中国科学院机构知识库网格系统: 检索

FOV Constraint Region Analysis and Path Planning for Mobile Robot with Observability to Multiple Feature Points 期刊论文 OAI收割
International Journal of Control, Automation and Systems, 2021, 卷号: 19, 期号: 11, 页码: 3785-3800
作者: Hongxuan Ma; Wei Zou

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收藏 | 浏览/下载：2/0 | 提交时间：2024/06/06

mobile robot multiple points path planning the field-of-view

Analysis and Design of Pre-Imaging System of Integral Field Imaging Spectrometer Based on Lenslet Array 期刊论文 OAI收割
SPECTROSCOPY AND SPECTRAL ANALYSIS, 2018, 卷号: 38, 期号: 10, 页码: 3269-3272
作者: Liu Jian-li; Zhang Rui; Chen Jian-jun; Sun Ci; Yin Lu

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收藏 | 浏览/下载：53/0 | 提交时间：2019/08/21

Lenslet array Integrated field of view imaging spectrometer Telecentric off-axis three-reflection system Field of view off the axis

Design and fabrication of imaging optical systems with freeform surfaces (EI CONFERENCE) 会议论文 OAI收割
Current Developments in Lens Design and Optical Engineering XIII, August 13, 2012 - August 15, 2012, San Diego, CA, United states
作者: Zhang F.; Wang L.; Wang L.; Wang L.; He X.

收藏 | 浏览/下载：33/0 | 提交时间：2013/03/25

Freeform surfaces provide more degrees of freedom for design of optical systems and enhance the ability of compensation and correction aberrations. Freeform surfaces are of advantage to balance the unsymmetrical aberrations especially for the wide-field off-axis optical systems. This paper focus on an off-axis reflective optical system which focal length is 550mm F# is 6.5 and field of view (FOV) is 76. The system adopts some freeform surfaces. We discuss the problems we noticed in processes of design manufacture measurement and alignment and the solutions. At last the periodical research result and the expected performance are given. 2012 SPIE.

Nanoscale patterns made by using a 13.5-nm Schwarzschild objective and a laser produced plasma source (EI CONFERENCE) 会议论文 OAI收割
Optical Micro- and Nanometrology IV, April 16, 2012 - April 18, 2012, Brussels, Belgium
作者: Wang X.; Wang X.; Wang X.; Wang Z.; Wang Z.

收藏 | 浏览/下载：37/0 | 提交时间：2013/03/25

Lithium fluoride (LiF) crystal is a very promising candidate as nanometer resolution EUV and soft X-ray detector. Compared with other EUV and soft X-ray detectors charge coupled device and photographic films LiF crystal has high resolution large field of view and wide dynamic range. In this paper using LiF crystal as EUV detector and a Schwarzschild objective (SO) working at 13.5nm as projection optics mesh images with 4.2 m 1.2 m and 800 nm line width and pinhole patterns with 1.5m diameter are acquired in projection imaging mode and direct writing mode respectively. Fluorescence intensity profiles of images show that the resolution of mesh image is 900 nm and the one of pinhole image is 800 nm. In the experiments a spherical condense mirror based on normal incidence type is used to eliminate the damage and contamination on the masks (mesh and pinhole) caused by the laser plasma and the energy density is not decreased compared with that the masks are close to the plasma. The development of the SO the alignment of the objective and the imaging experiments are also reported. 2012 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).

Design and simulation of CMOS star sensor lens with large relative aperture and wide field (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
Zhong X.; Jin G.

收藏 | 浏览/下载：60/0 | 提交时间：2013/03/25

A 50mm focal length F/1.25 Gaussian type optical system is designed in this paper which has 20field of view. Actual star image adding optical cross-talk effect of CMOS(Complementary Metal Oxide Semiconductor) detector is simulated by non-sequential ray tracing in ZEMAX optical design and analysis software to evaluate its performance. The distortion relative to image spot centriod is introduced and calculated by simulated star images which is less than 0.03% of lens in this paper. Thermal adaptability is discussed by opt-mechanic thermal analysis which shows the RMS spot radius of marginal filed changes less than 0.7m under 10C temperature gradient and changes less than 1m during homogeneous temperature changing from 40C to 40C. The results of analyses and simulations show the design of this lens can achieve the requirement of high precision CMOS star sensor well. 2011 IEEE.

Design of reimaging F/1.0 long-wavelength infrared optical system (EI CONFERENCE) 会议论文 OAI收割
International Symposium on Photoelectronic Detection and Imaging 2011: Advances in Infrared Imaging and Applications, May 24, 2011 - May 24, 2011, Beijing, China
作者: Zhang X.; Zhang X.; Zhang X.

收藏 | 浏览/下载：36/0 | 提交时间：2013/03/25

A reimaging F/1.0 long-wavelength infrared optical system is proposed. The design has a flexible opto-mechanical layout. The design process is as follows. Firstly the catadioptric reimaging system consists of two reflecting mirrors and a relay lenses. Two reflecting mirrors make up of the first imaging system and are therefore free of chromatic aberrations while low dispersion lenses were used in the reimaging system so the optical system do not need achromatic design for a high image quality. Then to correct high-order aberrations resulting from large relative aperture more parameters need to be used with aspheric or diffractive surfaces due to modern optic technology development. Here aspheric is selected for easily manufacture. Finally the design is completed with the help of ZEMAX software. The effective focal length of the objective is 120mm and the field of view (FOV) is 4. The simulated final design shows adequate image quality and the modulation transfer function (MTF) is close to diffraction limit. The effect of the surrounding environmental temperature is analyzed using the concept of thermal defocusing and the thermal compensation is discussed. 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).

Design and calibration of the solar irradiance monitor (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: Yang D.-J.; Gong C.-H.; Wang Y.-P.; Ye X.; Fang W.

收藏 | 浏览/下载：26/0 | 提交时间：2013/03/25

The solar irradiance monitor (SIM) with the design accuracy of 5 used to monitor the secular changes of the total solar irradiance on FY-3 satellite takes the sun-scanning measurement method on-orbit. Compared to the sun-tracking measurement method this method simplifies the structure and cuts the cost but the measuring accuracy is affected by the sun-synchronous orbit sunlight incidence angle and the installing angle of the SIM in the satellite. Through the ground calibration experiment studies on the affection of different sunlight incidence angles to the measurement accuracy. First by the satellite tool kit (STK) simulation software simulates the orbital parameters of the sun-synchronous satellite and calculates the Sun ascension and declination at any time. By the orbit coordinate transformation matrix gets the components of the Sun vectors to the axes of the satellite and base on the components designs the field of view and the installing angles of the SIM. Then designs and completes the calibration experiment to calibrate the affection of the incidence angles. Selecting 11 different angles between the sunlight and the satellite X-axis measures the total solar irradiance by the SIM at each angle and compares to the irradiances of the SIAR reference radiometers and gets the coefficient curves of the three channels of the SIM. Finally by the quadratic fitting gets the correction equations on the incidence angles: R 1=5.7110-52 -2.45310 -3+1.0302 R2=2.8410-5-1. 96510-3+1.0314 and R3 =1.7210 -52-4.18410-4+0.9946. The equations will aimprove the on-orbit measurement accuracy of the solar irradiance and are very important to the on-orbit data processing after the satellite launched. 2011 SPIE.

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：39/0 | 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.

Research on infrared dim-point target detection and tracking under sea-sky-line complex background (EI CONFERENCE) 会议论文 OAI收割
International Symposium on Photoelectronic Detection and Imaging 2011: Advances in Infrared Imaging and Applications, May 24, 2011 - May 24, 2011, Beijing, China
作者: Dong Y.-X.; Zhang H.-B.; Li Y.; Li Y.; Li Y.

收藏 | 浏览/下载：111/0 | 提交时间：2013/03/25

Target detection and tracking technology in infrared image is an important part of modern military defense system. Infrared dim-point targets detection and recognition under complex background is a difficulty and important strategic value and challenging research topic. The main objects that carrier-borne infrared vigilance system detected are sea-skimming aircrafts and missiles. Due to the characteristics of wide field of view of vigilance system the target is usually under the sea clutter. Detection and recognition of the target will be taken great difficulties.There are some traditional point target detection algorithms such as adaptive background prediction detecting method. When background has dispersion-decreasing structure the traditional target detection algorithms would be more useful. But when the background has large gray gradient such as sea-sky-line sea waves etc.The bigger false-alarm rate will be taken in these local area.It could not obtain satisfactory results. Because dim-point target itself does not have obvious geometry or texture feature in our opinion from the perspective of mathematics the detection of dim-point targets in image is about singular function analysis.And from the perspective image processing analysis the judgment of isolated singularity in the image is key problem. The foregoing points for dim-point targets detection its essence is a separation of target and background of different singularity characteristics.The image from infrared sensor usually accompanied by different kinds of noise. These external noises could be caused by the complicated background or from the sensor itself. The noise might affect target detection and tracking. Therefore the purpose of the image preprocessing is to reduce the effects from noise also to raise the SNR of image and to increase the contrast of target and background. According to the low sea-skimming infrared flying small target characteristics the median filter is used to eliminate noise improve signal-to-noise ratio then the multi-point multi-storey vertical Sobel algorithm will be used to detect the sea-sky-line so that we can segment sea and sky in the image. Finally using centroid tracking method to capture and trace target. This method has been successfully used to trace target under the sea-sky complex background. 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).

The stability design and realization of airborne platform based on TMS320F2812 (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
作者: Zhang X.; Zhang X.; Zhang X.

收藏 | 浏览/下载：40/0 | 提交时间：2013/03/25

Airborne electro-optical stable platform can isolate movement and vibration of the airframe stabilizes the optic axis of the photoelectic detector realize the observation and tracking for the object. It has comprehensive application value in army and cicil field. Most of present airborne platforms are analogic control system digital control system can improve the system general performance digital control is the development direction of platform systems. In view of the requirements of isolating disturbances and stabilizing optical axis of high-precision photoelectric guidance system a three-axis stabilized platform system centering on the rate gyro was designed. The disturbance-isolation theory of the stabilized platform was analyzed and the control structure including multiple closed-loops was designed. At last a controller of the servo system based on TMS320F2812 DSP has been designed. Experiment results meet the technical index and precision requirement and illustrate the practicability and effectiveness of the scheme. 2011 IEEE.