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Xiong X.,Institute of Spacecraft System Engineering CAST | Wang J.,Institute of Spacecraft System Engineering CAST | Zhang P.,Beihang University
Safety and Reliability of Complex Engineered Systems - Proceedings of the 25th European Safety and Reliability Conference, ESREL 2015 | Year: 2015

A new method of failure detection for damaged or floating control surface is proposed, which is only based on the information of electric actuator, avoiding the combined effects caused by the concurrent failure of control surfaces. By constructing the model of actuator system and observing the characteristics of internal physical parameters of actuator under floating/damage failure, the relationship between actuator’s armature current and the failure mode is found and the judgment theorem is given. The feasibility of the proposed method is verified by simulation example. The comparison of performance between the proposed method and the traditional FDI (failure detection and identification) method (Filter Method) on detecting concurrent failure of control surfaces is showed. The results suggest that the proposed failure detection method is efficient and accurate in detecting and locating the failure regardless of whether or not the system noise is considered. This method is independent from the complexity of the flight control system since it is only based on single electric actuator. Therefore it could be used for both linear system and nonlinear system. The proposed failure detection method is efficient and applicable in realistic engineering scenario. © 2015 Taylor & Francis Group, London.


Shi W.J.,Institute of Spacecraft System Engineering CAST | Zhang Y.B.,Beihang University | Hu W.P.,Beihang University
Advanced Materials Research | Year: 2013

In this paper, a fatigue life prediction method for fiber reinforced polymer composite lamina is proposed. Based on two independent introduced damage variables, the damage degree of fiber and the damage degree of matrix, the issue of lamina fatigue is transformed into the study of damage evolution for fiber and matrix. Subsequently, the damage driving force and the damage evolution equations for the fiber and the matrix are constructed, respectively. Then, a novel parameter identified method is conducted. Finally, with the failure criterion for the lamina presented, the fatigue life prediction method of the composite lamina is proposed. © (2013) Trans Tech Publications, Switzerland.


Sun W.,Institute of Spacecraft System Engineering CAST | Niu F.,China Academy of Launch Vehicle Technology | Wang X.,Institute of Spacecraft System Engineering CAST | Zeng F.,Institute of Spacecraft System Engineering CAST
Jixie Qiangdu/Journal of Mechanical Strength | Year: 2016

Based on iSIGHT multidisciplinary optimization platform integrated finite element analysis software ABAQUS, the sub-model technology, global optimization strategy, hybrid iterative optimization algorithm and parametric modeling method of spline curve were used in optimization design of sealed-module structures, which greatly reduced the single-solving time and improved the efficiency of entire optimization process. The weight and stress of sealed-module structures are reduced significantly after optimized and the optimization result are verified by hydrostatic test. This method solves a problem of high stress of sealed-module and provides a referenced technical route for optimization design of sealed-module in future. © 2016, Journal of Mechanical Strength. All right reserved.


Liu Y.,Institute of Spacecraft System Engineering CAST | Liu Y.,Harbin Institute of Technology | Tan C.,Institute of Spacecraft System Engineering CAST | Zhao Y.,Harbin Institute of Technology
Hangkong Xuebao/Acta Aeronautica et Astronautica Sinica | Year: 2015

In order to overcome the drawbacks of constant wear rate and wear factors randomness hypothesis and to accurately predict the dynamic process of mechanical wear reliability, a time-variant wear equation of joint clearance is constructed by using a nonlinear equivalent spring-damp contact force model and discretization of wear process. Then, the joint wear evolution equation is converted into a time-dependent reliability equation by introducing a PHI2 method and defining an up-crossing rate. Therefore, a wear reliability analysis method which combines the mechanical multibody dynamics considering time-variant clearance with PHI2 is put forward. At last, by taking a two-axis positioning mechanism of satellite antennas as an example, dynamic reliability of the mechanism, parameters reliability sensitivity and their influence on reliability are studied. Results show that contact force is the dominant factor of reliability which is 10 times sensitive than other factors before the end of the product's steady wear process stage, while joint clearance will be the new dominant factor of reliability after this stage. What's more, there is a critical value for joint clearance, and appropriate augmentation of joint clearance before this critical value is propitious to the improvement of product's reliability. Compared to the current methods where randomness is emphasized, while the nonlinear process of wear and the consequence of concomitant time-variant clearances to product reliability are neglected, the present method could accurately analyze the dynamic process of wear and wear reliability. ©, 2015, AAAS Press of Chinese Society of Aeronautics and Astronautics. All right


Bin B.,CAS Institute of Mechanics | Ning L.,CAS Institute of Mechanics | Nin P.,CAS Institute of Mechanics | Nin P.,Institute of Spacecraft System Engineering CAST | Han Z.,CAS Institute of Mechanics
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2013

As the development of semiconductor technology, the manufacture process of CCD sensors has been improved continuously. In recent years some new technologies appear on CCD sensors. Analog pixel Binning technology is one of them. In this paper, a new signal-processing system of digital pixel binning based on bi-cubic filtering algorithm is designed.The system overcomes the shortcomings of losing some image details, caused by analog pixel binning which does simply summation of pixel signals. The signal-processing system of digital pixel binning can keep high frequency information through bi-cubic filtering algorithm, which can improve the contrast and MTF of the remote sensing images. This system can achieve pixel binning with lower computational complexity and also it has the good real-time capability for large-scale remote sensing images. © 2013 SPIE.


Zhang Z.,Institute of Spacecraft System Engineering CAST | Wang J.,Institute of Spacecraft System Engineering CAST | Li L.,Institute of Spacecraft System Engineering CAST | Cheng Z.,Institute of Spacecraft System Engineering CAST
Safety and Reliability of Complex Engineered Systems - Proceedings of the 25th European Safety and Reliability Conference, ESREL 2015 | Year: 2015

Satellite orbit insertion and attitude establishment process is the pivotal condition of mission success, and the mission risk of which is also the focus of engineering. To identify the mission risk eff ectively and evaluate it quantitatively, the risk analysis based on PRA has been carried out during the process of the product development through MLD, FMEA, ESD, ETA and FTA. The methods of identifying the satellite initiating events and the reliability data collecting, processing of satellite products are given, which provide the reference and basis for the further applications of the satellite PRA. © 2015 Taylor & Francis Group, London.


Zhu L.,Institute of Spacecraft System Engineering CAST | Qiao M.,Institute of Spacecraft System Engineering CAST | Li X.,Institute of Spacecraft System Engineering CAST | Chen Q.,Institute of Spacecraft System Engineering CAST
2015 3rd International Conference on Electric Power Equipment - Switching Technology, ICEPE-ST 2015 | Year: 2015

Future spacecraft's solar array is required for high power, long life and small attitude control pressure. High voltage solar array is an important development direction of solar array in the future. The electrostatic discharge will be caused by the interactions between the high voltage solar array and the plasma in the space environment in LEO. Thus, the threshold voltage of ignition discharge and secondary discharge of a high-voltage solar array needs to be determined. In the paper, the vacuum plasma environment in LEO orbit was simulated to study the threshold voltage of ignition discharge and the secondary discharge of high-voltage solar array. The triple-junction GaAs solar cell with rigid substrate specimens was used for the experiment. The threshold voltages of ignition discharge and secondary discharge with and without electrostatic discharge protection were determined in LEO orbit in the paper which can be used as the reference of electrostatic discharge protection. Experiments were conducted in the absence of protection and appropriate protective measures conditions, respectively. The threshold voltages under the ignition discharge and secondary discharge were identified in the condition of absence of protective measures and different protective measures. In the state of the specimen without protection, the occurrence of ignition discharge threshold voltage was 95V. The threshold voltage of secondary discharge was 130V and the location of the secondary discharge occurred in parallel with the gap of 1.079mm. In the case of protective measures, the threshold voltages of the ignition discharge and the secondary discharge have improved significantly. In a word, the experiments demonstrate the effectiveness of the protective measures. © 2015 IEEE.


Zhang Y.-T.,Institute of Spacecraft System Engineering CAST | Cai Z.,Ministry of Industry and Information Technology Software and Integrated Circuit Promotion Center | Liu S.,Harbin Engineering University
Dianbo Kexue Xuebao/Chinese Journal of Radio Science | Year: 2011

Aiming at the propagation characteristics of electromagnetic waves in loss media, a modified alternative direction implicit finite difference time domain (ADI-FDTD) method is proposed to solve the problem. The modified method can improve the disadvantage of the traditional ADI-FDTD method, which improves the computational efficiency on the cost of accuracy. The unconditional stability of the algorithm is proved, while the numerical dispersion is also analyzed. The algorithm is validated effectively, and it could also improve computational accuracy, which has been proved by examples comparison. The algorithm is applied to analyze the scattering of a metal sphere in air, on the bottom of ground and sea. The simulation shows that the amplitude and oscillation of the scattering increase in the loss media. Copyright © 2011 by Editorial Department of Chinese Journal of Radio Science.


Yuan B.F.,Institute of Spacecraft System Engineering CAST | Gao S.,Institute of Spacecraft System Engineering CAST | Li X.,Institute of Spacecraft System Engineering CAST
Applied Mechanics and Materials | Year: 2014

The joint-locking device is an important component used to lock some equipments in the satellite. In this paper, a joint-locking device is designed to lock the deployable equipment in the satellite. The working principle of its locking mechanism is analyzed, exhibiting such characteristics as light weight, small dimensions and strong locking ability. Thermal deformation analysis on the joint-locking device is conducted using finite element method. The simulation results show that the joint-locking device possesses high thermal stability and can meet design requirements. © (2014) Trans Tech Publications, Switzerland.


Yan D.,Institute of Spacecraft System Engineering CAST | Wang L.,Institute of Spacecraft System Engineering CAST
ICEIEC 2015 - Proceedings of 2015 IEEE 5th International Conference on Electronics Information and Emergency Communication | Year: 2015

Satellite network has the advantage of global coverage and simple access, so it is considered to be an important part of next generation Internet. In this paper, we propose a novel traffic prediction based dynamic routing technique for double-layered satellite networks, which is called TPDR. It has a double-layered structure, which is composed of LEO layer and GEO layer. TPDR supports new nodes to join the network, and prevent the manager nodes from becoming overloaded based on traffic prediction. In the end, the performances of end-to end delay and manager packet loss rate are evaluated by simulations. © 2015 IEEE.

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