中国科学院机构知识库网格系统: 检索

Research on Distributed Intelligent Protection Strategy of distribution network based on Reinforcement Learning 会议论文 OAI收割
Chongqing, China, December 17-19, 2021
作者: Cui SJ(崔世界); Zeng P(曾鹏); Hu ED(胡恩德)

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收藏 | 浏览/下载：24/0 | 提交时间：2022/04/13

deep reinforcement learning distributed protection strategy distribution network protection intelligent protection device New power system

EAST新快控电源保护系统的设计 期刊论文 OAI收割
强激光与粒子束, 2020, 卷号: 32
作者: 武旭; 王林森

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收藏 | 浏览/下载：26/0 | 提交时间：2020/11/23

EAST's new quick control power supply carrier phase shift power failure power protection system protection circuit EAST新快控电源载波移相电源故障电源保护系统保护电路

The study of heart monitor based Atmega128L (EI CONFERENCE) 会议论文 OAI收割
2nd World Congress on Computer Science and Information Engineering, CSIE 2011, June 17, 2011 - June 19, 2011, Changchun, China
作者: Chen J.; Zhang Y.

收藏 | 浏览/下载：27/0 | 提交时间：2013/03/25

This paper introduces a realtime system which can acquire process store and display heart sounds and electrocardiogram(ECG) of the human body at the same time. It is composed of superior microprocessor-Atmega128L large capacity Flash and the new type LCD. All hardwares adopt low power design and surface mounting package. The system do not affect the daily living and working of human being when it is used so it is suited for clinical and family monitoring. Springer-Verlag Berlin Heidelberg 2012.

Design of semi-physical simulation for small satellite by virtual display (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
Xu K.; Lv Y.; Jin G.

收藏 | 浏览/下载：23/0 | 提交时间：2013/03/25

Semi-physical simulation of attitude control system is the more synthetically test and verify for designing of small satellite control system. It is an important means of small satellite development. However the results of current semi-physical simulation system have a lot of non-intuitive. Compare with the actual environment the simulation environment still has striking disparity. So the shortcomings affect precision of simulation. Based on the virtual display technology the group semi-physical simulation system has been constructed for attitude control of small satellite due to the combination with xPC real-time environment the simulation computer high-precision single-axis air-bearing turntable reaction wheel air thrust device fiber gyroscopes sensors synchronizer power subsystem and wireless devices virtual display computer etc. Semi-physical simulation achieved the visual simulation in orbit and tracked new information of virtual environment of space into real-time simulation computer. Simulation results show that the simulation system for real-time attitude and orbit position of small satellite semi-physical simulation has an excellent display effect. At the same time Real-time transfuse of orbit information provides a more accurate space environment simulation. The simulation system of small satellite attitude control to design and evaluate the more direct and convenient. (2012) Trans Tech Publications Switzerland.

Evaluation of the operating range for ground-based infrared imaging tracking 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 Z.-D.

收藏 | 浏览/下载：50/0 | 提交时间：2013/03/25

Ground-based infrared imaging tracking system (GIITS) is of great importance for aerial target warning and guard. The operating range is one of the key performance specifications on the other which should be calculated calculate the radiation power received on the detector in order to analysis whether the output signal meets the detection requirements or not analyzed and studied during the whole GIITS design process. The operating range is mostly influenced by a few factors without considering the effect of the background radiation. By improving of the traditional method including atmospheric attenuation a new operating range calculation model of the GIITS was established based on two requirements. One is that the image size of observed target should meet the requirement of the processor signal extraction. The number of the pixel occupied by target image should be more than 9. The other is that the signal noise ratio (SNR) of the GIITS should not be less than 5 to meet the requirements of the target detection probability and spatial frequency. The SNR calculation equation in form of energy is deduced and the radiation characteristic of the observed target and background are analyzed. When evaluate the operating range of the GIITS using the new method the performance of GIITS and feature of target and background. This paper firstly makes analysis and summarization on the definite localizations of the traditional operating range equation of the GIITS. The localizations are mainly in two aspects. On one hand we should successively calculate two operating range values according to two requirements mentioned above and choose the minimum value as the analytic result. In the end the dispersion of the image and the effect of image dispersion are not considered in the traditional method an evaluation of operating range for fighter aircraft is accomplished as an example. The influence factors in every aspect on operating range were explored by the calculated result. The new operating range calculation model provides the theoretical basis for the design and applications as well as the comprehensive evaluation of a GIITS. 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).

United steering of control moment gyros for small satellite with limited gimbal rate (EI CONFERENCE) 会议论文 OAI收割
2010 IEEE International Conference on Information and Automation, ICIA 2010, June 20, 2010 - June 23, 2010, Harbin, Heilongjiang, China
Xu K.; Jin G.; Chen C.

收藏 | 浏览/下载：21/0 | 提交时间：2013/03/25

Single Gimbal Control Moment Gyroscopes (SGCMG) can could provide large control torque and quick attitude maneuver rate to small satellites without any increase in power volume and mass which will help small satellites become more powerful. Singularity avoidance and failure steering are two important problems to SGCMGs and also the main focus in this field. A new united steering law for SGCMGs with capabilities of singularity avoidance and quick transition of singularity surfaces is developed in this paper. To ensuring the existence of null motion the commanded output of controller was changed real-timely as the variation of singularity measurement of SGCMGs which can avoid the gimbal angle rate saturation. This developed steering law could help the SGCMGs provide real-time control toques in spite of limitation of gimbal angle rate. Simulation analysis is conducted for a certain 4-SGCMG system mounted on a small satellite. Simulation results indicate that the steering law is very effective in singularity avoidance. 2010 IEEE.

Timing generator of scientific grade CCD camera and its implementation based on FPGA technology (EI CONFERENCE) 会议论文 OAI收割
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optoelectronic Materials and Devices for Detector, Imager, Display, and Energy Conversion Technology, April 26, 2010 - April 29, 2010, Dalian, China
作者: Li Y.; Li Y.; Li Y.; Li Y.

收藏 | 浏览/下载：37/0 | 提交时间：2013/03/25

The Timing Generator's functions of Scientific Grade CCD Camera is briefly presented: it generates various kinds of impulse sequence for the TDI-CCD video processor and imaging data output acting as the synchronous coordinator for time in the CCD imaging unit. The IL-E2TDI-CCD sensor produced by DALSA Co.Ltd. use in the Scientific Grade CCD Camera. Driving schedules of IL-E2 TDI-CCD sensor has been examined in detail the timing generator has been designed for Scientific Grade CCD Camera. FPGA is chosen as the hardware design platform schedule generator is described with VHDL. The designed generator has been successfully fulfilled function simulation with EDA software and fitted into XC2VP20-FF1152 (a kind of FPGA products made by XILINX). The experiments indicate that the new method improves the integrated level of the system. The Scientific Grade CCD camera system's high reliability stability and low power supply are achieved. At the same time the period of design and experiment is sharply shorted. 2010 Copyright SPIE - The International Society for Optical Engineering.

Transceiving protocol designc for a free space optical communication system (EI CONFERENCE) 会议论文 OAI收割
2008 International Conference on Optical Instruments and Technology: Optical Systems and Optoelectronic Instruments, November 16, 2008 - November 19, 2008, Beijing, China
Hualong W.; Wanxin S.; Zhongbao X.

收藏 | 浏览/下载：61/0 | 提交时间：2013/03/25

A new transceiving protocol is demonstrated for a Free Space Optical (FSO) communication system and it's discussed in two parts: the transmitting protocol and the receiving protocol. During the discussion of these two parts the cooperation of them is also discussed. Different from wired communication an FSO system modulates the data on a narrow beam of laser transmitting through the free space or the atmosphere and the protocol presented in this paper is mainly optimized for terrestrial Free Space Optical links in which the signal channel of the system is mainly the atmosphere. Due to the complex composition and activity of the atmosphere this signal channel brings in great influence on the transmitting laser in it for example the absorption and scattering of the atmosphere molecules and aerosols the scintillation of received laser power caused by the turbulence of the atmosphere all of which results in a much higher Bit Error Rate (BER) of the communication system. Thus in designing a protocol for an FSO system more effort should be taken in the encoding of the data stream the synchronization of the data stream error checking and exception handling. The main function of the transmitting protocol includes interfacing the outer input data with a parallel port buffering the input data encoding the input data stream serializing the parallel data and output the serialized data. It also has an output management unit to manage the activity of each part of the transmitting protocol. The main function of the receiving protocol includes filtering and synchronizing the input serial data stream paralleling the serial data stream decoding the input data error checking exception handling and interfacing the outer receiver with a parallel port. The entire transceiving protocol could be programmed into a single FPGA chip to improve system integrity and reduce the system cost. The presented protocol could be taken as "protocol transparent" for outer interfaces meaning that when interfacing the presented system to an outer system you don't have to consider what protocol the outer system transceiving data stream is under for example the TCP/IP protocol or anything else in the case that its I/O interface is a parallel port. Simulation and final experiment prove that the protocol presented is working fine at a certain bit rate scale. 2009 SPIE.

808nm high-power high-efficiency GaAsP/GaInP laser bars (EI CONFERENCE) 会议论文 OAI收割
Optoelectronic Materials and Devices III, October 27, 2008 - October 30, 2008, Hangzhou, China
作者: Wang Y.

收藏 | 浏览/下载：28/0 | 提交时间：2013/03/25

808nm high power diode lasers which is rapidly maturing technology technically and commercially since the introduction in 1999 of complete kilowatt-scale diode laser systems have important applications in the fields of industry and pumping solid-state lasers (DPSSL). High power and high power conversion efficiency are extremely important in diode lasers and they could lead to new applications where space weight and electrical power are critical. High efficiency devices generate less waste heat which means less strain on the cooling system and more tolerance to thermal conductivity variation a lower junction temperature and longer lifetimes. Diode lasers with Al-free materials have superior power conversion efficiency compared with conventional AlGaAs/GaAs devices because of their lower differential series resistance and higher thermal conductivity. 808nm GaAsP/GalnP broad-waveguide emitting diode laser bars with 1mm cavity length have been fabricated. The peak power can reach to 100.9W at 106.5A at quasicontinuous wave operation (200s 1000Hz). The maximum power conversion efficiency is 57.38%. Based on these high power laser bars we fabricate a 1 3 arrays the maximum power is 64.3 W in continuous wave mode when the current is 25.0A. And the threshold current is 5.9A the slope efficiency is 3.37 W/A. 2008 SPIE.

Application of CMOS APS star tracker with large FOV in attitude and angular velocity determination (EI CONFERENCE) 会议论文 OAI收割
Advanced Sensor Systems and Applications III, November 12, 2007 - November 14, 2007, Beijing, China
Lu D.; Guang J.; Shaoju W.; Tao C.

收藏 | 浏览/下载：34/0 | 提交时间：2013/03/25

The paper deals with the spacecraft attitude determination problem using a new kind of star tracker with large FOV based on CMOS APS. Star tracker has been developed since 1970s and proved to be the most accurate sensor ever used in the spacecraft attitude determination systems. But the traditional CCD star tracker also has some disadvantages such as small FOV high power consumption low sample rate and low working angular rate limit which prevent the use of CCD star tracker in attitude large angle maneuvering process. The new kind of star tracker based on CMOS APS has no such disadvantages and is more applicable on modern low-cost agile small satellites. Its higher sample rate and working angular rate limit over traditional CCD star tracker make it more adapt for spacecraft angular velocity determination. Because of the large FOV of the star tracker the mathematical model of traditional CCD star tracker with a small FOV is not appropriate. So a new mathematical model was quoted to fit the star tracker with a large FOV. An alternative adaptive algorithm was also introduced in the paper. It can help the EKF algorithm work lacking of accurate covariance of the observation noise. An optimal estimation algorithm was used to estimate the angular velocity directly from the star tracker measurements. Mathematic simulation results indicate the CMOS APS star tracker can give accurate attitude information and estimated angular rate. The method can be used as the chief attitude determination system design of low-cost satellite without gyros or be used as a backup strategy in the event of gyro failures to enhance the reliability of the attitude determination system.