中国科学院机构知识库网格系统: 检索

Comprehensive analysis of tropical rooftop PV project: A case study in nanning 期刊论文 OAI收割
HELIYON, 2023, 卷号: 9, 期号: 3, 页码: e14131
作者: Wang, Xuecheng; Gao, Xing; Wu, Yuming

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收藏 | 浏览/下载：16/0 | 提交时间：2023/06/10

Rooftop photovoltaics Nanning Azimuth angle Tilt angle Solar energy

Amplitude variation with angle and azimuth inversion to estimate fracture properties in shale-gas reservoirs 期刊论文 OAI收割
GAS SCIENCE AND ENGINEERING, 2023, 卷号: 111, 期号: -, 页码: -
作者: Huang, Guangtan; Ba, Jing; Gei, Davide; Carcione, Jose M.

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收藏 | 浏览/下载：5/0 | 提交时间：2023/08/02

Amplitude variation with angle and azimuth (AVAZ) Decoupling Aspect ratio Fractures Saturating fluid

Wavefield propagation characteristics in fracture-induced TTI double-porosity medium 期刊论文 OAI收割
ACTA PHYSICA SINICA, 2013, 卷号: 62, 期号: 13
作者: Kong Li-Yun; Wang Yi-Bo; Yang Hui-Zhu

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收藏 | 浏览/下载：17/0 | 提交时间：2018/09/26

fracture-induced TTI double-porosity fracture dip angle fracture azimuth angle

Wavefield propagation characteristics in fracture-induced TTI double-porosity medium 期刊论文 OAI收割
ACTA PHYSICA SINICA, 2013, 卷号: 62, 期号: 13
作者: Kong Li-Yun; Wang Yi-Bo; Yang Hui-Zhu

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收藏 | 浏览/下载：25/0 | 提交时间：2018/09/26

fracture-induced TTI double-porosity fracture dip angle fracture azimuth angle

Wavefield propagation characteristics in fracture-induced TTI double-porosity medium 期刊论文 OAI收割
ACTA PHYSICA SINICA, 2013, 卷号: 62, 期号: 13
作者: Kong Li-Yun; Wang Yi-Bo; Yang Hui-Zhu

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收藏 | 浏览/下载：15/0 | 提交时间：2018/09/26

fracture-induced TTI double-porosity fracture dip angle fracture azimuth angle

Analysis of zenith pass problem in a roll-pitch optics seeker (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Electronics and Optoelectronics, ICEOE 2011, July 29, 2011 - July 31, 2011, Dalian, China
作者: Jiang H.

收藏 | 浏览/下载：28/0 | 提交时间：2013/03/25

There are mainly two kind of structures for a missile two-axes seeker which is always mentioned as elevate-azimuth and roll-pitch. The elevate-azimuth structured seeker has been studied for a long time and it is applied in all sort of missiles. Not only structure design but also control algorithm of the elevate-azimuth seeker are deeply developed. But for elevate-azimuth seeker there are several disadvantages such as big size and large abaxial angle blind. So the elevate-azimuth seeker gimbal angle is designed up to 65 according to relative references. In modern air war it is important for a missile to have the ability of "first recognize" and "first attack". That means the air to air missile seeker is required to be a system with large gimbal angle and large abaxial launch angle. With the mentioned requirement roll-pitch seeker with its advantages smart size and large gimbal angle is studied widely and deeply. The pitch angle of roll-pitch is up to 90 while its roll angle up to n 360. But there are also some disadvantages for the roll-pitch seeker the most troublesome one is the zenith pass problem. The zenith pass problem is brought about from the gimbal kinematics it is said that when target moves in the center of image plane roll servo command gotten from the kinematics algorithm will go to infinite. Math model of zenith pass problem is proposed in this paper and two ways to solve the problem are brought forward. 2011 IEEE.

Non-linear compensation algorithm of LOS locating in aerial remote sensor (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
作者: Li J.; Li Y.; Li Y.; Li Y.; Li Y.

收藏 | 浏览/下载：29/0 | 提交时间：2013/03/25

A non-linear light-of-sight(LOS) locating compensation algorithm for certain aerial remote sensor is presented in this paper. The LOS locating system is composed of two main components which are an inertial reference frame to provide coarse LOS locating and a 2-axis Fast Steering Mirror to remove the frame's residual error. The azimuth and elevation of LOS are both affected by the FSM two-degree-of-freedom rotation which should be dealt with to raise the accuracy of LOS location. This paper extrapolates LOS locating algorithm of FSM by coordinate transformation and gives corresponding deviation analysis for different LOS poiting angles. It is found that the angle deviation grows rapidly with range of FSM's travel enlarging so the deviation must be eliminated. Through the data analysis for deviation a non-linear compensation algorithm is proved effective to reduce the error of LOS significantly. Taking LOS changing in [-3 deg 3 deg] as an example two analytic expressions are given and the LOS locating accuracy rises by 34 times compared with non-linear compensation unused and the cross coupling of LOS loating is 0.08%. 2011 IEEE.

Study on the azimuth bearing scheme of a large Alt-azimuth telescope (EI CONFERENCE) 会议论文 OAI收割
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Large Mirrors and Telescopes, April 26, 2010 - April 29, 2010, Dalian, China
作者: Wang H.; Dai S.; Zhang J.; Wang H.; Zhang J.

收藏 | 浏览/下载：38/0 | 提交时间：2013/03/25

The azimuth bearing schemes in typical large Alt-azimuth telescopes especially the 3.5-m APO telescope and the 4.1-m SOAR telescope were analyzed. A scheme of high-angular contacted thrust ball bearing integrated with a radial ball bearing was put forward. According to the Hertz contact theory the corresponding parameters were designed for engineering application. The static performance parameters within the range of 60 85 original contact angle were calculated. Compared with the traditional plane thrust ball bearing the results shows that the high-angular (80) contact thrust ball bearing has more benefits at bearing strength and rigidity for large telescope. The 1500mm diameter prototyping bearing shows good performance including the axial jitter is 0.009mm the radial jitter is 0.006mm the maximum starting torque without load is 30N·m and the load capacity is more than 30t which offers advanced technique path for the buildup of the high precision azimuth shafting and the whole telescope system. 2010 Copyright SPIE - The International Society for Optical Engineering.

Application of adaptive Kalman filter technique in initial alignment of strapdown inertial navigation system (EI CONFERENCE) 会议论文 OAI收割
29th Chinese Control Conference, CCC'10, July 29, 2010 - July 31, 2010, Beijing, China
作者: Liu P.

收藏 | 浏览/下载：26/0 | 提交时间：2013/03/25

In order to improve the alignment precision and convergence speed of strap-down inertial navigation system but in the active system most noise statistical characteristics are unknown an initial alignment method based on Sage-Husa adaptive filter is presented. We also derived the exactitude alignment error model and adaptive Kalman filter equation in the azimuth of small misalignment angle. As usual in this case known the noise statistical characteristics we introduce the adaptive Kalman filter. It uses the information of observed data Kalman filter is suitable on-line estimation noise statistical characteristics and state simultaneously in order to improve the filter continuously so the filter has a higher estimation accuracy than the conventional Kalman filter. By simulating verifying the adaptive Kalman filter enhances the convergence speed and alignment accuracy effectively.

Error analysis and test study of fiber optic gyroscope north-finder (EI CONFERENCE) 会议论文 OAI收割
Advanced Sensor Systems and Applications II, November 8, 2004 - November 12, 2004, Beijing, China
Zhang Z.; Sun J.; Wu K.

收藏 | 浏览/下载：21/0 | 提交时间：2013/03/25

North-finder system is an important application of the inertial technology. It provides true north azimuth information to f all kinds of ground-based equipment. This paper designed a dynamic automatic north-finder based on the modulation output of fiber optic gyroscope (FOG). In this scheme the sine output signal of the FOG was sampled and disposed and then the real north of surveyed point on the surface of earth was calculated. The deviation caused by the base tilt was compensated by an accelerator. The output signals of FOG and accelerator were computed combined with the position sampled from increasing encoder by digital signal processor. Successive rotating technique was adopted to modulate the FOG signal periodically. Most of the low frequency part of random gyro drift errors was compensated. The north-finder accuracy was improved compared with the traditional static measuring method. The test result shows the FOG automatic north-finder obtains 2' true north angle accuracies within not more than three minutes can meet the orientation need of artillery terrain measurement vehicle armored car unmanned drive vehicle geodetic survey and tunnel exploration.