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	Efficient rotation estimation for 3D registration and global localization in structured point clouds 期刊论文 OAI收割 IMAGE AND VISION COMPUTING, 2017, 卷号: 67, 页码: 52-66 作者: Ma, Yanxin; Guo, Yulan; Lei, Yinjie; Lu, Min; Zhang, Jun \| 收藏 \| 浏览/下载：34/0 \| 提交时间：2019/12/12 Structured point clouds Small overlaps Registration Global localization ICP Direction angle
	Data processing method of multi-position strap-down north seeking system based on SVD (EI CONFERENCE) 会议论文 OAI收割 2011 International Conference on Mechatronic Science, Electric Engineering and Computer, MEC 2011, August 19, 2011 - August 22, 2011, Jilin, China Shen C.-W.; Liu C.; Yu S.-B.; Wang Z.-Q.; Li J.-R. 收藏 \| 浏览/下载：34/0 \| 提交时间：2013/03/25 With the aim to fit the sin wave curve of a multi-position strap-down north seeking system and to calculate the real north angle accurately the principles of the system and the algorithm of singular value decomposition(SVD) are introduced. The factors influencing the measuring precision are also analyzed. Then the algorithm is adopted to fit curves. Experimental results indicate that the singular value decomposition is very precise for its error sum is 1.1102V and the squared error is 2.8mV. Moreover for phase angle measurement measured six times in same direction the squared error is 24 (1). The method based on SVD can satisfy the system precision requirements of curve-fitting north seeking systems. 2011 IEEE.
	Effect of gimbal point displacement on optical axis pointing precision in an image seeker (EI CONFERENCE) 会议论文 OAI收割 2011 International Conference on Electric Information and Control Engineering, ICEICE 2011, April 15, 2011 - April 17, 2011, Wuhan, China 作者: Zhang X.; Zhang X.; Zhang X. 收藏 \| 浏览/下载：37/0 \| 提交时间：2013/03/25 A concentric glass spherical dome was usually chosen as the transparent window mounted in front of the optical lens in an image seeker. However optical ray had to change its direction when propagating through the dome due to refraction unless passing through the center of the dome which demanded gimbal point coincide with the center of the dome exactly. In fact gimbal point displacement could not be eliminating due to fabrication assembly and vibration therefore the optical axis pointing error generated. In this paper the effect of gimbal point displacement on optical axis pointing precision in an image seeker was analyzed and the theoretical expression of the optical axis pointing error was derived based on geometric optics and the error dynamics was explored by numerical. Take a visible light image seeker as a case the thickness of concentric glass spherical dome was 8mm and the inner radius was 72mm and the optical axis pointing errors varying dynamically with the look angle and the gimbal point displacement were shown in graph. When the gimbal displacement was 0.11mm the maximum optical axis pointing error was 0.054mrad that is equal to the instantaneous field of view (IFOV) corresponding to the camera system whose focal length was 120mm and pixel size was 6.5m. Furthermore with the gimbal displacement increasing the optical axis pointing error increased linearly. The analyzed results provided a theoretical basis for the displacement range which had to be limited strictly in the gimbal design process. 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：18/0 \| 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.
	Simulations and experimental studies of diffuser/nozzle pumps (EI CONFERENCE) 会议论文 OAI收割 4th International Symposium on Precision Mechanical Measurements, August 25, 2008 - August 29, 2009, Hefei/Jiuhua Mountain, Anhui, China 作者: Li W.; Li W. 收藏 \| 浏览/下载：23/0 \| 提交时间：2013/03/25 An investigation of diffuser/nozzle micropumps is presented. Numerical simulations are done using CFD program ANSYS/Flotran. The simulations show when the opening angel is small the flow in the diffuser/nozzle is steady the mass flow is increasing with the adding opening angle. But when the opening angel continues increasing the pressure grads will be bigger than zero. It means that the static pressure is gradually going up along the diverging direction. The fluid near the wall stops flowing because the velocity decreases rapidly and the dynamic pressure is not big enough to overcome the increasing of the static pressure. Finally the fluid flows reversely from the backward position of higher pressure area this makes the separation flow of fluid the diffuser is full of reverse fluid. And this results in the dropping of mass flow at last. The simulations also show that the performance of diffuser with a round inlet is better than that with a sharp inlet. The mass flow of micropumps with different opening angles different inlets are measured. The experimental results agree well with the simulations. 2008 SPIE.
	Research on 10.6 m laser beam monitoring in CO2 laser processing system (EI CONFERENCE) 会议论文 OAI收割 Infrared Materials, Devices, and Applications, November 12, 2007 - November 15, 2007, Beijing, China 作者: Gao Y.; Shao S. 收藏 \| 浏览/下载：24/0 \| 提交时间：2013/03/25 It is a key point of CO2 laser beam monitoring in the CO 2 laser processing system to achieve alignment between CO2 laser and PL (pointing and launching) system. By monitoring the angle offset of CO2 laser beam the compensation can be gotten witch is given to fast-steering mirror to rectify the direction of laser beam. But the normal photoelectric detector can not get the laser signal because of CO2 laser's high energy and long wavelength. Its wavelength is 10.6m and its power can reach kW level. Consequently it is difficult to detect the high-energy 10.6m laser beam directly. So we monitored the output mirror of laser resonator superseded the laser beam indirectly. The laser beam monitoring system could be designed based on CCD laser auto-collimation angular measurement principle and image processing method. In this paper application of CCD laser auto-collimation angular measurement principle and image processing method for CO2 laser beam monitoring system is introduced particularly After design fabrication and alignment the monitoring system can be used for experimental study that including angular measurement accuracy and angle offset measurement of CO2 laser beam. Angle offset range and angle variation rule of CO2 laser beam is also can be acquired for further research.
	Data preprocessing of the exterior field of vision assembling photogrammetric camera (EI CONFERENCE) 会议论文 OAI收割 3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment, July 8, 2007 - July 12, 2007, Chengdu, China 作者: Li J.; Li J.; Li J.; Liu J.; Liu J. 收藏 \| 浏览/下载：72/0 \| 提交时间：2013/03/25 Transmit array photogrammetric camera can obtain image which is high geometric fidelity and high photogrammetric quality. However the single chip array CCD image sensor camera can't meet the need of measuring precision and photogrammetric covering area. In order to obtain large numbers of information and extensive photogrammetric covering area we must increase field of vision angle and improve photogrammetric covering area. And all these objects can be realized by exterior field of vision assembling photogrammetric camera. Two side work must be done before images which obtained by exterior field of vision assembling photogrammetric camera be used in photogrammetry. First all assembling camera focal plane need be converted to a benchmark coordinate focal plane to realize camera digital assembling. Second images must be re-sampled and processing. Because of coordinate conversion two images from different assembling cameras can be established function relation which a pixel of image from a camera is corresponding to a pixel of another image from different camera. But through this conversion some pixels maybe extrusion together and other pixels separate on an image area. So interpolation direction finding(IDF) is used to obtain these pixels and realize image re-sampling. In this paper the structure of exterior field of vision assembling photogrammetric camera is analyzed and the coordinate conversion method of exterior field of vision assembling photogrammetric camera and image gray re-sampling method also can be discussed. All the works are based to data pretreatment of exterior vision assembling photogrammetric camera.
	Novel fast measurement method of twist angle and optical retardation of liquid crystal display (EI CONFERENCE) 会议论文 OAI收割 Asia Display 2007, AD'07, March 12, 2007 - March 16, 2007, Shanghai, China Huang X.; Lu Y.-T.; Kong X.-J.; Jing H.; Fu G.-Z.; Jin H. 收藏 \| 浏览/下载：15/0 \| 提交时间：2013/03/25 A novel method is proposed to measure twist angle and optical retardation of liquid crystal display in this paper. The new method which is one of single-wavelength methods has three characteristics introducing a method of measuring the total intensity ratio of the transmitted light to eliminate the influence of absorption by the polarizer using circularly and homogeneously aligned LC cell (CH-LC) as a unique polarization-converting device analyzer using variable sector diaphragm and photodetector to detect the total intensity of transmitted light whose original polarization direction is continuously changed from 0 to arbitrary angle CH-LC liquid crystal display and so on. The twist angle () and optical retardation (nd) can be derived by using Jones matrix analysis and a curve fitting where and nd are fitting parameters. Experiment proved the results are accurate the process of operation is fast the devices are economical.
	The Simulation measurement experiment and calibration for Solar Total Irradiance Monitor on board (EI CONFERENCE) 会议论文 OAI收割 ICO20: Remote Sensing and Infrared Devices and Systems, August 21, 2005 - August 26, 2005, Changchun, China Yupeng W.; Wei F.; Bingxi Y. 收藏 \| 浏览/下载：37/0 \| 提交时间：2013/03/25 STIM (Solar Total Irradiance Monitor) can be used on sun-synchronous polar orbit weather satellites to measure the total solar irradiance. It contains three independent and identical wide view absolute radiometers. They are mounted on the satellite in an angle which ensure the sun scan over the field of view of the absolute radiometers. This measurement method doesn't need the instrument tracking the sun but the sun scan over the field of view of the absolute radiometers in each orbit cycle. The paper presents the measurement method of simulation for solar irradiance measurement and calibration by mounting the instrument on a two-axis rotation table. By controlling the rotation angle velocity of the instrument in the meridian direction being the same as that of the weather satellite's on orbit we can measure the solar irradiance when the sun scan over the field of view of the absolute radiometers to simulate the onboard state. And we have operated the measurement with the prototype of STIM. The SIAR-1 is traceable to WRR and serves as a transfer standard. So simultaneous comparison measurements between SIAR-1 and each of the three wide view absolute radiometers are measured to provide calibration corrections to the instrument. And we have a further study at the influence of stray light to the measurement results. This paper presents the method of simulation experiment and calibration for solar irradiance measurement with Solar Total Irradiance Monitor on board.