Abstract:Having the performance of real-time, autonomous, robust and high capability, cyber-physical Systems (CPS) are a kind of intelligent complex systems which combined sense and control, computation and communication with physical object tightly in network environment. The notion, development and framework of CPS are presented, and the different between CPS and embedded system, WSN and IoT are discussed at first. Then, the application and research of CPS in the fields of electric power, traffic, medical and aeronautic & astronautic are summarized, and the outstanding challenges about CPS are pointed out. Finally, the future research and development directions of CPS are discussed.

Abstract:Aimed at linear time-invariant system, a performance-oriented controller parameters tuning method is proposed based on Guardian Maps stability theory. First, the expected dynamic properties and stability margin of closed loop system are transformed into a problem of regime matrix eigenvalue assignment, and then the Guardian function is computed to determine all the controller parameters under condition of the plant parameters known. Simultaneously, the controller parameters are fixed, and the allowable range of system parameters can also be obtained. The method with strong universality can be used for PID, state feedback as well as adaptive controller parameters tuning, etc. Simulation results show that this proposed method is effective.

Abstract:The characteristics of long endurance solar powered UAV airborne power and energy storage system is studied and analyzed, and a general design method and process are proposed based on energy balance relation and aerodynamic parameters. The relation formula of energy storage battery (second power supply) weight Qb, solar cell area Ss with the parameters such as weight Qj, flying velocity v, lift-drag ratio k, motor efficiency ηm, propeller efficiency ηB and airborne equipment electric power Pb is derived. On this basis, through a study of the hybrid energy storage with the gravitational potential energy, the relation formula of storage battery weight ratio is derived. This design method is effective through the calculation process and comparison, and the method can provide a reference for the general design method of the long endurance solar power UAV.

Abstract:Instead of the chromate salt chemical conversion treatment for aerospace magnesium alloys, a technology of the rare earth salt chemical conversion is studied and the corrosion resistance is evaluated as well. These micrographs of specimen surface are investigated by metallographic microscope. The corrosion behaviors of magnesium alloy and conversion coating are assessed by means of potentio- dynamic polarization curves and immersion tests. The experimental results indicate that a yellow-brown conversion coating is formed subsequently on the specimen surface, the conversion technology condition is a mixture solution including 3 g/L CeCl3·H2O、5g/L KMnO4 and the other at room temperature. The formation of the rare earth conversion coating and the composition of the coating are discussed by the principle of thermodynamics. The research results indicate that the composition of the coating includes MgO,CeO2,MnO2,Mg (OH)2 and Ce (OH)4. During the initial of the rare earth salt conversion, mass gain is a linear growth with time. After 30min, mass gain is approximately unchanged.

Abstract:For the change of battlefield situation and other reasons, the unmanned aircraft Vehicles (UAV) in formation flight need flight delay in target attack. In the equal-altitude flying mode, the delay path planning method is presented based on hierarchical planning. First, this paper selects the best delay movement area based on the minimum risk value, and then adopts the delay path planning method to form the delay maneuver path satisfying the delay time and the requirement of flight constraints. Through analyzing and calculating risk of each track segment near the value, the UAV maneuver flight delay safe zone is determined and by using an analytical method the planning algorithm hover delay path is proposed based on the delay, delay time and the flight track constraints requirements. This algorithm is utilized to generate the time delay path satisfying the requirement of arrival time delay. The simulation results show that the hover delay path planning algorithm can accurately track the delay needed planning, plan a total time within the stipulated time, and meet the flight time delay requirement of UAV.

Abstract:In order to explore the flexible organizational pattern of operational resources under information conditions, role concepts are introduced for standardizing the management of the operational resources information. This paper builds up a Layered granularity structure model of operational resources organization, analyzes the self-related structure and attributes within the operational resources and proposes the process of operational role encolding suited to the operational substance cell data based on the above mentioned. The case application is validates that the approach proposed in the paper can confirm the flexible unification between expression and information standardization for physical entities, and it is easy to realize dynamical extending and compatible criterion within different layers, which provides a basic support in designing and modeling flexible organization for operational resources.

Abstract:Aimed at the problem that the basic probability assignment of multiple sensors cooperation with target identification in practical application is liable to cause low decision-making reliability, a reasoning mechanism of multiple sensors cooperation with target identification based on BP neural network and D-S evidence theory is presented. Firstly, BP neural network theory and D-S evidence theory are summarized simply. And then, target identification reasoning frame is built, and the algorithm's feasibility is reasoned. At last, an actual example is simulated, and by information fusing the basic probability assignment of uncertainty drops to 0.0008, the analysis and the simulation show that the reasoning mechanism is effective.

Abstract:Ultra-wideband frequency-stepped signal is an effective radar signal, but its anti-jiamming ability is not enough, and its pulse-width time is too long. To solve these problems, an imaging algorithm based on sparse frequency-stepped signal is proposed, the use of which can complete the target imaging with less resource of time and spectrum. In the proposed algorithm, the echo data of sparse frequency-stepped signals are equivalent to the observed values of the echo data of the traditional frequency-stepped signals. Therefore, the reconstruction of the high-resolution range profile can be realized based on the compressive sensing (CS) theory. Then, the target scene imaging can be completed by range cell migration correction and azimuth pulse compression. The simulation results demonstrate that the use of the algorithm can achieve a high-resolution imaging while the transmitted frequency-stepped signal is sparse in frequency domain. Finally, the ground-based radar experiment data are adopted to verify the effectiveness of the proposed algorithm.

Abstract:In order to overcome the inadequacy of conventional RCS statistical models describing stealth target fluctuation, a new RCS statistical modeling method based on Gaussian mixture density model is presented. The two-order GMDM and distribution model are established respectively based on the simulation data of typical stealth target. The results show that the forward, side and backward fitting errors of GMDM are respectively 4.74%, 12.34% and 1.01%, while those of the model are 44.5%, 18.65% and 13.21%. And simultaneously when fitting order in number exceeds four-order, the fitting error of GMDM remains below 5% steadily, which can satisfy the precision demand of radar target simulation.

Abstract:Battle damage assessment in TBM reentry interception is studied from the perspective of tracking radar. Firstly, the paper analyzes two kinds of circumstances when reentry TBM is intercepted. Based on this, the ballistic coefficient method is applied to TBM battle damage assessment, and a method of calculating ballistic coefficient is introduced. Then a method of TBM Battle damage assessment based on ballistic coefficient estimation is put forward. By simulating the ballistic coefficients of three ballistic targets complete warhead, wreckage and litter pieces, the assessing method proved to be available. The influence of radar measurement accuracy on the evaluating error of ballistic coeficient is analyzed by simulation, and it comes to the conclusion that the improvement of radar measurement accuracy benefits the assessing accuracy of TBM battle damage. Finally, the effect of target maneuver on assessment is studied by simulating the warheads' contrails in maneuver-shifting contrail model and in collision-shifting contrail model, and the solution is summarized to avoid this effect.

Abstract:A novel cavity backed slot antenna based on multi-layer substrate integrated waveguide is designed and manufactured by utilizing the resonant cavity to form symmetrical field excitation, and its radiation characteristic is studied and simulated. The proposed antenna using double -layer SIW to realize its feeding circuit and cavity structure has the advantage of low profile, light weight and convenient integration. The promoting effect of ring-slot structure on the radiation performance is considered. Finally, the test structure with a bandwidth of -10 dB return loss at 150 MHz is manufactured. And the maximum gain is 8 dB, and the maximum cross-polarized radiation is -12 dB. The good agreement between the measured results and the simulated results demonstrates that the design method is effective.

Abstract:The uncertainty in air attack is a challenge to the generation of the optimization scheme in area air-defense operation disposition, and each situation of air attack corresponds with one optimum disposition scheme. In order to synthesize the optimum schemes under conditionsof every air attack to obtain the optimum seeking methods suitable for various different situations of air attack, optimal disposition schemes under each and every type of air attack are regarded as the ideal point, and by defining the concept of similarity degree between disposition schemes, the evaluated function is established. At last, the problem is transferred into one single object programming problem, and a disposition optimization method for area air-defense operation is proposed based on ideal point . The instance analysis indicates that this method is feasible and effective.

Abstract:In order to improve the robustness of visual moving object tracking, a tracking algorithm is proposed based on local patches and weighted background. Firstly, the local patches are sampled respectively from the foreground area and background area of the object. Secondly, the probability map of each patch to the frame image is calculated through the integral histogram based local exhaustive search. Finally, different weights are assigned to the searching results of patches by maximizing each probability map, and the final localization of the object in current frame is obtained by the weighted sum of the searching results of local patches. The experimental results indicate that the proposed algorithm exceeds the background weighted tracking and local patch based tracking in both tracking precision and tracking successful rate. Besides, the proposed algorithm is not too complex.

Abstract:On the basis of aperture coupled antenna, a wideband circularly polarized microstrip antenna coupled by orthogonal slots is designed in Ku band to broaden the bandwidth and improve the gain. In the antenna a layered structure with two square patches is taken as radiating elements, so the gain is improved with the broadening of the bandwidth. Coupling feedstructure is realized by adopting microstrip line with left-hand orthogonal slots (Left-Hand Orthogonal Slots) and the axial ratio is improved by optimizing slots size. The measured results show that 22.5% (VSWR<2) bandwidth and 16.2% 3 dB axial ratio bandwidth are achieved respectively and the gain is better than 9 dBi within 3 dB axial ratio bandwidth. The feed design of the antenna in the above structure is simple, and provides a reference for designing circularly polarized microstrip antenna.

Abstract:M sequence message is a typical message of HF data link. According to the statistical properties of M sequence message, this paper puts forward a new improved arithmetic coding, i.e. a semi-fixed probability estimative model based on frame structure proposed to quantify the probability of low probability symbols, a dynamic update mechanism of encoding interval length applied to update discretely encoding interval length in real time, and the algorithm caused the coding efficiency loss up to 10.04%. The test results show that when the quantity of M sequence message is from 2 to 9 and MIAC compression coding algorithm loses its compression ratio by 20% at most, compression time of the improved algorithm is lower than the original arithmetic coding at least 50%. And this will provide a new way of thinking for the study of the performance of data link system in the future.

Abstract:Multi-divided particle swarm optimization is putted forward based on dichotomy particle swarm optimization. Aims at how to confirm the number of divided particle, how to evaluate the ability of particle optimization and the ability of algorithm optimization, linear array synthesized pattern’s performance are studied by defined the rate of particle stagnancy and the rate of optimization, which involves low side-lobe beam pattern synthesis and low side-lobe beam pattern with nulling synthesis. The results of simulation indicate that the more times of particle divided the higher of optimization rate, and the constringency speed of PSO is fast, but the rate of particle stagnancy is almost same. However, more times of particle is not always good when synthesizing complex beam pattern. These characters show that the two indexes which can availably reflect the ability of particle optimization and algorithm optimization, can reliably estimate optimization ability of multi-divided particle swarm optimization from microcosmic point.

Abstract:Aimed at the strong bending condition of optical fibers near the stripping points probably leads the fibers to break, the distribution of the bending radius and the bending length near the fibers` stripping points are calculated and analyzed on the basis of the mathematics model of the unreeling kinematic attitude of the optical fiber cable during weapon flight movement. The relationship between the above two geometric quantities and the position of the stripping point are researched. And some other optical characteristic parameters such as the radius of the winding player, speed of the payout optical cable, line density of the optical cable are also studied respectively. The result indicates that the radius of curvature at the stripping point exist a minimal value 1.2 mm, and the value of the minimum almost has nothing to do with the above parameters. However, the bending radius and the bending length will be changed with the diversification of the stripping points location, payout layer, speed and fiber cables linear density.

Abstract:Empirical mode decomposition (EMD) is widely used in mechanical fault diagnosis, but its inevitable mode mixing in EMD exerts an influence on effectiveness. Mode mixing in EMD is studied, and two kinds of causes leading to mode mixing are found. One caused by the basic principle of EMD is called type-I mode mixing, such as mode down mixing and mode cross mixing, the other caused by faults of the sifting process is called type-II mode mixing, such as mode upward mixing. The improvement schemes are proposed according to the different mode mixings. For type-I mode mixing ，some supplemental measures such as abnormal event elimination, signal filter and supplemental signal added method are necessarily introduce in problem solving. For type -II mode mixing, the definition of intrinsic mode function is perfected, and the sifting process is improved. The simulating results show that the proposed schemes are effective.

Abstract:In order to precisely analyze the stability of reinforced soil slope under the action of earthquake load, a method combining finite element method, pseudo static analysis and strength reduction method are adopted to calculate the safety factor of reinforced soil slope under condition of earthquake load. The results show that the stability of reinforced soil slope is more sensitive to the acceleration of horizontal. In the analysis, the most acceleration of horizontal is -0.154 g and the most acceleration of vertical is 0.318 g.Through the calculation of seismic acceleration of different directions, the surface diagram of safety factor of reinforced soil slope under earthquake load is obtained. And is defined to evaluate the effect of earthquake of different directions and the horizontal direction is the most dangerous. This research provides some effective reference for the earthquake resistant design of reinforced slope.

Abstract:The paper discuss particularly international actuality from movement track,simulation precision,construct periods and economy character aspects to space manipulators. Three-dimensional microgravity simulation is emphasized in view of three-dimensional movement character. Scissor style gas suspension microgravity simulation equipment is put forward. The scheme integrates advantage of gas suspension, has flex big ratio and structure close，level has been solved by the use of the advantages of air flotation with dynamic, integrated force feedback servo control system can solve the problem of vertical direction with the move. The novel system can simulate the spatial microgravity environment with complex movement for space manipulators.

Abstract:In view of many uncertain factors existing in the characteristics of network security evaluation, a new network security comprehensive evaluation method is proposed based on the unascertained mathematics theory. Based on the analysis of network security risk, the index system and evaluation space of network security risk evaluation factors are established. The unascertained mathematical method is used in the network security risk comprehensive evaluation, and based on the theory of unascertained mathematics, the new unascertained mathematics concept of unascertained measurement expectation, comprehensive evaluation unascertained measure vector, the unascertained evaluation two value effect expectation and two value effect variance are defined. Based on the new unascertained concept, an unascertained mathematic model of network security risk comprehensive evaluation is established. The model is applied by real example, and the evaluation result is expressed by an unascertained rational number. The example shows that the method is simple and effective. This study provides a new way for the network security comprehensive evaluation.