Abstract:In order to improve the flow control ability of plasma actuator, further optimization of the endwall actuation layouts is needed. Different endwall millisecond pulse plasma actuation layouts are carried out on lowspeed cascade wind tunnel. The experiment results show that the influence of the lateral flow on the endwall is greater than the axial flow. The layouts of plasma actuators are of vital importance to the flow control effects. The tangential plasma actuation layout is optimal for controlling the corner separation and total pressure loss coefficient could be reduced by 11.8% at 50% span. Nevertheless, with the change of the angle of attack, the layout of the actuator is no longer being tangential to the separation line on the endwall, weakening the flow control effect. An appropriate actuation layout is necessary for controlling the scope of the attack angle requirement. The appropriate increase of the plasma actuators could effectively promote the mixing of jet and near wall airflow and improve the flow control effect.

Abstract:In order to solve the problem of pressure and temperature back propagation in twostage pulse detonation engine, this paper proposes two different kinds of jet nozzles with several planks or bosses. And with hydrogen as fuel and air as oxidizer, detonation initiation with different planks or bosses is simulated. The results indicate that detonation can be initiated when the number of planks is 3 or 4. When the number of bosses is 3, 4 or 5, detonation can be initiated successfully. When the number of planks or bosses is 4, the detonation initiation effect is the best by shock wave focusing, and the effect of preventing pressure and temperature back propagation is also well. On the whole the effects of planks or bosses on preventing pressure and temperature back propagation is very limited.

Abstract:Based on the steadystate process of the gas with RF heating after being ionized in the plasma density Non-uniform distribution conditions in quartz tube, the effect of two kinds of antennas, includes 1 Loop and Boswell, on wave fields analyzed in this paper. Helic program is used to solve four coupled radial differential equations for each kz to obtain the wave field along different direction. The result shows that antenna L motivates a strong electrostatic weak magnetic wave field, antenna B motivates a strong electrostatic strong magnetic wave field; within the antenna range, the antenna B motivates the electric field more strongly than L, and the more power is coupled into plasma. The antenna L is more sensitive to the density gradient, and the affect scope of the plasma near the antenna is greater than that of the B. The wave field motivated by the antenna B is more strong.

Abstract:On the basis of aircraft coordinates calculated by latitude and longitude conversion, this paper utilizes the BP neural network for predicting the spatial position of aircraft in accordance with the acceptable level of safety 5×10-9 put forward by the International Civil Aviation Organization. On the basis of observing the longitudinal deviation distribution law, it is assumed that it conforms to the Gumbel distribution and the K-S test method is used for verification. The verification result is then adopted to build a collision risk model for risk assessment of obstacles height in airport clearance. The paper provides a new way to evaluate clearance condition for selecting airport location and administrate obstacles in airport clearance.

Abstract:Aimed at the problems that QAR data are hard to obtain and the accuracy of existing air traffic fuel consumption estimation methods is poor, this paper presents a method to estimate fuel consumption of air traffic based on radar trajectory and echo state network. Firstly, the QAR data are used to train the multiparameter echo state network fuel flow rate estimation model. And then, in order to make the model suitable for radar trajectory data, the key influencing factors of the fuel flow rate are extracted by the method of sensitivity analysis, and lessparameter fuel flow rate estimation model is constructed with parameters such as flight state, vacuum speed and altitude. Finally, the model is verified by 20 real trajectories. The results show that the relative error of this model is about 4%, its accuracy is improved by 40% than that of the BADA model.

Abstract:On the basis of the agility evaluation of airdefense and antimissile command system through deeply analyzing, this paper establishes a corresponding evaluation index system. Aimed at the problem that at present the index weighting exists in some shortcomings by adopting AHP and other singleclass methods, an agile fuzzy comprehensive evaluation method based on AHP and RAGA-PPC is proposed. Firstly, the indexes are quantified, then the weights of the indicators are determined by using AHP and RAGAPPC, and the results of the agility evaluation are obtained by fuzzy comprehensive evaluation. The evaluation model adopts the subjective and objective comprehensive weighting method, reflecting the will of decisionmakers, and avoiding the subjective evaluation of arbitrariness. Finally, the evaluation model is verified, and the relevant guidance suggestions are put forward.

Abstract:Aim at the rare and strong subjectivity of evaluation method on regional air route network capacity, this paper puts forward a dynamic capacity evaluation model based on directed graph theory. The model fully extracts the characteristics of air route network which can abstract the complex air route network with multi source and sink into standard air route network with single source and sink, introduces the impedance formula of air route to integrate controller factors into objective capacity assessment and uses the algorithm of FordFulkerson to solve the capacity and critical paths of air route network. Finally, this paper takes a flight information area as an example, analyses the capacity characteristic of the air route network and finds out bottleneck capacity of critical paths is 354.4 sor/h, which prove the accuracy and effectiveness of the model.

Abstract:The rocket is in unpowered flight at the separation phase of missile and rocket of air launch system and the trajectory is prone to interference from the upper level gust. In order to research the responses of discrete gust of air launch system at separation phase, the influence of gust is simulated by using the grid velocity method, the finite volume method is used to solve unsteady Euler and NS equation, and the separation process is calculated by using CFD dynamic grid. The simulation platform is built by the modular method, including update module of rocket’s status and grid, CFD calculation module of force and moment, solution of flight status parameters and discrete gust interference module. The separation process under 1cos gust disturbance is calculated by using the simulation platform, and the aerodynamic characteristics of the rocket and the carrier with or without gust disturbance are compared and analyzed. The results show that the air launch system can satisfy the requirement of rocket ignition after the separation of missile and rocket in the absence of gusts. After a discrete gust of wind, stability of the air launch system is destroyed after encountering discrete gust and may cause launch to fail, raising a higher requirement for the design of the control rate.

Abstract:Extracting micromotion features from human radar echo data is a key to human target classification. Aimed at the problem that the traditional spectrum structure is hard to realize the fine recognition of similar body size, a method of human body identity authentication based on stack sparse autoencoder is proposed. First of all, this paper constructs a stacksparse selfencoder network, performs unsupervised pretraining by using human micromotion data, and extracts human micromotion features at different layers. Then the paper inputs the features into the softmax classifier for supervised training, and adjusts the network parameters by crossvalidation. Finally, the paper uses the trained network for human target classification. The average recognition rate of 3 people on the measured data set of different people reaches 83%, and is better than that by the method of extracting spectral structure feature classification.

Abstract:As a complicated distributed system, radar network system encounters various attacks. In order to study the impact of cyber attacks on the performance of radar network system, a kind of replay attack mode for radar network system is proposed. Firstly, a target motion model and a system model are established. Then, the influence of the replay attack on the position estimation error of the monostatic radar is analyzed. For the abovementioned reasons, the influence on the tacking performance of the radar network system is extended. Finally, the relationship between the attack parameter and the position estimation error is studied. The state estimation error of monostatic radar and radar network system under replay attack, as well as the relationship between singlestation radar and radar network estimation error and attack strength are obtained by simulation. The simulation results show that for monostatic radar, replay attacks can cause huge tracking errors, and the attack effect is directly proportional to the attack strength. When the target of replay attack is a radar network system, a reasonable selection of attack parameters is required to produce a significant attack effect.

Abstract:Aiming at the actual demand of omnidirectional chassis control, an intelligent control method based on fuzzy immune neural network PID algorithm is proposed to set parameters of the path tracking controller of the chassis to realize the precise motion control of the chassis. According to the structural characteristics of the neural network algorithm and the fuzzy algorithm, the fuzzy neural network model is established and the model is trained by the method of error back propagation. The immune algorithm is used to determine the learning rate and then, the dynamic tuning of the PID parameters is realized. After that, the kinematic model of the chassis is established. Then, based on Matlab platform, the relevant algorithm is simulated. Finally, the neural network model is established and trained via the Tensorflow structure under the Linux Ubuntu system and the algorithm is then implemented. When the chassis carries out trajectory tracking in different directions at a 5 m/s speed, the maximum error of the process is 4.88 cm, the average error is 0.25 cm. Simulations and experiments both show that the algorithm can effectively control the chassis to meet requirements of thecontrol of the omnidirectional chassis.

Abstract:MIMO radar imaging relies on data acquired by a large number of transceivers, and a small number of MIMO radar can be used to realize high resolution imaging of the target by means of compressed sensing sparse recovery theory. This paper utilizes the Patterncoupled sparse bayesian learning algorithm applied to MIMO radar imaging. For this reason, the paper proposes a MIMO radar imaging method based on PCSBL. The method utilizes the corresponding characteristics at the target adjacent scattering points described by a patterncoupled hierarchical Gaussian prior and the Expectation Maximization algorithm for realizing the iterative estimation of the hypeparameter, and for further reconstructing the radar target block region accurately. The simulation results show that this method is better than the traditional Fourier and Sparse bayesian algorithm, and is better than the OMP algorithm in scattering point reconstruction.

Abstract:The measurement error in geomagnetic navigation is a key factor of affecting the accuracy of geomagnetic navigation, and the carrier interferential magnetic field, including eddy current magnetic field, is the main factor of error. At present, a large number of carriers made of ferromagnetic materials inevitably cause eddy magnetic fields and other interferential magnetic fields. Therefore, this paper establishes a simulation model of eddy interferential magnetic field of highspeed moving carrier by adopting COMSOL Multiphysics simulation software. First, the relationship between permanent magnet and uniform magnetic field is studied. It turned out to be that the stronger the remains of permanent magnet, the stronger the uniform magnetic field, which provides a theoretical basis for simulating the geomagnetic field. Secondly, the influence of eddy current magnetic field on geomagnetic measurement is analyzed when the carrier rotates at constant speed. Finally, the distribution of eddy current field is studied when the carrier swings. The results show that the eddy current magnetic field increases with the increase of velocity, and the eddy current magnetic field is mainly located in the middle of the carrier. The simulation results provide a theoretical basis for the error modeling and the magnetic field correction technology in the future geomagnetic navigation.

Abstract:This paper presents a discrete cooperative pursuitevasion strategy when a high value vehicle or a evader launches a defender as a countermeasure against an incoming enemy interceptor. This paper utilizes a linear quadratic differential game formulation for analyzing arbitraryorder linear players dynamics, and gives out the optimum solutions for discrete quadratic performance index. The paper takes into the consideration of the game composed of two agents, i.e. the optimal cooperative evasion strategy for the evader, the optimal cooperative pursuit strategy for the defender, and the optimal strategy of the homing interceptor for pursuing the evader and for evading the defender. The obtained guidance laws are dependent on the zeroeffort miss distances of two pursuerevader pairs: interceptor with the evader and defender with homing interceptor. The simulation results are used to validate the defensive effect under cooperation. The advantages of cooperation are shown. Compared with the conventional oneonone guidance law, the cooperation greatly reduces the maneuverable requirements from the defending missile. The simulation also shows that the algorithm is good in robustness to the uncertainty of weight.

Abstract:Aimed at the problems that the frequency hopping signal and the interference signal are delayed due to the processing time of the interfering signal and the distance between the jammer and the transmitter receiver, an adaptive cancellation technique based on algorithm superposition least mean square (LMS) algorithm is proposed. At the same time, on the basis of the theoretical analysis, the proposed improved LMS algorithm is applied to the FPGA platform for simulation experiments. Firstly, the adaptive algorithm simulation platform targeted by the frequency hopping signal and the interference signal is simulated by simulink simulation platform. Secondly, the original signal and the offset waveform are obtained by ISE software. Finally, the signaltointerference ratio is obtained by Matlab. The simulation results show that the algorithm is good in suppression effect.

Abstract:Aimed at the problems that in wavelet domain communication system, the traditional generation method of basis function is different from Transform Domain Communication System based on frequency domain, and the traditional threshold decision algorithm is difficult to eliminate the interference effectively in wavelet domain communication system, Consecutive Mean Excision （CME）algorithm and Forward Consecutive Mean Excision（FCME）algorithm are introduced into amplitude spectrum shaping module of wavelet domain communication system. The two algorithms divide the wavelet transform domain into two parts, i.e. the interference subband and the noise subband. They utilize the recursive method of continuous iteration and successive approximation for calculating the threshold adaptively, effectively eliminating different types of interference without estimation of the noise power. The simulation results show that these two algorithms are prior to the traditional threshold algorithm under the condition of strong interference. And in the case of audio interference, the antiinterference performance of CME algorithm is superior to FCME; in the case of narrowband interference, the antiinterference performance of FCME algorithm is better than that of CME; and in the case of linear frequency modulation jamming, the two algorithms behave close to each other.

Abstract:This paper designs a synchronous controller to realize the function projective synchronization of the different structures, and applies the Lyapunov principle to the stability of the system. Simultaneously, the linearity independence of the coefficient vector of the uncertain parameters in the QCNN system is deduced, and the estimation of the uncertain parameters is realized. Both theoretical and simulated results demonstrate that the function projective synchronization of the two different structures hyperchaotic systems are scientific rationality. Also the uncertain parameters return to the ideal values gradually. The research results provide theoretical guidance for the application of nanoelectronic chaotic system in secure communication and image encryption.

Abstract:This paper studies the law of the effect of the VAE redispersible emulsion powder content on the tensile properties of polymermodified cement based composed joint sealant (PCJS) systematically by single factor test. A new kind of PCJS is produced by adding VAE redispersible emulsion powder into styreneacrylic emulsion based cement compound joint sealant. Under condition of different polymer powder content, the tensile strength, early tensile strength, tensile breaking elongation, peak strain and tensile modulus of PCJS are measured respectively. Moreover, the tension failure modes of the PCJS with different content of VAE redispersible emulsion powder are recorded and investigated. The effect of different cure condition and emulsion powder content on early tensile strength of PCJS is studied. The composite effect of styreneacrylic emulsion (SAE) and VAE redispersible emulsion powder on the modification of PCJS is studied. The results show that no obvious differences in materials early tensile strength emerge at the temperature variation of 30o C. The tests on specimens with full curing date of 28 days show that as the added proportion of VAE redispersible emulsion powder increases, significant growth in both PCJSs tensile strength and tensile modulus can be observed. In addition, the tensile failure mode is transformed from cohesive failure to adhesive failure with the increase of polymer powder content. Besides, the tensile deformation capacity of PCJS increases first and then decreases along with the increasing of the VAE redispersible emulsion powder content. Besides, the PCJS can optimize the performance of tensile deformation, as the VAE redispersible emulsion powder is added into it by 2%~3%.