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2019, 39(6): .

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2019, 39(6): .

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Applied Research on Damage Effectiveness Evaluation of Guided Explosive Bomb

ZHAO Xiao-xu, HAN Xu-guang, WU Hao, XU Yu-xin

2019, 39(6): 551-557. doi:10.15918/j.tbit1001-0645.2019.06.001

Abstract(979) PDF(473)

Abstract:
Based on the equivalent structure of real targets,the application of damage effectiveness evaluation of guided explosive bombs was studied. For infrared imaging and GPS guidance modes, the end ballistic characters were analyzed, and for designated power warhead, the relationship between the damage effectiveness and fuze explosion height and guidance precision was studied. From the simulation results, using the infrared image guidance mode, when the explosion height was increased, the explosion point was farther away from aiming point, it was harder for the fragments to hit the target;using GPS guidance mode, with the bomb embedded system, the explosion point could be adjusted to be just above the target, so the fragments could hit the target below and get better damage effect; so the damage effectiveness was not only related to warhead and fuze, but also related to guidance mode.From simulation analysis, the guidance mode has little effect on the dynamic power field of the warhead, so in the process of warhead research, in order to get the best warhead structure and explosion height, the guidancemode can be ignored and damage dimensionalities alone can be used to evaluate the warhead damage effectiveness.

Study on the Parameter Sensitivity of RHT Concrete Model by Orthogonal Test Technique

LIU Dian-zhu, LIU Na, GAO Tian-ci, GE Yu-guang, WANG Yu-tao, GAO Quan-chen

2019, 39(6): 558-564. doi:10.15918/j.tbit1001-0645.2019.06.002

Abstract(926) PDF(422)

Abstract:
Based on theoretical analysis, analytical parametersA, N, B, M, B_Q,f_s/f_c,T_ten,D₁andE_f,minwere analyzed by orthogonal test to assess the sensitivity of parameters in the RHT concrete model. The Autodyn program was used to simulate the penetration depth of the projectile with different parameters and different values. The sensitivity of the parameters was quantitatively analyzed, and the nine parameters were ranked as:B>E_f,min>T_ten>f_s/f_c>N>M>D₁>B_Q>A. The comparative analysis of damage nephogram and penetration depth derived from three typical numerical tests indicate that the parametersB, E_f,minandT_tenhave a significant influence on the numerical simulation results, which should be accurately determined by reliable technical means.

Experimental Study on Explosion Shock Wave Damage Effect of Tempered Glass with PVB Interlayer

ZHONG Wei, SHOU Lie-feng, WANG Zhong-qi, TIAN Zhou, LIU Jun, HE Zeng, LI Wei-chang

2019, 39(6): 565-570. doi:10.15918/j.tbit1001-0645.2019.06.003

Abstract(822) PDF(845)

Abstract:
For the purpose of getting the shock wave overpressure threshold and impulse threshold of the tempered glass with a PVB (polyvinyl butyral) interlayer, some experiments of tempered glass were carried out. Several experiments were finished on the tempered glass with the thickness of 6 mm+1.52 mmPVB+6 mm. In each experiment, the blast shock wave parameter tests were performed and the experimental overpressure-time histories were recorded. By observing and recording the experimental phenomena, the experiment near the critical value of the damage threshold was determined. Therefore, combining the test results of the blast shock wave with the experimental design and experimental conditions, the shock wave overpressure threshold and impulse threshold of 6 mm+1.52 mmPVB+6 mm thickness tempered glass were obtained. Experimental results show that the overpressure threshold of the 6 mm+1.52 mm PVB+ 6 mm thickness tempered glass is between 41 and 55 kPa, and the impulse threshold is between 180 and 299 kP a·ms.

Study on the Strain Rate Effect of Cement Mortar

YANG Zheng-wen, LI Jin-zhu, HUANG Feng-lei

2019, 39(6): 571-577. doi:10.15918/j.tbit1001-0645.2019.06.004

Abstract(956) PDF(446)

Abstract:
To investigate the influence of strain rate on stress-strain relation and dynamic strength, uniaxial compression strength, elastic modulus and poisson's ratio of mortar were measured by quasi-static experiments.The one-dimensional stress experiment was carried out by using split Hopkinson pressure bar(SHPB), dynamic damage and stress-strain relation of the cement mortar with various length-diameter ratios at different loading rates were obtained,and the relation of DIF(dynamic strength increase factor) and strain rate was studied.The results show that dynamic compressive strength increases significantly with increasing strain rate.The DIF with thin specimens are smaller than those with thick specimens when diameters are the same, but length-diameter ratios are different.By comparing the recovered specimens, as the strain rate increases, the damage of the specimen increases, and the fragment size decreases.It is found that the failure energy increases with the growing of the strain rate.

Study on the Law of Penetration of Reinforced Concrete by Warhead with Forecabin

ZHAO Hong-wei, HE Yuan-ji, CHENG Li-rong, HAN Xiu-feng

2019, 39(6): 578-582. doi:10.15918/j.tbit1001-0645.2019.06.005

Abstract(1029) PDF(365)

Abstract:
In order to analyze the influence of target parameters on a certain type forecabin warhead penetration ability under critical penetrating velocity conditions, nonlinear finite element analysis software LS-DYNA and the reinforced solid element modeling method were adopted to set up the forecabin warhead penetration target 3D simulation model. The influence of the change of parameters, such as target angle and attack angle, on the penetrating ability of warhead at an extreme speed was obtained. The calculation results agreed well with the experimental results. The research results show that target angle has a significant impact on warhead penetration capability, and a certain range of negative attack angle is conducive to the penetration of warhead under the condition of an extreme penetration speed.

Indentation Mechanical Model and Deformation Coordination Mechanism of Composite Spherical Array Sandwich Structure

ZHOU Xiao-song, ZHANG Yan-bing, MEI Zhi-yuan

2019, 39(6): 583-588,596. doi:10.15918/j.tbit1001-0645.2019.06.006

Abstract(951) PDF(474)

Abstract:
In order to reveal the deformation coordination mechanism of the composite spherical array sandwich structure from the view of structural mechanics, the indentation mechanical model of the typical local plate lattice for the structure was established under a concentrated load.For a rectangular plate with elastic support of four points and equal moment constraints of four edges, the elastic bending deflection under a concentrated load was treated as the superposition of deflections under two cases, a concentrated load with elastic support of four points and free boundary of four edge sadded to equal moments along four edges. The former was further decomposed into the deflection of rigid plate with elastic support of four points and elastic plate with rigid support of four points and free boundary of four edges under the same concentrated load.The latter was also further decomposed into the deflection of the elastic plate with equal moments along two opposite edges and along the other two opposite edges with the same simply supported boundary. The analytical solutions of three plates with different spans and concentrated force positions were compared with finite element method results, demonstrating the accuracy of the proposed solution. Results show that the mechanical model effectively can effectively reveal the bending deformation mechanism and guide the parametric design of the composite spherical array sandwich structure.

Manipulator Double Close Loop Autonomous Localization Control of High-Voltage Cable Mobile Operation Robot

JIANG Wei, ZHOU Zhi-yuan, CHEN Wei, YU Lian-qing, LI Hong-jun, WU Gong-Ping

2019, 39(6): 589-596. doi:10.15918/j.tbit1001-0645.2019.06.007

Abstract(994) PDF(523)

Abstract:
In order to improve the automation degree and operation efficiency of operation process of the mobile operation robot for high voltage transmission line,on the premise of operation space positioning by the electromagnetic sensor,a double closed-loop autonomous localization control method was proposed for the robot manipulator based on BP network and visual servo,and a corresponding autonomous localization double closed-loop control system was also designed. In one of the closed-loop,a BP network was used to solve the inverse kinematics of the manipulator so as to achieve rough localization. The other closed-loop was arranged to achieve the fine localization of the manipulator through the visual servo to obtain a feature parameter. Combining the rough localization and fine localization,the autonomous localization and docking control between the operation object and robot manipulator were achieved. The simulation experiment was arranged to divide the alignment control of the manipulator and the bolt/nut into three direction localization controls inX,YandZdirection. Results show that,through the adjustment of the control algorithm,the error of the three directions can converge to the ideal value at a faster speed and higher precision,and the algorithm can adapt for different parameter structures of the drainage plate,satisfying the need of the special mobile operation robot control in real-time,stability and adaptability for different structure design requirements. Finally,the effectiveness and the practicality of the proposed method were verified by the experiments of the drainage plate bolts field operation.

Cooperative Guidance Law for Hypersonic Targets with Constrained Impact Angle

TAN Shi-li, LEI Hu-min, WANG Bin

2019, 39(6): 597-602. doi:10.15918/j.tbit1001-0645.2019.06.008

Abstract(949) PDF(345)

Abstract:
A cooperative guidance law was proposed for intercepting hypersonic target with constrained impact angle. In the direction of perpendicular to the line-of-sight (LOS), the acceleration command was developed based on the nonlinear disturbance observer and the nonsingular terminal sliding mode theory to ensure the LOS rate converging to zero and the LOS angle converging to the desired angle, i.e. the constrained impact angle. Along the LOS direction, the acceleration command was designed based on the multi-agent consensus control algorithm to ensure all the relative distances from the missiles to the target reaching the agreement in finite time and every missile hitting the target at same time. Simulation results for the scenario of four missiles intercepting a hypersonic target demonstrate the effectiveness of the proposed guidance law.

Sparse Feature Extraction for Variable Speed Machinery Based on Sparse Decomposition Combined GST

YAN Bao-kang, ZHOU Feng-xing, XU Bo

2019, 39(6): 603-608. doi:10.15918/j.tbit1001-0645.2019.06.009

Abstract(855) PDF(291)

Abstract:
In order to extract fault impulse feature of variable speed machinery from strong background noise, a sparse feature extraction method based on sparse decomposition combined generalized S transform (GST) was proposed in this paper. Firstly, multi-resolution generalized S transform (MGST) was used to pursuit the optimal atom in each iteration, to get normalized time-frequency spectrums with different scales, and to find the maximum energy and corresponding time-frequency factors to build an optimal atom. Then, an orthogonal matching pursuit (OMP) was used to decompose the signal into several optimal atoms, and the efficiency of atoms pursuit was improved with MGST. Finally, the theoretical locations of impulses were calculated according to the location of first impulse in the sparse representation signal, and the fault was diagnosed through the comparison of theoretical and measured locations. The results of simulation and experiment validate the performances of the proposed method, being better than traditional GST method and OMP method in precision and decomposition speed.

Dynamic Prediction of Pure Electric Vehicle Battery State of Health by Optimized and Graded T-S Fuzzy Control

CHEN De-hai, HUA Ming, ZOU Zheng-ming, REN Yong-chang

2019, 39(6): 609-614. doi:10.15918/j.tbit1001-0645.2019.06.010

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Due to the state of health (SOH) prediction of pure electric vehicle power battery relates to many non-linear factors and complicated algorithms, it is difficult to accomplish in singlechip platform. In order to overcome the difficulty, a new method was proposed. Firstly, a method for counting the accumulative charging cycles was used to calculate the number of battery use cycles. Then the nonlinear relationship between SOH and the number of cycles, the variation of internal resistance and the value of voltage drop were transformed into a discrete two-dimensional datasheet. According to the use conditions, the SOH values under different estimation methods could be obtained by using the binary look-up table method. Secondly, taking the number of cycles, voltage drop and internal resistance variation as input and the weight of corresponding SOH as output, a SOH dynamic prediction model was established based on T-S fuzzy control. According to the weights and boundary conditions, the SOH could be calculated. The simulation results show that the proposed method has a maximum prediction error of 4.3% and a response time of 55 ms, and the prediction effect is much better than that of the existing methods.

Control of Free-Floating Space Dual-Arm Robot for Capturing Moving Targets

LI Liang, LI Jian-fei, ZHANG Da-wei, WANG Ning-fei

2019, 39(6): 615-623. doi:10.15918/j.tbit1001-0645.2019.06.011

Abstract(774) PDF(623)

Abstract:
A dynamic model of free-floating dual-arm robot system was established for the task of capturing a moving target. For the tracking process of open-chain, the adaptive method was used to achieve the convergence of speed estimation and target tracking at the same time,to ensure that the two arms captured the target simultaneously. At the same time, the feedback control law concerning the coupling and floating model was designed. For the docking process of closed-chain, the movement of the dual arm was planned coordinately according to the constraints. Meanwhile, a coordinated impedance control algorithm for dual-arm space robot system was designed based on feedback linearization, with which the impedance of the dual-arm parallel system could be independently configured. The simulation shows that compared with pure tracking, the tracking method achieves a rapider capture process and a straighter track, and the internal force is effectively cut down and the docking is smoother in the closed chain process due to the dual-arm impedance control.

A Scheduling Algorithm for the Cloud Computing System with the Dynamical Feedback of Server State

XIE Zhi-qiang, SHAO Xia

2019, 39(6): 624-631,637. doi:10.15918/j.tbit1001-0645.2019.06.012

Abstract(895) PDF(459)

Abstract:
To solve the problem of the task scheduling result affected by the state change of server in the cloud computing system, a scheduling algorithm for the cloud computing system with the dynamic feedback of server state (DFSS) was proposed. Firstly, a sliding window model was proposed for the scheduling algorithm to reflect the server busy state in real time. And then, a weight curve model of time window and an average utilization rate model were used to compute the average utilization rate and improve the predict accuracy of the server. Finally, a server feedback weight strategy was proposed based on the average utilization rate to calculate dynamic rank value of every task node, and all task nodes were sorted by their dynamic rank value in order and respectively schedule them. The experiment result indicates the proposed algorithm can effectively reduce the task Makespan.

Influence of Trigger Mode on Acquisition Time of Low-Speed-Camera Image Sequence

WANG Chao, LIU Mei-ling, LIU Zhen-yu, MA Qin-wei, WANG Yuan-yin

2019, 39(6): 632-637. doi:10.15918/j.tbit1001-0645.2019.06.013

Abstract(973) PDF(347)

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In order to enable low-speed cameras to acquire high time precision image sequences, the study mainly investigated the acquisition time accuracy and the error of image sequences of low-speed cameras triggered by three typical modes (hardware trigger mode, software trigger mode and continuous acquisition trigger mode).The acquisition time was obtained by a method based on a light-time coding technique. First, the time message was encoded into each photo by the light-time coding technique, and the exact acquisition time of the photos was obtained. Second, the travel time error was calculated by comparing the time interval between every two images with the standard value. Experimental results indicate that the travel time errors of the hardware trigger and continuous acquisition trigger modesare ±0.1 ms, while the error of the software trigger mode is 32.2 ms. For experiments with high time precision requirement, the hardware trigger and continuous acquisition trigger modes are suggested.

A Fast Gesture Recognition Method Based on Stacked Sparse Autoencoders Multi-Feature Fusion

QIANG Yan, DONG Lin-jia, ZHAO Juan-juan, ZHANG Ting

2019, 39(6): 638-643. doi:10.15918/j.tbit1001-0645.2019.06.014

Abstract(950) PDF(565)

Abstract:
In order to solve the pro blem of poor gesture segmentation extraction, low image recognition rate and difficult recognition, a multi-feature fusion method was studied for fast gesture recognition. Firstly, a skin color distribution model was established based on the YCbCr color space model, removing the most of non-skin color interference from the complex background, so as to realize the gesture segmentation. And then, taking the texture image of the gesture ROI (region of interest), the shape image and the significant visual image as self-coding network input, the different types of features were linearly merged according as 5-layer stacked sparse autoencoders network framework. Finally, a SVM (support vector machine) classifier based on RBF (radial basis function) kernel function was used to classify the characteristic data, so as to realize the gesture recognition for different types of gestures. Experimental results show that, compared with other gesture recognition methods, the recognition rate is higher and the extraction characteristics are more representative. The average recognition rate can reach 95.05%.

Determination of Geometric Factor for Ground-Based Raman-Mie Lidar with Bi-Static Configuration

JI Hong-zhu, CHEN Si-ying, ZHANG Yin-chao, CHEN He, GUO Pan

2019, 39(6): 644-649. doi:10.15918/j.tbit1001-0645.2019.06.015

Abstract(930) PDF(404)

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A pure aerosol correction method was presented to improve the calibration precision of the geometric factor profile for ground-based Raman-Mie lidar. Firstly, the analytical expression and the effect factors on the estimation error were analyzed theoretically, and compared with the Raman-Klett repeat correction method. The experiment results show the insensitive property of the pure aerosol correction method to the estimation error of lidar ratio. Then the effect of the determined geometric factor profile on aerosol extinction coefficient profile was further discussed.

Launch Vehicle Integrated Electronic System Design Based on Directed Graph Method

YAO Guo-wei, ZHANG Feng, CAO Jian-wen, DENG Zhi-jun

2019, 39(6): 650-654. doi:10.15918/j.tbit1001-0645.2019.06.016

Abstract(768) PDF(343)

Abstract:
Integrated electronic system on launch vehicles suffers from the complex information interaction and transmission process among functional modules. To solve the problems above, a launch vehicle integrated electronic system based on directed graph was proposed in this paper. Functional modules on launch vehicles were regarded as nodes in the directed graph, while information flows were the edges among those modules. Based on the enacted directed graph, an adjacency matrix was then established to represent the complex integrated electronic system. The transfer length and arrival matrix were calculated and analyzed to optimize the whole integrated electronic system. Compared with the traditional design, the proposed system achieves a terser information interaction and transmission process. Moreover, the transmission efficiency of the proposed system can be improved by 37.5%.

The Control Effect of Silver Ion-Thermal Energy Compound Impact Disinfection Technology on the Biofilm of the Domestic Hot Water System Pipeline Wall

ZHANG Hui-jin, YANG Yan-ling, LI Xing, LIU Yong-wang, ZHAO Li

2019, 39(6): 655-660. doi:10.15918/j.tbit1001-0645.2019.06.017

Abstract(905) PDF(331)

Abstract:
Aiming at biosafety problem in the domestic hot water system (DHWS), the inactivation efficiency of biofilm microorganisms on the living hot water pipeline wall by the disinfection methods of silver ion, thermal energy and silver ion-thermal energy compound impact disinfection technology was comparatively studied. The results show that, the concentration of silver ion and the temperature of the hot water have a significant influence on inactivation of the total number of bacteria and Escherichia coli of the biofilm on the DHWS pipeline wall. The effect of silver ion-thermal energy compound impact disinfection technology is better than that of single silver ion disinfection or thermal energy thermal energy significantly. The effect of compound impact disinfection technology with 60℃ hot water, 0.05 mg/L silver ions and 60 min of disinfection is close to single thermal energy disinfection technology of 70℃, but the disinfected biofilm becomes thin and shed, and biofilm structure is damaged significantly. And the silver ion-thermal energy compound impact disinfection technology can significantly improve the inactivation effect of biofilm microbes on the wall of DHWS pipeline and can kill the pathogenic microorganisms efficiently, which is a valuable technology for safety disinfection and water quality protection of DHWS.

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