Abstract:Aimed at the problem of the multiple fault diagnosis of redundant system, a multiple fault diagnosis strategy for redundant system based on probability is proposed to reduce the computation and the expectant costs under condition that a probability value is set as a probability threshold and the multi-fault state whose probability is lower than the value of this probability threshold is neglected. First, this strategy is used to optimize the relation matrix model, and give up the multi-fault states whose probability is lower than the probability threshold. And then, Rollout algorithm is used to optimize the information entropy based diagnosis strategy. The example demonstrates that though the expectant costs are lowered by the strategy into a certain accuracy, a great proportion of the expectant test costs is reduced ,the size of the fault-test relation matrix model is minimized, and the calculation time is reduced.

Abstract:In view of the hypersonic vehicle quasi-equilibrium glide reentry problem, the various constraints in the process of reentry are analyzed. Process constraints are converted to a bank angle constraint at different stages, and a bank angle file is designed based on the above described. With the performance indicators of maximum cross-range and minimum aerodynamic heating, GA combined with pattern search method is used to find the optimal solution for the reentry trajectory while the terminal constraints are dealt by using the penalty function. The simulation shows that the reentry trajectory satisfactory to the various constraints can be planned by using the designed bank angle file. The speed of the algorithm optimization is raised, and still more close to the online program. This method can be used for rapid trajectory optimization and research in the covered area.

Abstract:The three-dimensional flow fields both in front and at the back of the rotor of a low-speed axial compressor are measured in detail and the contrastive analysis is performed in a state of approximative stall and stall by utilizing a five-hole probe. Based on the dynamic variable curve of the static pressure on the surfaces of the casing in the entrance and the exit under the condition of a stall state, the spatial structure of the stall region and the dynamic characteristic of flow parameters are researched, a differential equation model is established to describe the dynamic process of the airstream in a stall state, and the model is also validated by the experimental data. The results show that the backflow happens in the stall region, the included angle between the backflow speed and the partial airstream in direction is 110°. The radial scope occupied by the backflow region exceeds the blade tip region by 70%, and the axial scope is the span in front of the stator. The flow parameters, such as pressure and velocity etc., fluctuate damply with time in the stall region, and the dynamic variable process can be described by a two-order system.

Abstract:Compared with the conventional aerodynamic control, the aerodynamic resistance and heating can be reduced if a flight vehicle is controlled by adopting mass moving control under condition of flying at a high speed. By so doing the maneuverability and agility of vehcles can be enhanced greatly to provide qualifications for the improvement of the control efficiency and precision of the vehicles. In this paper, taking an interception missile flying at the last stage as a control target, based on the coupled nonlinear system of the missile constructed math model, in view of the influefnce of the aerodynamic parameters and that of the indeterminate factors of the collectivity parameters, and the chattering of the system in the control process , a quick terminal sliding mode control system is developed via backstepping and integral. Through the stability analysis and the simulation of the masses locomotion, the results show that the method is effective and feasible.

Abstract:In order to solve the existing problems of ATS software architecture, such as tight coupling, unclear layer arrangement, weak openness, bad portability and reusability etc, the framework and component standards of automatic test markup language are discussed and analyzed firstly. And then, according to the idea of services oriented architecture, web services technology and the browser/server structure, the architecture of the ATML-based test software is built and described from logic view, develop view and process view. In a certain integrated test system, an automatic test software for a certain type of missile is developed based on the ATML software architecture. The result shows that the test software is stable and reliable in the missile test process, and has the charateristics of modularization, clear layers, loose coupling and good portability.

Abstract:In order to solve the nonlinear tracking problems, a new nonlinear filter algorithm, i.e. stong tracking unscented kalman filter, on maximum posterior estimation is presented. The new algorithm adopts minimal skew simplex sampling strategy to reduce the computation time and insures the accuracy as well. Unexpected maneuvering is tracked stabely by using strong tracking filter to calculate single-step forecast mean square error. The recursive equations of time -varying noise statistic estimator are given through exponential weight of the constant noise statistic estimator to calculate statistical property of system condition noise. For this reason, the capability of dealing with variable noise statistic is improved.The simulation results show that the tracking performance of the new method is better than that of the unscented kalman filter(UKF) and that of the extended kalman filter (EKF).

Abstract:In order to solve the low right track association probability of statistical association method under condition of dense target and cross track which fails to right associate to the target accurately, this paper proposes a track association algorithm on intutionistic fuzzy bi-threshold based on traditional track association using fuzzy bi-threshold through introduction of non-membership functions, and determines membership functions and non-membership functions in line with association peculiarity. Finally, the paper associates the crossing tracks observed by two radars by utilizing Monte-Carlo simulation, and compares the fuzzy bi-threshold algorithm with the traditional track association algorithm.The results show that the correct association probability is improved from 45.1% to 49.8% , and this indicstes that the algorithm is better in adapting to the association of intensive track.

Abstract:To solve the problem of single scattering point type of feature extraction of existing estimation method, and the difficulties of engineering implementation, a kind of method for extracting three-dimensional precession features based on netted radars is proposed. Firstly, the length of the radar line of sight direction between two strongest scattering points is obtained by using the netted radar to observe range profile sequences of ballistic target, and the relation that projected lengths with time is extracted. Then, the parameters in the equation is estimated by the Least squares estimated method (LSCE). After that, profited from the multi-view of netted radar, Three-Dimensional Precession Features is extracted on the basis of projected components of different precession angular frequency. Computer simulation proves the effectiveness and stability of the extraction method, and the results reach up to the expected effects.

Abstract:Hypersonic target type recognition is an important link in the actual anti-missile combat. On the basis of analyzing the speed characteristic, highly characteristics, and track features of hypersonic target performance, the grey incidence theory is adopted to determine the comparative sequence, process the characteristic data in normalization, select appropriate characteristic indexes, and calculate the incidence coefficient and grey incidence degree. By doing so, a model of hypersonic target type recognition is constructed. The simulation results show that the model is effective, and this provides an effective way for identifying the hypersonic target types.

Abstract:In order to meet the needs of the precision assessment of the fall points in missile design and experiment, this paper, taking missile accuracy evaluation system of the fall points as a research object, designs and develops system database, data processing subsystem and evaluation subsystem based on the needs of thinking way in general design of the system. And simultaneously the paper gives detailed calculation steps and computational models of modules. The stability and maintainability of the system are tested by an actual example of a software application. The design of the system provides a technological support for equipment stereotypes, operational application and for the research and development unit to verify the design idea and inspect the production technology.

Abstract:Cognitive Navigation is a new method of autonomous navigation for Unmanned Combat Aerial Vehicle, and intelligent real-time path planning is the most important function of Cognitive Navigation for UCAV autonomous flight.The new topic on UCAV intelligent path planning of cognitive navigation is discussed by learning from human brain. Firstly, the research status of UAV real-time path planning is surveyed, and its development trends are summarized. Secondly, in order to obtain higher intelligence and wider adaptability under the complex battlefield with different tasks, the intelligent path planning of cognitive navigation is proposed for the first time, the basic connotation and the complete cognitive cycle are illustrated, and the main functions of the novel technology are illustrated. Finally, some key technologies presented clearly indicate the way to the further research.

Abstract:According to Equivalent Circuit Model and Electromagnetic Topology Theory, a method of evaluating the shielding effectiveness(SE) based on BLT equation is proposed, and the basic principle of BLT equation is introduced, the BLT equation of cavity-seam coupling described is derived,the function relationship between SE and related parameters such as enclosure dimensions, aperture dimensions is not only built up, but also can be used in an extension situation including off-centre aperture and arbitrary polarization direction. The effect of the aperture shape, aperture area, and the test point on SE are also analyzed. The SE of single aperture is simulated within a frequency domain from 0 GHz to 1 GHz, compared with the CST results. The results indicate that the relationship between SE and the frequency of incident wave can not only be described accurately by this method, but also can the resonant frequency of the shielding enclosure be estimated effectively.

Abstract:A double screen FSS with positive reflection phase gradient(the general with negative slope),above 0.83 reflection magnitude value and partially reflection features at 5.42~5.80GHz is designed and fabricated, the new waveguide antenan bandwidth is broadened, gain is improved and directivity is enhanced by applying the double screen FSS as a radome on the radiation orientation.The FSS radiation enhanced and scattering reduced mechanism are analyzed by adopting ray theory and Fabry-Perot resonator model, and the capabilities of new antenna are validated by simulation and experimentation. The results show that: the bandwidth of the antenna is increased by 34.6% and the gain of the antenna is enhanced by 6.94 dB, and the half-power beam width of E-plane and H-plane are reduced by 240 and by1280 respectively.

Abstract:Aimed at a decline in interference effect, a smart noise mathematical model is buit up based on sinusoidal modulation in accordance with convolution modulation in the time domain,and then a smart noise jamming is designed based on incomplete sinusoidal convolution modulation to realize interference with linear frequency modulation signal. The result of simulation shows that the interference signals can produce false targets group to cover the real echo signals of a certain distance unit, which can also be easily covered by the nonlinear superposition sidelobe.By so doing, the defect of convolution jamming signal being behind the real target echo is overcomed.

Abstract:In this paper, a method of single carrier frequency domain pre-equalization suitable for air-ground communication system uplink is brought forward under the condition of frequency-selective Rayleigh slow fading channel. A model of pre-equalization system is designed on the basis of this method. In the model, the downlink pilot signal is compared with the local one to perform channel condition estimation on ground station, and then the pre-equalization of uplink signal is processed by utilizing the acquired channel condition information. Finally, the uplink signal equalization is conducted on airborne receiver. The signal processing procedures of the method are analyzed and the coefficient of the pre-equalization are obtained based on zero-forcing criterion and minimum mean square criterion. By comparing the BER performance of different equalization schemes, the simulation results show that the error-floor effects will arise when pre-equalization is implemented only on ground transmitter; whereas, when bit error rate is 10-5, a 2 to 3 dB gain in performance is expected by the equalization made again on airborne receiver after ground pre-equalization in comparison with the former single carrier frequency equalization method with a linear equalization structure.

Abstract:Visual tracking is one of the most popular research topics in the domain of computer vision. It is a challenging task to develop an effective and efficient tracking algorithm because of template drift problems. To alleviate the drift, the multiple instance learning (MIL) method has been applied to target tracking. However, there must be a sufficient amount of useful data for online MIL to learn at the outset, which actually increases the computational complexity. In this paper, an effective tracking algorithm is proposed which uses an online MIL based on the compressed appearance model to accomplish object tracking. In order to decrease the computational complexity and obtain sufficient data for online learning adaptive appearance model, Features are extracted by non-adaptive random projections of the multi-scale image feature space based on compressive sensing theories. The experimental results on various videos show that the proposed method has a satisfactory performance in real-time object tracking.

Abstract:The performance of local oscillator anti-phase balance mixer is analyzed by using the system analysis method. Then, a double balance mixer is designed by adopting the LT5522 chip. Finally, the practicality circuits of a receiver are tested and analyzed. A mirror frequency suppression filter is configured at the input end of the mixer, and a low noise amplifier is configured at the input port. By doing so, the whole down-mixer circuits observe a better noise factor, and this noise factor is less than 1.2 dB of the whole circuits to satisfy the needs.

Abstract:According to the entanglement-assisted quantum error-correcting code (EAQECC) theory, a geometry character of a quaternary linear code stabilized a maximal entanglement EAQECC is presented. On the basis of this character and the theory of Cap in projective space, methods for constructing such Caps by combinational mathematics and search algorithm are designed, and good codes from such Caps are determined. Many maximal entanglement EAQECCs are constructed from these obtained Cap codes. Almost all the maximal entanglement EAQECCs constructed here are optimal or near optimal EAQECCs, and some of them are the improved parameters of EAQECCs previously known; and some of them are new ones, but are very difficult to be obtained by using the known methods.

Abstract:Aiming at the problem that Cellulars of 2-dot Quantum-dot Cellular Automata were easy to switch when signal was inverted in the vertical direction.A method to transfer the signal inverting operation from vertical to horizontal was proposed.A XOR gate of 2-dot QCA and a full adder based on the XOR gate structure were designed with this method. The simulation to the function of the circuit was given through the Genetic Simulated Annealing Algorithm based on the semiclassical model of QCA. The simulation results validated the feasibility and the validity of this method. Compared to the traditional 4-dot QCA, the 2-dot QCA takes advances of fewer amounts of the electrons and the quantum dots required by 25%, higher integration by6.2%.

Abstract:This paper mainly studies the battlefield material provision mission planning problem under the condition of uncertain environments, and builds up a corresponding uncertain programming model. In consideration of the NP-hard nature of the battlefield material provision mission planning problem, the paper introduces an elicitation algorithm, i.e. a new artificial bee colony algorithm. which is modified and is constructed to be suitable for solving the battlefield material provision mission planning problem. And through the performance comparison of this algorithm with other algorithms, the algorithm is effective. Finally, an application study of 13 mission targets is presented and the model is verified. The results show that the optimal plan under the uncertain environments is more practical.

Abstract:An improved FMEA method is proposed in order to deal with multi-granularity problem in evaluating failure modes. Firstly, the 2-tuple linguistic representation is applied in evaluating the pre-set sample E to eliminate the effect of multi-granularity and attain the value of the basic linguistic term. Then, the grey relational theory is applied to the calculation of the gray degree to determine the risk priority of the failure modes. The result shows that the risk priority of the failure modes is explicit.