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Robust Landmark Detection and Position Measurement Based on Monocular Vision for Autonomous Aerial Refueling of UAVs 期刊论文  OAI收割
IEEE TRANSACTIONS ON CYBERNETICS, 2019, 卷号: 49, 期号: 12, 页码: 4167-4179
作者:  
Sun, Siyang;  Yin, Yingjie;  Wang, Xingang;  Xu, De
  |  收藏  |  浏览/下载:53/0  |  提交时间:2018/10/02
Precision Work-piece Detection and Measurement Combining Top-down and Bottom-up Saliency 期刊论文  OAI收割
International Journal of Automation and Computing, 2018, 卷号: 15, 期号: 4, 页码: 417-430
作者:  
  |  收藏  |  浏览/下载:17/0  |  提交时间:2021/02/23
Application of interferometry measurement in large-scale optic-electrical theodolite (EI CONFERENCE) 会议论文  OAI收割
2012 International Conference on Sensors, Measurement and Intelligent Materials, ICSMIM 2012, December 26, 2012 - December 27, 2012, Guilin, China
作者:  
Sun Z.
收藏  |  浏览/下载:42/0  |  提交时间:2013/03/25
Interferometry is a very important method in high accuracy measurement for optical system. This article briefly introduced the conception of interferometry and took a product of 4D Technology as an example to carry on the measurement. A large-scale optic-electrical Theodolite in assemblage was measured  and its primary mirror was 400mm in diameter. With the analysis of the results  some micro adjustments of the mechanical structure proceed  and it made the system perform better. The final results of the whole system is 1.061 in P-V value and 0.1136 in RMS value (=632.8nm)  this meets the demand of optical design and practical application. The result demonstrates that interferometry is a good way to be utilized and optimize in the procedure of assemble. (2013) Trans Tech Publications  Switzerland.  
The approximate calculation of atmospheric path radiance in close range and horizontal direction (EI CONFERENCE) 会议论文  OAI收割
2012 International Conference on Sensors, Measurement and Intelligent Materials, ICSMIM 2012, December 26, 2012 - December 27, 2012, Guilin, China
作者:  
Sun Z.;  Chen Y.;  Zhang Y.
收藏  |  浏览/下载:33/0  |  提交时间:2013/03/25
Atmospheric path radiance is the key factor in the accuracy of objective radiation measurement. In the traditional radiation character measurements  it is compared with the results of MODTRAN and measurement in experiment. It is revealed that the accuracy of software is 7.8%  under the help of the atmospheric observation equipment  and the formula is 4.9%  MODTRAN and other software likewise  which could demonstrate the validity of the pproximate calculation formula in close range and horizontal direction. In this article  the indeterminacy rate could be around 10~20%  in the process of deducing and experiment  it is highly restricts the measurement accuracy of objective radiation. For this reason  the validity of the approximate calculation formula in close range and horizontal direction is fully proved  it is quite significant to develop the study of measure and calculation in path radiance. The approximate calculation formula for path radiance in close range and horizontal direction is expressed in this article  which supply a new method in approximate calculation of path radiance for objective radiation measurement. (2013) Trans Tech Publications  Switzerland.  
Design of the real-time autofocusing system for collimator with long focus length and large aperture (EI CONFERENCE) 会议论文  OAI收割
2011 International Academic Conference on Numbers, Intelligence, Manufacturing Technology and Machinery Automation, MAMT 2011, December 24, 2011 - December 25, 2011, Wuhan, China
作者:  
Zhang X.;  Zhang X.;  Zhang X.
收藏  |  浏览/下载:42/0  |  提交时间:2013/03/25
Large aperture collimator which has been widely used for calibrating and testing various optical devices plays an essential role in correlative laboratories. As being the basic testing and calibration equipment  the large aperture collimator's accuracy should be much higher than the device under testing in order to ensure the accuracy of the measurement. However  the process of adjusting the collimator is extremely complicated due to the collimator's large aperture and long focal length. So it is difficult to ensure the measurement's quality and easy to cause the system being vulnerable to the surrounding environment. One of the most common problems is defocus. In order to solve the problem above  this issue presents a new type of autocollimator autofocusing system which uses pentaprism instead of using large-aperture plane mirror  semiconductor lasers as light source and CCD sensor as receiver. The system is smaller  lighter  and more convenient when using. The computer simulation shows that the autofocusing system's resolution could reach the accuracy of 40m. If we use the relevant algorithms to execute the sub-pixel scanning  the resolution could reach the accuracy of 10m. It shows that the system could satisfy the required testing precision of testing large aperture optical device.  
Embedded image grabber and processing system based on camera link (EI CONFERENCE) 会议论文  OAI收割
2012 World Automation Congress, WAC 2012, June 24, 2012 - June 28, 2012, Puerto Vallarta, Mexico
作者:  
Wang Z.;  Zhao Y.;  Zhao Y.;  Zhao Y.
收藏  |  浏览/下载:34/0  |  提交时间:2013/03/25
Simulation test research of using the Ritchey-Common method for the detection of large flat mirror (EI CONFERENCE) 会议论文  OAI收割
2012 International Conference on Frontiers of Advanced Materials and Engineering Technology, FAMET 2012, January 4, 2012 - January 5, 2012, Xiamen, China
作者:  
Zhang X.;  Zhang X.;  Zhang X.
收藏  |  浏览/下载:17/0  |  提交时间:2013/03/25
Laser pulse coded signal frequency measuring device based on DSP and CPLD (EI CONFERENCE) 会议论文  OAI收割
International Symposium on Photoelectronic Detection and Imaging 2011: Laser Sensing and Imaging; and Biological and Medical Applications of Photonics Sensing and Imaging, May 24, 2011 - May 26, 2011, Beijing, China
作者:  
Zhang H.-B.;  Wang T.-F.;  Guo R.-H.;  Li Y.;  Li Y.
收藏  |  浏览/下载:38/0  |  提交时间:2013/03/25
Laser pulse code is an anti-jamming measures used in semi-active laser guided weapons. On account of the laser-guided signals adopting pulse coding mode and the weak signal processing  it need complex calculations in the frequency measurement process according to the laser pulse code signal time correlation to meet the request in optoelectronic countermeasures in semi-active laser guided weapons. To ensure accurately completing frequency measurement in a short time  it needed to carry out self-related process with the pulse arrival time series composed of pulse arrival time  calculate the signal repetition period  and then identify the letter type to achieve signal decoding from determining the time value  number and rank number in a signal cycle by Using CPLD and DSP for signal processing chip  designing a laser-guided signal frequency measurement in the pulse frequency measurement device  improving the signal processing capability through the appropriate software algorithms. In this article  we introduced the principle of frequency measurement of the device  described the hardware components of the device  the system works and software  analyzed the impact of some system factors on the accuracy of the measurement. The experimental results indicated that this system improve the accuracy of the measurement under the premise of volume  real-time  anti-interference  low power of the laser pulse frequency measuring device. The practicality of the design  reliability has been demonstrated from the experimental point of view.  
Performance test of steel tube enclosed thermistors in air temperature measurements (EI CONFERENCE) 会议论文  OAI收割
3rd International Conference on Measuring Technology and Mechatronics Automation, ICMTMA 2011, January 6, 2011 - January 7, 2011, Shanghai, China
作者:  
Yang H.;  Yan F.;  Yan F.;  Peng J.
收藏  |  浏览/下载:32/0  |  提交时间:2013/03/25
The performances of two steel tube enclosed precision thermistors are tested in a well controlled air environment to determine if the thermistors have enough accuracy for 0.01C levels of air temperature gradient measurement. Three Fluke's 5641 and three 5610 thermistors were tested for 24 hours in Fluke's 7008 calibration bath in the first step. In the second step  the performances of these two thermistors in steady state and transient state air temperature environments were tested for 8 hours separately. The results illustrate that  two of the 5641s were airproofed in a temperature well controlled tube  when steel tube enclosed precision thermistors are used in air temperature measurement  there are unstable departures from each other with a maximum 8.8 mC in constant air medium and 27 mC in temperature changing air medium. The transient-time errors are too large to show the true amounts of temperature changes for air temperature measurement. 2011 IEEE.  
The Research of real time auto-recognition of the moire fringe (EI CONFERENCE) 会议论文  OAI收割
International Symposium on Photoelectronic Detection and Imaging 2011: Advances in Imaging Detectors and Applications, May 24, 2011 - May 26, 2011, Beijing, China
Wang M.-J.; Wu Z.-G.
收藏  |  浏览/下载:19/0  |  提交时间:2013/03/25
Measuring the movement of raster by the method of moire fringe has the advantage of high sensitivity  high resolution and non-contacted measurement. The characteristic of moire fringe is that the image is white alternate with black  the angle of the stripes is uniform  the width of the stripes is uniform  the terminators of the stripes aren't clear. A fast method that can figure out the width and angle of the moire fringe precisely is put forward in this paper. It calculates the angle the stripes firstly. According to the principle of the minimum mean squared error (MMSE)  the closer a series of data is  the smaller the value of the MMSE will be. The method is described as follows: It takes the image's center as the origin  180 beelines pass through the origin with the same angle interval. it calculates the value of the minimum mean squared error of the 180 beelines and find out the least one among those  then the angle of the moire fringe comes out primarily. In order to improving the calculating precision of moire fringe  60 equal angles are divided in the neighborhood of the angle  then a precise angle of moire fringe is calculated according to the principle of the MMSE. After getting out the angle of the moire fringe  we begin to calculate the width of moire fringe. A line vertical with the moire fringe is drawn  and we can get the width of the moire fringe by the vertical line. In order to get over the influence of the noise  an effective area with the shape of diamond is selected in the image. The data of area is accumulated and projected according to the direction of moire fringe  and a sine curve come out. The width of moire fringe can be obtained by getting the position of the first wave crest  the position of the last wave crest and the number of wave crest. Experiments prove that the precision of the method put forward in this paper is enhanced in comparison with the traditional frequency method  the precision of width calculation achieves to 99.6% according to the evaluation indicators of width detection error. The computing speed is boosted largely compared with traditional method  and it can achieve with 15 ms  that satisfying the demand of real time. 2011 SPIE.