Abstract:Plasma flow control, as a novel active flow control technique, has become a newly-rising focus in the international aerodynamics and aerothermodynamics fields. The character and research status quo of plasma aerodynamic actuation modeling are introduced in the paper. A detail specification of four basic models of plasma aerodynamic actuation is discussed. The simulation technologies, the merits and defects of the methods are discussed. The development direction of plasma flow control is analyzed. More researches based on particle simulation will be developed in the future. More and more factors, such as the unsteady characteristic of plasma aerodynamic actuation, will be considered in modeling, which makes the simulation model much more accord with the physical process. Researches of higher inflow velocity will be carried on to meet the application demand. The deep simulation research is a help to revealing the physical essence of plasma aerodynamic actuation and its interplay with boundary layer .so as to promote the research and development of plasma flow control technology in our country.

Abstract:This paper mainly studies the traffic discharge conversion on asphalt pavement and presents that the property of main landing gear can be known by the load circle radius, tire pressure, wheel-tread and radius ratio, distance between tandem and radius ratio. Characteristics of wheel-tread and radius ratio, distance between tandem and radius ratio on current airplane are analyzed based on probability theory. Wheel-tread and radius ratio of typical dual wheel gear is 3.32, the dual tandem dual wheel gear is classified into three models by distance between tandem and radius ratio 6.791 and the wheel-tread and radius ratios 4.0 and 5.0. By applying the fatigue principle and the conversion standard of tensile stress of the bottom of sub-base and the fatigue equation as the conversion standards, selecting 7kinds of typical construction to calculate the greatest tensile stress of the bottom of sub-base for the iso-type gear and hetero-type gear of different the load circle radius and tire pressure, the conversion coefficient of the gear is obtained and the traffic discharge conversion relation between the design airplane and other airplanes is established. The traffic discharge conversion satisfies the principle that the asphalt pavements designed according to the different design airplanes are equal in thicknesses.

Abstract:The thesis establishes a network simulation system for real-time confrontation of simulated air combat in order to evaluate the confrontation effectiveness and capability of air combat, introduces the design approach, framework and function of the system and applies the least square fitting arithmetic in resolving the problems like the non-continuous track of simulated entity and the shaking of picture. Based on the Vega simulation software, it creates complex special effects of various kinds on battlefield and figures out the visualization of non-visual physical quantum. The system can make dynamic show of missile's attack to relevant target in different situations, including sorts of simulated information like special effects, sound effects, etc, with a fluent picture, a stable system performance and a desirable interactive capability. The visual simulation program, developed by means of Visual C++, resolves specific problems like visual drive and automatic viewpoint switching. The simulated result shows the simulated air combat process can be vividly represented in real time and an intuitionist evaluation of the combat effectiveness and capability is provided.

Abstract:The Inertial Navigation System(INS) testing equipment is developed aiming at self-maintenance and fast testing, so as to improving the whole system maintenance and repairing ability. Based on the Compact PCI bus, after analyzing the testing requirements of the testing equipment, the 32-bit serial code receiving and transferring circuit board and the SXZ circuit board are developed, the relevant driving programs are developed, too. Using LabWindows/CVI, the testing software is developed adopting techniques such as timer, asynchronous timer, threading pool, data protection and minitype database, etc. The developed testing equipment play an important role during the maintenance of the type of airplane, for it's high precision, fast failure diction speed, simple operation, high automatization and easy use and maintenance.

Abstract:Considering the mutually interacting phenomenon of such aspects as trajectory, orbit and system, this paper designs a suitable trajectory and presents a mathematical model of system/trajectory/orbit integration design and optimization for the small-sized multi-stage solid rocket. By adopting Adaptive Simulated Annealing, Hooke-Jeeves direct searching method, Multi-Island Genetic Algorithm, Successive Approximation method and Directed Heuristic searching method, a major/trajectory/orbit integration optimization for a multi-stage solid rocket is performed aimed at 300 km LEO, and then the optimization results of the five methods are compared with each other. According to the results, here comes to a conclusion that: the model of integration optimization is reasonable; parameter optimization of major design integrated with trajectory optimization digs out the vehicle's merit to a great extent; what's more, the optimization has great effect on vehicle design, and the liquid fuel consumed in orbit-transfer is decreases by 12%. The models and the software can be generalized to the scheme demonstration and conceptual design of other solid rockets.

Abstract:In order to achieve an optimal attack effect during the air combat in coordination, missile-target optimal assignment is an effective method in the process of attack in coordination. On the theoretical basis of operational efficiency and operational research, a missile-target optimal assignment mathematical model for multi-target attack in coordination is established. Then, based on the analysis of the basic particle swarm optimization (PSO) algorithm, an improved particle swarm optimization (IPSO) algorithm is proposed, and there are three improvements: 1. Adaptive adjustment of inertia weight; 2. Amelioration of particle velocity and position; 3. Betterment of optimization strategy. And this algorithm is applied in solving the missile-target optimal assignment problem of coordination air combat (MTACAC). The simulation result indicates that those advantageous improvements can expedite the convergence speed of the PSO algorithm and improve its local and global search ability. The IPSO algorithm, compared with the basic PSO algorithm and the genetic algorithm (GA), is better in finding the optimum assignment solution more quickly and effectively for the multi-target attack in coordination.

Abstract:Mainly consisted of simulating system, the present TACAN equipment is difficult to associate with the date equipment system and is necessary to make digital improvement. The digital technology of IF signal, which is on the basis of Software Radio, has been used broadly in the current communication field. The hardware system made up of FPGA and DSP is the implement platform of advanced digital signal processing technology used in the practical projects. First, the characteristics of TACAN signal are analyzed；Second, the IF signals are processed by using digital technology on the basis of a hardware system which is composed by FPGA and DSP. The result proves that this algorithm meets the performance demand of TACAN system. Compared with the conventional system, TACAN provides many benefits in the economization of power and space.

Abstract:The spectrum estimation method which is based on the eigenstructure of array signal correlation matrix is one of the main parameter estimation methods. With the deep-going research in application, the requirement for two dimensions parameters estimations becomes more and more urgent. In this paper, the dimension-separated coupling problem in 2D-MUSIC algorithm is discussed. Though the discussion, the characteristic of coupling array which is decided by the linear correlation between horizontal axis vector and vertical axis vector of array is obtained. And the characteristic shows that larger sensor redundancy exists in the traditional planar array. On the basis of this, An F-shaped array for 2D-DOA estimation is presented, with which, the decoupling 2D-MUSIC algorithm in the dimension-separated manner is implemented. Though analysis and simulation, and in comparison with other algorithms, this algorithm is less in computation load, higher in precision and sensor utilization rate.

Abstract:In order to improve the detection performance of constant false alarm detectors in multi-targets environment and effectively control the rise of false alarm rate at the clutter edges, a new CFAR detecting algorithm (OSUMGO-CFAR) is proposed based on efficient unbiased minimum-variance estimation (UMVE). In this algorithm, OS and UMVE methods are respectively adopted to create two local noise power estimations, the maximum value of them is used to set an adaptive detection threshold. Under SwerlingⅡassumption, the analytic expressions of MGF and ADT in homogeneous background are derived , again the analytic expressions of Pd in multi-targets environment and the peak of false alarm rate at clutter edges are derived. With numerical analysis, the CFAR-LOSS and peak of false alarm rate are taken respectively as the measurement of performance in multi-targets environment and at the clutter edges. The analysis results show that the algorithm is better than OSTMGO and GOSGO in performance in non-homogeneous background.

Abstract:Orthogonal Frequency Division Multiplexing (OFDM) technique is an efficient data transmission technique with good immunity for the effects of multi-path channel interference, inter-symbol interference, narrowband interference and high frequency spectrum utilization ratio. It has been widely used in practice. Automatic identification and modulated parameter estimation of communication signal of OFDM are key technologies in non-cooperative communication and software radio. Aiming at the detection methods of OFDM signal based on higher order cumulants, the paper proposes a novel method used to detect OFDM signal in the fading channel based on four higher order moments. This method can detect OFDM from signal-carrier modulated signals (MPSK or MQAM) .Theory analysis and simulation date can prove that the algorithm has beautiful detection and identification defection and fading signal adaptability.

Abstract:In the baseband signal processing of high precision GPS receiver, the measurement accuracy of carrier phase smoothing pseudo-code measurement is greater than that of pseudo-code measurement. The traditional phase-smoothed pseudo-range algorithm is suitable for the condition that the number of smoothing epochs is not too great, but this will not hold true in the application situation of the short time multi-epoch smoothing. So the deficiency of the traditional phase-smoothed pseudo-range algorithm is analyzed under the condition of smoothing epochs increased. The complementary Kalman filtering is then employed as a novel smoothing algorithm in comparison with the traditional one, and the corresponding mathematical analysis of complementary Kalman filtering is provided, the feasibility of the algorithm is also analyzed. The simulation results show that because the influence of all relevant errors is taken into account in the complementary Kalman filtering, its smoothing precision is higher than that of the traditional one when the number of smoothing epochs exceeds 500.

Abstract:The evaluation of equipment system performance reliability is one of the most important items in the reliability evaluation work of the armament products. In the past, few consideration is given to the problem whether the radar equipment system working performance can reach the requirement or not, while evaluating the radar reliability of working performance (RWP). This paper shows that the problem of the equipment reliability is a basic starting point in the evaluation of radar equipment system performance reliability and defines the reliability in performance of radar equipment system. According to the limitation of the using condition, the reliability in performance of radar equipment system is defined as a narrow sense working performance reliability and a broad sense working performance reliability. Through the analysis of the radar equipment system performance reliability, we get to know that the radar equipment system reliability is a parameter to tell how long the radar equipment performance can hold on, and an important guide line in evaluating the radar equipment efficiency. In this paper, the evaluation of the performance reliability of new type radar equipment system is carried out from both the narrow sense working performance reliability and the broad sense working performance reliability, and an evaluation model of the new type radar equipment system working performance based on the narrow sense RWP and broad sense RWP is given, which can provide a scientific basis for the equipment maintenance decision-making and the establishment of related maintenance strategy.

Abstract:The damage grade assessment of the sap gateway is an important basis for the rush-repair scheme making. The traditional method can only give the qualitative result, but can't provide quantitative result, thus a greater error is caused in assessment result. First, this paper gives the partition criterion of the damage grade, then analyzes the factor that influences the damage degree of the sap gateway and determines the attribute and values. Furthermore, the Bayesian network for assessing the damage grade of the sap gateway is established, the network parameters are given by utilizing the experiences of experts, and the united probability distribution formula of the damage degree is deduced. Finally, an example is given, which is solved by reasoning platform GeNIe. The conclusion is drawn that the Bayesian network model can introduce the random factors influencing the damage degree, and by well combining the experiences of experts with the damage data, the probability relationship of the variables is given. The assessment result is consistent with the numerical simulation result.

Abstract:In order to settle the problem of choosing radar spare part transportation route, an evaluation index system of transportation route choice plan is established. In view of the problem that many indexes involved in route choice can not be quantified, the weight of index is hard to be determined or low in creditability, an information entropy method is adopted to obtain the entropy weight of each index in the evaluation index system and the grey fuzzy evaluation of transportation route choice plan is performed by combining the fuzzy theory and grey theory in application. Finally the reasonable sequence of choosing the route is gained. The result can be a help to the commander in making a quick decision and the model is of some instructive value in improving the spare part support effectiveness in wartime.

Abstract:To improve the efficiency of maintaining and servicing Aero REPM-BLDCM, detecting the fault in time is of great importance. Thus, an efficient method of failure diagnosis and mistake detection, by using the inherent characteristic of running BLDCM, through an analysis of bus-current ripple and in combination with Hall position signal, is put forward. Combing with Hall-signal, the DC-link current ripple wave can help filter out the broken switch tube. The correctness of the result based on theoretical analysis is tested and verified by simulation and experiment, which offers a scientific reference for the further researches in electronic protector and fault diagnosis device of REPM-BLDCM.

Abstract:Focusing on the problem that the GPS signal is susceptible to interference, an adaptive anti-jamming algorithm based on FCGA（Floating point number Coded Genetic Algorithm）is presented. First, according to the analysis of the output signal of the adaptive array, the relation formula between the radiation pattern of the adaptive array and the weighted vectors is induced. Then, the objective function with constraint conditions is obtained by LCMV criteria（Linear Constrained Minimum Variance criteria）and optimized by using the FCGA. Finally, the simulation experiment of 22-unit uniform circular array is carried out for its radiation pattern and output SINR. The results show that, by using this method, the main beam can be kept in the directions of the desired signal, and simultaneously the hollow beam is formed in the directions of the interference signal. Thus, the output SINR is not depressed, but kept constant. The goal of interference cancellation is achieved.

Abstract:In order to analyze Complementary Code Keying (CCK) performance on the additive white Gaussian noise (AWGN) channel, an idea of M-ary Quaternary Orthogonal Keying modulation (MQOK) is proposed in this paper, based on the analysis of the common traits of CCK and M-ary Bi-orthogonal Keying (MBOK). Again this paper analyzes that MQOK has the merits of simpler demodulation structure and more adaptable to higher data transfer than MBOK and points out that CCK coding modulation is considered a concrete way to realize MQOK. By analyzing the performance of MQOK on AWGN channel in detail, new closed-form formulae for CCK are gained with its own modulation feature. Comparison between the numerical result and the simulation result of Monte Carlo shows that the difference of the required signal-to-noise (SNR) between the numerical and simulation is less than 0.5 dB with any certain bit-error probability and symbol-error probability, which confirms that these formulae are more accurate and practical, and the approach to analyzing CCK performance by MQOK is available.

Abstract:The paper deals with simulation of the rotor vibration in a journal bearing. The rotor is maintained in equilibrium during rotation by a fluid pressure wedge created by an oil film. These bearing forces can be modeled as a rotating spring and damper system. The rotor motion is described by complex coordinates of the rotor centerline. The real part of the position vector is a rotor displacement in the X-direction while the imaginary part is a displacement in the perpendicular direction, as we say in the Y-direction. The equation of motion is containing complex variables as a function of time. Equation parameters are complex quantities as well. The paper demonstrates how to solve such an equation using Simuling.

Abstract:With the rapid development of meta-materials, the requirements for the precision of measurement of the effective electromagnetic parameters become increasingly high. A research on the measurement of the effective electromagnetic parameters has been made and free-space method is presented. Compared with other methods, this free-space method is a untouchable and nondestructive test method ,and when using this method, the sample is not strictly required in shape and technology but it should be homogeneous in thickness and big enough in test area to avoid diffraction effects at the edges. An effective way is proposed for solving the multi-valued problem and phase-shift ambiguity problem in the parameter inversion process by the theoretical analysis. The effective electromagnetic parameters of air and meta-material samples are tested by using the free-space method, and in comparison with the results of the wave-guide method in the band (8 GHz-14 GHz), the results indicate that this test method is correct, reliable and practical.

Abstract:The complete classification of 4-dimensional optimal self-orthogonal codes of code length is presented. The establishment of the optimal orthogonal code matrix and the formation of linear equations between the two links will determine the problem of optimal orthogonal code transforming into that of solving linear equations. Results identify all generator matrixes of the optimal orthogonal code, and further are not equivalent to the optimal orthogonal codes since the integrity of classification, and the generator matrices and weight polynomials of these 4-dimensional optimal self-orthogonal codes are also given. Therefore, the optimal orthogonal code parameters, structural characteristics and equivalence problem have been completely solved.