Cui Y.,Institute of Telecommunication Satellite |
Guan X.,Beijing Institute of Control Engineering |
Tang L.,Beijing Institute of Control Engineering |
Wang Q.,Beijing Institute of Control Engineering |
Zheng G.,Tsinghua University
Proceedings of the International Astronautical Congress, IAC | Year: 2016
Improvement of image acquisition capability, agility and cycle revisit capability are the goals of agile remote sensing satellites. However, higher capability of payload and higher agility bring new challenges to the satellite structure and control system. Among them, the vibration caused by the attitude control actuators with high-speed rotor is a troublesome and urgent problem to be settled, for the reason that such vibration will significantly affect the performance of the payloads. Sensors used for high capability satellites are highly sensitive to the vibration and even the micro-g lever vibration will affect the image quality. This paper is focused on the vibration isolation of reaction wheel and control moment gyro (CMG) and introduces the measurement to suppress the vibrations produced by these actuators. In this paper, a dynamic model of the CMG disturbance vibration is established and a 6-DOFs passive isolation platform with three isolation spring is developed. With the help of optimization method, the isolators are designed and series of ground tests are carried on the isolator to verify its performance. Results show that the vibration isolator effectively decreases the disturbances caused by CMG, and the reduction ratio of the vibration delivered to the basement is higher than 80%. Copyright © 2016 by the International Astronautical Federation (IAF). All rights reserved.
Zhao J.,Jiangsu Key Laboratory of New Energy Generation and Power Conversion |
Zhao J.,Institute of Telecommunication Satellite |
Huang W.,Jiangsu Key Laboratory of New Energy Generation and Power Conversion |
Zhou Y.,Jiangsu Key Laboratory of New Energy Generation and Power Conversion |
Jiao R.,Institute of Telecommunication Satellite
Diangong Jishu Xuebao/Transactions of China Electrotechnical Society | Year: 2014
In recent years, the Z-source inverter and the quasi-Z-source inverter are proposed to solve the limitations of the traditional voltage source inverter, which attract a great deal of attention. However, the shortcomings of those two topologies limit their further developments. Here a new type of tapped inductor quasi-Z-source inverter is researched to achieve higher boost ability and smaller capacitor voltage stress. This paper first proposes the generalized DC side small-signal model by using the state-space averaging method, and analyses the impact of the vary in boost network parameters and shoot-through zero state on the system based on the transfer function. The closed-loop regulator of the DC bus voltage is also designed to improve the dynamic performance of the system. Finally, simulations and experiments are carried out to validate the above characteristics.
Li D.-Z.,Institute of Telecommunication Satellite |
Yu D.-Y.,China Aerospace Science and Technology Corporation |
Ma X.-R.,China Aerospace Science and Technology Corporation
Gongcheng Lixue/Engineering Mechanics | Year: 2011
It is difficult to calculate the sensitivity coefficients of multiple eigenvalues for large complex structures due to lack of usual differentiability with respect to a design variable, and the equilibrium equation constraints if exists in the model will lead to nonconvex programming. Consequently the global optimum is difficult to find. To avoid this intractable issue, this paper presents a new optimization model for truss structures. The optimized problem is formulated as compliance minimization with volume and fundamental frequency constraints via semidefinite programming (SDP), and the compliance and fundamental frequency in traditional models are casted as semidefinite matrix constraints, both the cross section and compliance are viewed as variables. In this way, the sensitivity coefficients of multiple eigenvalues are circumvented. The SDP model is applicable both to single and multiple eigenvalues. The theoretical results and the practical use of this model are illustrated by examples at the end of the paper.
Wang X.,Institute of Telecommunication Satellite |
Li Y.,Institute of Telecommunication Satellite |
Renwang Z.,Institute of Telecommunication Satellite
Safety and Reliability of Complex Engineered Systems - Proceedings of the 25th European Safety and Reliability Conference, ESREL 2015 | Year: 2015
An application oriented layered index method for satellite constellation reliability is proposed through the study of the current constellation reliability research, as well as the existing problems. This paper first analyzed the definition of constellation reliability, and then discussed the constellation failure based on individual applications, finally proposed the Layered Index Method of application reliability evaluation considering the relationship among different applications. The contribution of this paper is: (i) the function, the condition, and the period in satellite constellation reliability analysis were defined based on constellation application failure and connection failure; (ii) a parameter system for con- stellation reliability evaluation was constructed; (iii) (iv) the steps of computing constellation reliability index were given. © 2015 Taylor & Francis Group, London.
Hu D.,Institute of Telecommunication Satellite
Zhongguo Kongjian Kexue Jishu/Chinese Space Science and Technology | Year: 2015
A novel algorithm called Kernel fuzzy C-means imputation (KFCM-I) was proposed for the incomplete data of satellite reaction wheel. The centers and radius of the known fault samples were clustered by the KFCM, and the incomplete data points were replaced by the chosen data points for keeping the sample data completely, which were chosen from the known fault data by the similarity calculation and were the most similar to the incomplete data point. Then the similarity was adopted to diagnose the test sample data. Two scenarios were considered, one was that all the feature data missed at the same time, and the other was that each data missed at the random time, but the locations of all the missing data points were random. Compared with directly excluding the outlier or missing data points in engineering, when the missing data is less than 13% of the total test data, the accuracy of KFCM-I is higher than 90%, while the missing data is between 13%~20%, the accuracy also achieves at 80%. The KFCM-I algorithm is more accuracy and has low computation, which is an useful reference to the engineering. ©, 2015, Chinese Academy of Space Technology. All right reserved.
Zhou J.,Beijing Institute of Technology |
Lu Q.,Beijing Institute of Technology |
Liu F.,Beijing Institute of Technology |
Li Y.,Institute of Telecommunication Satellite
PLoS ONE | Year: 2016
Because of the importance of ultra-wideband (UWB) radar in various applications, short pulse generation in UWB systems has attracted a lot of attention in recent years. In order to shorten the pulse, nonlinear transmission line (NLTL) is imported, which expands the application of step recovery diode (SRD) for pulse generation. Detailed analysis and equations for this SRD and NLTL-based pulse generation are provided and verified by simulation and experimental results. Factors that could cause pulse waveform distortions are also analyzed. The generator circuit presented in this paper generates 130ps and 3.3V pulse, which can be used in UWB radar systems that require sub-nanosecond pulses. © 2016 Zhou et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Li Y.,Institute of Telecommunication Satellite |
Le H.,CAS Institute of Electronics |
Xu Z.,Beijing Institute of Technology |
Zhou J.,Chongqing Communication College
2015 IEEE 6th International Symposium on Microwave, Antenna, Propagation, and EMC Technologies, MAPE 2015 | Year: 2015
A Ka-band low temperature co-fired ceramic (LTCC) transceiver is demonstrated in this paper. The proposed module is composed of several bare monolithic microwave integrated circuits (MMIC) and passive circuits. These MMICs including LNA, phase shifter, attenuator, SPDT switch, driver amplifier, power amplifier have been mounted onto LTCC substrate. The passive circuits like bandpass filter and waveguide to microstrip transition have been embedded into the substrate. The whole transceiver is fabricated in a 36mm×20mm×1.1mm LTCC board with eleven layers. The front-end is designed to operate from 34 to 36 GHz. Measurement shows that the gain of the receiver is 33 dB; noise figure is less than 4.2 dB. Output power of transmitter is greater than 24.6 dBm, while the measured gain is more than 25 dB. The implementation of this transceiver indicates that LTCC technology is well suited for highly integrated microwave and millimeterwave module. © 2015 IEEE.
Liu L.,China Academy of Space Technology |
Liu L.,Institute of Telecommunication Satellite |
Shan J.,York University |
Zhang Y.,DFH Satellite Co.
Journal of Spacecraft and Rockets | Year: 2016
Large deployable hoop-truss antennas are widely used in satellite communication systems for their high antenna gain and small packed volume. Knowledge of the deployment dynamics of the large deployable hoop-truss antenna and its coupling with spacecraft attitude motion are essential for the design of deployment mechanisms and attitude control systems. In this paper, a spacecraft with two flexible solar panels, which are reduced by Craig-Bampton component modal synthesis, is modeled by natural coordinate formulation. A large deployable hoop-truss antenna is modeled with the absolute nodal coordinate formulation. Both lead to a constant-mass matrix without the centrifugal and Coriolis forces. The whole dynamics model is used to solve the attitude and the reaction moment during the deployment process. Nonsynchronous deployment phenomena due to the structural flexibility and the decay of the driving force are investigated, and results show that these phenomena can increase the stresses suffered by the hoop truss, which should be considered in the design of a large deployable hoop-truss antenna. Copyright © 2016 by Likun Liu, Jinjun Shan, and Yan Zhang. Published by the American Institute of Aeronautics and Astronautics, Inc.
Xiaodong H.,Institute of Telecommunication Satellite |
Nan X.,Institute of Telecommunication Satellite |
Diqing L.,Institute of Telecommunication Satellite
33rd AIAA International Communications Satellite Systems Conference and Exhibition, ICSSC 2015 | Year: 2015
In support of next-generation satellite communication systems and other payload processing capabilities, a flexible and high-performance bus architecture is under development which has changed data transmission mode in traditional communication satellite platform at its core. This paper outlines the digital architecture design, validation and applications in a Chinese communication satellite as well as major technological achievements. The design of the flexible bus has capability to optimize payload bus network, enhance the anti-interference and fault-tolerance design, and reduce dry mass of satellite. Current program status is described as well as potential new application as the bus standard interface could also be used in others payload devices, to buildup high speed network among others payload devices. © 2015, American Institute of Aeronautics and Astronautics Inc, AIAA. All Rights Reserved.
Feng X.,Institute of Telecommunication Satellite |
Tan Q.,China Aerospace Science and Technology Corporation |
Liang Z.,Institute of Telecommunication Satellite
Proceedings of the 2011 6th International ICST Conference on Communications and Networking in China, CHINACOM 2011 | Year: 2011
Satellite mobile communication is one of the most important directions in satellite communication. In this paper the development of satellite mobile communication system is summarized, then the technical evolution is listed from the point of system, satellite and terminals, and finally its standard progress is described. © 2011 IEEE.