlinear EOMs for simple digital computation via a field-programmable gate array (FPGA) board in order to achieve fast response. Finally, experimental validation is conducted to show the favorable performance of the designed OIS; i.e., it is able to stabilize the lens holder to the desired position within 0.02 s, which is much less than previously reported times of around 0.1 s. Also, the resulting residual vibration is less than 2.2–2.5 μm, which is commensurate to the very small pixel size found in most of commercial image sensors; thus, significantly minimizing image blur caused by hand shaking. View Full-Text
Keywords: optical image stabilizer (OIS); image blur; nonlinear equations of motion (EOMs); lead-lag controllers; field-programmable gate array (FPGA); mobile camera phones optical image stabilizer (OIS); image blur; nonlinear equations of motion (EOMs); lead-lag controllers; field-programmable gate array (FPGA); mobile camera phones
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).
SciFeed

Share & Cite This Article

MDPI and ACS Style

Wang, J.H.-S.; Qiu, K.-F.; Chao, P.C.-P. Control Design and Digital Implementation of a Fast 2-Degree-of-Freedom Translational Optical Image Stabilizer for Image Sensors in Mobile Camera Phones. Sensors 2017, 17, 2333.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Sensors EISSN 1424-8220 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top