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Analysis on the influence of random vibration on MEMS gyro precision and error compensation (EI CONFERENCE) 会议论文  OAI收割
2011 3rd International Conference on Mechanical and Electronics Engineering, ICMEE 2011, September 23, 2011 - September 25, 2011, Hefei, China
作者:  Li M.
收藏  |  浏览/下载：24/0  |  提交时间：2013/03/25
In order to improve its precision in dynamic environment  a Kalman filter was designed. Firstly  two sets of random drift data of MEMS gyro were respectively analysed  and it was found that the variance of random drift under random vibration significantly increased and its mean also changed. Then calculation results show that attitude angle error under random vibration is 2.6  while in the static test it is 0.25. Analysis on the characteristics of random drift was carried out  and it is found that it can be treated as stable  normally distributed random signal. Finally  a corresponding Kalman filter was designed. The results indicated that after filtering the variance of random drift is reduced to 0.0282  26.4% of pre-filtering and the attitude angle error is reduced to 1.5  57.7% of pre-filtering. The above method can effectively compensate for the attitude angle error of MEMS gyro caused by random vibration. This study can be a reference to the application of low-cost MEMS gyro in aircraft navigation. (2012) Trans Tech Publications  Switzerland.  
new nearly optimal codebooks from relative difference sets 期刊论文  OAI收割
ADVANCES IN MATHEMATICS OF COMMUNICATIONS, 2011, 卷号: 5, 期号: 3, 页码: 521-527
Zhou Zhengchun; Tang Xiaohu
  |  收藏  |  浏览/下载：26/0  |  提交时间：2013/10/08
Research on object shape detection from image with high-level noise based on fuzzy generalized hough transform 会议论文  OAI收割
2011 International Conference on Multimedia and Signal Processing, CMSP 2011,, Guilin, Guangxi, China, May 14, 2011 - May 15,2011
Ji, Yuan; Mao, Li; Huang, Qingqing; Gao, Yan
收藏  |  浏览/下载：26/0  |  提交时间：2014/12/07
Design and image restoration research of a cubic-phase-plate system (EI CONFERENCE) 会议论文  OAI收割
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Advanced Optical Manufacturing Technologies, April 26, 2010 - April 29, 2010, Dalian, China
作者:  Zhang J.;  Zhang J.;  Zhang J.;  Shi G.;  Zhang X.
收藏  |  浏览/下载：26/0  |  提交时间：2013/03/25
Wave-front coding technology is a novel jointly optical and digital imaging technology which can greatly extend the depth of focus of optical systems. The image restoration process is an important part of wave-front coding technology. Using wave-front coding makes the modulation transfer function(MTF) values of the optical systems change little over a range of several times the depth of focus  which means the system MTF is quite insensitive to defocus  and there is no zero in the passband. So we can design a single filter for the restoration of images in different defocus positions. However  it's hard to avoid noise during image acquisition and transmission processes. These noises will be amplified in the image restoration  especially in the high frequency part when the MTF drop is relatively low. The restoration process significantly reduces the system signal to noise ratio this way. Aimed at the problem of noise amplification  a new algorithm was proposed which incorporated wavelet denoising into the iterative steps of Lucy-Richardson algorithm. Better restoration results were obtained through the new algorithm  effectively solving the noise amplification problem of original LR algorithm. Two sets of identical triplet imaging systems were designed  in one of which the cubic-phase-plate was added. Imaging experiments of the manufactured systems were carried  and the images of a traditional system and a wave-front coded system before and after decoding were compared. The results show that the designed wave-front coded system can extend the depth of focus by 40 times compared with the traditional system while maintaining the light flux and the image plane resolution. 2010 Copyright SPIE - The International Society for Optical Engineering.  
Improvement of urban land use and land cover classification approach in arid areas 会议论文  OAI收割
Proceedings of SPIE - The International Society for Optical Engineering, Image and Signal Processing for Remote Sensing XVI, Toulouse, France, 2010
Qian; Jing1; 2; Zhou; Qiming1; Chen; Xi2
收藏  |  浏览/下载：35/0  |  提交时间：2011/08/23