With consideration of attitude control problem for hypersonic vehicle capable of wide-envelop maneuvering flight in the presence of strong nonlinearity and coupling effects, actuator saturation problem, as well as the variations of multiple aerodynamic parameters and external disturbance, and in combination with model-assisted Active Disturbance Rejection Control (ADRC) technique, a Trajectory Linearization Control (TLC) based coordinated control framework with characteristics of anti-saturation and active disturbance rejection is constructed and discussed. Firstly, for the simplicity of control, the attitude and angular rate subsystem is described in strict feedback form with uncertainties. Secondly, based on the principle of ADRC, tracking differentiator is applied to arrange the nominal attitude command and its derivative to handle the actuator saturation problem existed in TLC design. Extended state observers with model information incorporated are designed in dual-loop to estimate the lumped disturbances to reduce the effects on tracking performances. Thirdly, based on the principle of TLC, feedforward tracking law and stabilizing control law are developed, based on which, attitude tracking error can be stabilized along the nominal command. The simulation results show that the proposed control scheme exhibits great robustness against multiple disturbances during reentry flight, and anti-disturbance control with high precision under large guidance command can be satisfied.

In order to implement fast target detection for aerial reconnaissance image,an Efficient Subwindow Search (ESS) target detection method based on Ittis saliency map and maximum saliency density is presented.Itti model is used to generate saliency map,then the ESS method based on maximum saliency density is designed.The main idea is to transform the salient target detection into an issue of maximum saliency density,then to localize the maximum saliency density in global optimum using branch-and-bound algorithm.The experimental results show that the proposed method is able to realize fast target detection,with average time cost for target detection of 36.6 ms,and detection rate of 83.2%.

It is difficult for the commander and decision-maker to obtain the related information from complicated battlefield situational elements for judging the trend of battlefield.Aiming at this problem,we regarded the battlefield situation as a grey system,used the grey system theory to classify the acquisition of situational elements,and analyzed the degree of correlation between the elements to provide the basis for the commander to make decision.The data of battlefield situational elements was predicted by establishing a combined model of GM(1,1)-RBF model and DGM(2,1)-RBF models.To increase the prediction performance, the improved algorithm was used to optimize the single model of the combined models.Simulation result shows that the optimized combined models has much higher prediction accuracy and efficiency.

Aiming at the problem of flight conflict detection,the basic concepts of aircraft flight conflict is introduced.Under the hypothesis of steady flight,a model of aircraft's flight path prediction is established.Based on this model,through calculating the minimum horizontal distance between two aircrafts and analyzing the vertical distance in the time of horizontal conflict,the model of flight conflict detection is established and the method for flight conflict detecting is presented,which provides a theoretical reference for flight conflict detecting.

In order to enhance the global search ability of Biogeography-Based Optimization (BBO) in multi-threshold image segmentation,and improve its optimization performance,an Improved BBO (IBBO) algorithm is proposed.Firstly,a polyphyletic migration operator is introduced,which can better generate new eigenvalue from the searching space and effectively improve the population diversity.Secondly,a new dynamic mutation operator is created,which can dynamically change the mutation range and improve the operation efficiency of algorithm,enabling the algorithm to quickly converge to the global optimum.Then,a greedy selection operator is used instead of the original elitist selection operator,to accelerate the convergence process by using the strategy of survival of the fittest.Finally,IBBO algorithm is applied to the maximum entropy-based multi-threshold segmentation.Experimental results of image segmentation show that the proposed IBBO algorithm operates much faster than the exhaustive algorithm,and the optimization performance is better than that of the standard BBO algorithm and PSO algorithm.

Analysis is made to topological structure of command and control network and its characteristics based on the theory of complex network and the organization characteristic of the command and control network.The main factors that have influence on information flow efficiency of the command and control network are presented,based on which the concept of network attack dominance is proposed,and an evaluation index system is established for it accordingly.Analytic hierarchy process is used for evaluation of the network attack dominance,which provides a reference for evaluating the effect of network attack.

To the problem that object tracking based on single color feature often results in a poor performance in robustness,an improved object tracking algorithm by fusing multiple features is proposed.In order to enhance the important features,an adaptive method of choosing object color histogram is presented to get an accurate color model of the object.Meanwhile,Local Binary Pattern (LBP) operator is used to construct the target texture feature model.Uncertainty measurement method is then introduced into feature fusion to adjust the relative contributions of different features adaptively,and the robustness of the algorithm is significantly enhanced.Experimental results indicate that:Compared with the traditional additive or multiplicative fusion,the proposed method has higher robustness,can implement object tracking in complex scene,and provides a more effective description to the object.

Temperature drift is one of main errors in Fiber Optic Gyro (FOG),which can be divided into two terms:a random error term associated with system error and environmental disturbance,and a trend term caused by temperature change.An improved AR model of FOG temperature drift and its modeling method were proposed.Firstly,AR model of the random error term was established,and then the trend term was introduced in the AR model.The measured FOG temperature drift data was used for modeling and verifying the validity of model.Results show that:1) The proposed model can accurately predict the gyro drift output under different temperature variations,and the predicted value can effectively compensate for the drift error; and 2) The FOG temperature drift after compensation is reduced to lees than 20% of that before compensation.Visual software was developed based on Labview,which is of practical value in assessment and prediction of the gyro temperature characteristics.

The use of coordinated detection technology can effectively improve the target tracking accuracy. Traditional coordinated detection fusion algorithm uses the measurement obtained in polar coordinates system for filter fusion. When it is transformed into Cartesian coordinates system, coupling error will be introduced, and the system delay error with unknown statistical property cannot be restrained, thus reducing the tracking accuracy. Centralized fusion method is adopted in this paper. Firstly, the measurement data by multiple platforms are de-biased and time alignment is performed, and it is transformed into Cartesian coordinates system, making the measurement noise be Gaussian distribution with known parameters. Then, the measured value through de-biased transformation and the measured covariance matrix after correction are input to the fusion center;and fusion algorithm is constructed by taking the advantage that H∞ filter is insensitive to the statistical property of error, which effectively overcome the influence of multi-platform system delay error fluctuation, and improves the fusion accuracy. The simulation results show that the proposed algorithm can effectively improve the coordinated detection fusion accuracy.

The use of coordinated detection technology can effectively improve the target tracking accuracy.Traditional coordinated detection fusion algorithm uses the measurement obtained in polar coordinates system for filter fusion.When it is transformed into Cartesian coordinates system,coupling error will be introduced,and the system delay error with unknown statistical property cannot be restrained,thus reducing the tracking accuracy.Centralized fusion method is adopted in this paper.Firstly,the measurement data by multiple platforms are de-biased and time alignment is performed,and it is transformed into Cartesian coordinates system,making the measurement noise be Gaussian distribution with known parameters.Then,the measured value through de-biased transformation and the measured covariance matrix after correction are input to the fusion center;and fusion algorithm is constructed by taking the advantage that H∞ filter is insensitive to the statistical property of error,which effectively overcome the influence of multi-platform system delay error fluctuation,and improves the fusion accuracy.The simulation results show that the proposed algorithm can effectively improve the coordinated detection fusion accuracy.

For the modulation recognition problem of Orthogonal Frequency Division Multiplexing (OFDM) signals and Single Carrier Linear Digital (SCLD) modulation signals at low Signal-Noise-Ratio (SNR),a recognition method based on Synchrosqueezed Wavelet Transform (SWT) is proposed.The SWT algorithm is used to extract the wavelet ridge and wavelet frame information of the signal,then the variance of wavelet ridge after differential and median filtering is used to distinguish OFDM signals and single carrier signals,and the ridge and frame features are used to accomplish the intra-class recognition.Simulation results show that in Rayleigh-additive white Gaussian noise channel with low SNR,the proposed method has a good recognition effect.

To ensure the best attacking effect of the air-to-ship missiles,an attack pattern extending the endgame penetration route of the missiles to underwater was proposed,referencing to the research idea of air/water trans-media vehicle,and study was made to its global path planning.Analysis was made and a model was established for the comprehensive defense capability of the ship to air and sea.Then,to guarantee the efficiency of the planning algorithm,the Multi-colony's Particle Swarm Optimization (MPSO) algorithm was used for optimal searching.The corresponding fitness function and evolutionary strategy were designed,and simulation was made.The simulation result shows that the algorithm can achieve global path planning to the weapon passing through different media.

The terminal guidance law is a key technology for the missile to attack target accurately,which has great influence on guidance precision of missile.To the problem of missile guidance in attacking the maneuvering targets,a variable structure guidance law was designed based on variable structure theory and father-offspring combined selection Genetic Algorithm (GA).Also,an adaptive reaching law and saturation function were used instead of symbolic function to reduce chattering of the system.Simulation results show that the variable structure guidance law based on father-offspring combined selection GA can find the global optimum solution and has high accuracy and robustness.Besides,it has low demand to the normal overload of missile,and the trend of the overload is stable during the guidance.The method has practical value in engineering.

The limited combat resource is one of the important factors that restrict the capability of shipboard aircrafts in attacking the ground targets.The force assignment of shipboard aircraft is studied,based on which a new force assignment optimization model is built up for surface-target attacking.It is put forward that the reasonable usage of the combat resources should also be taken into consideration besides the original target value and attacking risk.Analysis of examples shows that:with given combat resources and targets for attacking,the method can optimize the force assignment scheme to certain degree.

The concept of airborne waveguide holographic sighting display technology is introduced with its technical features and advantages,and the current situation of researches on this technology is summarized.Analysis is made to the critical technologies of the waveguide holographic sighting display and each of the critical technologies.Based on which,the development tendency and prospects of the waveguide holographic sighting display technology in the future are presented.

In frequency source designed by using GPS satellite signals to tame the ground crystal oscillator, there is interference noise in frequency deviation between GPS and crystal oscillator.If using Kalman filter to process the frequency deviation directly,outliers in the signal noise will influence the accuracy of filtering.In this paper,a Kalman filter algorithm based on minimum sum function estimation was proposed,which used the weighing matrix derived by influence function of M-estimation to judge whether the frequency deviation has outlier,thus to correct it for new filter information.The method has been used for some frequency calibration systems.The results show that the influence of outliers on the filtering accuracy can be effectively suppressed,and the output frequency accuracy is higher than 5.0×10-12.

Since the minimum drop-interval is not applicable to air-launched mines,the concept of “tactical minimum drop-interval” is proposed.According to the trajectory characteristics of airdropped mine,the factors that have effect on dispersion error are analyzed,the dispersion error correlativity when multiple mines are dropped continually is discussed,and the mathematical models are established.Then,a method for determining the tactical minimum interval of airdropped mines is presented.Finally,simulation is made based on the mathematical models.The selection of the tactical minimum interval with consideration of dispersion error,and its effect on the operational effectiveness,are analyzed according to the simulation results.

In order to study the influence of temperature on imaging quality of vehicle-mounted sight,the influence of temperature variation on structure parameters of the optical system was analyzed.Based on which,and with some wheeled artillery sight as the study object,the optical system model was established,and simulation analysis was made to the system model by setting different ambient temperatures.The root-mean-square value of diffused spots was used to represent the imaging quality of optical system,and the change law of imaging quality for this sight at different temperatures was obtained.Simulation results show that the imaging quality of this sight at low temperature is better than it at high temperature as a whole,with the best quality at about -20℃.This study lays a foundation for further evaluating the influence of temperature on the imaging performance of vehicle-mounted photoelectric system,and is of great reference value to the environmental adaptability design of new vehicle-mounted sight.

Currently,the instrument flight procedure is usually presented by planar graphs and tables.In this paper,a visual flight program verification method is put forward based on the three-dimensional (3D) geographic information system WorldWind.A 3D virtual environment was set up in WorldWind.Then,the airport anchor points,track and navigation station coordinates and other key parameters were entered,and processed by 3D coordinate transformation and interpolation.By using the data obtained,an instrument flight procedure was generated in the 3D environment,and flight simulation was made.Experiments show that,the proposed system can complete the 3D visualization of instrument flight procedures rapidly,and has good expansibility,which can be used for the auxiliary design and verification of instrument flight procedures.

Due to the roll,pitch,yaw disturbance,the shipborne photoelectric servo device has a great influence on the system steady sate and dynamic accuracy.To improve the target remote tracking accuracy on the sea surface,the CA model least square method is used together with ship-to-earth coordinate transformation filtering,and the velocity is fed forward to the velocity loop of double closed-loop servo control system.The position loop and velocity loop adopt first-order or second-order lag-lead series correction adjuster,based on different tracking states.The first-order and second-order adjuster can be switched into another one in the program,so as to achieve a good tracking effect.Finally,a 19-bit high-precision rotary transformer is added to form a complete double closed-loop servo control system for improving the tracking accuracy.In a test,a certain ship-borne photoelectric servo device performed target remote tracking with medium wave infrared tracking mode.The result shows that: 1) The maximum miss distance is 35″;and 2) The composite angle value of rotary transformer feedback is in agreement with the actual angle value of target measured by radar,and the maximum tracking error is only 100″,which is far less than the tracking accuracy of 4′ required in engineering.

In order to improve the accuracy of passive localization,a localization algorithm using the Time Difference of Arrival (TDOA) and Gain Ratio of Arrival (GROA) measurements is proposed based on Constrained Total Least-Square algorithm (CTLS).Firstly,a pseudo linear equation is established by using TDOA/GROA measurements.Taking the correlation of coefficient noise in pseudo linear equation into consideration,CTLS method is used for modeling,Lagrange multipliers together with the Newton iterative method are used for solution.Simulation results show that: 1) When the noise is relatively low,the proposed method approximates the lower limit of CRLB; 2) When the noise is higher,the proposed method offers better localization accuracy compared with the two-step WLS method; and 3) With the increase of parameter c/w,the localization mean square error of this proposed algorithm is also less than that of the two-step WLS method.

In view of the complicated, changeful and uncertain air-combat environment, the fuzzy Petri net based reasoning algorithm was studied. Then, an intelligent tactical decision-making method based on fuzzy reasoning Petri net was established, which changed the qualitative decision reasoning process into quantitative matrix operation. For the redundancy and possible conflict of rule, rough set theory was used to refine the tactical decision-making rule database, thus to simplify the fuzzy reasoning Petri net structure, improve the efficiency of tactical decision reasoning, as well as realize intelligent decision-making for UAV attack and defence. Simulation results demonstrate the feasibility and validity of the proposed method

An approach for the selecting continuous tracking navigation area was proposed to solve the problem of navigation area selecting for FLIR visual navigation of air vehicles.The mission of FLIR visual navigation was analyzed,and 4 kinds of commonly used navigation modes were summarized.Then,a navigation area selecting method integrating rough selecting,accurate selecting with stability analysis was designed as for the mission of continuous tracking navigation area selection,based on image variance calculation,continuation straight line feature detection and Frieden gray level entropy.The basic principle,implementation steps and flow chart are given here.The application experiments indicate the practicability,efficiency and adaptability of the designed approach.

To the sorting problem of Multiple-Input and Multiple-Output (MIMO) radar signals,by using the idea of matched filtering in radar receiver,a cluster matched filtering-based sorting algorithm of radar countermeasure reconnaissance is proposed.Pulse signals intercepted by radar reconnaissance receiver constitute the pulse group to be tested,with the first pulse being used as the reference signal.Cluster matched filter operation is made to the reference signal and the pulse group to be tested.When the operation result exceeds the threshold,it is judged that the tested pulse signals are in the same channel as the reference signal;otherwise,they are not in the same channel.After removal of signals in the same channel,sortingcontinues to be performed again,until sorting of all tested pulse signals is completed.Experimental simulation shows that the proposed sorting algorithm has strong anti-noise capability and low sorting error rate,is less affected by inter-pulse jitter,requires less number of intercepted signals,and easy to be implemented in engineering.

Remaining lifetime prediction is of vital importance in equipment maintenance and repairment.Most of the remaining lifetime prediction methods now available only use the current degradation information of equipment,but does not take full advantage of the historical lifetime information,while this information always contains the evolution information of equipment lifetime,which is of great significance for accurate predicting of the remaining lifetime.To solve this problem,a remaining lifetime prediction method is proposed by integrating the stochastic degradation process with hazard rate.Firstly,the equipment degradation process is modeled as a Wiener process,and then Cox proportional hazard model is used for modeling,which integrates the influence of equipment degradation process on the hazard rate,thus attaining the purpose for using the historical monitoring information.Furthermore,parameters of the degradation model are updated with the current degradation monitoring information by Bayesian method,based on which,the remaining lifetime can be predicted,hence realizing effective fusion of equipment historical data and current data.Finally,the proposed method is verified by the degradation measurement data of laser generator.It is demonstrated that the proposed method is valid,with certain application value.