This paper analyzes the mission of new-type long-range air-to-air missile combat system of systems,through which the contribution evaluation index system of the new-type long-range air-to-air missile is developed.The Analytic Network Process (ANP) is utilized to determine the weights of the indexes.Then,an improved ANP-fuzzy synthetic evaluation method for quantitative assessment of the contribution of the new-type long-range air-to-air missile is proposed.The rationality and correctiveness of the proposed contribution evaluation index system and the evaluation method are verified in a case study.

To solve the consensus problem of general linear multi-agent systems under the time-varying delay control input and double-ended stochastic cyber attacks,a new method is proposed.The impact of both cyber delay and the stochastic cyber attacks on the system is considered in this paper,and the occurring probability of stochastic cyber attacks conforms to stochastic Bernoulli distribution.The mathematical model of the closed-loop control system is established under the time-varying delay control input and double-ended stochastic cyber attacks.Based on Lyapunov stability theory and Linear Matrix Inequality (LMI) theory,a multi-agent system consistency theorem under time delay and cyber attacks is proposed,which gives sufficient conditions to ensure the system consistency in the mean square sense.Finally,the effectiveness of the theoretical method is verified by simulation experiments.

Aiming at the uncertainties of an unmanned helicopter system and its controller,based on the idea of eigenvalue perturbation,a normalized non-fragile controller is designed to ensure the system′s good robustness and flight performance.Firstly,the T-S fuzzy model of the nonlinear attitude dynamics for an unmanned helicopter is established.Secondly,based on the idea of eigenvalue perturbation,a normalized design is carried out for the nominal part of the system to make the eigenvalue perturbation of the nominal part insensitive to the system uncertainties.Thirdly,considering the system uncertainties and the additive perturbation of the controller gain,a fuzzy non-fragile controller is designed for the uncertain part.Based on Lyapunov theory,the stability of the closed-loop system is analyzed,and the controller parameters are solved by Linear Matrix Inequality (LMI) method.Finally,the simulation results show that the designed controller has good robustness.

To improve the performance of wideband radar in High-Resolution Range Profile (HRRP) target recognition,an improved One-Dimensional Convolutional Neural Network (1D-CNN) model is proposed.In view of the inadequate samples and low Signal-to-Noise Ratio (SNR) of the target,global average pooling is employed to regularize the whole network model and prevent over-fitting.In view of the similar shape and size of real and fake targets,the recognition performance of targets with different shapes and sizes is analyzed.The experimental results show that the proposed model can realize the recognition of target categories and sizes effectively under the condition of limited training samples and noise interference.The proposed model is helpful for automatic target recognition based on radar high-resolution range profile in the case of similar shape and size of real and fake targets,inadequate samples and low SNR.

In single-frame infrared dim and small target detection,in view of the complex background of an image and the diversity of target morphology,an algorithm is proposed,in which background suppression of the image is carried out,then candidate points are extracted by threshold segmentation,and finally the residual noise points are removed by energy concentration.In the preprocessing part,in view of the diffusion of small targets and the dynamic distribution characteristics of the image plane,the morphology is improved and the background is suppressed by using multi-directional filtering template.In the part of threshold segmentation,a multi-directional gradient threshold segmentation method is proposed.The gradient values of eight directions with different step sizes are calculated,and the number of gradients exceeding the threshold is counted to screen out the target points.Experiments show that the proposed detection method can effectively solve the problems of diffusion and multi-morphological characteristics of dim and small targets.

Synthetic Aperture Radar (SAR) images can be reconstructed by using random undersampled data.The smoothed l0 norm (SL0) method is a compressed sensing SAR image reconstruction method with fast reconstruction speed and a simple algorithm.However,the steepest descent technique used in the method may result in the phenomenon of contour jaggies in the iteration direction,which greatly increases the time consumption of SAR image reconstruction.In addition,the Gaussian fitting function that is used in the method has a poor matching degree to the discrete l0 norm,which will affect the accuracy of image reconstruction,and the resolution of the reconstructed SAR image is not high enough.To solve the above problems,an SAR image reconstruction method based on Almost-Hybird Newton Smoothed l0 norm (A-HNSL0) is proposed by introducing the approximate hyperbolic tangent function and the hybrid optimization algorithm.Experimental results show that the proposed method makes certain improvements to both the reconstruction speed and the reconstruction accuracy under the same external conditions.

In conventional array signal processing and the radar system,the use of arrays for signal source location,especially for Direction of Arrival (DOA) estimation,is a very important problem.Most of the radar system treats multipath echo interference as unexpected clutter noise.Therefore,the complex multiple scattering environment has a negative effect on the resolution of the radar system and target positioning accuracy.Based on Multiple Input Multiple Output (MIMO) radar,Time Reversal (TR) is introduced to take advantage of the space diversity of multipath propagation in the scene of multiple scattering,so as to enhance the performance of the current DOA estimation algorithm.Simulation results show that,compared with the conventional Capon algorithm,the TR-based MIMO radar Capon estimation algorithm has good estimation performance and strong sidelobe suppression ability,and the estimated results are more accurate under the condition of low SNR in complicated multipath environment.

An improved visual odometer algorithm based on ORB features is proposed for resolving the problem of large odometer errors due to the matching information redundancy of image feature points and high mismatching rate of the feature points in the Visual Simultaneous Localization and Mapping (VSLAM) visual odometer.First,this paper suggests module decomposition for the images and deletion of low-quality image modules and key points by using the gray scale change rate and the efficiency factor of subregion features,so as to resolve the problem of low extraction efficiency in the course of key point extraction and unreasonable distribution of the key points.As for the mismatching of excessive invalid feature points in the process of two-frame image matching,this paper proposes a method of deleting the feature points that are not in the image view of last frame in the image of current frame by using the camera pose of last moment.Test results show that the improved visual odometer algorithm has higher precision in camera pose estimation compared with the previous one.

The high reflector is usually used in laser gyroscope,high-energy laser system and other national defense fields.Surface defects are unavoidable in the process of processing,which will seriously damage the high-reflective film system and even the substrate,and seriously affect its performance.At present,the complex surface defects of the high reflector are still the focus of research.In view of the light scattering characteristics of the defects,an electromagnetic simulation model of repetitive continuous scratch defects with a triangular cross section is established by using the Finite Element Method (FEM).The variation of integral scattering intensity of defects with different sizes and the difference of detection spatial scattering distribution at different locations are studied when a Gaussian beam is incident,and the curve of light scattering intensity of defects is obtained.It can reflect the relationship between defect size and integral scattering distribution and the optimal detection location of spatial scattering.The research results can provide a theoretical guidance for the research of nondestructive detection methods for surface defects of the high reflector.

Nowadays,with the development of communication networks,unstructured “soft data” (such as audio,text,microblog,blog,BBS,et al) with the characteristics of fuzziness,randomness and subjectivity emerges in large numbers.The effective integration of unstructured “soft data” with structured “hard data” from traditional physical sensors is of great practical and urgent significance for the comprehensive understanding of complex situations.On the basis of explaining the concept and connotation of fusion of soft and hard information,this paper focuses on the knowledge extraction of unstructured “soft data” and uncertainty information representation and reasoning technology.Finally,to address the urgent need of improving the performance and robustness of the soft and hard information fusion system,this paper makes a thorough discussion on the following four aspects:performance analysis and evaluation of the fusion algorithm,correlation analysis of information and its fusion,task and resource scheduling,and research and development of the application system.

The general situation of the American National Fire Control Symposium (NFCS) is introduced,and its main content is analyzed in detail.The following four conclusions can be obtained from the preliminary study:The USA puts great emphasis on the study of fire control,but little is known to the public due to secret-related reasons;The American study on fire control has a long history,and its current study field has changed dramatically;NFCS can serve as a window,through which we can know about the American understanding of fire control from public channels;NFCS not only has fixed study directions,but also increases its study directions in response to new requirements.Therefore,the development of the American fire control has a bright future.

In view of the fast speed and strong maneuverability of offshore threat targets and in order to improve the quality and speed of solving the problem of USV formation′s firepower allocation in coastal defense,a multi-constraint dynamic firepower allocation model of USV formation in line with the actual battlefield is established,and the improved ant colony algorithm is used to solve the model.The model not only considers the dynamic motion of threat targets and multi-facet resource constraints comprehensively,but also places higher demands on the search ability of the algorithm.The improved algorithm can avoid falling into local optimum on the basis of satisfying the global search by adjusting the update mode of the pheromone and adopting the time-varying volatile factor.The result of Monte Carlo simulation shows that：Compared with the traditional ant colony algorithm,the improved algorithm can greatly improve the effectiveness, convergence and real-time performance of solving the USV formation′s firepower allocation problem in coastal defense,and has certain application value.

In view of the requirements of selecting the data source UAV in the networked navigation system,the ranging positioning model and data source selection problem of the clustered UAVs are studied.Based on Particle Swarm Optimization (PSO) and the chaos theory,a Chaos Particle Swarm Optimization (CPSO) is proposed.The relative distance is used to establish the discrete linear positioning model of the UAV,and the data source selection algorithm takes the Geometric Dilution of Precision (GDOP) as the fitness function.The estimation result is gradually optimized through the iteration of the velocity-position update equation.The initial population is processed by chaotic mapping,which avoids the problem of falling into the local optimal solution.The simulation results show that the proposed algorithm has higher calculation precision than PSO,and the computation time is only 14.6% of that of the traversal method.In addition,increasing the value of the learning factor within a certain range can improve the algorithm′s calculation efficiency.

To solve the problem that the ship′s wake causes large carrier landing error of UAVs,dynamic inversion and the adaptive control method are used to design an automatic carrier landing control law.The control law can overcome the uncertainty of the model and external disturbances,achieve good tracking results of pitch rate and angle of attack,and guarantee the boundedness of the adaptive parameters through the projection operator.The trajectory tracking controller based on dynamic inversion is used to achieve accurate trajectory control and reduce the tracking error of ship landing.The simulation results show that the proposed control method has high tracking accuracy and good robustness,and can meet the longitudinal control requirements of UAV′s carrier landing under air wake.

To deal with the problem of refined track initiation for formation targets,a refined track initiation algorithm for formation targets based on statistical distance property is proposed.Firstly,the tracking trajectory of the formation as a whole is established and then scheduling detection is carried out.Secondly, preassociation and region division of the radar echo measurements are performed,and then the measurement confirmation matrix and the distance distribution matrix are built.Finally,statistics of the properties of the distance distribution matrix are obtained.According to the statistical results,the independent track initiation of individual targets is completed.The simulation results show that,compared with the modified logic method and the track initiation algorithm based on the formation centroid,the proposed algorithm has better performance on improving Correct Track Initiation Probability (CTIP) and suppressing the false track,and has fine engineering applicability.

The fighters are the main force in air combat.At high Angle-of-Attack (AOA),the stability and maneuverability of the fighters change drastically,and dangerous conditions such as stall,deviation and spin are prone to occur.In this paper,the F-16 fighter is used as the analysis object to solve the 3D maneuverable attainable equilibrium area based on the theory of attainable equilibrium sets,and analyze the local stability of the balance point by using the eigenvalue,which can provide a safe and reliable decision reference for the pilot in the maneuver process of the air combat.The simulation results show that the attainable range in the high angle-of-attack area is drastically reduced and asymmetrical,which is very limited for the driver′s stable control and operation,and it is consistent with the actual situation.

When the attitude calculation of the quadrotor is performed in a magnetic interference environment,the attitude calculation accuracy will be affected.In order to reduce the influence of magnetic interference on the pitch angle and the roll angle,an improved method based on Extended Kalman Filter (EKF) is proposed.First,based on the EKF,the measured value of the accelerometer is used as an observation to solve the pitch angle and the roll angle.Then,the measured values of the accelerometer and the magnetometer are simultaneously used as an observation,and the EKF is used again to solve the yaw angle.In the second EKF solving process,an adjustable variance measurement matrix is added to adaptively change the Kalman gain,adjust the observation to correct the state prediction,and reduce the influence of magnetic interference on the yaw angle.Finally,the algorithm is verified based on the self-developed flight control system.The verification results show that the proposed algorithm can improve the attitude calculation accuracy of the quadrotor in a magnetic interference environment and the anti-magnetic interference performance of the quadrotor attitude fusion algorithm is enhanced.

To solve the problem that the accuracy of the horizontal control range is not high when the quadrotor aircraft hovers at a certain point under the condition of no satellite signal indoors,the paper proposes a quadrotor aircraft hovering method based on Blob analysis.The method obtains the horizontal position information through the Openmv machine vision module installed at the bottom of the aircraft, transmits the horizontal position information,and obtains the horizontal speed after the interference signal filtering processing and the IMU data fusion calibration,thereby realizing the hovering of the indoor color block of the aircraft.In this experiment,PXhawk flight control is used as the test platform,and a satisfying control precision is obtained by using the incremental PID control algorithm.The experimental results show that the quadrotor aircraft hovering method based on Blob analysis effectively improves the horizontal offset accuracy and the horizontal offset range is ±5 cm,which verifies the feasibility of the method.

In order to get rid of the edge points which are not related to line detection,obtain complete line edge points and extract line segments accurately,a new line segment extraction method based on predicted direction search and edge curvature constraint is proposed.Firstly,the dual-threshold method is employed to detect the edge points of the target to track its edge contour.Meanwhile,the direction information contained in the edge points generated by the latest tracking of edge points is used to predict the search direction of the next edge point.The depth-first search method is used to cross the break points along the predicted direction and continue to search the edge points,which effectively avoids wrong selection of bifurcation paths and ensures a more complete edge contour.Secondly,the curvature and length constraints of the edge are employed to extract the edge points of the line segments in the edge contours.Finally,the line segments are fitted by using the edge points of the line segments,and the final line segments are obtained by merging the discrete line segments.The experimental results show that the proposed method can effectively deal with edge fracture and bifurcation,extract complete line segments and end-point information accurately and quickly.The performance of the proposed method is superior to that of the existing line segment extraction methods.

In previous passive sonar signal simulation,the characteristics are not strong,and the fidelity of the radiation noise signal is low,which cannot reflect the actual array element reception signals.To solve the problem,a mathematical model of underwater target radiation noise from its generation to reception from fixed detection nodes and mobile detection nodes is established by using the Doppler effect of moving targets.The radiation noise signal of underwater targets in different states and the radiation noise signal received by the passive sonar are simulated.A simulation software which can display the simulated sonar-received signals under different parameters is generated.The simulation results can meet the requirements of practical engineering applications.

A new image registration algorithm based on multi-scale corner and Harris transformation is proposed,whose core idea is the combination of Harris operator and the Laplace image pyramid.The original image is sampled down on different scales and the corner of the obtained image is detected.The angle of the corner and the ratio of maximum values of the scale response (scale fine positioning) are obtained.Then the image is rotated and translated to complete the image registration.Theoretical analysis and simulation results show that the algorithm has higher registration accuracy and less computation amount.

A multispectral common-aperture telescope optical system using off-axis three mirrors with big caliber,high magnification rate,compact configuration,and low adjustment complexity is introduced in this paper. The system can realize the common-aperture design of the infrared system,the visible light system and the laser system,which can be applied to the airborne electrooptical reconnaissance equipment.Based on the coaxial three-mirror structure,the initial structure of the system is obtained by using the primary aberration formula.The caliber of the system is 240 mm,and the magnification rate is 12.When the end of the system is connected with an infrared convergence system whose focal length is 110 mm and whose detector is 640×512@15 μm,the focal length of the infrared system can be 1320 mm.When the end of the system is connected with a visible light convergence system whose focal length is 121 mm and whose detector is 1920×1080@5.5 μm,the focal length of the visible light system can be 1452 mm.Therefore,the common-aperture design of the visible light system and the infrared system is realized.The design results of the telescope optical system show that the imaging quality is close to the diffractive limit and the aberration is well corrected.