Table of Content

31 May 2016, Volume 37 Issue 5

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Paper

Research on Bionic Active Sonar Covert Detection Technology Based on Dolphin Whistle Signal

YIN Jing-wei， LIU Qiang， CHEN Yang， ZHU Guang-ping， SHENG Xue-li

2016, 37(5):  769-777.  doi:10.3969/j.issn.1000-1093.2016.05.001

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To solve the poor covert of active sonar detection system, a bionic active sonar covert detection technology is proposed on the basis of dolphin whistle signals. At the transmitting terminal，the LFM signals are hidden in dolphin whistles to design an covert active sonar bionic detection signal. This signal is similar to dolphin whistles in the ocean，so we can use the biological environmental noise in the ocean to achieve active sonar covert detection. At the receiving terminal, the adaptive correlator is used as an active sonar processor. The adaptive correlator has a strong ability to match the marine environment. It can automatically match the marine channels, and reduce the multipath spreading loss effectively, thus getting higher signal-to-noise ratio processing gain than the matching filter. The adaptive correlator contributes to long-range detection. The simulation and the sea experiment proof the covertness and effectiveness of the proposed bionic active sonar covert detection technology based on dolphin whistle signals.

Research and Development on a 13MJ Pulsed Power Supply for Electromagnetic Launcher

ZHANG Ya-zhou, LI Zhen-xiao, JIN Yong, LUO Hong-e, TIAN Hui, LI Bao-ming

2016, 37(5):  778-784.  doi:10.3969/j.issn.1000-1093.2016.05.002

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With the development of the electromagnetic launch technology, the requirement of the pulse power supply (PPS) is increasing, of which the output current is required to have MA level amplitude, pulse width of several milliseconds, rapid rising and flat-topped wave. A 13 MJ capacitor-based PPS of which rated operational voltage is 10 kV was developed. The PPS is of multi-module parallel structure and composes of 13 1 MJ pulse forming subsystems. Each subsystem has 20 50 kJ pulse power modules. The maximum short-circuit discharge current of every module is about 65 kA. Charging system adopts high voltage capacitor charging power supply based on series resonance converter. Control system has two-level control structure which uses a synchronized code signal to control the sequential discharging. Measurement system based on PXI system and master-slave network structure can satisfy the requirements of distributed measurement. The performance of the system is test under artificial loading, and the experimental research on electromagnetic launching device is carried out. The experimental results show that 13 MJ PPS has high reliability and meets the requirements of EML experiment, and its output current waveform is flexible and adjustable.

Research on Aerodynamic Characteristics of Terminal Sensitive Projectile with S-C Shaped Elastic Wings

LYU Sheng-tao, LIU Rong-zhong, GUO Rui, MA Xiao-dong

2016, 37(5):  785-790.  doi:10.3969/j.issn.1000-1093.2016.05.003

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Two-way fluid-structure interaction method is used to study the aeroelasticity of non-parachute terminal sensitive projectile (TSP). The wing deflection law and aerodynamic characteristics of TSP system are studied, and the effect of angle of attack on the aerodynamic parameters and wings’ deflection is analyzed as well. The results show that the drag coefficient and torque coefficient increase first and then decrease with the increase in the angle of attack, and the lift coefficient monotonically increases with the increase in the angle of attack. The free flight tests show that the simulation results of TSP with elastic wings are closer to the experimental results than the simulation results of TSP with rigid wings.

Evaluation of Anti-jamming Performance of Radio Fuze Based on Fuzzy Comprehensive Judgment

LI Yue-qin, YAN Xiao-peng, HANG He-ping, SHAO Ming-gang

2016, 37(5):  791-797.  doi:10.3969/j.issn.1000-1093.2016.05.004

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How to accurately evaluate the anti-jamming ability of radio fuze objectively and quantitatively is an important issue in the field of radio fuze. The factors which affect the anti-jamming performance of radio fuze are analyzed according to the characteristics of radio fuze. Eight evaluation indexes which describe the different aspects of radio fuze anti-jamming performance are set up based on power, time, efficiency and jamming signal. An evaluation index architecture is set up. A two-stage fuzzy comprehensive evaluation model for anti-jamming performance evaluation of radio fuze is established based on the evaluation index architecture. The factor set, factor weight set, membership function and other key factors of the model are analyzed and determined. An example is used to illustrate the feasibility of the proposed method. It can provide a new approach to solve the difficult problem of anti-jamming performance evaluation of radio fuze.

Numerical Investigation on Effect of Solid Fuel Ramjet Geometry on Solid Fuel Regression Rate

GONG Lun-kun, CHEN Xiong, ZHOU Chang-sheng, LI Ying-kun, ZHU Min

2016, 37(5):  798-807.  doi:10.3969/j.issn.1000-1093.2016.05.005

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In order to investigate the influence of solid fuel ramjet geometry on regression rate of solid fuel, a 2D axisymmetric turbulent flow and combustion program is developed. The Navier-Stokes governing equations are solved by using MUSCL reconstruction method and AUSMPW+ flux splitting technique, k-w SST turbulence model, 7 species/3 reaction kinetics finite rate model and second-order moment turbulence-chemistry model. The effects of inlet diameter, grain diameter, nozzle throat diameter and geometrical similarity on regression rate are studied. The simulation results show that the inlet diameter and grain diameter affect the regression rate mostly, while geometrical similarity and nozzle throat diameter have less effect on it. The variation of regression rate is caused by the variation of turbulent viscosity and flame position directly; port-to-inlet-diameter ratio has the most important influence on regression rate, and the regression rate has a linear relation with port-inlet-diameter ratio.

Numerical Simulation of the Trajectory of Travelling Projectile Penetrating into Pre-drilled Target

DENG Jia-jie, ZHANG Xian-feng, CHEN Dong-dong, GUO Lei, HE Yong

2016, 37(5):  808-816.  doi:10.3969/j.issn.1000-1093.2016.05.006

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Based on projectile-target separation method，numerical simulation method of 3D deformable travelling projectile penetrating into a pre-drilled target is proposed by using Forrestal semi-empirical resistance via user subroutine of ABAQUS. The reliability of user subroutine and simulation model is verified. The influences of offsetting, incidence angle and angle of attack on trajectory are analyzed. The results show that any influence factor affects the trajectory and penetration depth. The pre-drilled hole on target has significant oriented effect for the penetration of travelling projectile. Under the combined influence of offsetting, incidence angle and angle of attack, the pre-drilled hole on target has limitation in oriented function and a ricochet may occur under the condition of extreme impact.

Preparation and Hydro-reactivity of Ball-milled Aluminum-based Hydro-reactive Metal Materials

WANG Chuan-hua, GUO Xiao-yan, ZOU Mei-shuai, YANG Rong-jie

2016, 37(5):  817-822.  doi:10.3969/j.issn.1000-1093.2016.05.007

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To enhance the efficiency and rate of aluminum/seawater reaction, a high-energy milling method was used to prepare Al-based hydro-reactive materials via a multiple variable speed cycle process. Scanning electron microscope, thermogravimetry and specific surface test are used to characterize the microstructure and oxidation characteristics of the materials. The amount of hydrogen produced by reaction between Al-based materials and seawater is recorded in real-time using an metal/water reaction device. The hydro-reactivity of Al-based hydro-reactive metal materials is studied. The research results show that the high-energy milling can significantly enhance the reaction activity of Al-based materials and seawater. The reaction efficiency of aluminum powder after ball milling is two times of its original reaction efficiency. Addition of bismuth in the process of ball milling can further enhance the reaction activity of Al-based hydro-reactive materials. The total yield of reaction can reach 71.2%. The reaction rate of hydrogen generation in the fast stage is 210.7 mL/(min·g). The prepared Al-based hydro-reactive metal materials are very promising for hydrogen production and high energy hydro-reactive metal fuel propellants.

Preliminary Research on Formation Mechanisms of Edge Spalling in PBX Milling

XIE Feng-ying, ZHANG Qiu, LIU Wei, HUANG Jiao-hu, TANG Shi-long

2016, 37(5):  823-828.  doi:10.3969/j.issn.1000-1093.2016.05.008

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In view of controlling and optimizing of edge quality of polymer bounded explosive (PBX), the macroscopic and microscopic characteristics as well as the formation mechanisms of edge spalling formed by milling a HMX-based PBX are studied using microscopic photography and scanning electron microscope (SEM). Research results show that the edge spalling is formed by crack expanding toward inside workpiece at a large cutting depth, while the edge integrity is better when the cutting depth is not larger than 0.1 mm. Intact particles are few in the region of edge spalling due to transcrystalline fracture and twin crystal separation of damaged explosive particles, and the micro-damages, such as crack along crystalline boundary, polymer cracking and void, are mainly due to tensile stress and shear stress when a crack expands toward free-surface.

A Theoretical Study of Forced Motion for Dual-spin-stabilized Projectiles with Canards

CHANG Si-jiang, WANG Zhong-yuan, LIU Tie-zheng

2016, 37(5):  829-839.  doi:10.3969/j.issn.1000-1093.2016.05.009

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To provide a deep understanding of dynamic properties of dual-spin-stabilized projectile with canards, the forced motion induced by periodic disturbance of canards installed on the forward body is studied. A simplified seven degree-of-freedom rigid body dynamic model for this projectile is established. A linearized model of pitching and yawing motion is deduced by using the equations of transverse motion with the assumption of small angle of attack. The corresponding special solution of the forced term driven by periodic disturbance of canards is also obtained. The resonance conditions and influencing factors, such as canard deflection angle, canard placement, and ratio of axial moment of inertia, of this forced motion are discussed by analyzing the fast and slow arm turning rates of angle of attack and the forced amplitude numerically. The spin lock-in for the forward body is preliminarily analyzed under the condition of large angle of attack, and both the expressions of stable orientation angle and critical angle of attack for spin lock-in are proposed.

Recursive Sliding Mode Control for Hypersonic Vehicle Based on Nonlinear Disturbance Observer

CHEN Chen， MA Guang-fu， SUN Yan-chao， LI Chuan-jiang

2016, 37(5):  840-850.  doi:10.3969/j.issn.1000-1093.2016.05.010

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A recursive terminal sliding-mode controller (RTSMC) with nonlinear disturbance observer (NDO) is proposed for the longitudinal dynamics model of generic hypersonic flight vehicle in the presence of external disturbances, unknown dead-zone nonlinearity and system uncertainties. RTSMC employs a recursive procedure which contains a set of terminal manifolds to make system tracking error converge to zero in a finite time. The dead-zone nonlinearity of the actuator is simplified as unknown input disturbance. For the compound disturbance generated by the external disturbances and system uncertainties, a novel NDO is developed, which can reduce the conservatism of RTSMC and eliminate the influence of dead-zone nonlinearity on system. The stability of the proposed control strategy is proved by means of Lyapunov theory. Several numerical examples are provided to compare and verify the proposed method.

Waveform Design of MIMO Radar Based on Transmitting Pattern Synthesis

HUANG Zhong-rui, ZHOU Qing-song, ZHANG Jian-yun

2016, 37(5):  851-858.  doi:10.3969/j.issn.1000-1093.2016.05.011

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A new method about the transmitting pattern synthesis of multiple-input and multiple-output (MIMO) radar is proposed in order to maintain the uniform elemental power constraint and low peak-to-average power ratio (PAPR) of the transmitted waveform. A basis matrix set is constructed, which can convert the solution of covariance matrix into the optimization of the coefficients of basis matrix set. It can not only reduce the computing complexity of the original optimal model but also can be solved effectively by the primal-dual interior point method. The identity matrix is included in the basis matrix set, which can satisfy the uniform elemental power constraint. And the scale factor of the desired beam is set as the unite variance so as to reduce the matching error of the MIMO radar pattern. The matrix decomposition and alternate optimal method are used to design the transmitted waveform which can effectively descend the PAPR based on the convex optimization. The simulation results are presented to verify the efficiency of the proposed method.

Mechanism Investigation on Transient Process of Oscillatory Suppression by Lorentz Force

ZHANG Hui, FAN Bao-chun, LIU Meng-ke

2016, 37(5):  859-865.  doi:10.3969/j.issn.1000-1093.2016.05.012

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The flow of weak electrolyte solution can be controlled by Lorentz force generated by the suitably-chosen electromagnetic field. Lorentz force can be used to suppress the vortex shedding and eliminate the vortex street in the flow around a bluff body for the suppression of vortex-induced vibration (VIV). To investigate the evolutions of VIV suppression by Lorentz force, an exponential polar coordinate system is set up on a moving cylinder, and the stream function-vorticity equations considering the Lorentz force and its initial/boundary conditions, an expression of hydrodynamic force on the cylinder surface as well as the cylinder response equations are then derived. The whole evolutions of cylinder from resting and then undergoing development and suppression due to Lorentz force are calculated and discussed. The development process of cylinder vibration, vortexes shedding and energy transfer, and the deformation and shift of drag-lift phase diagram are described. The results show that the reason of cylinder oscillation is the periodic vibration of lift which is induced by wake vortexes due to flow separation. The fluid flow near boundary layer is changed and the flow separation is suppressed by the Lorentz force on the surface of cylinder so that the flow field tends to symmetry and the periodic vibration of lift is suppressed. The cylinder oscillation can be suppressed and even eliminated for a large value of Lorentz force.

Research on Calculating Method of Strong Light Interference High Temperature Radiation Energy Sparse System

SHI Yao-tao, CHEN Shou-qian, WAN Zi-nan, LI Tao,

2016, 37(5):  866-871.  doi:10.3969/j.issn.1000-1093.2016.05.013

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Light interference radiation energy is a key parameter to design a light interference source, and the interference effect depends on the size of radiation energy. Under the assumption of a high-heat combustion product being sparse, a method to calculate strong light interference radiation energy is proposed. The sparse system is layered in space. Each metal oxide particle is regarded as a grey body radiation source, the radiation energy from particles and the exchanged heat between different layers are calculated, and the emitted light from the surface of system is counted. Al and KClO₄ are used as fuel to verify the proposed calculating method. The results show that the proposed calculating method can be used to calculate the radiation energy from strong light interference source and infrared decoy bomb.

Reaction Behaviors of Al/PTFE Materials Enhanced by W Particles

REN Hui-lan, LI Wei, LIU Xiao-jun, CHEN Zhi-you

2016, 37(5):  872-878.  doi:10.3969/j.issn.1000-1093.2016.05.014

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The reaction behaviors of four kinds of Al/W/PTFE materials prepared by compression molding and sintering are studied by split Hopkinson pressure bar (SHPB) and high speed photography. The results show that yield strength and failure strength are improved with the increase in mass fraction of W. The stress-strain curve of the material in quasi-static compression tests can be divided into elastic stage, hardening stage and failure stage. The impact reaction process of Al/W/PTFE material includes deformation, failure and combustion reaction. The calculated results indicate that the strain-rate reaction threshold and unit energy threshold of material increase with the increase in content of W.

Modeling and Experiment of Contact Arc Length in SiC Monocrystal Cutting

WANG Jia-bin， LI Shu-juan， LIANG Lie， TANG Ao-fei， MA Lei

2016, 37(5):  879-887.  doi:10.3969/j.issn.1000-1093.2016.05.015

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Silicon carbide (SiC) is widely used in high-power devices and IC industry due to its good physical and mechanical properties. However, it is difficult to be processed (cutting, lapping and polishing) because of its high hardness and brittle. In the fixed diamond abrasive wire sawing of SiC monocrystal, the cutting force changes dynamically due to various factors. The effect of direct factor on cutting force is contact arc length between wire saw and workpiece. The moving processes of wire saw and worpiece are analyzed for the generation of contact arc length. A model of wire sawing process with reciprocating movement is established. The simulated and experimental errors are also discussed, and the cutting depth of model is determined based on the single abrasive scratch experiment. The simulation and experimental results show that the proposed model can predict the contact arc length in terms of different processing parameters.

Research on Milling of Ni-based Alloy Honeycomb Material at Ice Fixation and Cryogenic Temperatures

WANG Feng-biao, HOU Bo， YUAN Kai, WU Di, ZHOU Lian-jie

2016, 37(5):  888-894.  doi:10.3969/j.issn.1000-1093.2016.05.016

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Considering the burr and collapse edge of machined low stiffness and thin-walled nickel-based alloy honeycomb material using in aerospace, the fixation and processing method should be improved. The material is treated by ice fixation method. CNC milling machine is used for the cryogenic processing. The honeycomb milling properties and the causes of machining defects are analyzed. Low-temperature milling mechanism of ice fixation is established. Results show that, compared to the traditional processing way, the quality of surfaces milled at ice fixation is significantly improved, and the processing defects are effectively suppressed. The cutting depth has greater influence on surface quality than spindle speed. The proposed method can be used to improve the strength of honeycomb. The effects of cutting parameters on milling force are analyzed: the cutting depth has the most significant effect on milling force, followed by spindle speed and feed speed.

Simulation Investigation on Crack Initiation and Propagation in Ultrasonic Assisted Grinding of Ceramics Material

LIANG Zhi-qiang， TIAN Meng， WANG Qiu-yan， WANG Xi-bin，

2016, 37(5):  895-902.  doi:10.3969/j.issn.1000-1093.2016.05.017

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Based on smoothed particle hydrodynamics (SPH) method, the initiation and propagation of the cracks in the process of single abrasive impacting a workpiece are simulated during ultrasonic assisted grinding of ceramics material, and the removal characteristics and surface layer damage of material under different ultrasonic impact speeds are revealed. The simulation results show that the lateral and radial cracks occur initially when single abrasive is pressed into the workpiece at a certain depth under different impact speeds. With the increase in impact speed, the fractures in action area are significantly reduced, and the critical pressed depth of abrasive is decreased when a lateral crack is generated, while the critical pressed depth of abrasive is unchanged obviously when a radial crack is generated. By observing the propagation of the two kinds of crack with the increase in the pressed depth, it can be found that the propagation velocity and geometric size of lateral crack decrease, while the radial crack has no obvious change. The results show that the ductile region removal of ceramics material is enhanced with the increase in impact speed, while the damage of surface layer is not enlarged, and the surface quality is improved.

Research on Failure-rate-based Tool Replacing Strategy

WANG Xin-gang， LYU Chun-mei， ZHAO Yu-qian， CHEN Xiao-ming

2016, 37(5):  903-908.  doi:10.3969/j.issn.1000-1093.2016.05.018

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The failure rate of cutting tools is taken as the research object, which has an effect on the reliability of whole machining process. A mathematical model for the dynamic reliability of machining process is established based on the reliability analysis method and the maximum likelihood estimation, in which the cutting parameters are determined as random variables, and the failure rate formula of each tool is also derived. On this basis, a simple method is presented for determining the tool replacing time and the corresponding job according to their respective failure rate. The research results show that, when the reliability of whole machining process system is below a certain threshold value, the proposed model can be used to define which and when cutting tool must be replaced in time in the certain working procedure, of which the failure rate is the biggest. This allows us to make the most of each tool and reduce the number of tool replacing so as to decrease the cost. Meanwhile, a simple algorithm is proposed to keep high process reliability by ensuring that tools are replaced before their failures.

Electromagnetic Shielding of Overload Experiment Device for Fuze Based on Electromagnetic Driving Technology

WANG Wen-Hao， BI Shi-hua， XIANG Hong-jun

2016, 37(5):  909-915.  doi:10.3969/j.issn.1000-1093.2016.05.019

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The electromagnetic driving technology can be used to simulate the high overload environment in the process of fuze launching, but it may stimulate magnetic field, which has negative effects on the test fuze. Thus, it is necessary to take the electromagnetic shielding measures for test fuze. The structure and working principle of the overload experiment device for fuze based on electromagnetic driving is introduced, and then the electromagnetic shielding cover for test fuze is designed. A simulation model is established for fuze overload experiment device based on electromagnetic driving, and then the intensity of magnetic field in fuze is analyzed at three occasions: without shielding cover, shielding cover made by aluminum, shielding cover made by aluminum and steel. The results show that the maximum magnetic field in fuze is 1.54 T, 0.17 T and 4.2×10^-5 T at the occasions mentioned above, respectively, which means that the shielding cover made by aluminum and steel has better shielding performance.

A Model of Calculating Spare Parts Demand Volume by Considering Preventive Maintenance

HU Qi-wei， JIA Xi-sheng， ZHAO Jian-min

2016, 37(5):  916-922.  doi:10.3969/j.issn.1000-1093.2016.05.020

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Spare parts are the material basis of equipment operation and maintenance, and spare parts procurement usually takes a large share of equipment lifecycle cost. The traditional methods of calculating the spare parts demand volume only consider the requirements of corrective maintenance, and cannot be used to calculate the spare parts demand volume by considering preventive maintenance. A model of calculating the spare parts demand volume based on age replacement policy is proposed. A discrete algorithm for the model is presented. An example analysis is carried out to verify the applicability and effectiveness of the proposed model. The proposed model is compared with traditional calculation model. The research results show that the proposed model can be used to improve the accuracy of calculating the spare parts demand volume. It can be also used to calculate the spare parts demand volume for any long planning horizon and analyze the spare parts cost in equipment lifecycle process.

A Novel Fault Diagnosis Algorithm of Testability D matrix Based on Quasi Information Entropy

TIAN Heng, DUAN Fu-hai, JIANG Xiu-hong, SANG Yong

2016, 37(5):  923-928.  doi:10.3969/j.issn.1000-1093.2016.05.021

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Testability D matrix that is the core of testability analysis includes all information of faults and test of system. Exact manipulation of D matrix could greatly increase the efficiency of fault diagnosis. A local information entropy formula is given, and a new algorithm, called quasi information entropy, is proposed based on the analysis of the D matrix traditional processing methods. The proposed algorithm combines the characteristics of traditional global and local optimization algorithms, so it has the ability of global and local optimization and the same applicability as the traditional deposing methods. The availability of the fault diagnosis algorithm is verified by two examples, which show that the proposed algorithm of manipulating the testability D matrix has prominent advantages, such as reduced diagnostic procedure, shorted diagnostic time and reduced cost.

A New On-line Filtering Method Based on Improved EMD Algorithm

HUANG Jing, LI Chang-chun, YAN Hao, YANG Xue-song, LI Jing

2016, 37(5):  929-935.  doi:10.3969/j.issn.1000-1093.2016.05.022

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The normal digital filter cannot achieve a good filtering result since the characteristics of electro-hydraulic servo system makes the frequency of noise signal close to the frequency of useful signal. The empirical mode decomposition algorithm is improved to remove these noise signals exactly from data. The definition of extreme points is extended, a judging formula of envelope interpolation is given, and a new decomposition end judgment condition is added. The improved EMD method has better effect and decomposition efficiency on the signal from electro hydraulic servo system. It can meet the real-time filtering requirements. This new filter based on improved EMD method is used in electro-hydraulic servo system, and the normal digital filter is compared with the original EMD method. The test results show that this new filter has a good application effect and less consuming time.

Research Notes

Modeling and Design of Trajectory of Multi-MAVs for Coveraging Multi-targets in Non-cooperative Manner

DU Ye-hong, YU Hao, ZHANG Jun, LI Jie, XU Xing-jian

2016, 37(5):  936-944.  doi:10.3969/j.issn.1000-1093.2016.05.023

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To improve the adaptabilities of reconnaissance and attack of multi-MAVs, the trajectory of multi-MAVs for coveraging the multi-targets in non-cooperative manner is modeled. The take-off point coordinates of MAVs are simulated using cloud model, and the taking-off direction is simulated by Monte Carlo method. The target zone model, MAV detection model, take-off point model, flight direction model and trajectory model are established. To improve the efficiency of the optimization design, the minimum number of simulations is determined based on the stability analysis of the expected coverage. The multi-target problem is solved by MOGA, and the regional coverage trajectory of multi-MAVs in non-cooperative manner is determined. The problems that can be solved by the schemes are analyzed according to the ratio of detecting radius to target zone radius. The designed trajectories reduce difficulty in control, and take coverage, the number of MAVs and flying range of MAV into account.

An Emitter Threat Evaluation Method Based on Rough Set and TOPSIS

YANG Yuan-zhi， WANG Hong-wei， SUO Zhong-ying， CHEN You， FAN Xiang-yu

2016, 37(5):  945-952.  doi:10.3969/j.issn.1000-1093.2016.05.024

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The threat evaluation of emitters is regarded as a multi-attribute decision-making problem. A complete model for computing the threat metric values is established to realize the quantitative representation of the emitter threat degree, which is based on the rough set (RS) and technique for order preference by similarity to solution (TOPSIS), thus solving the problem of measuring emitter threat degree in real-time and quantitation without priori information. For the subjective limitation of structuring the standardized decision matrix in the process of determining the weights in TOPSIS, the RS theory is applied to compute the significance of evaluation indicators to obtain the weight coefficient, which is confirmed by calculating the rough dependability among evaluation indicators and evaluation results, avoiding the influence of subjective weight. The simulation result is consistent with the original data, which could prove the effectiveness of the proposed algorithm. In addition, the quantifiable threat function would contribute to assess and rank the threats more accurately. The results show that the proposed method has some practical value in engineering and could be used to evaluate the emitter threats.

Research on Flux-weakening Control Strategy with Overmodulation of PMSM Control System

TU Qun-zhang， LIN Jia-kun， ZENG Fan-qi， ZOU Shi-chao， LU Ying

2016, 37(5):  953-960.  doi:10.3969/j.issn.1000-1093.2016.05.025

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To broaden the speed range of motor control system and meet the requirements of system for strong torque response capability and the large torque output characteristics, an overmodulation method is applied to PMSM control system based on the flux-weakening control strategy. The demand of the motor response is different in the complex and changeable operating condition. Simulations and experiments are carried out. The simulations and experimental results are analyzed. Compared to the flux-weakening control strategy without overmodulation, it is found that the introduction of overmodulation method can make the system take full advantage of DC bus voltage. The torque response and large torque output are improved, and the speed response time is reduced by using the proposed method. At the same time, the working efficiency of motor is in accordance with the application requirements.