Yuan S.-M.,Navy Academy of Armament |
Du H.-S.,Navy Academy of Armament
Zhongguo Guanxing Jishu Xuebao/Journal of Chinese Inertial Technology | Year: 2011
A transfer alignment simulation and verification scheme based on the ship motion is proposed to improve the simulation fidelity for shipborne inertial navigation system. Compared with conventional schemes, the new scheme can bring motion parameters that are more close to actual motion environment by using the 6-degree of freedom ship motion. The designed space transform algorithm realizes the transform between space motion parameters and analogy input of main inertial navigation devices. The transform of analogy input for slave SINS devices is realized by the calculation of logical lever arm and carrier flexure. The algorithms and solution procedures of each model are given. The velocity plus attitude matching algorithm can reach 0.02° of horizontal angle and 0.05° of azimuth angle in 10 s. The simulation result shows that the scheme is feasible and practical, and can also provide references for the analysis and verification of transfer alignment schemes in other fields.
Li B.,Tsinghua University |
Li B.,Navy Academy of Armament |
Mu C.,Tsinghua University |
Bai T.,Navy Academy of Armament |
Liu Z.,Aerospace System Engineering Shanghai
Hangkong Xuebao/Acta Aeronautica et Astronautica Sinica | Year: 2014
Different from the traditional object tracking technology, extended object tracking (EOT) doesn't ignore the target's physical extension. Instead, EOT simultaneously estimates both the centroid's kinematical state and the physical extension of the target. A random matrix based EOT approach characterizes the physical extension with a random symmetrical positive definite matrix, i.e. the ellipse/ellipsoid, and establishes a measurement model which is suitable for EOT. In order to improve the tracking performance when the target maneuvers, an ellipse/ellipsoid fitting based EOT approach is proposed based on the relationship between the ellipse/ellipsoid and the symmetrical positive definite matrix. Furthermore, a hybrid approach for EOT is presented to combine the advantages of the abovementioned two EOT approaches. Simulation results show that the hybrid approach can appropriately decide whether the target is maneuvering and choose a better approach. The physical extension estimation error of the hybrid approach is lower than the other approaches, and the estimation performance of the centroid's kinematical state is also better.
Zhou X.,PLA Air Force Aviation University |
Zhou X.,Navy Academy of Armament |
Zhang F.-M.,PLA Air Force Aviation University |
Zhou W.-P.,Navy Academy of Armament |
And 2 more authors.
Wuli Xuebao/Acta Physica Sinica | Year: 2012
In order to overcome the disadvantages of existing complex network robustness research models in which only the local influences of disabled nodes and topological robustness are considered, the node load, utmost load and disabled model are defined by node efficiency and a new method to evaluate complex network functional robustness is proposed in which the whole influence of disabled nodes is considered. The complex network functional robustness is evaluated by the final disabled node proportion after beat and the optimized evaluation arithmetic is given. Experiments show that this method is effective and feasible in evaluation of complex network functional robustness in which the node load is considered, and it is applicable for large scale complex networks. © 2012 Chinese Physical Society.
Zhou W.,Navy Academy of Armament |
Wang Z.,Nanjing University of Science and Technology |
Zhou C.,Nanjing University of Science and Technology
Proceedings - 29th International Symposium on Ballistics, BALLISTICS 2016 | Year: 2016
Drag-ring correction schedule for one dimension trajectory correction projectile, with the characteristics of simple control actuator, reliable action, low cost, and greatly improving the ground vertical intensity etc., has been applied on the shells and achieved good application effect in recent years. Two aspects are extremely important in the implement of this projectile: First, the corresponding firing elements (i.e., the elevation angle) should ensure that the flight distance of uncontrolled projectile is greater than or equal to the desired distance. Second, real time identification of the characteristic parameters of the projectile should be performed based on the measurements of a segment of flight data. However, high altitude meteorological conditions cannot be obtained in practice, which makes it extremely difficult to ensure that the average impact point center of uncontrolled projectiles is consistent with the generalized target, and brings a great impact for the accuracy of trajectory prediction and the trajectory correction effect. For those problems, in this paper the corresponding equivalent wind parameters are obtained based on a few rounds of the impact point data of the uncontrolled shells test-fired in advance, to ensure the validity of the setting firing elements and trajectory prediction. Furthermore, the number of test-fired and the different methods and their effects of getting the equivalent wind parameters are analyzed. The research content reported in this paper is able to provide useful guide for the application of the trajectory correction technique for the one dimensional trajectory correction projectile.
Mao C.,Wuhan Naval University of Engineering |
Liu Z.,Wuhan Naval University of Engineering |
Qiu Z.-M.,Navy Academy of Armament |
Lu F.-X.,Wuhan Naval University of Engineering
Dandao Xuebao/Journal of Ballistics | Year: 2012
To improve the operational effectiveness of electromagnetic pulse bomb(EMPB) with cascaded flux compression, the characteristics of fuse and warhead matching were analyzed based on the directed radiation property, and the coordination system of EMPB was built. Based on the coordination system, the numerical method for the optimal detonation time of the fuse was proposed. By numerical optimization, the effect of parameters of bomb encountering target on registration precision of active antenna was obtained. The calculation figures show that the pitching angle is the principal factor affecting the registration precision. The numerical simulation results offer theoretic basis for setting attack parameters and tactical use of EMPB.
Xiao J.,Wuhan Naval University of Engineering |
Liu W.,Navy Academy of Armament |
Zhang S.,Navy Academy of Armament |
Zhang J.,Navy Academy of Armament
Qiangjiguang Yu Lizishu/High Power Laser and Particle Beams | Year: 2010
Aperture coupling is a main coupling mode through which ultra wide band(UWB) electromagnetic pulse(EMP) can disturb or damage many equipments. Coupling effects of slots with different shapes in a cuboid object are studied using finite difference in time domain(FDTD) method. Selecting slots with dimension of several millimeters as research object, coupling effects by varied incident angles and varied pulse widths are analyzed. Interior resonance effect, increase effect around slots and several distributing rules of electric field in the cavity are got. The main results include: clear increase effect occurs around rectangle slot; coupling coefficients of triangle slot and array are obviously smaller than that of other slots; coupling effect of incident pulse with short pulse width is obviously better than the one with long pulse width; coupling effect weakens as incident angle diminishes.
Zhou X.,Navy Academy of Armament |
Zhnag J.-W.,Navy Academy of Armament
Binggong Xuebao/Acta Armamentarii | Year: 2015
In order to evaluate the node importance of complex weighted network, the node importance contribution matrix and node importance evaluation matrix of weighted network are defined, and a method which uses node importance evaluation matrix to evaluate the node importance of complex weighted networks is proposed. The proposed method considers both node's role in network information transmission, degree, edge weight and adjacent nodes' importance contributions. The node degree, efficiency value and edge weight are used to measure the importance contributions of adjacent nodes. Finally, an optimized algorithm of which time complexity is O(n2) is presented. Experimental results show that the method is effective and feasible. © 2015, China Ordnance Society. All right reserved.
Yang W.,Navy Academy of Armament
2014 6th International Conference on Wireless Communications and Signal Processing, WCSP 2014 | Year: 2014
In cognitive radio sensor networks, one of the fundamental tasks is cooperative spectrum sensing by multiple cognitive radio (CR) sensors to improve the spectrum detection performance. However, during each cooperative sensing process, extra energy is consumed by the selected sensors through local sensing, data reporting, and data fusion activities. Thus, cooperative sensing processes call for energy efficiency. This paper investigates two practical optimization problems related to energy efficient cooperative sensing issue. One focuses on the sensors selection in a single process, with the objective to minimize the total energy consumption meanwhile the expected sensing performances are achieved. The other is an online problem, which schedules participant sensors for each process with the aim to enable the network to perform as many as cooperative sensing processes, therefore increasing the network lifetime. Due to the NP-hardness of the proposed problems, we propose heuristic algorithms for them respectively. Extensive experiments by simulations demonstrate the effectiveness of the proposed algorithms. Using the proposed algorithms, more cooperative sensing processes can be realized and the network lifetime can be extended significantly. © 2014 IEEE.
Wang L.,Yantai University |
Li G.,Yantai University |
Liu J.,Navy Academy of Armament |
Mao W.,Yantai University
Xi'an Dianzi Keji Daxue Xuebao/Journal of Xidian University | Year: 2013
The performance of classical two dimensional (2-D) Direction-Of-Arrival (DOA) estimation algorithms degrade substantially in the presence of coherent environment. A new DOA matrix method-DOA matrix method based on data matrix reconstruction (DMR-DOAM) is proposed for 2-D DOA estimation in the coherent source environment. The proposed algorithm reconstructs two Toeplitz equivalent covariance matrices by using cross-correlation information among receiving data from arrays. Decorrelation and 2-D DOA estimation can be realized via the eigen-decomposition of the new DOA matrix. The algorithm can retain the advantages of the traditional DOA matrix method, such as automatical parameter alignment and no need of 2-D search spectrum peak. The equivalent covariance matrices only use the middle column of classical covariance matrices, so the calculation amount is reduced, and the algorithm can be realized easily. Furthermore, the paper analyzes the estimation performance and influencing factors of the proposed algorithm. Theoretical analyses and simulation results both show that the proposed algorithm is effective.
Meng X.Y.,Northwestern Polytechnical University |
Qiu Z.M.,Navy Academy of Armament |
Zhang P.,Navy Academy of Armament
Advanced Materials Research | Year: 2014
A new discrete chemical plume model based on CFD was established, which avoids the shortcomings of the current model. In this model CFD was applied to simulate the turbulent environment of chemical plume, while the chemical substances contained in the plume were modeled as discrete phase. Utilizing this model, chemical plume under water was simulated numerically and analyzed hereafter. The transport characteristics of simulated plume were consistent with existing experimental results. Based on the simulation results, the effect of flow field on plume transport was also analyzed. The model proves an efficient approach to simulate the transport process in different environment, as well as analyze various types of actual situations. Moreover, this model can provide the theoretical basis for plume tracking algorithm research and simulation platform, which promotes significantly the research on chemical plume tracking. © (2014) Trans Tech Publications, Switzerland.