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2021, 41(2): .

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2021, 41(2): .

Abstract(451) PDF(166)

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Impact Resistance of Glass Fiber Reinforced Plastic-Polyurethane Foam Sandwich Panels Against Projectiles

LI Jinzhu, LI Mingjing, LI Haisheng, HUANG Fenglei

2021, 41(2): 121-129. doi:10.15918/j.tbit1001-0645.2019.306

Abstract(826) PDF(322)

Abstract:
To study the ballistic performance of epoxy resin FRP/polyurethane foam sandwich composite targets, tungsten alloy spherical fragments were fired from a ballistic gun to impact single-layer targets with different thicknesses and sandwich targets with different combinations of glass fiber reinforced plastic polyurethane foam plates. The failure morphology of the targets at different incident velocities was obtained. The initial and residual velocities of the fragment were measured by high-speed photography, and the ballistic ultimate velocity of the target was estimated by up-down adjustment velocity method. The influence of structural characteristics on the specific absorption energy of the composite target was analyzed. Research results show that the main ways of energy absorption are drawing and tensile fracture of glass fiber, the relation between the specific absorption energy of the target plate and the surface density is quadratic parabola, and the THOR formula is more suitable for calculating the ballistic limit of sandwich plates.

The Damage Effect of the Equivalent Target of the Tank Engine Under EFP Oblique Penetration

KE Yuan, LIU Yan, HUANG Fenglei

2021, 41(2): 130-136. doi:10.15918/j.tbit1001-0645.2020.018

Abstract(776) PDF(278)

Abstract:
Aiming at damage effect of the tank engine under the action of explosive formed projectile (EFP), structural equivalent design of a typical tank engine and its protective structure, and the penetration experiments of EFP at different penetration angles on the equivalent target of the engine were carried out. Combined with LS-DYNA software, the penetration effect of EFP on the protective plate (steel) at different EFP penetration angles was analyzed. Not only the hole size and damage area of the equivalent target of the engine were obtained, but the remaining kinetic energy after the EFP passed through the target was also obtained. Research indicates that with the increase of the EFP penetration angles, the damage area formed on the steel target increases, and the damage effect of the projectile on the aluminum box is weakened. The experimental results are basically consistent with the simulation results, verifying the effectiveness of the simulation. The maximum failure size of the EFP to the steel target shows an upward trend with the increase of the penetration angle. The residual kinetic energy of the EFP through the steel target decreases with the increase of the penetration angle. When the penetration angle isα≥ 57°, the EFP cannot penetrate the steel target and cannot cause damage to the aluminum box.

Numerical Simulation of Validation and Influence Factors ofExplosion Accident Caused from LPG Tank Leakage

SUN Baoping, ZHANG Haiying, LÜ Shuran, CHEN Wenying

2021, 41(2): 137-142. doi:10.15918/j.tbit1001-0645.2019.294

Abstract(642) PDF(226)

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The safety problem of liquefied petroleum gas (LPG) is significantly important since it is a frequently used chemical substance prone to ignition and explosion. The explosion case of LPG tanker in Linyi, Shandong, was investigated by the UDM model in PHAST software under the method of parameter controlling. The results show that the direction of leaking affects the explosion scenario remarkably. When it is upward or downward, the leaking and jet radiations have a minimum or maximum effect area, respectively, while horizontal, a liquid pool would be formed. With the increase of ambient temperature, the leaking and expansion distances and the influence area of flash fires increase while the jet flame radiation decreases, especially within the distance of 150~200 m. The surface-roughness affects little to the jet radiation intensity while the explosion shock wave shows a revered relation with it.

Formation and Separation Behavior of the Triple-Layer EFP

ZHENG Yuanfeng, MA Hongbing, XIAO Yanwen, YU Qingbo, WANG Haifu, GE Chao

2021, 41(2): 143-150. doi:10.15918/j.tbit1001-0645.2020.012

Abstract(745) PDF(241)

Abstract:
The formation process and separation of the explosive formed projectile (EFP) formed by triple-layer tandem EFP were investigated based on numerical simulation, by which the formation process of triple-layer tandem EFP was described and the influence principle of different liner materials on the separation of triple-layer EFP was also revealed. The simulation results indicate that the formation process of triple-layer EFP consisted of impact phase, closing phase and free fight phase. In the impact phase, kinetic energy exchange mainly occurred during the axial impact of triple-layer liners, producing velocity difference in the axial direction, which was the main reason for the separation of triple-layer EFP. In the closing phrase, triple-layer liners stretched and closed gradually while impacting with each other in the axial and radial direction, which further affected the formation process and separation of triple-layer liners. In the free flight phase, the velocity and appearance of triple-layer EFP tended to be stable and the impact no longer existed, and distance between the three EFPs became larger as time progressed. In addition, different liner materials had an importance influence on the separation of triple-layer EFP, the 45#steel liner not only achieved fast separation from the front copper liner, but also effectively obstructed the separation from the following copper liner. Further numerical simulation results show a good agreement with the X-ray experiment results, which demonstrates the efficiency of the numerical simulation.

Numerical Simulation of Influence of Hit Position on Detonating Heavy Explosive Reaction Armor

YU Qingbo, ZHONG Shiwei, XIAO Yanwen, ZHAO Hongwei

2021, 41(2): 151-157. doi:10.15918/j.tbit1001-0645.2019.255

Abstract(655) PDF(212)

Abstract:
This paper mainly focuses on the research on the detonation of heavy explosive reactive armor by the shaped charge warhead. The pre-processing software TrueGrid was used to establish a numerical calculation model for the detonation of heavy explosive reactive armor by the shaped charge jet, and the nonlinear dynamics software LS-DYNA was used to conduct a numerical simulation study on the problem. The post-processing software LS-prepost was used to obtain the influence of different impact positions on the detonation characteristics and scattering characteristics of ERA. Numerical simulation results show that the impact position has a significant influence on the detonation and scattering behavior of ERA. The closer the impact position is toward the edge of ERA, the lower the peak detonation wave pressure after the detonation of the interlayer charge; the later the flying plate starts to move, the shorter the acceleration time of the flying plate is, and the lower the flying velocity is, the longer duration interference to the jet will be.

A Novel Algorithm for Autonomous Real-Time Route Planning ofAUV Based on Sub-Target and Level Set Method

SHENG Liang, SU Ning, LUO Rong, FENG Wei

2021, 41(2): 158-168. doi:10.15918/j.tbit1001-0645.2019.296

Abstract(742) PDF(239)

Abstract:
To solve the unsafe obstacle avoidance and low planning efficiency problems resulted from the more idealized obstacle model of the current underwater obstacle avoidance route planning algorithm, an autonomous real-time route planning algorithm based on the sub-object method and level set method was proposed. Based on the partial contour information of obstacles detected by AUV(autonomous underwater vehicle) forward-looking sonar, the algorithm was arranged to estimate the size and center position of obstacles in stages, and then to obtain safe and reliable sub target points. And then, a rolling sub target method was used to realize complete obstacle avoidance and a level set method was used to improve the planning speed. The simulation results show that the novel algorithm can achieve 100% obstacle avoidance, and the performance quality of the route after obstacle avoidance appears a little debased than that of the global optimal route obtained by the level set method:the average increase of route length and sailing time are less than 5%.

Target Tracking Method Based on Fusion of Triple Neural Network and Area Adaptation

WANG Jianzhong, ZHANG Chiyi, SUN Yong

2021, 41(2): 169-176. doi:10.15918/j.tbit1001-0645.2020.010

Abstract(775) PDF(261)

Abstract:
In order to solve the problems of fast motion blur, background similar interference and target state change in the process of target tracking, a target tracking method (TAA+TripleRPN) that combines the triple area candidate neural network (tripleRPN) algorithm with the tracking area adaptive strategy (TAA) was proposed based on siamese network tracking algorithm. The triple-area candidate neural network updates the network matching template in real time based on the current tracking results, which improves the sensitivity of the tracker to changes in the target state. Through the regional adaptive strategy, based on the scores of the classification candidates of the regional candidate regression network, the two groups of network outputs are selected optimally, which improves the robustness of the algorithm's long-term tracking. For the problems of similar background interferences and target state changes, the TAA+TripleRPN tracker can achieve better tracking performance. On the OTB2015 dataset, the algorithm has an AUC of 66.31% and a CLE of 88.28%. The verification and application are implemented in actual scenarios, and the tracking effect is good.

Research on Data Driven Control of a Small Flexible Wing Aircraft

ZHANG Zhide, WANG Zhengjie, HAO Zhiyuan

2021, 41(2): 177-185. doi:10.15918/j.tbit1001-0645.2019.288

Abstract(671) PDF(240)

Abstract:
The passive morphing of the flexible wings caused by the gust of wind will reduce the unstable motion disturbance to flight. The small flexible wing aircraft is believed to be a solution to the problem of small aircraft being susceptible to gust disturbance, as well as meeting the characteristics of portable weapons. However, due to the fact that the small flexible wing aircraft has no ailerons and other characteristics different from the conventional aircraft layout, the two problems emerge from the flight test data analysis-the all-moving tail control efficiency is low and prone to nonlinear saturation problems, and the coupling problem caused by using the tail to simultaneously control the pitch and roll channel. A data-driven model-free adaptive controller scheme was presented. The simulation results prove that the presented controller has better control effect than the traditional single-channel PID controller.

Study on Biomimetic Subsection Compound Guidance Law Considering Field of View Angle of Seeker

WANG Zhengjie, CAI Changqing, HUANG Weilin

2021, 41(2): 186-192. doi:10.15918/j.tbit1001-0645.2019.281

Abstract(676) PDF(247)

Abstract:
Due to the weight limit of the loadable load, the micro-miniature ammunition often uses the strap-down seeker. At the end of the ammunition attack, a small field of view angle is required to ensure effective tracking and striking of the target. In nature, the tracking strategy and trajectory of the predatory fruit fly can provide reference. Based on the tracking strategy of the dragonfly, the segmentation guidance law was proposed, that is, the initial segment would quickly adjust the ammunition posture into the tail chase mode when tracking the target, and capture the target using the motion camouflage tracking strategy in the latter half of the tracking. In the initial guidance section, the parallax angle was controlled by the sliding mode control law to adjust the ammunition to the tail-following attitude. The final guidance section used the motion camouflage guidance law with the focus at infinity for target tracking, and between the initial guidance section and the final guidance section. The second-order smooth interface law was used for the transition. The simulation results of the bionic segmentation composite guidance law show that compared with the traditional proportional guidance law, the required overload of the ammunition in the final guidance section is small, and the target is closer to the center of the field of view, which can reduce the ammunition in the final guidance section. The overload and the field of view of the seeker can be used to effectively improve the attack accuracy.

Digger: a Fuzzer with an Improved Path-Recording Method

LIANG Hongliang, CHEN Yixiu, PEI Xiaoxiao, XIE Zhuosi

2021, 41(2): 193-200. doi:10.15918/j.tbit1001-0645.2019.270

Abstract(653) PDF(183)

Abstract:
Fuzzing and concolic execution are two important techniques in the area of binary analyzing and testing,and they are able to complement each other well.To find deep bugs in the code,a new path-recording approach was proposed to make concolic execution assist fuzzing.And the approach was implemented in a tool called Digger.The Digger was arranged to deal with target programs that require input from files or with extra arguments.The Digger was evaluated on an example program as well as real-world applications (e.g.,coreutils,catdvi,etc.).Experimental results show that by using the new path-recording approach,Digger can reach higher code coverage and find more bugs than a well-established tool,i.e.,Driller.

Satellite Formation Control Strategy with Tube-Based MPC

ZOU Hengguang, SONG Jiliang, WANG Junzheng, ZHANG Lei, SHI Dawei

2021, 41(2): 201-206. doi:10.15918/j.tbit1001-0645.2000.100

Abstract(856) PDF(216)

Abstract:
A tube-based model predictive control strategy was proposed for geostationary satellite formation control. Based on the Clohessy-Wiltshire Hill (CWH) equations, the relative orbit motion model was constructed. By designing the uncertainty tube, the proposed robust model predictive controller can overcome the uncertainties brought by model mismatch. The simulation was carried out by Matlab/Simulink. Numerical results show that the proposed controller can maintain the satellite formation by dealing with various orbits perturbations and model uncertainties properly.

Effect Law of Navigation Receiver Tracking Loop Under Electromagnetic Interference

ZHANG Qinglong, WANG Yuming, CHENG Erwei, MA Liyun, CHEN Yazhou

2021, 41(2): 207-213. doi:10.15918/j.tbit1001-0645.2019.318

Abstract(765) PDF(197)

Abstract:
In order to investigate sufficiently the lockout law of the navigation receiver's tracking loop under multi-source electromagnetic interference, a model of the lockout effect of the tracking loop under dual-source electromagnetic interference was studied. Analyzing the mathematical model of the equivalent carrier-to-noise ratio of the correlator output under electromagnetic interference, a model of the tracking loop lockout effect under dual-source electromagnetic interference was established. Then an experiment platform was set up with a single-source and dual-source electromagnetic interference to carry out an injection experiment for the Beidou navigation receiver. During the experiment, four different combinations of interference signals were selected, and under the experiment of each combination, different signal power combinations were obtained. Finally, the experiment data were used to verify the effect model, showing the model errors all within 1.5 dB. This model reveals the internal relationship between dual-source and signal-source interference in the navigation receiver tracking loop, providing a guide for further research on the law of navigation receiver effect.

Adaptive Cruise Predictive Control Based on Particle Swarm Optimization

ZHOU Jiaming, ZHANG Liangxiu, YI Fengyan, PENG Jiankun

2021, 41(2): 214-220. doi:10.15918/j.tbit1001-0645.2019.274

Abstract(1419) PDF(231)

Abstract:
To further improve the predictive control accuracy of multi-objective adaptive cruise system, an adaptive cruise predictive control algorithm based on particle swarm optimization was proposed. Firstly, a longitudinal kinematics model with front vehicle acceleration disturbance of adaptive cruise system was established and linearly discretized. Then, synthesizing the distance error, relative speed, acceleration and impact, a quadratic multi-objective optimization performance index function and multi-parameter constraints were designed, and an adaptive cruise predictive control optimization problem was constructed. Finally, in order to solve the problem easily, the objective function and constraints were deduced into a normative form with predictive control increment as the optimization variable, and the optimal control law of adaptive cruise predictive control was solved based on particle swarm optimization algorithm. The simulation results of Maltab/Simulink under multiple working conditions show that the optimal control law solved by particle swarm optimization algorithm can control the self-driving vehicle to maintain better tracking and self-adaptability.

Control Algorithms for Positive Definite Matrix Manifolds

AUNG Naing Win, SUN Fupeng, ZENG Shunan, SUN Huafei

2021, 41(2): 221-225. doi:10.15918/j.tbit1001-0645.2019.280

Abstract(662) PDF(228)

Abstract:
Nonlinear problems appear in many fields. How to deal with nonlinear problems is a hot topic in scientist attention. On the structure and control problems of control systems,in this paper,making use of the geometric structure of positive definite matrix manifold,a control system was designed with positive definite matrix as its output. In order to make the system output as close to the corresponding index as possible,a corresponding natural gradient algorithm was designed according to different measured structures,and some experiments were carried out to verify the effectiveness of the algorithm.

A Clustering Algorithm Based on Statistical Manifold

SUN Huafei, SONG Yang, LUO Yihao, SUN Fupeng

2021, 41(2): 226-230. doi:10.15918/j.tbit1001-0645.2019.304

Abstract(930) PDF(274)

Abstract:
Considering the difference of local statistical properties between data points,and combining withK-means algorithm,a novel clustering algorithm based on statistical manifold was proposed. By calculating the mean and covariance of the neighborhood of the data points,the original data point cloud was mapped to the normal distribution family manifold to form the parameter point cloud. Different measurement structures were constructed on the normal distribution family manifold,andK-means method was applied to cluster the parameter point cloud,so as to classify the corresponding original data. To verify the effect in the point cloud denoising,the algorithms based on different difference function were used to denoise the point cloud with high density noise,and simulation analysis was carried out. The simulation results show that the algorithm using KL divergence as difference function can get a better denoising effect,verifying the potential of the algorithm in denoising application.

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