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Table of Content

    30 June 2011, Volume 32 Issue 6
    Paper
    Neural Sliding Mode Control for Tracking of Axis of Firepower of Unmanned Turret
    TIAN Jian-hui, QIAN Lin-fang, XU Ya-dong, CHEN Long-miao
    2011, 32(6):  641-645.  doi:10.3969/j.issn.1000-1093.2011.06.001
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    Referring to the problems of system parameter perturbation caused by fire aiming mechanism existed in tracking system of axis of firepower of unmanned turret and external disturbances existed in system input while gun is firing, a neural sliding mode control strategy is given. This approach uses a nonsingular terminal sliding mode manifold to guarantee that the controlled system can reach the sliding mode manifold and equilibrium point in finite time from any initial state. A Radial Basis Function(RBF)neural network is applied to compensate adaptively the upper bound of uncertainty, and to ensure the sliding mode motion. The stability of the controller and the convergence of the tracking error of axis of firepower are proven by Lyapunov criterion. The simulation results show that the accuracy and robustness of tracking control of the axis of firepower are guaranteed, and chattering of the sliding mode control is reduced by the RBF neural network’s learning without sacrificing its robustness. The control scheme is valid.
    Isolation and Characterization of 246-Trinitrophenol Degrading Isolates
    SUN Xiu-yun, SHEN Jin-you, WANG Lian-jun, LI Jian-sheng, HAN Wei-qing
    2011, 32(6):  646-650.  doi:10.3969/j.issn.1000-1093.2011.06.002
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    2,4,6-Trinitrophenol (also known as picric acid, TNP in short) is a kind of important energetic material, widely used in the field of manufacturing of the initial explosive. For the purpose of bioremediation of TNP, using TNP as sole carbon and nitrogen source, three TNP degrading isolates, are isolated from the soil contaminated in long term by TNP. Among the three TNP degrading isolates, NJUST16 exhibits the best TNP degrading ability. NJUST16 is identified as Rhodococcus sp. through morphological observation, 16S rDNA sequence analysis and phylogenetic characterization. The cleavage of benzene ring, the elimination of nitro groups and the absence of intermediate accumulation are identified by the analysis of UV, FTIR, et al, indicating complete mineralizaition of TNP by NJUST16.
    The Finite Element Analysis of Moisture Diffusion and Stress in HTPB Propellant Grain
    WANG Yu-feng, XING Yao-guo, LI Gao-chun, ZHANG Yong
    2011, 32(6):  651-656.  doi:10.3969/j.issn.1000-1093.2011.06.003
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    The mathematical model and the FE model of moisture diffusion and stress are proposed for studying the effects of humidity on solid rocket motor, and the FEM is employed to simulate the moisture diffusion and stress in HTPB grain. The results indicate that, the effect of humidity on grain can not be ignored. The hygroscopic condition of grain increases with increasing of humidity of environment, and the moisture diffusion can lead to moisture stress. The largest Von Mises stress appears at star needle. The speed of moisture diffusion is higher at high temperature. The moisture protection need to be noticed in stockpile and use of solid rocket motor.
    Chaotic Controlling and Synchronization in Second Harmonic Generation Using Time-delay FeedbackModulation Pump Field
    YAO Zhi-hai, LI Jian-yu, FENG Xiu-qin, TAN Zuo-lin, HUANG Han
    2011, 32(6):  657-662.  doi:10.3969/j.issn.1000-1093.2011.06.004
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    A method for chaotic controlling and synchronization based on delay feedback parameter modulating pump field is proposed. If suitable delay time and controlling strength in second harmonic generation (SHG) are used, chaotic behaviors can be controlled into periodic behaviors by delay feedback parameter modulating. The simulation results show that two or more SHG systems can reach chaotic synchronization when their pump fields are modulated by delay feedback. Although they have different initial conditions, this method can realize chaotic controlling and synchronization in several SHG systems, thus it lays the foundation for solution of multi signal chaotic secure communication problems.
    Image Region Adaptive Detection of Multi-target Track
    HE Jia-yi, LIAO Gui-sheng, YANG Zhi-wei
    2011, 32(6):  663-667.  doi:10.3969/j.issn.1000-1093.2011.06.005
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    Aiming at the problem of low visible moving target track detection, combining image processing and curve fitting, an approach of multi-target detection is presented. On the basis of range-time image, which is accessed through processing radar echo, using phase congruency model to detect edge, the edge connected region with congruency edge orientation is obtained by combining adaptive region growing technology. The target moving track and moving parameters are estimated using clearing technology and least squares fitting. The simulation results show that, the method can detect multi-target track under low signal noise ratio, and it is difficult to detect multi-target track with phase congruency model.
    SAR Ground Moving Target Imaging Based on Sparse Signal Representation
    QIAN Jiang, LV Xiao-lei, LI Liang-hai, XING Meng-dao
    2011, 32(6):  668-673.  doi:10.3969/j.issn.1000-1093.2011.06.006
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    An approach of ground moving target imaging based on sparse signal representation is proposed to overcome the Rayleigh limitation in resolution. The echo from ground moving target can be modeled as sparse LFM signal, thus its decomposition with sparse signal representation is natural. Compared with the Range-Doppler method, the imaging method of the sparse signal representation has the feature of super-resolution, which is beneficial for moving target detection. The simulation and real data experiments show the validity of the approach.
    Filtered Synchronization Based Narrowband Delay Technique for Continuous-chaos Frequency-modulating Signal
    JIANG Fei, LIU Zhong, BAO Bo-cheng, HU Wen
    2011, 32(6):  674-679.  doi:10.3969/j.issn.1000-1093.2011.06.007
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    A narrowband delay technique for continuous-chaos frequency-modulating signal (CCFMS) is proposed to realize broadband signal delay using narrowband delay techniques with chaotic filtered synchronization. Based on the dynamic generation principle of CCFMS, response system of dynamic model of CCFMS is constructed. And synchronization impact on delay performance is discussed by computing the maximum conditional Lyapunov exponent. Compared with the traditional delay techniques, this narrowband delay technique can reduce amplitude-phase uniformity, the insert loss and the cost of delay equipment. Simulation results show this technique can save the delay bandwidth by 65%.
    A Novel Blind Recovery Method of Self-synchronizing Scrambling Polynomial
    LV Xi-zai, SU Shao-jing, HUANG Zhi-ping
    2011, 32(6):  680-685.  doi:10.3969/j.issn.1000-1093.2011.06.008
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    In order to get the self-synchronizing scrambling information of the unknown lines in digital communication, a novel method of blind detection of the order of self-synchronizing scrambling polynomial is proposed based on deeply studying the statistic characteristics of reduplicate codes in self-synchronizing scrambled sequence on condition that the number of “0” or “1” bit in source is imbalanced. Later, an algorithm for estimating the feedback position in self-synchronizing scrambling polynomial, which is better than the method of Walsh transformation, is offered with the idea of combinatorial imbalance. The results of experiment and simulation verify the correctness of the theory analysis and the validity of the whole algorithm.
    Robust Adaptive Backstepping Control for Mass Moment Missile with Dynamic Surface Filtering
    GAO Chang-sheng , LI Jun-long, JING Wu-xing, LI Rui-kang
    2011, 32(6):  686-690.  doi:10.3969/j.issn.1000-1093.2011.06.009
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    Based on the inversion technology, tracking control problems on the pitch and yaw channel of the mass moment missile with dual-moving masses are solved. Based on the established affine control model, and taking into consideration of the uncertain factors such as moving mass's velocity, acceleration, guides and so on, the robust adaptive inverse control law is given. To solve the calculating expansion problem that exists in backstepping methodology, a sliding mode filter to estimate the derivative of the virtual control variable is designed. Since the gain coefficient derives from backstepping can't guarantee the ideal performance index, genetic algorithm is used to optimize the controller parameters. Simulation results demonstrate that the algorithm is effective.
    Design and Error Compensation of MEMS Rotating Modulation AHRS
    XU Ye-feng, QIU Hai-tao, HE Meng-ke, MENG Qing-ji
    2011, 32(6):  691-696.  doi:10.3969/j.issn.1000-1093.2011.06.010
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    In order to achieve medium-precision, low-cost attitude and heading reference system (AHRS), the approach of using rotating modulation technology based on low-performance micro electronic mechanical system (MEMS) gyro is proposed. The features of gyro’s scale factor error and acceleration related error in rotation-modulation situation are studied. The new errors caused by rotation-modulation are also analyzed such as rotating decomposition error, whirlpool error, etc. For different error sources, the compensation methods and the corresponding compensation results are given. Experiment results show that, after error compensation, the rotation-modulation approach can improve the performance of MEMS gyro by about 30 times, the system’s attitude and heading maintain accuracy will be better than 1°/h by using the 30°/h-drift MEMS gyro.
    Performance of Arc-ion Plating Ti0.7Al0.3N Coatings on PCrNi3MoVA Steel
    ZHANG Jian , GUO Ce-an, ZHANG Gang2, HAO Shi-ming
    2011, 32(6):  697-702.  doi:10.3969/j.issn.1000-1093.2011.06.011
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    A Ti0.7Al0.3N coating was deposited on PCrNi3MoVA steel for gun barrels by arc ion plating(AIP). The mechanical properties of the coatings are investigated and it is found that the hardness of the coatings increases approximately by a factor of 6.5 in comparison with that of the PCrNi3MoVA steel. The wear mechanism in Ti0.7Al0.3N coatings can be mainly characterized by adhesive and micro-abrasive wear while the dominant wear mechanism for the PCrNi3MoVA steel are severe abrasive wear and plastic flow. the coefficient of steady-state friction of the Ti0.7Al0.3N coatings ranged from 0.52 to 0.57, which is lower than that of the PCrNi3MoVA steel ranged from 0.73 to 0.78. The oxidation tests are performed at 750 ℃,800 ℃ and 850 ℃ in air for 3 h and it is found that due to dense oxides mixture film of Al203 and TiO2 on the coatings,the Ti0.7Al0.3N coatings exhibits excellent oxidation in air at 850 ℃ while severe oxidation happens to the PCrNi3MoVA steel at 750 ℃.The potential dynamic polarization measurements show that the corrosion potential of the Ti0.7Al0.3N coatings is approximately 200 mV higher than that of PCrNi3MoVA steel in 3.5 mass% NaCl solution, which indicates a great enhancement in corrosion resistance occurred to the Ti0.7Al0.3N coatings.
    The Research of Performance of Tungsten Tube Prepared by Chemical Vapor Deposition
    MA Jie, WEI Jian-zhong, WANG Cong-zeng, FAN Ai-ling
    2011, 32(6):  703-706.  doi:10.3969/j.issn.1000-1093.2011.06.012
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    Refractory metal tungsten tubes of different diameter have been prepared successfully by chemical vapor deposition with the mixture of WF6 and H2. The purity, density, micro-hardness, residual stress and strength of tungsten tubes at different deposition temperatures (500 ℃, 600 ℃, 700 ℃) were tested and analyzed. The results show that tungsten tubes prepared in this way demonstrate high purity and high density. At different deposition temperatures, micro-hardness values of tungsten tube of different radius(3-20 mm) change between 500 and 800 HV. A relatively high residual stress exists along the tungsten tube circumference, radius of the direction. And the tensile strength range is 300-500 MPa.
    Segregation in Continuous Casting Billet and Flat-bulb Steel of 10CrNiCu and Its Effect on Properties and Performances
    GUO Chun-huan, YANG Yang, CHEN Feng-qiu, YANG Shu, LIU Rui-tang
    2011, 32(6):  707-711.  doi:10.3969/j.issn.1000-1093.2011.06.013
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    In order to investigate effect of rolling process on the segregation and performances in continuous casting billet and its flat-bulb steel products of 10CrNiCu steel, and by means of original position statistic distribution analysis and micro shear test, segregation in continuous casting billet and its flat-bulb steel products of 10CrNiCu steel and influence of the segregation on the performances are investigated in this paper. The results indicate that S segregation has noticeable effect on the service performance of 10CrNiCu products and the maximum segregation degree of S in the flat-bulb steel of 10CrNiCu is about 2.5. In the bulb, the strength of the surface is higher than the middle portion, because of the serious segregation in the middle portion.
    Integrated Perception System for Mobile Robot and Its Improved Registration
    FU Meng-yin,YANG Yi,ZHU Hao,WANG Li-ping
    2011, 32(6):  712-718.  doi:10.3969/j.issn.1000-1093.2011.06.014
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    With the integrated perception system of camera and laser ranger, the problems based on feature point matching are researched. Combined with 3D laser ranger and camera working features, referring to the problem of laser ranger mixpixels and edging points, associated scanning sequence filter (ASSF) is designed. The influence of registration feature point extraction from mixpixels is largely decreased, extraction precision is increased, and the registration results of 3D laser ranger and camera are more accurate. Besides, laser ranger coordinate origin position calibration method based on structure feature is proposed, which reduces the measuring error of laser ranger. The research results show that the integrated perception system can accurately perceive mobile robot running environment.
    Influence Analysis of Various Factors to Acquiring Probability of Anti-ship Missile with Shooting at Target'sImmediate Position
    ZENG Jia-you
    2011, 32(6):  719-724.  doi:10.3969/j.issn.1000-1093.2011.06.015
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    Anti-ship missile with shooting at target's immediate position only shoots at target's immediate position without considering target's maneuver and measuring target's states during the programmed flight period, which increases the factors of influencing the acquiring probability. The traditional computing models can not reflect the influence of various factors on the acquiring probability roundly. Therefore, the computing models for the acquiring probability of anti-ship missile with shooting at target's immediate position is constructed by considering various factors gradually and regarding the platform position error, target's maneuvering limit and target's position indication error as circular distribution. Simulation results show that the main factors influencing the acquiring probability of the anti-ship missile with shooting at target's immediate position are the attack distance and azimuth coverage; various errors also have not to be neglected influences on the acquiring probability; and acquiring probability is hard to reach 0.99 when the target's position indication error is 5 km or the platform position error is 3 km.
    Coordinated Jamming Task Assignment Model and Algorithm Based on Region Covering
    HUANG Jun, SHAN Hong, MAN Yi
    2011, 32(6):  725-732.  doi:10.3969/j.issn.1000-1093.2011.06.016
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    In order to guarantee the optimized objective of region jam covering and the least energy consumption, a networking architecture based on regional cluster and a multi-object integer programming mathematic model are built to solve the task assignment problem of coordinated jamming operated by low-power jammers. Based on this, a complete coverage case and an incomplete coverage case are investigated. To solve one-target covering problem and multiple targets covering problem, a multi-dimensional knapsack model and a multi-choice multi-dimensional knapsack model are built separately. Combining with the heuristic algorithm, an integer coding based hybrid genetic algorithm for the complex knapsack problem is proposed. Simulation results demonstrate that this model is feasible and the algorithm is effective.
    Numerical Research on Microbubble Drag Reduction Downstream of Partial Ventilated Cavity
    XIANG Min, ZHANG Wei-hua, ZHANG Zi-bo, TU Ji-yuan
    2011, 32(6):  733-738.  doi:10.3969/j.issn.1000-1093.2011.06.017
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    Numerical research on microbubble drag reduction downstream partial ventilated cavity is carried out based on an Eulerian-Eulerian two-fluid approach. The gas leakage model resulted from the re-entrained jet at the rear of partial ventilated cavity is proposed and integrated into the numerical model. The turbulent dispersion force model was improved to take into account the effect of high void fraction. Numerical model was firstly validated through application on a microbubble drag reduction experiment for an axisymmetric object. Then simulations on bubbly flow created by partial ventilated cavity were implemented where the vortex regions behind the cavity and the bubble distribution were successfully captured. Based on the simulation results, the friction drag and form drag caused by bubbly flow downstream of the ventilated cavity is analyzed. It is concluded that for the objects with high form drag coefficient, it can be more effective to use partial cavity for drag reduction than supercavity, because the partial cavity which is composed of cavity drag reduction and microbubble drag reduction can obtain high friction drag reduction while keep low form drag.
    Comprehensive Review
    Research Development of High g Penetration Acceleration Test and Its Correlative Technology
    XU Peng, ZU Jing, FAN Jin-biao
    2011, 32(6):  739-745.  doi:10.3969/j.issn.1000-1093.2011.06.018
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    Based on the recent researches of the author and his collaborators on penetration acceleration test, the paper summarizes and reviews the researches both in China and abroad on high g acceleration field test during projectile penetration into hard target with high velocity for over the last decade,especially the on-board test application in acceleration test. The paper also summarizes correlative technology on penetration acceleration test, including the anti-high shock capability and calibration of accelerometer, and the anti-proshock ability of battery. At last, based on the existing research works and potential national defense demands, the development trends and problems worth of consideration in the field are demonstrated.
    Research Notes
    The Multi-axial Optical System Study for Fire Control Dynamic Performance Testing
    WANG Chun-yan, JIANG Hui-lin, WANG Lu, WANG Xiao-man, WANG Zhi-jian
    2011, 32(6):  746-751.  doi:10.3969/j.issn.1000-1093.2011.06.019
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    In order to improve the test accuracy of the self-propelled weapons' dynamic performance index, a method is proposed to test fire control dynamic performance parameters on the Moving Base. Using coexistence of CCD digital imaging and the human eye observation, the optical system is designed. In addition, the testing system about fire control dynamic performance is developed. The high accuracy measurement of seven-key indicators is realized, such as stability accuracy. In order to guarantee the axis consistency of the test equipment, the multi-axis consistency detecting device is developed. The measuring precision of the system is ensured. The application shows that, the accuracy reaches 0.1 mil, and it is easy to use, and has strong adaptability.
    Research on ATP System Technology of Laser Communication Terminal in Space
    HU Zhen, JIANG Hui-lin, TONG Shou-feng, SONG Zheng-xun
    2011, 32(6):  752-757.  doi:10.3969/j.issn.1000-1093.2011.06.020
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    The improved acquisition, tracking, and pointing (ATP) system of the developed airborne laser communication terminal with high precision is presented. The optical antenna, coarse tracking assembly, fine tracking assembly, and point-ahead assembly in the ATP system are designed and the prototype is developed. The coarse tracking and the fine pointing control model of the compound-axis system is established and their performance is simulated. In order to further verity the error compensation ability of the ATP system, the experiments to reduce the pointing error are done in the platform vibration simulation system. The results show that if the control frequency bandwidth of the coarse tracking system for the ATP system is about 5.5 Hz and that of the fine pointing system is about 350 Hz, the pointing error is less than 2 μrad. The performance of the ATP system is improved.
    A Temperature Compensation Method of High-precision V/F Converter
    DONG Ming-jie, WANG Bo, SHI Yong-sheng, GAO Zhi-feng
    2011, 32(6):  758-763.  doi:10.3969/j.issn.1000-1093.2011.06.021
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    Through the theoretical analysis of charge balance type V/F converter, the main factors of the V/F converter zero temperature drift and scale factor temperature drift are found out. For zero drift, the principle of selecting components is proposed. The zero temperature drift from -40 ℃ to 60 ℃ of the converter is not greater than 0.5 Hz in the range -200 kHz~200 kHz of the output frequency. For the scale factor temperature drift, a simple temperature compensation circuit is designed. Through the temperature compensation, the average temperature coefficient of the V/F converter scale factor can be controlled within 2×10-6/℃.
    Target Tracking Technique for Radar Network Under the Distributed Jamming
    XU Hai-quan, WANG Guo-hong, GUAN Cheng-bin
    2011, 32(6):  764-769.  doi:10.3969/j.issn.1000-1093.2011.06.022
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    Under the distributed jamming, the detection probability of target decreases and it makes track unstable and brings down the track lifetime. In order to deal with the above problem, the multi-radar MHT algorithm is proposed. Firstly, distributed jamming is discriminated by range difference. Secondly, jamming power is estimated and the improvement factor is constructed to increase the detection probability. Then target states are estimated by MHT algorithm based on data compressing. The simulation results show that the algorithm can increase the track lifetime and has good performance on anti-jamming and is significance in practical application.
    Interacting Multiple Model Based on Kalman Filter Applied in GPS Point Positioning
    LU Jian-shan, WANG Chang-ming, SONG Gao-shun, ZHANG Ai-jun
    2011, 32(6):  770-774.  doi:10.3969/j.issn.1000-1093.2011.06.023
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    The problem of GPS positioning using single model is that, single model can’t adapt to the changes of operating conditions or maneuvering process. In order to solve this problem, Interacting Multiple Model (IMM) is employed here. The algorithm of IMM based on Kalman filter is explained in detail and the application in GPS positioning is introduced. With the data of GPS static point positioning, it is proved that IMMKF of varying noise models can adapt to the changes of operating condition well. And the simulation of dynamic positioning shows that, multiple models can be fused effectively with IMMKF, and the disadvantage of single model can be overcome in a great degree.
    Guaranteed Cost Observer Design for Uncertain Networked Control Systems
    SUN Lian-kun, WAN Zhen-kai, ZHANG Gui-ling
    2011, 32(6):  775-780.  doi:10.3969/j.issn.1000-1093.2011.06.024
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    The problem of the guaranteed cost observer design is studied referring to uncertain networked control systems with communication constrain. Through introducing the send on delta (SOD) scheduling strategy at the ends of sensor, the unimportant information occupancy to network resource is reduced and the system model is obtained. The sufficient condition for existence of the guaranteed cost observer under output feedback is given by using Lyapunov stability theory. Moreover, the parameters of the observer are determined by using LMI and orthogonal complement method, hence the cost matrix is optimized. At last, the simulation verifies the validity of the method.
    Modeling and Simulation of the Optimal Terminal Guidance of Missile for Indirect Aiming
    XU Wen-xu, LI Zhao, ZHANG Geng-yu
    2011, 32(6):  781-784.  doi:10.3969/j.issn.1000-1093.2011.06.025
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    In order to research the impact of maneuver target on guidance accuracy, the target maneuvering statistical characteristics described as differential of target acceleration is colored-noise-sequence, and related system state model is established. This method has larger range of target maneuver pattern than statistics of white-noise-sequence. The system state model is solved by Kalman filtering algorithm to realize the closement of optimal guidance loop. Simulation result indicates that the hit precision has been improved greatly when engaged for high maneuver targets such as lower-flying helicopter without changing the missile hardware. The paper provides design reference for optimal guidance of indirect aiming missile.