中国科学院机构知识库网格系统: 检索

Image-based numerical simulation of the local cyclic deformation behavior around cast pore in steel 期刊论文 OAI收割
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, 2016, 卷号: 678, 页码: 347-354
作者: Qian, LH; Cui, XN; Liu, S; Chen, MA; Ma, PH

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Cyclic deformation Low-cycle fatigue Local stress/strain behavior Image-based simulation Chaboche's model

LED display image correction based on computer simulation (EI CONFERENCE) 会议论文 OAI收割
2012 International Applied Mechanics, Mechatronics Automation Symposium, IAMMAS 2012, September 7, 2012 - September 9, 2012, Shenyang, Liaoning, China
Zheng X.-F.; Chang F.

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For the purposes of correcting the LED display image a method based on computer simulation is proposed. First the development of the LED display panel is introduced. Second analyze the causes of the problem which image in LED display panel has serious high nonuniformity and introduce the existed correction techniques which are used to reduce the nonuniformity of LED display image. Simultaneously point out the ground for shortcomings of these techniques. Third describe the principle of correction method based on computer simulation detail from two steps which are the luminous collection and luminous copulation. Forth describe the realization steps of this method in accordance with the third step. Finally this method is supplied in a LED display panel whose resolution is 640480. Experimental results show that this method is able to reduce the non-uniformity of images from 11.06% to 0.98%. (2012) Trans Tech Publications Switzerland.

Comparison and simulation of subpixel imaging modes for linear CCD (EI CONFERENCE) 会议论文 OAI收割
2012 3rd International Conference on Information Technology for Manufacturing Systems, ITMS 2012, September 8, 2012 - September 9, 2012, Qingdao, China
作者: Li Y.; He B.; Li Y.; Li Y.; Li Y.

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Subpixel technique of linear CCD is effective to enhance the spatial resolution without increasing the focal length of optics and reducing the pixel size. To compare image quality of two main subpixel imaging modes quincunx sampling and four-point sampling a method to quantitatively evaluate image quality of subpixel based on MTF was proposed. The MTF of quincunx and four-point sampling modes were derived. Analytical results shows that theoretical limiting resolution of quincunx sampling and four-point sampling is improved to 1.4 and 1.86 times respectively and MTF values at Nyquist frequency of two modes are increased by 0.1106 and 0.1679 respectively. MTFA in (0 0.5) of two subpixel imaging modes were calculated and results illustrates that four-point sampling offers much more improvement with image quality than quincunx sampling at the cost of double amount of data. A model for simulating subpixel imaging using Matlab was established and simulation results of spoke target verify the theoretical analysis. (2012) Trans Tech Publications Switzerland.

Design of motion adjusting system for space camera based on ultrasonic motor (EI CONFERENCE) 会议论文 OAI收割
International Symposium on Photoelectronic Detection and Imaging 2011: Space Exploration Technologies and Applications, May 24, 2011 - May 26, 2011, Beijing, China
作者: Sun Z.

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Drift angle is a transverse intersection angle of vector of image motion of the space camera. Adjusting the angle could reduce the influence on image quality. Ultrasonic motor (USM) is a new type of actuator using ultrasonic wave stimulated by piezoelectric ceramics. They have many advantages in comparison with conventional electromagnetic motors. In this paper some improvement was designed for control system of drift adjusting mechanism. Based on ultrasonic motor T-60 was designed the drift adjusting system which is composed of the drift adjusting mechanical frame the ultrasonic motor the driver of Ultrasonic Motor the photoelectric encoder and the drift adjusting controller. The TMS320F28335 DSP was adopted as the calculation and control processor photoelectric encoder was used as sensor of position closed loop system and the voltage driving circuit designed as generator of ultrasonic wave. It was built the mathematic model of drive circuit of the ultrasonic motor T-60 using matlab modules. In order to verify the validity of the drift adjusting system was introduced the source of the disturbance and made simulation analysis. It designed the control systems of motor drive for drift adjusting system with the improved PID control. The drift angle adjusting system has such advantages as the small space simple configuration high position control precision fine repeatability self locking property and low powers. It showed that the system could accomplish the mission of drift angle adjusting excellent. 2011 SPIE.

The design of real-time monitoring the electromechanical actuator operation state based on the CANoe (EI CONFERENCE) 会议论文 OAI收割
2nd Annual Conference on Electrical and Control Engineering, ICECE 2011, September 16, 2011 - September 18, 2011, Yichang, China
作者: Zhang J.; Wu D.; Zhang J.; Zhang J.

收藏 | 浏览/下载：19/0 | 提交时间：2013/03/25

In order to realize the real-time state data monitor of the electromechanical actuator(EMA) the EMA and other subsystem establish a ground half physical experiment simulation platform based on the CAN bus. The CANoe software decodes the received EMA CAN data and showes the result in the image window. The decoding data contains the EMA current motor operation state EMA angle and etc. Through these real-time display data the EMA operation state could be monitored and the EMA failure could be located fastly. 2011 IEEE.

Study on supper resolution reconstruction based on staggered arrays (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Electronic and Mechanical Engineering and Information Technology, EMEIT 2011, August 12, 2011 - August 14, 2011, Harbin, China
Yuan Z.; Xing Z.; Guang J.

收藏 | 浏览/下载：24/0 | 提交时间：2013/03/25

The image resolution can be improved without increasing the requirement to optical imaging systems' parameters and decreasing the size of CCD pixel by staggered arrays technology which arranges several CCDs in a specific mode. In this paper an image super resolution method of improving the image resolution for 1.5 times both in two directions by 4 linear arrays staggered based on this technology is presented which avoids the large computation in a single time by use of circulation method. This method is proved effective by the digital simulation and a simulated experiment platform is constructed to test its feasibility. The image resolution is improved for 1.42 times of the unreconstructed image according to the imaging experiment of resolution chart which is closed to 1.5 times in ideal case. And also the reconstructed and unreconstructed images are evaluated by the image information entropy which proves that the reconstructed image contains more information. 2011 IEEE.

Research on image restoration of Roll-Swing imaging seeker (EI CONFERENCE) 会议论文 OAI收割
3rd IEEE International Conference on Advanced Computer Control, ICACC 2011, January 18, 2011 - January 20, 2011, Harbin, China
作者: Zhang H.; Zhang H.

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To achieve a correct image receiving for Roll-Swing imaging seeker the mechanism and imaging process is analyzed. The causes of image rotation are discussed. The influence of the frame encoders' precision on imaging de-rotation quality is analyzed. The Roll-Swing imaging seeker is designed for high-speed aerocraft thus the received images are greatly degraded due to atmospheric turbulence. A new method of image restoration is proposed for turbulence-degraded images in this paper. The method is to get point spread function (PSF) based on the estimation of optical transfer function (OTF) according to the optical system design simulation. Finally to obtain the restored image constrained least squares filtering is used with the known PSF. The experiment results indicate that the new restoration method has a favorable effect to satisfy requirement of the automatic target recognition. 2011 IEEE.

Method of improving the accuracy of image motion measurement for panoramic aerial cameras (EI CONFERENCE) 会议论文 OAI收割
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optoelectronic Materials and Devices for Detector, Imager, Display, and Energy Conversion Technology, April 26, 2010 - April 29, 2010, Dalian, China
作者: Jia P.

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To improve the accuracy of image motion measurement for panoramic aerial cameras the paper proposed a method of real-time image motion measurement based on 2D spatial correlation. An auxiliary area CCD is positioned paralleled to the main linear TDI CCD in the focal plane of the camera. For every frame of the image sequence taken by the auxiliary CCD a prediction on the displacement of the current image in the flight direction is made based on the forward image motion velocity. The current and the reference images are combined together for 2D-correlation which products an image motion vector. By decomposing the vector both the forward and pendulum-swing image motions can be determined. The demanding computational requirements for the real-time 2D-correlation are covered by a joint transform optical correlator. Simulation test results show that the accuracy is improved and the measurement error is within 0.2 pixels for input images with SNR=1 dB. 2010 Copyright SPIE - The International Society for Optical Engineering.

Panoramic aerial camera image motion measurement using a hybrid system (EI CONFERENCE) 会议论文 OAI收割
2010 3rd IEEE International Conference on Computer Science and Information Technology, ICCSIT 2010, July 9, 2010 - July 11, 2010, Chengdu, China
作者: Jia P.

收藏 | 浏览/下载：28/0 | 提交时间：2013/03/25

Image motion compensation is significantly important for aerial camera photograph. To execute the compensation we must determine the image motion exactly. This paper proposes a method of real-time image motion measurement for panoramic aerial cameras based on image processing using a hybrid system. Two cameras are simultaneously used in the hybrid system. One main linear CCD for imaging while the other auxiliary low resolution high frame rate area CCD for determining the image motion based on 2D spatial correlation. The demanding computational requirements for the real-time 2D spatial correlation are covered by a joint transform optical correlator. Simulation test results show that the accuracy is improved and the measurement error is within 0.2 pixels for input images with SNR=1 dB. 2010 IEEE.

Design of ground-based physical simulation system for satellite-borne TDI-CCD dynamic imaging (EI CONFERENCE) 会议论文 OAI收割
Optoelectronic Imaging and Multimedia Technology, October 18, 2010 - October 20, 2010, Beijing, China
作者: Zhang L.; Zhang L.; Sun Z.

收藏 | 浏览/下载：24/0 | 提交时间：2013/03/25

As we know the existence of image motion has a bad effect on the image quality of satellite-borne TDI CCD camera. Although many theories on image motion are proposed to cope with this problem few simulations are done to justify the proposed theories on ground. And thus in this paper a ground-based physical simulation system for TDI CCD imaging is developed and specified which consists of a physical simulation subsystem for precise satellite attitude control based on a 3-axis air bearing table and an imaging and simulation subsystem utilizing area-array CCD to simulate TDI CCD. The designed system could realize not only a precise simulation of satellite attitude control whose point accuracy is above 0.1 and steady accuracy above 0.01/s but also an imaging simulation of 16-stage TDI CCD with 0.1s its integration time. This paper also gives a mathematical model of image motion of this system analogous with satellite-borne TDI CCD and detailed descriptions on the principle utilizing area-array CCD to simulate TDI CCD. It is shown that experiment results are in accordance with mathematical simulation and that the image quality deteriorate seriously when the correspondence between the image velocity and signal charges transfer velocity is broken out which suggest not only the validity of the system design but also the validity of the proposed image motion theory of TDI CCD. 2010 SPIE.