Taiyuan Satellite Launch Center
Taiyuan Satellite Launch Center
Shen Y.-H.,Taiyuan Satellite Launch Center |
Lu C.-H.,Taiyuan Satellite Launch Center
2015 International Conference on Computer Science and Applications, CSA 2015 | Year: 2015
In order to satisfy the need of cross platform, fault information standard description, and network transmission in networked fault diagnosis, the paper introduced the specific planning and implementation method based on LabVIEW. Relevant research was based on the capacities of LabVIEW cross platform and of XML standard description. The XML description method of typical fault information was given. Network transmission of fault information was realized by means of the client/server mode in a LAN through TCP protocol. The technique of VI Scripting and structured design were adopted to create and run software module dynamically in the server to meet the need of transmitting and processing different fault information in future. In the client, producer and consumer mode was used to enhance the security to avoid the loss of data. A constructed simulation system verified the feasibility of planning. The research production is useful for implementing practical networked fault diagnosis system further in future. © 2015 IEEE.
Shen Y.,Taiyuan Satellite Launch Center |
Hou Y.,Taiyuan Satellite Launch Center |
Li Z.,Taiyuan Satellite Launch Center
2016 2nd IEEE International Conference on Computer and Communications, ICCC 2016 - Proceedings | Year: 2017
Test is in order for fault diagnosis. In order to satisfy the need of cross platform, test information standard description, and network transmission in networked fault diagnosis, the paper introduced the specific planning and implementation method based on LabVIEW and Multisim. Relevant research was based on the capacities of LabVIEW cross platform. Test data were produced by Multisim. The XML description method of typical test information was given. Network transmission of test information was realized by means of the client/server mode in a LAN through TCP protocol. The technique of VI Scripting and structured design were adopted to create and run software module dynamically in the server to transmit different test information in future. In the client, producer and consumer mode was used to enhance the security to avoid the loss of data. A constructed simulation system verified the feasibility of planning. The research production is useful for implementing practical networked fault diagnosis system further. © 2016 IEEE.
Xu B.,National University of Defense Technology |
Zhang Z.,National University of Defense Technology |
Hou Y.,Taiyuan Satellite Launch Center |
Liu H.,National University of Defense Technology
IEEE Transactions on Plasma Science | Year: 2017
Liquid dielectrics are very important and useful in pulsed power systems, due to their unique characteristics of large energy storage densities, ease of circulation, and low cost. They are applicable to power systems which have complex geometries. Propylene carbonate (PC), as a kind of polar liquids, shows bright prospects in compact pulsed power sources because of its great permittivity, high electrical breakdown stress, and broad environmental operating ability. In this paper, a dielectric breakdown experiments were conducted with a microsecond pulsed power source and a test cell with spherical electrodes. The breakdown properties of PC and PC-based nanofluids (NFs) were investigated by changing the increasing rate of the charging voltage. Besides, the influence of nanoparticles on the dielectric breakdown characteristics of PC was analyzed. Results show that with a slow increasing rate of the charging voltage, the introduction of nanoparticles greatly improved the breakdown stability of PC; while with a fast increasing rate of the charging voltage, NFs exhibited much larger mean breakdown voltage. We also demonstrated that the improvement effect of NFs' dielectric performance could be explained by the energy band theory very well. IEEE
Xu Y.,Beihang University |
Chang Q.,Beihang University |
Yu Z.,Taiyuan Satellite Launch Center
Science China Technological Sciences | Year: 2012
This paper studies the key techniques of the measurement and communication system for inter-satellite links (ISLs) of global navigation satellite system. A fixed link topology is designed based on the analysis of inter-satellite geometric properties and spatial parameters of the standard Walker24/3/2 constellation. This design can achieve full network coverage with small number of hops, significantly reduce the number of ISLs, and enhance the feasibility and reliability of the system. A new time-division duplex mode, as well as an integrated measurement and communication scheme, is proposed based on the designed topology. Furthermore, mathematical formulas, error models, and modification methods regarding two-way ranging and time synchronization algorithms using spread spectrum non-coherent data frame for this new system are comprehensively discussed. Theoretical analysis and simulation studies demonstrate that our design, compared with current GPS systems, has higher ranging and time synchronization precision, improved measurement efficiency, and higher channel utilization ratio and data transmission rate. It has no restrictions of constellation configuration, making it suitable for both MEO and the future MEO/GEO hybrid constellations. The results in this paper can serve as strong technical support for the next generation of GNSS ISL. © 2011 Science China Press and Springer-Verlag Berlin Heidelberg.
Feng F.,Academy of Armored force Engineering |
Si A.,Academy of Armored force Engineering |
Zhang H.,Taiyuan Satellite Launch Center
Procedia Engineering | Year: 2011
Aimed at the problem of the feature of nonstationary vibration signal can not be extracted easily; the bispectrum analysis technique was researched in this paper. Bispectral characteristic frequency faces were searched along the parallel to the diagonal line at certain step in the bispectral modulus field, and the mean magnitude was calculated to get the feature parameters. The method was applied in fault feature extraction of piston-pin of diesel engine successfully. Finally, the piston-pin faults were diagnosed associated with genetic neural network. © 2011 Published by Elsevier Ltd.
Liu D.,Wuhan Naval University of Engineering |
Zhang X.,Wuhan Naval University of Engineering |
Chen C.,Taiyuan Satellite Launch Center
Journal of the Optical Society of America A: Optics and Image Science, and Vision | Year: 2015
We have proposed a method for rectangular illumination in a (u, v) coordinate system with high collection efficiency and favorable uniformity. In our proposed approach, with the target plane rotating at a certain angle around the z axis, one of the diagonals on the rectangular target plane moves to the coordinate axis; then, we partition the light source and target plane into grids. The intersection points of the grids are in one-toone correspondence from the source to the target plane. This improved method will avoid the one-to-many correspondence topological relationship in the traditional (u, v) mapping method; uniformity of the illuminance pattern will be promoted. Based on this method, lenses are designed for rectangular target plane illumination; uniformity over 0.83 and efficiency of about 0.92 are obtained with a 1 mm × 1 mm LED Lambertian source. © 2015 Optical Society of America.
Zaixin Z.,Taiyuan Satellite Launch Center |
Zaixin Z.,National University of Defense Technology |
Lizhi C.,National University of Defense Technology |
Guangquan C.,National University of Defense Technology
IET Image Processing | Year: 2014
Fuzzy c-means (FCM) clustering algorithm has been widely used in image segmentation. In this study, a modified FCM algorithm is presented by utilising local contextual information and structure information. The authors first establish a novel similarity measure model based on image patches and local statistics, and then define the neighbourhood-weighted distance to replace the Euclidean distance in the objective function of FCM. Validation studies are performed on synthetic and real-world images with different noises, as well as magnetic resonance brain images. Experimental results show that the proposed method is very robust to noise and other image artefacts. © The Institution of Engineering and Technology 2014.
Fan J.,Taiyuan Satellite Launch Center
Chinese Control Conference, CCC | Year: 2015
A matrix inequality approach is proposed for local stabilization of a class of uncertain linear systems subject to time-varying input delays, actuator saturation, and norm-bounded disturbances. Delay-dependent stability and stabilization conditions by using the linear state-feedback control law are obtained to guarantee the uniform boundedness of solutions of the closed-loop systems. Besides, an admissible maximum bound of disturbances can be ascertained to ensure the existence of a non-empty set of initial conditions. An optimization framework is formulated further for the maximization purpose of the admissible upper bound of disturbances and the size of the set of initial conditions. A numerical example is provided to demonstrate the effectiveness of proposed design techniques. © 2015 Technical Committee on Control Theory, Chinese Association of Automation.
Long Z.,Taiyuan Satellite Launch Center
Proceedings of the 28th Chinese Control and Decision Conference, CCDC 2016 | Year: 2016
In this paper, the three-axis rotational maneuver of flexible spacecraft is investigated and a robust composite controller is presented. The composite controller consists of a proportional-plus-derivative (PD) sub-controller which accomplishes the spacecraft attitude maneuver and a positive position feedback (PPF) sub-controller which suppresses the elastic vibration of flexible appendages. Utilizing angular velocities and quaternion of the spacecraft, the PD controller generates the control torques which act on the rigid body of flexible spacecraft. Utilizing the vibration modal information of the spacecraft flexible appendage, the PPF controller generates the piezoelectric inputs which act on the flexible appendage. Moreover, the composite controller is robust with respect to structure parameter uncertainties of flexible spacecraft. By properly choosing an elaborate Lyapunov function, the robust asymptotical stability of the whole closed-loop system is proved theoretically. Finally, simulations are included to illustrate the effectiveness of the proposed controller. © 2016 IEEE.
Hao Y.,Taiyuan Satellite Launch Center |
Shang L.,Taiyuan Satellite Launch Center
Lecture Notes in Electrical Engineering | Year: 2013
To support more and more satellite and launch vehicle missions, tracking, telemetry and command (TT&C) system is challenged by requirements of more equipments operation, more complex system management and more intelligent decision-making. With the development of information technology (IT), promoting IT usage in TT&C system is the only way to meet the challenge. Based on the views of IT evolution stages, information integration issues, combined with TT&C system, this paper proposed a TT&C information integration management model and a corresponding application system, which both have three levels, a base-level with automation as subject, a middle-level with process management as subject and a high-level with intelligence as subject. Comprehensive discussion shows that the information integration stage in IT evolution is the key development stage for TT&C system. To improve information integration efficiency and ability, the three-layer model is an instructive model for practical application. © 2013 Tsinghua University Press, and Springer-Verlag.