Table of Content

25 April 2014, Volume 35 Issue 4

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Paper

High Accuracy Algorithm for SINS/Odometer Integrated Navigation System

ZHAO Hong-song, MIAO Ling-juan, SHEN Jun

2014, 35(4):  433-440.  doi:10.3969/j.issn.1000-1093.2014.04.001

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To solve the problems induced by the scale factor error of odometer (OD) and the installation error of inertial measurement unit in the vehicle strapdown inertial navigation system (SINS)/OD integrated navigation system, a SINS/OD integrated navigation algorithm is proposed, in which a new measurement equation is established and a fault detection method is introduced. This algorithm can effectively improve the navigation accuracy, and accurately detect the fault in time. It can also be suitable for the navigation mode aided by vehicle kinematics constraints to provide a fault-tolerant scheme for OD fault. The simulation results show that the algorithm is effective.

Research on Large Angle-of-attack Spin Resonance Movement of Aerodynamic Asymmetric Projectile

SHU Jing-rong， ZHANG Ji-chun， CHANG Si-jiang

2014, 35(4):  441-447.  doi:10.3969/j.issn.1000-1093.2014.04.002

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The aerodynamic asymmetry can produce a periodic forced interference to the angular motion of projectile when it rotates. Under certain conditions, this can form a rotating motion of the projectile longitudinal axis relative to the velocity vector in which the angle between the long itudinal axis and the velocity vector is fixed. This kind of rotating motion can be used to realize the stable scanning of terminal sensitive ammunition. On the premise of considering the forces and moments, including asymmetric aerodynamic force and moment, the motion differential equation of projectile is established, and the angle-of-attack equation in complex number form is derived. On the basis of angle-of-attack equation, the conditions under which projectile can form stable spin resonance movement are discussed. The simulating calculation of a certain aerodynamic asymmetric projectile is performed. The result shows that aerodynamic asymmetric projectile can form spin resonance movement under certain conditions, which provides theoretical support to the pneumatic design for terminal sensitive ammunition.

Statistical Main Lobe-to-sidelobe Ratio of Noise Frequency Modulated Continuous Wave

WENG Xiao-ming， GU Hong， SU Wei-min

2014, 35(4):  448-453.  doi:10.3969/j.issn.1000-1093.2014.04.003

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The matched filter output of noise frequency modulated continuous wave (NFMCW) has the random sidelobes which are presented as a uniform noise floor. The mathematical expressions of peak sidelobe ratio (PSLR) and integrated sidelobe ratio (ISLR) of NFMCW with Gaussian power spectral density are derived via the statistical regularities of the sidelobes. The results indicate that PSLR depends on correlation time length, signal effective modulation bandwidth and Doppler frequency. ISLR depends on correlation time length and Doppler frequency, and the signal effective modulation bandwidth is irrelevant. The Monte-Carlo experimental results are consistent with the derived results.

Research on Decoupling Algorithm for Control Coupling of a Spinning Missile Autopilot

SONG Tao， LIN De-fu， WEI Zhi-jun， LI Chuan

2014, 35(4):  454-460.  doi:10.3969/j.issn.1000-1093.2014.04.004

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The application of acceleration autopilot in spinning missile is restricted by the control coupling resulting from the actuator kinetics. A model of spinning missile autopilot is established, and the transfer function matrix of the equivalent actuator is derived. The methods of optimal actuator leading angle compensation and decoupling control based on dynamic output feedback are studied. Simulation results show that, with increase in the ratio of actuator band to rotating frequency, the control coupling becomes larger. The optimal actuator leading angle compensation is suitable for engineering application, but when the rotating frequency and the actuator frequency are increased, the decoupling effect deteriorates and the actuator control efficiency decreases. The complete decoupling can be achieved by using the method of decoupling control based on dynamic output feedback, and the measured errors have little effect on the application. However, this method needs a precise actuator kinetics model, and the complexity of compensator is closely related to the actuator order.

Numerical Simulation of Flow Field in Abrasive Water Jet Nozzles

JIANG Yu-ying， GONG Lie-hang， XU Xin-lin， WANG You-cheng

2014, 35(4):  461-467.  doi:10.3969/j.issn.1000-1093.2014.04.005

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The dynamics characteristics of multiphase flow are further improved by adding polyacrylamide into the pre-mixed abrasive water jet (AWJ), thereby improving the operation efficiency and reducing the nozzle wear, which is very important for cutting, drilling and other operations using this technology. Multiphase flow in abrasive suspension jet (ASJ) nozzle is simulated based on Cross equation. The results show that the method can accurately describe the dynamics characteristics of ASJ compared with experimental data. The dynamics characteristics of multiphase flow are analyzed by simulation approach. The results indicate that ASJ can reduce the drag force, raise the velocity of jet and improve the jet concentration compared with AWJ. It can also reduce the turbulent intensity of multiphase flow in the core area and make the abrasive particles distribute more uniformly.

Numerical Study of Interaction of Two Bubbles in Underwater Explosion

LI Jian， RONG Ji-li， LIN Xian-kun， XIANG Da-lin

2014, 35(4):  468-474.  doi:10.3969/j.issn.1000-1093.2014.04.006

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Subroutines which define the hydrostatic pressure and boundary conditions of the three-dimension fluid field are developed based on MSC.DYTRAN software. The volume-acceleration model is introduced to determine the initial condition of bubble pulsation in underwater explosion. The numerical simulations are compared with the results of validated experimental data. The calculated results of pulsation radius and period of single bubble are well agreement with the experimental results. The interaction of two bubbles is studied systematically, and the relative law of that the dynamic behaviors of bubbles are closely related distance and initial angle is summarized. The bubble model and numerical simulation arevaluable to correlative theory research and engineering calculation.

Experimental Study of Ventilated Supercavitating Flows around a Hemisphere Cylinder

DUAN Lei, WANG Guo-yu, FU Xi-neng

2014, 35(4):  475-483.  doi:10.3969/j.issn.1000-1093.2014.04.007

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To understand ventilated supercavitating flows around a hemisphere cylinder, the unsteady process of development of ventilated supercavity and the flow field of wake around a hemisphere cylinder are observed by means of a digital particle image velocimetry system and a high speed video camera. The results show that a steady transparent air area is observed near the foreside of the ventilated supercavity in the process of development of ventilated supercavity, and there is a vortex in the rear of supercavity. Water and air mixed area is full of the rear part, and finally bubble shedding in large scale appears, which has great effect on the flow field at the rear of a hemisphere cylinder. Compared to no-ventilated conditions, the range of low velocity area in the wake obviously expands，and the velocities of measuring points in various profiles decrease. The upper and lower velocimetry ropes stretch backward and enlarge by degrees as the ventilated cavity region extends rearward, becoming many dispersed velocimetry groups that gradually dissipate downstream.

Research on Optimum Location and Depth of Noise Jammer

YANG Ri-jie, MIAO Kang-le, HAN Jian-hui, ZHAN He

2014, 35(4):  484-488.  doi:10.3969/j.issn.1000-1093.2014.04.008

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The propagation problem of noise signal is solved using the decomposition and synthesis of broadband signals in frequency domain based on normal mode theory. The influences of included angle and distance between submarine and jammer, and the emplacing depth of jammer in given battlefield situation and ocean environment on jamming effect are studied. The result shows that the emplacing depth of jammer has a important influence on the jamming effect in far-field, which was ignored in previous researches. On the basis of the research, the optimum location and depth of noise jammer are obtained via further calculations.

Research on Orthogonal Frequency Division Multiplexing Underwater Communication Based on Differential Amplitudeand Phase-shift Keying Modulation Using Acoustic Vector Sensor

MA Xu-zhuo, FANG Er-zheng

2014, 35(4):  489-494.  doi:10.3969/j.issn.1000-1093.2014.04.009

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To further improve the quality of underwater acoustic communication on the premise that the bandwidth utilization rate is not reduced, an orthogonal frequency division multiplexing (OFDM) underwater communication system using acoustic vector sensor and differential amplitude and phase-shift keying (DAPSK) modulation is presented by describing the principle of DAPSK modulation and vector signal processing technology. According to the actual sound velocity gradient, the true acoustic channel is modulated using the channel modulator. The performance of system is researched. The results show that the spatial gain can be obtained by the linear combined signal processing, including pressure and particle velocity data from acoustic vector sensor gains. And the performance of OFDM underwater communication system using acoustic vector sensor and DAPSK modulation is better than that of the scalar one.

Shifting Evaluation of Integrated Transmission Based on Back Propagation Neural Network

WANG Ye, TAO Gang, LI De-qing, MA Yue-feng

2014, 35(4):  495-500.  doi:10.3969/j.issn.1000-1093.2014.04.010

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To improve the shifting comfort, the peak of the turbine speed change rate, the average rate of the turbine speed change and gear are determined as three objective evaluation indices, which are defined in detail, and an objective description of shift quality evaluation for tracked vehicle equipped with integrated automatic transmission is given using back propagation neural network (BPNN) according to its basic principle. A BPNN model used for evaluating shift quality is established and trained by using the BPNN toolbox in Matlab/Simulink software, and an objective evaluation shift software is designed specially using GUI box in Matlab environment. The comparison of the test results with the subjective ratings shows that the developed evaluation method has a better consistency with the traditional one, which can also enhance the objectivity, pertinency and flexibility of this system.

Volumetric Error Modeling and Compensation of Precision Measuring Platform Based on Multi-system Theory

ZHANG Dong-xu, YANG Ping, YANG Feng, WANG Zhan-shuai, XIE Yin-hui, GUO Yin-biao

2014, 35(4):  501-508.  doi:10.3969/j.issn.1000-1093.2014.04.011

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A volumetric error model is proposed according to the working characteristics and the geometric errors of a large-size optical element precision measuring platform. The volumetric error model is based on multi-system theory, and the topological structures of the multi-system theory are described by the number arrays of low-order body. To testify the volumetric error model, a new combined measurement experiment by the application of laser interferometer, double-ball bar, laser displacement sensor and other relative instruments is conducted for measuring the geometric and volumetric errors of the measuring platform before and after error compensation. The error compensation experiments show that the volumetric error is reduced from -70.01~22.14 μm to -4.22~5.8 μm, which also reflects the validity of the volumetric error model.

Online Error Estimation of Fiber-optic Gyroscope Strapdown Attitude and Heading Reference System Aided by Star Sensors

ZHENG Zhen-yu, GAO Yan-bin， HE Kun-peng， HOU Jian-jun

2014, 35(4):  509-515.  doi:10.3969/j.issn.1000-1093.2014.04.012

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An online error estimating method for shipborne strapdown attitude and heading reference system aided by star sensor is proposed. The constant drift of gyro can be estimated by taking the inertial attitude provided by star sensors as a reference. The zero bias of accelerometer can be estimated by taking the integral quantity of specific force as observed value and the projection of gravity on inertial space as reference. The method needs no disassembly of system, which is well suitable for online calibration. The method allows the complete division of error estimations of gyro and accelerometer, which meets the requirement of real time system. Computer simulation shows that the method can be used to evaluate the constant drift of fiber-optic gyro（FOG）and the zero bias of horizontal accelerometer in strapdown attitude and heading reference system（SAHRS）online with the evaluated accuracy of 0.02°/h and 50 μg, respectively.

A Multi-agent Intelligent Decision Approach Based on Fuzzy Analytic Hierarchy Process for Service Status of ElectronicCountermeasures Equipment

ZHANG Zhong-min， LI Jun-shan， SONG Ping₂, YAN Qi-fei

2014, 35(4):  516-522.  doi:10.3969/j.issn.1000-1093.2014.04.013

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A multi-agent intelligent decision support system based on fuzzy analytic hierarchy process（FAHP）for service status of ECM equipment is proposed according to the technical features and the support decision situation of electronic countermeasures（ECM）equipment. A hierarchical structure model of criteria system is established based on the analysis of the influencing factors of ECM equipment service status. A triangular fuzzy number complementary judgment matrix is made up by the fuzzy Delphi to calculate the weight vector of each criterion. Thus, a fuzzy comprehensive evaluation of service status could be made using a sorting method based on the weight vector of triangular fuzzy number in terms of possibility degree model. Finally, an intelligent decision support system using multi-agent is built, and the system structure, work flow and implementation techniques are presented. The research method can overcome the dependence of the traditional support decision models on equipment operating data, and provide a new idea for plan-making of the equipment support.

Study of Trajectory Planning for UCAV Formation Cooperative Attack

TANG Chuan-lin，HUANG Chang-qiang，DU Hai-wen，HUANG Han-qiao，DING Da-li，LUO Chang

2014, 35(4):  523-530.  doi:10.3969/j.issn.1000-1093.2014.04.014

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The issue of formation attack trajectory planning for cooperative air-to-ground attack of unmanned combat aerial vehicles (UCAVs) is investigated. A formation trajectory planning model is built based on single UCAV three degrees of freedom equations, relative movement model and UCAV initial and terminal states constraints. The cost function is constructed, which consists of single UCAV threat and task time, number of equivalent collisions and time error of executing command. The solution framework of optimal control method is formed based on the formation model and cost function. The whole trajectory is optimized by dividing it into three segments, and every segment is resolved by hp adaptive pseudospectral method. The simulation results show that the optimized formation attack trajectory satisfies the constraints, and the formation attack trajectory planning model is provn to be effective.

Research on Milling of Plain-woven Carbon Fiber-reinforced Composites

SU Fei, YUAN Jun-tang, YU Bin-bin, WANG Zhen-hua

2014, 35(4):  531-539.  doi:10.3969/j.issn.1000-1093.2014.04.015

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In view of the hardness, brittleness and machining difficulty of fiber-reinforced composite material, a milling mode is put forward to machine the carbon fibre-reinforced plastics（CFRP）, of which the fiber fabric stands vertically. The quality and the microstructures of the machined surfaces are analyzed. The blind-slot milling testes on plain-woven carbon fiber-reinforced composites are conducted. A scanning electron microscope is used to observe the microstructures of the machined surfaces and the swarf. The results show that the delamination is decreased by 30.44% on average with the increase in the cutting speed v_c; and it is increased by 73.49% on average with the increase in the feed speed v_f. There are 5 kinds of micro-fractographs of fiber weft and 2 kinds of micro-fractograps of fiber warp. In this milling mode, the intertexture structure can improve the machined surface quality of the front wall of slot, and the machined surface of the bottom of slot is smooth. Therefore, this milling mode is feasible. But there are some serious defects on the region of the cut-out side where a vulnerable place is. The results provide some useful references for the choice of milling mode and the quality improvement of machined surfaces.

Research on Patterns of Unit Behavior Based on Air Defense Equipment Command Task

WANG Yu-zhe, ZHOU Lin, WANG Yi, XU Yong

2014, 35(4):  540-546.  doi:10.3969/j.issn.1000-1093.2014.04.016

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In order to analyze the individual and support characteristics of the units in equipment command task, the task flow is used as the basic prototype. On analysis of the equipment support command system of the brigade air defense force, a conceptual model of unit behavior in equipment command task is established on the base of complex adaptive system (CAS) theory. The computing model corresponding to basic behaviors of unit is set up according to the operating mechanism of particle swarm algorithm (PSO). At last, on the basis of parameter design and simulation experiment, the diversity and global state of units behavior in equipment command task in different cognitive levels are studied, and the relationship of parametric variation among units perception, support needs and task importance is found out, which will help the further construction of the equipment support command system and the improvement of its task flow.

Research Notes

Numerical Simulation of Leakage Process of TNT Charges

MENG Xiang-yao， QIU Zhi-ming， ZHANG Peng₂, HAN Shou-peng， SONG Bao-wei

2014, 35(4):  547-551.  doi:10.3969/j.issn.1000-1093.2014.04.017

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A mathematical model for leakage of TNT charges is built based on Fick's law and the two-film theory in accordance with the basic process of dissolution-diffusion-desorption. This model is used to simulate numerically the leakage processes of TNT through rubber material both under water and in the air in the case of one-dimension, and the concentration distributions of explosive charges in the material at different times and the stable diffusion flux are obtained. The simulation results are consistent with the experimental data in the literature. The rationality of the model is verified. The main factors affecting the leakage process, such as coating material thickness and external medium, are analyzed. The results show that the leakage of TNT under water is easier than in the air.

H_∞ Optimal Output Tracking Control for Dual-controlled Missile with Tails and Reaction Jets Based on Dynamic Inverse Theory

WANG Qing， JIANG Yi-fan， DONG Chao-yang， ZHANG Ying-xin

2014, 35(4):  552-558.  doi:10.3969/j.issn.1000-1093.2014.04.018

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A control scheme is proposed for dual-controlled missile with tails and reaction jets based on the dynamic inverse theory and H_∞ optimal output tracking control. In the scheme, the nonlinear factor of dual-controlled missile is considered, the dynamic inverse loop is used as inner loop of control system to counteract the nonlinear factor, and the robust controller is used as outer loop under the consideration of uncertainty and disturbance. The robust controllers are designed with H_∞ control and optimal output tracking control to restrain the disturbance and preference uncertainty effectively and improve the tracking performance of control system. Simulation results show that the control system possesses better robustness and improves the tracking performance of system.

Model and Data Processing of Arbitrary Two-position North Finder

XUE Hai-jian， GUO Xiao-song， ZHOU Zhao-fa

2014, 35(4):  559-566.  doi:10.3969/j.issn.1000-1093.2014.04.019

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In order to improve the efficiency of north finder, a gyro north finder model for arbitrary two-position north finding is presented. It can collect the signals in two places which are less different, reduce the rotation time of turntable, and save the whole north finding time to some extent. In order to further improve the north finding accuracy, a wavelet threshold de-noising method is introduced, and a new double- parameter adjustable threshold function is proposed. The function is simple and easy to calculate without segmental values. The north-seeking experiment in arbitrary two-position is conducted on the developed principle prototype. The results show that the north finding accuracy within 160 s is higher than 0.02°, the north-finding time is saved，and the new de-noising threshold function greatly improves the north finding accuracy.

Analytical Methods for Sensitivity of Acoustic Field in Shallow Water to Uncertain Environmental Parameters

CHENG Guang-li， HU Jin-hua， ZHANG Ming-min

2014, 35(4):  567-571.  doi:10.3969/j.issn.1000-1093.2014.04.020

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For the purpose of analyzing the effect of uncertain environmental parameters on acoustic field in shallow water, the functional relations between acoustic field and uncertain environmental parameters are constructed by nonintrusive polynomial chaos expansion (NPCE) method, and an analytical method for the local sensitivity of acoustic field to single uncertain parameter is proposed. A method for analyzing the qualitative sensitivity is presented according to the variation of probability distribution of acoustic field before and after the variation of certain uncertain parameter when more parameters are uncertain, and then the global sensitivity is quantitatively calculated by introducing the Sobol index method. The results show that the proposed methods can be used to obtain the sensitivity of acoustic field in shallow water to certain parameters quickly, which can be use to optimize the model of uncertain environmental parameters.

Modeling and Simulation of Unmanned Underwater Vehicle Parking on Seabed

ZHANG Bin, SONG Bao-wei, ZHU Xin-yao， ZHU Qi-feng

2014, 35(4):  572-576.  doi:10.3969/j.issn.1000-1093.2014.04.021

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According to the movement characteristics of unmanned underwater vehicle(UUV) parking on the seabed, a numerical simulation model is established, which is suitable for large angle of attack movement. A new control method of auxiliary thrusters is put forward. The diving movement of UUV underwater is simulated. The change rules of the angle of attack, sideslip angle, velocity and pitch angle of UUV during diving and parking are analyzed. The simulation results show that the axial velocity of vehicle is gradually decreased to approach zero under the action of fluid resistance. Meanwhile, under the action of the auxiliary thrusters, the vehicles's diving speed is limited within a safe range. This means the UUV's angle of attack gradually increases to about 90 degrees. The pitching angle of vehicle can be controlled in a reasonable range under the interaction of two auxiliary thrusters, too, which means the vehicle can park on the seabed with a proper attitude.