Table of Content

31 July 2017, Volume 38 Issue 7

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Contents

2017, 38(7):  0. 

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Paper

Research on Evaluation Method of Comprehensive Power of High Explosive Warhead and Its Application

WANG Shu-shan， HAN Xu-guang， WANG Xin-ying

2017, 38(7):  1249-1254.  doi:10.3969/j.issn.1000-1093.2017.07.001

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The quantitative evaluation method of comprehensive power of warhead is studied. The principle and method of quantitatively characterizing and evaluating the comprehensive power of warhead by using the damage area are proposed. The calculation model of damage area combined with the target damage model is deduced. The model of power field is validated and amended based on the experimental data. The damage area is calculated, and the comprehensive power is evaluated and analyzed. The results show that the proposed warhead comprehensive power evaluation method can realize the normalized quantitative characterization and evaluation of comprehensive power, and can be used quantitatively to analyze the damage capabilities of different ammunitions against the same target and the same ammunition against different targets. Key

Calculation and Simulation of Leakage of Stepseals in Main Piston of Hydro-pneumatic Springs

GUI Peng， MAO Ming， CHEN Yi-jie， GUO Jian-juan， GAO Xiao-dong， NING Dan

2017, 38(7):  1255-1262.  doi:10.3969/j.issn.1000-1093.2017.07.002

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To study the working stability of Stepseals in main piston of hydro-pneumatic springs in a wide range of temperature, a fluid dynamic seal model is established based on mechanics of materials and hydrodynamics. The theoretical formula of Stepseals leakage is deduced. The effects of temperature, piston velocity, pre-compression ratio and groove dimensions on leakage are analyzed using film pressure data from finite element models. Results show that the increase in piston velocity, the decrease in pre-compression ratio and the increase in groove dimensions lead to more leakage of Stepseals, and higher temperature also causes more leakage in allowable temperature range. Key

Study on Angular Motion Characteristics of Spin-stabilized 2D Trajectory Correction Projectile under the Effect of Fixed Canards

WU Ying-feng， ZHONG Yang-wei， WANG Liang-ming

2017, 38(7):  1263-1272.  doi:10.3969/j.issn.1000-1093.2017.07.003

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An angular motion equation in complex form is established to study the angle of attack and velocity characteristics of spin-stabilized 2D trajectory correction projectile under the effect of fixed canards. The solution of forced motion when the canards spin at a constant rate and the analytical solutions of transient and steady state responses when the canards generate step excitation are both derived. The relationships between the amplitude and phase angle of average deflection angle and the parameters of the fixed canards are presented by deriving the analytical solutions of average velocity deflection angle. The flight stability conditions of spin stabilized 2D trajectory correction projectile under the effect of fixed canards are proposed. The result shows that the projectile should avoid resonance without control, and should limit the maximum increment of angle of attack and the equilibrium angle of attack with control. In addition, the phase angle of average deflection angle has a lead angle ahead of the roll angle of fixed canards. The results provide some references for the studies of flight stability and guidance method of spin-stabilized 2D trajectory correction projectile. Key

Design of Nonlinear Active Disturbance Rejection Acceleration Tracking Controller for Gliding Guided Projectiles

XU Qiu-ping, CHANG Si-jiang, WANG Zhong-yuan

2017, 38(7):  1273-1281.  doi:10.3969/j.issn.1000-1093.2017.07.004

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Considering the problem of acceleration tracking of gliding guided projectiles in the case of the uncertaint internal and external disturbances and the time delay of canard deflection command, a nonlinear active disturbance rejection acceleration tracking controller is designed based on the active disturbance rejection control technique. The controller is simple and easy to implement, and requires small amount of calculation and less parameters to be adjusted. The numerically simulated results show that the proposed active disturbance rejection controller can accurately control the output acceleration to track the acceleration command under the conditions of strong disturbance and delayed response of canard, and has better disturbance-resistant capability. Moreover, the canard deflection control command changes slowly from zero, which effectively reduces the control burden of canard system. In addition, the proposed controller has strong adaptability and robustness to the large-scale perturbation of the aerodynamic coefficients and the lag coefficient of canard. Key

Similarity-based Quantification Method for Anti-jamming Performance of Radio Fuze

LI Ze, YAN Xiao-peng, LI Ping, HAO Xin-hong, WANG Jian-tao

2017, 38(7):  1282-1288.  doi:10.3969/j.issn.1000-1093.2017.07.005

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In order to quantify the anti-jamming performance of radio fuze effectively, a similarity-based quantification method of radio fuze anti-jamming performance is proposed based on the definition of the radio fuze target function. The target function is determined through the analysis of the normal target echo signal. The similarity between this target function and output signals of fuze transceiver correlation channel under different types of information jamming are calculated separately. The smaller the similarity under a certain type of information jamming is, the stronger the anti-jamming performance is, and the weaker it is conversely. The proposed quantification method is validated on a continuous wave Doppler fuze for ground-to-ground projectile. Calculation example indicates that this method is objective, reasonable and operability, and can quantitatively evaluate the fuze anti-jamming performance under different types of jamming. Key

Dynamic Analysis of Projectile-borne Electronic Devices under Impact Loading

XU Xiao, GAO Shi-qiao, NIU Shao-hua, SHEN Li, LIU Hai-peng, OU Zhuo-cheng

2017, 38(7):  1289-1300.  doi:10.3969/j.issn.1000-1093.2017.07.006

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The dynamic responses of projectile-borne electronic devices which are protected by encapsulating material under impact loading are studied through numerical simulation. A LS-DYNA user defined material subroutine is established according to the ZWT nonlinear viscoelastic model which is used for simulating the dynamic response of the encapsulating material in the projectile. The simulations of projectile penetration were performed by adjusting the controllable parameters of ZWT model, such as nonlinear elasticity modulus, low strain rate Maxwell elastic constant, high strain rate Maxwell elastic constant, high strain rate Maxwell relaxation time and material density. Thus the dynamic responses of projectile-borne electronic devices could be obtained from the numerical results. The research results show that the shock absorption and protection effects of the encapsulating materials are better when the values of nonlinear elasticity modulus, low strain rate Maxwell elastic constant, high strain rate Maxwell relaxation time and material density are decreased. Key

A Calculation Model of Velocity of Tandem EFP with Double Layer Liners

WANG Zhe, JIANG Jian-wei, WANG Shu-you, REN Rei-chi

2017, 38(7):  1301-1306.  doi:10.3969/j.issn.1000-1093.2017.07.007

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A velocity calculation model of tandem EFP is proposed by analyzing the motion of elements in double-layer liners. The analysis shows that the difference in EFP axial velocities caused by radial velocity plays an important role in the separation of the tandem EFP. The velocity of EFP formed by outside liner increases with the increase in the curvature of outside liner and the thickness ratio of outside liner to inside liner. On the other hand, the velocity of EFP formed by inside liner decreases with the increase in curvature of outside liner, but increases with the increase in thickness ratio of outside liner to inside liner. The calculated results agree well with experimental data and simulated results by LS-DYNA.Key

Test Method for the Intensity of Lot Quality Level of Projectiles

MIAO Yun-fei, XU Rong, WANG Guo-ping, CHEN Dong-yang, YUN Lai-feng, ZHAN Zhi-bo

2017, 38(7):  1307-1313.  doi:10.3969/j.issn.1000-1093.2017.07.008

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The test method of the intensity of projectiles in batches is an important measure of assessing the quality level of projectiles. In order to seek a new test method, the influences of the structural errors of projectiles on the aerodynamic parameters are analyzed using a fast simulation calculation method based on the technology, combing the computational fluid dynamics (CFD) software and the empirical formula for calculating the aerodynamic parameters of projectiles. The database of aerodynamic parameters of projectiles is established. A simulation software based on the six degree-of-freedom model and the Visual Basic is programmed and validated for calculating the intensity of projectiles in batches. The order of influences of the mass, diameter, mass eccentricity, dynamic unbalance, initial swing angle, initial swing angular velocity and muzzle velocity on the intensity is achieved by analyzing the correlation between random factor and intensity. The process and application of the test method are proposed. The research results show that the proposed test method is available for the assessment of the quality level of projectiles in batches. Key

Calibration Method of Dimension Error of Accelerometer in Single-axial Rotation SINS

WANG Kun-ming, XIE Jian, ZHOU Zhao-fa

2017, 38(7):  1314-1321.  doi:10.3969/j.issn.1000-1093.2017.07.009

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Accelerometer dimension error leads to navigation velocity error under the carrier angular movement in strapdown inertial navigation system (SINS). This is particularly significant in single-axial rotation SINS. In order to improve the navigation accuracy, a new method is presented to realize the calibration of accelerometer dimension errors. A mathematical model of navigation and dimension errors is established by analyzing the mechanism of action of dimension errors in rotary condition. The equivalent errors of accelerometers are introduced into system as extended measurements to improve calibration effect. A calibration route is designed by observability analysis. The dimension error parameters are acquired by filtering. The simulated and experimental results show that the proposed method has higher calibration accuracy and speed compared with the method that uses speed error as observed quantity, and the amount of navigation velocity errors is decreased by about 50%.Key

Analysis and Design of Nonlinear Control System for Aircraft with Flap

ZHOU Di, DONG Jin-lu

2017, 38(7):  1322-1329.  doi:10.3969/j.issn.1000-1093.2017.07.010

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The design and controllability of autopilot of surface symmetric aircraft with flaps as actuators are studied. Compared with traditional aircrafts, such an aircraft lacks rudder in its yaw loop while using flaps as actuators. The motion dynamics model of such an aircraft is derived. The differential geometry method is used to analyze the controllability of the nonlinear control system described by this dynamics. This analysis has proved the controllability of the system. Based on the controllability analysis, a nonlinear optimal controller for the nonlinear coupled control system is designed using state-dependent Riccati equation method. Simulated results demonstrate that the roll angle and longitudinal overload can fast track the commands based on the system of weak controllability, and also testify the feasibility of two-channel control of aircraft. Key

Noise Suppression Method for Superfluid Gyroscope Based on Multiple-turn Circling Structure

ZHENG Rui, ZHAO Wei, FANG Ming-xing, DU You-wu

2017, 38(7):  1330-1335.  doi:10.3969/j.issn.1000-1093.2017.07.011

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Superfluid gyroscope is an interferometric gyroscope based on matter wave. One of the key problems that it faces is that its output noise is very high, so its high accuracy measuring capability cannot be exerted. A mathematic model of the gyroscope noise is established based on the analysis of hydrodynamic inductance for pipeline being circled with multiple-turns. Considering the influence of multiple-turns on superfluid gyroscope, the optimal quantity of turns is researched. A method for noise suppression based on multiple-turns circling is presented. Simulated results show that the noise of superfluid gyroscope is decreased gradually with the increase in multiple-turns. Based on common parameters, the noise of superfluid gyroscope with optimal multiple-turn circling is 1/4 of that without turn. The research results show that the measuring accuracy of superfluid gyroscope is increased remarkably by using the proposed method. Key

Improved Coning and Sculling Error Compensation Algorithms Based on Dual Quaternion for Strapdown Inertial Navigation System

XING Li, XIONG Zhi, LIU Jian-ye, HANG Yi-jun

2017, 38(7):  1336-1347.  doi:10.3969/j.issn.1000-1093.2017.07.012

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In order to improve the precision of the strapdown inertial navigation algorithm based on dual quaternion in the high dynamic environment, a trapezoid digital integral algorithm is applied to compensate the coning and sculling errors, which optimizes the attitude and velocity calculating algorithm and improves the calculating precision of the strapdown inertial navigation algorithm. During a sampling period of gyroscope and accelerometer, the angular rates of gyroscope outputs at previous and current times are both integrated by using the trapezoid digital integral algorithm, and the integral angle increment is used for the coning error compensation. The accelerometer outputs at previous and current times are integated by using the trapezoid digital integral algorithm, and the integral velocity increment and the integral angular increment are used for the sculling error compensation. Through the simulation of multi-group dynamic tracks, it is shown that the improved coning and sculling error compensation algorithms adopting the trapezoid digital integration have higher navigation precision than the traditional rectangular digital integration method when the inputs are angular rate and acceleration. The dynamics of the track is higher, and the performance advantage of the improved algorithm is more obvious. The analysis and comparison of kinematic vehicle experimental results further verify the performance advantage of the proposed improved algorithm.Key

Research on Rapid Missile Erection System Based on Gas-hydraulic Hybrid Drive

FENG Jiang-tao， GAO Qin-he， GUAN Wen-liang， YAO Xiao-guang， LI Liang

2017, 38(7):  1348-1357.  doi:10.3969/j.issn.1000-1093.2017.07.013

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In order to increase the erection speed of missile，an erection method based on gas-hydraulic hybrid drive is proposed. Mathematical models of high pressure gas vessel，piston accumulator，two-stage hydraulic cylinder，pneumatic throttle valve and hydraulic throttle valve are established. Simulation studies of erection driven by accumulator and gas vessel were completed, and the experiment of gas-hydraulic hybrid drive was accomplished. The results demonstrate that two gas-hydraulic hybrid drive schemes can accomplish erection process within thirty seconds. The control method of accumulator drive scheme is simple. However，the pressure inside the accumulator is high, the volume and mass of accumulator are large, and much energy is consumed in heating liquid. The accumulator is suitable for light load system. Gas and liquid are controlled separately in gas vessel drive scheme. A compound control mode is proposed. In the control mode, the gas is throttled to reduce the pressure in the first erection stage, and the liquid is throttled to complete braking load in the second erection stage. The deviation of experiment and simulation meets the system requirement. The displacement deviation is within 18 mm. The pressure deviation is large in the starting-braking period and variation period of cylinder stages. Cushion structure should be designed to ensure rapid and smooth erection. Key

Three-dimensional Numerical Simulation on the Propagation Characteristics of Detonation Wave in Gas-liquid Two-phaseContinuous Rotating Detonation Engine

LI Bao-xing, WENG Chun-sheng

2017, 38(7):  1358-1367.  doi:10.3969/j.issn.1000-1093.2017.07.014

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A gas-liquid two-phase detonation model with chemical reaction is established in cylindrical coordinates based on the conservation element and solution element method, and the three-dimensional numerical simulation of continuously rotating detonation engine is performed to investigate the propagation characteristics of gas-liquid two-phase continuously rotating detonation wave. The flow field structure and stable propagation of detonation wave at initial formation stage were obtained through the calculation. Meanwhile, the variation of flow field in the radial direction and the thrust performance are analyzed, and the propagation characteristics of two-phase detonation wave are revealed. The simulated results show that the flow field structure in the combustion chamber is consistent with the experimental results in Ref.\[4\]. Because of the convergence of outer wall and the divergence of inner wall, the detonation strength increases along the radial direction of the combustion chamber. The self-sustaining rotating propagation of detonation wave is realized. When the injection pressure and injection temperature are 0.2 MPa and 288.15 K, respectively, and the fuel droplet radius is 25 μm, the average thrust of the gasoline and oxygen-enriched air continuously rotating detonation engine is about 880 N, and the propagation frequency of detonation wave is about 4 390 Hz. Key

Measuring Technique of Reflected Blast Wave Pressure Based on Pressure Bar and Photonic Doppler Velocimeter

YANG Jun, LI Yan, ZHANG De-zhi, SHI Guo-kai, ZHANG Min, LIU Wen-xiang, WANG Zhao, XIONG Chen

2017, 38(7):  1368-1374.  doi:10.3969/j.issn.1000-1093.2017.07.015

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A pressure measuring system with combining pressure bar with photonic Doppler velocimeter (PDV) is developed for measuring the reflected blast wave pressure in strong electromagnetic interference environment. The axial velocity of PDV probe is eliminated by mounting it in a sliding structure. The velocity curve of bar’s rear surface has many peaks on it due to the multiple reflection of elastic wave in the bar. The velocity of elastic wave is obtained by fitting the takeoff points of the curve. The system response characteristics, effective measuring time and minimum measured pressure are analyzed. The system has been successfully used to measure the reflected blast wave pressure of spherical explosive. The results show that the response of the proposed system is lower than that of strain measuring system, and the minimum measured pressure of the proposed system is better than that of strain measuring system. The maximum pressure of explosion shock wave of spherical explosive is 463.5 MPa with rising edge of 5 μs. This research illustrates that the measuring technique based on pressure bar and PDV is feasible. Key

Analysis of Vortex Dynamics of Gas-liquid Two-phase Crossflows around a Porous Plate

LIU Tao-tao, WANG Guo-yu, ZHANG Nai-min, HUANG Biao

2017, 38(7):  1375-1384.  doi:10.3969/j.issn.1000-1093.2017.07.016

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In order to investigate the vortex structures of multiphase flows around a porous plate, the flow characteristics of gas-liquid two-phase crossflows were numerically simulated by using the RNG k-ε turbulence modeland the Level Set model. The simulated results are compared with the experimental results. The research results show that the separation point and the horseshoe vortex are formed since the crossflow is blocked by gas jet, which can be observed at the upstream of the jet hole. With the increases in the distance away from the wall, the separation point gradually gets close to the jet exit hole. The crossflow detours the jet and forms two counter-rotating vortices on the lateral edges of jet, and the vortex evolution depends upon the distance away from the wall. The counter-rotating vortex pairs (CVP) are formed in the jet region. The development process of the vortex pairs can be devided into 3 stages: in the near wake-region (i.e., close to the edge of the jet exit hole), the counter-rotating vortex pairs gradually form on the wall, and the increases in the heights of the vortex cores ae well as the distance between the cores lead to the expansion of vortex area. As the flow develops toward downstream, the area of CVP shrinks and even disappears entirely. Further downstream, the CVP appears again on the top of the jet corresponding to the formation of secondary vortex pairs in the near-wall region. Key

Geoacoustic Parameters Inversion of Bayes Matched-field: A Multi-annealing Gibbs Sampling Algorithm

GAO Fei, PAN Chang-ming, SUN Lei

2017, 38(7):  1385-1394.  doi:10.3969/j.issn.1000-1093.2017.07.017

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A multi-annealing Gibbs (multi-AG) sampling algorithm is developed to obtain a fast, accurate inversion result of ocean geoacoustic parameters. The proposed algorithm can deal well with huge computation load and high side lobe in multi-dimensional inversion of Bayes matched-field, and also eliminate the effects from the sampling bounds. The sensitivity of geoacoustic parameters to the matched-field processor is analyzed, which contributes to establish the multi-step inversion and annealing scheme. The Gibbs sampling algorithm is used to invert the highest sensitive parameters, which mean value is necessary to the following inversion steps. The inversion of remain parameters can be operated with annealing Gibbs sampling algorithm step by step. The inversion effects of Metropolis-Hastings, Gibbs, FGS, and multi-AG algorithms are compared through numerical experiment, and the research shows that multi-AG sampling algorithm can be used to obtain the inversion results with the smallest mean square deviation and the highest precision, while costing the least algorithm computation. Key

Passive Sonar Target Motion Analysis Based on Line-spectrum Instantaneous Frequency Estimation

LI Guan-fang, CUI Jie, YUAN Fu-yu

2017, 38(7):  1395-1401.  doi:10.3969/j.issn.1000-1093.2017.07.018

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A new target motion analysis method based on line-spectrum instantaneous frequency estimation for passive sonar feature information is studied. The proposed algorithm combines high-accuracy instantaneous frequency tracking with target motion analysis using the target feature information to extract high-accuracy Doppler frequency and calculate the motion parameters of targets quickly. Computer simulation and sea-trial results show that the method can be used to solve the target motion analysis problem without own ship maneuver. It can reduce the calculation convergence time more than four minutes under the same maneuvering conditions. Key

Numerical Investigations on Blast Resistance of Monolithic Tempered Glass Subjected to Shock Wave

LIU Jun, TIAN Zhou, ZHONG Wei, XIE Shu-hong

2017, 38(7):  1402-1408.  doi:10.3969/j.issn.1000-1093.2017.07.019

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Based on LS-DYNA, the Lagrange method is used to describe the monolithic tempered glass. The linear elastic material model and the erosion algorithm are used to study the monolithic tempered glass. The numerical model is well validated by the field experimental results. The overpressure-impulse curve of blast wave on monolithic tempered glass is obtained through the huge numerical simulation based on the validated model. The empirical formula of damage curve of monolithic tempered glass is also deduced, and the numerical results are compared to the experimental results. The research result shows that the numerical results have good agreement with the experimental results, and the overpressure-impulse curve can provide effective reference for blast resistant design of tempered glass. Key

Control and Mechanical Analysis of Clamping Deformation of Thin-walled Spherical Shell Workpiece during Vacuum Suction

HE Ze-di， TIAN Dong-ning， YANG Jin-chuan， YAO Zhi-hui

2017, 38(7):  1409-1415.  doi:10.3969/j.issn.1000-1093.2017.07.020

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The thin-walled spherical shell workpiece is liable to deform during clamping before machining. A standard aluminum-alloy shell is taken for example. A mathematical model is established based on spherical deformation mechanism and finite element analysis. The theoretical analysis and simulation optimization are carried out for clamping design of semi-spherical shell with vacuum suction. The influences of suction strength and clamping location on deformation in the state of air pressure under average distributed load are analyzed. The result shows that the clamping deformation of shell can be minished effectively by controlling the suction strength and modifying the clamping location so that the machining size accuracy is improved. The main design parameter of vacuum fixture is optimized for the location relationship between shell and fixture. Key

Application of Morphology Filtering Method in the De-noising of Firearms' Shoulder-force Signals

GONG Peng-han， ZHOU Ke-dong， HE Lei， LU Ye

2017, 38(7):  1416-1421.  doi:10.3969/j.issn.1000-1093.2017.07.021

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A novel morphology de-noising method, i.e., adaptive multi-scale morphological analysis algorithm, is proposed based on mathematical morphology for the noise interference introduced in the acquisition process of the firearms' shoulder-force signals. The open-closing and close-opening operations are used to extract the positive and negative impacts from noisy signals. According to the statistical distribution of noises, the results of morphological analysis for different scales are weighted and averaged, and the contradiction between detail preserving and noise filtering is resolved. Blocks signal in Gaussian white noises is studied through simulation, and the de-noising performance of the proposed method is measured by examining the signal noise ratio and mean square error. The results show that the proposed method is able effectively to suppress Gaussian white noises while preserving the features of blocks signal. Key

Reliability Analysis of Multi-state Cold Standby System with Repair Priority

CHEN Tong, DI Peng, YIN Dong-liang

2017, 38(7):  1422-1429.  doi:10.3969/j.issn.1000-1093.2017.07.022

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The maintenance mode of a multi-state cold standby system with two identical units is studied. According to the states of units, the single repair facility provides preventive maintenance and corrective maintenance, and the corrective maintenance has a higher priority. The residence time in the different performance levels of the operational unit, the preventive maintenance time and the corrective maintenance time are assumed to follow continuous Phase-type distribution, instead of exponential distribution or others typical distributions. The stationary distribution is built by using matrix analytic methods; and several performance measures of interest, such as the system stationary availability, operational time, mean time between system halt, failure arrival rate of repair facility and system failure rate, are obtained. Finally, the validity and applicability of the model are verified by numerical applications; and the influences of the preventive maintenance rate and the corrective maintenance rate on the system reliability measures are demonstrated. The study shows that the modeling of system reliability by Phase-type distribution can ensure the better analytical property of model, improve the description ability of model, and make the model have strong universality under the condition of some assumptions. Key

Adaptive Backstepping Tracking Control for Vehicle Semi-active Suspension System with Magnetorheological Damper

PANG Hui, CHEN Jia-nan, LIU Kai

2017, 38(7):  1430-1442.  doi:10.3969/j.issn.1000-1093.2017.07.023

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As for the control optimization and stability caused by the nonlinearities and uncertainties of vehicle semi-active suspension systems with magnetorheological (MR) damper, a nonlinear dynamics model of one-half vehicle suspension system is established with consideration of the security constraints of comprehensive control objectives for the controlled vehicle semi-active suspension. The tracking error between controlled plant and reference trajectory is constructed, and the corresponding control input functions of controlled plant are designed based on backstepping control method and Lyapunov stability theory. The adaptive control law based on projection operator is investigated, and further a kind of adaptive backstepping controller is developed, which can deal with constraint problem of vehicle suspension system. In order to validate the feasibility and effectiveness of the proposed control algorithm, a control simulation framework of vehicle vibration control system is established based on Matlab/Simulink software, and the proposed adaptive backstepping control algorithm is verified on this control simulation framework under the conditions of random and bump roads. The results show that the proposed control approach has better global asymptotic stability for control stability problem of vehicle semi-active suspension systems, and it can not only obviously improve the performance of ride comfort, but also ensure the various required safety performances of vehicle semi-active suspension.Key

Comprehensive Review

Research on Relationship among FirepowerMobilityProtection Performance and General Dimensions of Main Battle Tank

MAO Ming， MA Shi-ben， HUANG Shi-zhe

2017, 38(7):  1443-1450.  doi:10.3969/j.issn.1000-1093.2017.07.024

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The core task of tank overall design is to get the best overall performance, minimum size and minimum weight without increasing the technical difficulty of parts. Relationship among the three main performances and the general dimensions of main battle tank (MBT) is analyzed by decomposing the specifications of firepower, mobility and protection. An optimization model is established for MBT's firepower, mobility and protection performance based on physical dimension. Restraining the height of tank is the key to coordinate the firepower, mobility and protection performance of tank. Approaches to restrain the height, width and length of tank are proposed.Key

Research Notes

Design and Performance Analysis of a Metal Gasbag for Airborne Dispenser

ZHANG Cheng, WANG Hao, JIANG Kun, LIN Chang-jin, LI Bo

2017, 38(7):  1451-1456.  doi:10.3969/j.issn.1000-1093.2017.07.025

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Currently, the gasbag used in the external combustion type dispersion system in airborne dispenser is made of rubber/Kevlar. In view of its lower bearing strength and poorer oxidation resistance, a metal (304 stainless steel) gasbag is designed. The feasibility of the metal gasbag used in airborne dispenser is verified from two aspects of bearing strength and dispersing performance. A good performance of the metal gasbag is revealed through the static pressure bearing test. Its bearing strength is about 50% higher than that of rubber/Kevlar metal gasbag, while its weight is 45% lighter than that of rubber/Kevlar metal gasbag. And the dispersing experimental results show that the deformation of metal gasbag is symmetrical, which has little effect on bomblets' posture. Key