In view of the problems that there are many influencing factors on anti-jamming performance evaluation of Global Navigation Satellite System (GNSS) receivers and it is difficult for data fusion,a novel anti-jamming performance evaluation method is proposed based on the cloud model.Firstly,the anti-jamming performance evaluation index system is established according to the interference factors in the complex electromagnetic environment.Moreover,the qualitative indexes are further converted into qualitative indexes, which form the basis of cloud model evaluation with other quantitative indexes.Then,the golden section method is used to establish the evaluation level of the receiver performance,and the cloud digital characteristics of the indexes are calculated by using the cloud algorithm and the index weights,through which the intuitive comprehensive evaluation cloud is obtained.Finally,the final evaluation results are acquired by calculating the similarity between the comprehensive evaluation cloud and each standard evaluation cloud in the cloud model,and the anti-jamming performance evaluation is thus completed.The results show that:Compared with evidence theory and fuzzy comprehensive evaluation method,the proposed method can implement accurate and efficient evaluation on anti-jamming performance of multiple receivers,and the results of evaluation level are more comprehensive and intuitive.

In tracking process,Kernel Correlation Filter(KCF)algorithm is easy to lose the target due to the occlusion of the target or deformation and size change of the target itself.To solve the problem,this paper makes the following improvements based on the original algorithm.First,the method of detecting the response value of the model is added as the basis for determining whether the target is lost.Once the target is determined to be lost,the model will suspend updating,and the number of sampling windows will be increased to expand the target search range until the target is determined to be re-detected and located.The second is to add an adaptive multi-scale search strategy.Third,the Histogram of Oriented Gradient (HOG) feature adopted by the original algorithm is fused with the gray feature of the image as a new sample feature.In the infrared video sequence of experiment,the original algorithm and the improved algorithm were used to qualitatively compare and analyze the tracking effect.At the same time,the tracking accuracy tested in OTB-2013 was quantitatively evaluated.The experimental results show that the comprehensive performance of the improved algorithm and its robustness against occlusion,deformation and size change are improved.

Unmanned surface vehicles are finding more and more prominent applications in military field with the development of autonomous control technology.The intelligent control technology of Mine Countermeasures Unmanned Surface Vehicle (MCM USV) is one of the current research hotspots.Aimed at the local path planning problem of MCM USV,a hierarchical reinforcement learning method is proposed,which is used for training the evolutionary artificial neural network used as path planner of the UAV.The Unity physics engine is adopted to build a simulation environment,and a USV model with environment awareness and autonomous decision-making capabilities is established.Experimental result verifies the effectiveness of the algorithm on local path planning.

For small multi-rotor drones,there are vibrations caused by wind disturbances and motor vibrations during flight,which may increase the noise of sensors and lead to unstable flight.There is also the problem of complex adjustment of parameters due to uncertain structure and large external disturbances.To solve these problems,an improved Active Disturbance Rejection Control (ADRC) controller is proposed.The improved controller can greatly reduce the angular acceleration intermediate frequency noise based on the traditional frequency domain filter,compensate for the sensor and filter delay,and quickly track large disturbances.In addition,a tansig error feedback function is introduced to adjust the parameters of the observer.The improved controller only needs to adjust one parameter in most application scenarios by improving the traditional Extended State Observer (ESO),and can limit the expected angular velocity and angular acceleration.Simulation experiments prove that this algorithm can greatly reduce the impact of aircraft vibration and noise,and compensate for the phase lag of control data.The strong applicability of the algorithm has been verified through experiments on dozens of multi-rotor aircrafts of different sizes and configurations.

Traditional GPS jamming equipment can hardly meet the requirements of the operation against cruise missiles,thus a development scenario of networked GPS jamming system is proposed.The model of the operation loop of GPS jamming equipment cooperating with ground air defense firepower against cruise missiles is established.The capability indexes of nodes and the measurement index of edges are determined,and the operational effectiveness of the system is calculated based on information entropy.The model for calculating the contribution ratio of GPS jamming equipment system is proposed based on the general consideration of the cost and risk factors of equipment development.The application results show that,the GPS jamming equipment can create a large gain on the system operation effect and achieve a high system contribution ratio.Taking the cost and risk factors into consideration,the evaluation result of contribution ratio to system-of-systems is more practical and more significant for decision-making assistance.

The Phase-Code Orthogonal Frequency Division Multiplexing (PC-OFDM) signal was used in communication systems at first.When using as an external radiation source signal,it has the advantages of low interception,anti-interference and flexible waveform,and is an effective supplement to the existing civil external radiation source signal.In this paper,it is proposed to use the PC-OFDM signal as an external radiation source radar signal,and thus to extract the micro-motion characteristics of the low-altitude target with rotor blades.Firstly,the micro-motion echo model of bistatic radar is established based on PC-OFDM signal,and the parameterized expression of micro-Doppler is derived.To further solve the problem of difficult parameter extraction under low SNR conditions,a method for extracting micro-motion features based on stochastic resonance is proposed.The simulation verifies the feasibility and robustness of the method.

Aiming at the problems of the GMS algorithm of concentrated mismatching and poor robustness under few feature points,an improved algorithm based on the quality evaluation of feature matching is proposed.The algorithm does not depend on increasing the number of feature points.Instead,it calculates the homography matrix based on the high-quality matching pairs by introducing the quality factor of feature matching,and eliminates the mismatching to improve the matching accuracy.The experiment shows that:1) The algorithm not only solves the problem of mismatching concentration when there are few feature points in GMS algorithm,but also has less dependence on the number of feature points;2) The running time of the algorithm is shortened by 30% compared with that of ORB + RANSAC;and 3) The algorithm has higher robustness,higher accuracy and better real-time performance.

Army aviation Rotary-Wing (RW) aircrafts can implement Air-to-Ground Operation (AGO) support to ground troops as well as the traditional Close Air Support (CAS).At present,studies on the CAS of Fixed-Wing (FW) aircrafts have been carried out by some domestic researchers,but there are few reports on the relationship between the AGO Attacks Against Enemy Forces in Close Friendly Contact (AGO-AAEFCFC) and CAS.Aiming at the problems,and by taking the American army as the object of study,we make study on the basis of a series of USF Field Manuals and joint publications.Firstly,the AGO-AAEFCFC and traditional CAS operational models are reviewed and analyzed.Then,the relationship and difference between the AGO-AAEFCFC and CAS in aspects of combat purpose,application mode and concrete implementation are presented.

Taking ballistic missile interceptor in the atmosphere as the research object,the terminal guidance problem of the interceptor is studied.The definition of predicted hit point is given,the generalized predicted hit point is derived,and approximate theory is used to get its mathematical expression.Then,based on classical differential geometry,the curvature and torsion instructions of the differential geometry guidance law are derived.The differential geometry guidance law is designed based on the predicted hit point for use in the ballistic missile interception scene.On the basis of this guidance law,by introducing the autopilot and seeker equivalent models,the influence of the guidance control system on guidance accuracy is analyzed.By comparison with the two other guidance laws through simulation,it is demonstrated that the differential geometric guidance law based on predicted hit points has the superiority of reducing the required overload and the line-of-sight angular velocity.

A formation control algorithm based on distance constraints is proposed for multi-agent leader-follower strategy,and formation keeping and velocity tracking are realized simultaneously.The multi-agent system consists of a single leader and two followers.The single leader moves at a constant reference velocity, and the followers cannot measure the velocity of themselves or other agents.In order to track the speed of the single leader to achieve formation shape keeping,an adaptive control law is designed for the followers to estimate the velocity of the leader and keep each agent at the desired distance.Based on Lyapunov analysis and Barbalats lemma,the stability of the closed-loop system is proved,and the effectiveness of the proposed method is verified by simulation results.

Interference waveform decision-making based on the traditional Discrete Artificial Bee Colony (DABC) algorithm needs to iterate many times and its optimization probability is low.To solve the problem,a method for interference waveform decision-making based on optimal difference oriented chaotic multi-dimensional DABC algorithm is proposed.The method introduces optimal difference matrix to update nectar source,uses multi-dimensional search and greedy selection to determine the update dimension,and introduces Tent chaotic sequence to initialize the population,so as to solve the interference waveform decision model.The simulation results show that,compared with the traditional DABC algorithm and Genetic Algorithm (GA),the improved algorithm requires fewer times of iteration with higher optimization probability when making interference waveform decisions.The method can improve the performance of interference waveform decision-making system with certain universality.

According to the procedure of on-call submarine search with passive sonobuoy arrays,the deployment radius was explored by using probability theory and optimal search theory.When using sonobuoy array for on-call submarine search,the distribution characteristics of the initial position,speed and course of the submarine was studied,the analytic model of search probability was obtained,and the deployment radius that has the maximum submarine search probability,called improved deployment radius,was derived based on the model.The submarine searching model of anti-submarine helicopter using typical dropped sonobuoy array was established,and the submarine search efficiency was analyzed with Monte Carlo simulation according to the model.The simulation results show that: 1) The search probability obtained by computation with the analytic model is basically identical to that of the Monte Carlo simulation; and 2) Compared with the sonobuoy array using conventional deployment radius,the sonobuoy array with the improved deployment radius has higher search probability and requires less quantity of sonobuoys.

The future war will be a high-tech local war with high efficiency,coordination and throughout information running under the background of multi-service joint operations.The capabilities of situation awareness,planning and decision-making,command and control are no longer confined to the command post,but continuously extended to the tactical frontier environment.Firstly,the connotation and characteristics of the mobile edge are given,and then the development status of the US militarys mobile edge information service is summarized.Next,the mobile edge information service capabilities of the US military are generalized.Finally,some suggestions are given for the development of our military edge information service construction on four aspects,including further studying on edge information service military application requirements and typical application scenario,and strengthening the overall planning of edge information service capacity.

Because of the outstanding advantages of multiple UAVs in carrying out reconnaissance missions,it is of great significance to study the assignment method of the reconnaissance missions.Firstly,the classical models are introduced and classified,and their characteristics and applicability are discussed.Secondly,the centralized,distributed and mixed solution methods are summarized,the representative algorithm is introduced,and analysis is made on its advantages,disadvantages and application prospects.Finally,the shortcomings of the current multi-UAV reconnaissance task assignment methods in modeling,dynamic task assignment,uncertain task assignment,confrontational task assignment and large-scale task assignment are pointed out,and the future research directions are given.

The existing instruments and equipment cannot generate a radar signal environment that meets the requirements of dynamic performance detection of reconnaissance pods due to the limitation of data storage space and current signal generation methods.To solve the problem,a method of generating radar signals in the simulated real battlefield is proposed.Firstly,the main radar system signals generated by the enemys electronic countermeasure equipment are analyzed,and the corresponding mathematical models are established.Secondly, based on R&S Pulse Sequencer software and the software and hardware experimental platform of a radar simulator,through secondary development,Pulse Description Word (PDW) library of the original signal of the software is supplemented and the method of data transmission protocol is analyzed,and a radar signal environment generation experiment is conducted under laboratory conditions.Experimental results show that the generated radar signal can effectively simulate the signal environment generated by the enemys electronic countermeasure equipment in wartime,and can support the simulation of a long-term, high-density signal environment.At present,the method can be used for dynamic performance detection of reconnaissance pods.

Robust Least Trimmed Squares (LTS) estimation is used to detect anomalies in aerodynamic data.However,the aerodynamic data are massive and high-dimensional,which makes the matrix dimension of LTS solution be very high,and leads to huge spatial and temporal cost.In this paper,Iterative Singular Value Decomposition(ISVD) is introduced to solve the least squares problem of LTS,so as to realize faster anomaly detection.In the stage of empirical analysis,the data set of the configuration of an aircraft is adopted, and OLS,FastLTS and ISVD-FastLTS are used for anomaly detection and comparison.Experimental results show that ISVD-FastLTS can identify outliers more rapidly and accurately than the traditional methods.

The integration of radar and communication is conducive to improving the utilization rate of hardware resources and spectrum,and alleviating the phenomenon of spectrum congestion,which has become a research hotspot in recent years.The integrated signal modulated by direct information has high side lobe,and the integrated signal modulated by spread spectrum has large bandwidth.To solve the problems,an integrated waveform optimization method with weighted preprocessing is proposed.This paper analyzes the ambiguity function of multi-symbol Orthogonal Frequency Division Multiplexing integrated signal and the effect of correlation function on the ambiguity function,and utilizes the Whale Optimization Algorithm to select the weighting coefficients to improve the auto-correlation and cross-correlation performance of the original sequence,and then optimizes the peak sidelobe ratio performance of the ambiguity function.Simulation results show that:1) The proposed integrated waveform design method has a smaller bandwidth and the peak sidelobe ratio performance is further optimized;and 2) The communication rate and bit error rate performance satisfy the communication requirements,which makes it suitable for the integration of radar and communication.

Aiming at the problem that a single sensor cannot perform degradation modeling and remaining useful life prediction well during equipment condition monitoring,a method based on multi-sensor data is proposed for predicting the remaining useful life.First,a composite health index is constructed based on the degradation performance of the device.Then,the degradation of the device is modeled by using a nonlinear drift Wiener process.After estimating the model parameters by using the maximum likelihood method,the Probability Density Function(PDF)of the remaining useful life of the device is derived.Finally,the proposed method is evaluated and compared with the single sensor prediction results.The results show that this method has higher accuracy.

It is difficult for traditional cameras to identify projectiles because of the overlapping of images caused by partial occlusion of two projectiles.To solve the problem,a projectile recognition method under overlapped imaging of two projectiles based on light field imaging is proposed.The light field camera is taken as the detection device.According to the four dimensional parameters stored by the light field camera,the depth of each pixel in the image is estimated by using the focus stack method.It is found that the depth difference between adjacent pixels at the overlapping edge of the images varies greatly by analyzing the imaging features when two projectiles are partially occluded.Therefore,an edge detection model based on depth variation trend is established in combination with Kalman filter equation,so as to solve the overlapping problem of projectile imaging.It is found that when occlusion exists between the projectiles,the light field camera can effectively detect the overlapping edge of the images,which lays a foundation for the light field camera to accurately identify the number of projectiles and their coordinates.

Aiming at the phenomenon of “degeneration” of Bootstrap regenerated sub-samples under the condition of extremely small sub-samples,it is proposed to use prior information such as the test information of similar type of missile as a sample of Bootstrap method.It is pointed out that when using the prior information,the compatibility with field experimental information should be taken into consideration,and the consistency of the prior information from different sources should also be checked.A method for pre-processing the prior information to evaluate missile hit accuracy is proposed.Then,in order to avoid the introduction of too much prior information and “overwhelming” the field experimental information,an improved weight distribution scheme is proposed based on the importance sampling idea,and an improved Bootstrap method is obtained.Finally,combined with the missile hit accuracy evaluation example,the pre-processing of the prior information is completed.The simulation proves that the improved Bootstrap method can improve the point estimation and interval estimation of the landing point density,and enhance the credibility of the hit accuracy assessment.

Aiming at the problem of control coupling caused by projectile rolling,the influence of projectile rolling on the control coupling of guided projectiles is studied by using multivariable frequency domain response theory,and a decoupling method is given.The transfer function model of the steering gear control system is deduced.The control coupling characteristics are analyzed,and it is found that when the projectile rotation speed is less than the critical angular velocity,the influence of the control coupling can be ignored.When the projectile rotation speed is greater than the critical angular velocity,the pre-installation decoupling,series compensation decoupling and rudder angle feedback decoupling are studied respectively.The simulation results show that:1) The three decoupling methods can all achieve decoupling effect;2) The pre-installation decoupling structure is simple and easy to implement,but it has low accuracy and is greatly affected by the frequency of the input signal,which is suitable for ordinary guided shells;and 3) The complexity of the series compensation decoupling method is lower than that of rudder declination feedback decoupling,and it does not need to obtain the rudder declination feedback signal,which is suitable for high-precision guided projectiles.

When the aircraft files from one segment to the next one,it needs to judge whether the next segment is activated or not.In this paper,a new method is proposed for automatic activation of planned flight segment.By obtaining the current position and magnetic deviation of the aircraft,and combining with the longitude and latitude of magnetic difference of the corresponding positions of the adjacent three waypoints, the magnetic heading angles corresponding to the three waypoints and the aircraft position are calculated respectively.The difference between the magnetic heading angles is compared to determine whether it is activated or not.After the algorithm derivation is completed,the model is built based on SCADE SUITE,and the actual data sampling and simulation are carried out by using the JEPSSON chart.The simulation results show that:1) This method can activate the next segment stably and effectively;and 2) It is practical and effective,and is simpler in computation compared with the traditional methods.The method has been used successfully in actual flight and has achieved the expected effect.

Avionics Full Duplex Switched Ethernet (AFDX) is the hinge and kernel for implementing high-speed,large-volume data exchange among the avionics systems,and is one of the critical technologies of the distributed and integrated avionics system of the advanced,modern airplanes.The AFDX has the advantages of low-latency, high certainty,high reliability and so on.In order to meet the requirements of next-generation airborne network for high bandwidth,this paper proposes a gigabit AFDX switch technology based on SoPC FPGA with consideration of the existing AFDX technology.The critical technologies,system architecture design,function simulation and other aspects are described.The result of functional performance test shows that,the design meets the communication design of gigabit AFDX network,and its certainty and high-speed performance meet the requirements of communication architecture design.