Table of Content

30 October 2020, Volume 41 Issue 10

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Contents

2020, 41(10):  0. 

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Paper

Parameters Calculation of JWL EOS of FAE Detonation Products

ZHAO Xingyu, BAI Chunhua, YAO Jian, SUN Binfeng

2020, 41(10):  1921-1929.  doi:10.3969/j.issn.1000-1093.2020.10.001

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The JWL EOS parameters of detonation products for high explosives are generally determined by the cylinder test. However, the cylinder test is not suitable for fuel air explosives (FAE), which is cloud-like in a macro state. A method for calculating the EOS parameters based on the experimental data of FAE detonation in external field is established to determine the JWL EOS parameters of FAE detonation products. A back propagation neural-based genetic algorithm (BPNN-GA) is introduced into the method. The calculated values are compared with the data from the single- and multi-source external field experiments. The research shows that the introduction of BPNN-GA can simplify the EOS parameter optimization process and also improve the speed and accuracy. Based on the obtained JWL EOS parameters of FAE, the single- and multi-source FAE cloud detonation models are established. The profile of shockwave front from the simulation is consistent with the morphology of actual detonation shockwave. The maximum deviations between simulated and experimental values of the ground peak overpressure at the 50 m measuring points from single- and multi-source are 9.0% and 11.1%, respectively.

Synchronization Characteristics of Dual-motor Coupled Driving System of Tracked Vehicle

LI Chunming， GAI Jiangtao， YUAN Yi， ZHOU Guangming

2020, 41(10):  1930-1938.  doi:10.3969/j.issn.1000-1093.2020.10.002

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The synchronization characteristics of dual-motor coupled driving system was researched to improve the straight driving stability of tracked vehicle. The load balancing principle of power coupling mechanism of the driving system was analyzed. It is concluded that the power coupling mechanism can reduce the load difference between the two output terminals by 60%-80% when it was transferred to the two input terminals. According to the analysis results of the factors affecting the synchronization characteristics of the dual motor coupled driving system, a relative coupling synchronization control strategy based on fuzzy PID was proposed. The simulations with and without synchronization control were carried out when there was difference in the control errors between the two motors or there were unbalanced loads at the output terminals of the driving system. The simulated and test results show that the synchronization problem of the driving system is solved by combination of mechanical and control methods.

A Software Reconfiguration Scheme for the IMV System Based on Asynchronous Communication

LI Shao, FENG Liang, ZHANG Linghui, LI Yaowei

2020, 41(10):  1939-1949.  doi:10.3969/j.issn.1000-1093.2020.10.003

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With the application of the integrated modular vetronics (IMV) system in ground vehicles, the system management and software reconfiguration should be researched to improve the fault handling capability and the level of system reliability. The avionics system management standardized in the ASAAC specification is studied, and a system management and software reconfiguration scheme based on asynchronous communication is proposed for the characteristics of IMV system. In addition, the system management configurations, as well as the detail design of system management software and module management software are presented. The scheme is applied and tested in the desktop and embedded systems. The analyzed and experimental results show that the proposed method can reduce the communication load in a multi-module IMV system and effectively cope with common faults of IMV system， such as abnormal exit of application software, network disconnection, module power-off, as well as redundant software running, which enables the IMV system to retain stable and self-contained under the occurrences of these faults and their combinations.

Engineering Knowledge Acquisition Method Based on Functional Decomposition Structure Model

ZHAO Shubin， XU Cheng

2020, 41(10):  1950-1961.  doi:10.3969/j.issn.1000-1093.2020.10.004

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The acquisition and reuse of knowledge are of great significance for improving the efficiency of engineering design and reducing the duplication of work in design activities. A semi-automated knowledge acquisition method based on functional decomposition structure model is proposed for the diversified and structured knowledge forms in the engineering field. The construction of the structure template is completed based on functional decomposition, the named entity recognition technology is used to extract the key information related to the design from engineering texts, and then the topic clustering is realized based on the latent Dirichlet allocation model, based on which the key information and the functional decomposition structure are correlated. In accordance with the proposed method and procedure, the design of the prototype system is accomplished, and the complete functional decomposition and knowledge acquisition process are illustrated by the design of an automatic weapon and its breech locking mechanism. The result shows that the proposed method can be used effectively to reduce the human-involved work in the knowledge acquisition process. Knowledge reuse based on this can adapt to designers’ thinking and provide the knowledge of related fields for designers.

Thermochemical Reaction Characteristics of PTFE/Al Reactive Material

MAO Liang， YE Sheng， HU Wanxiang， JIANG Chunlan， WANG Zaicheng

2020, 41(10):  1962-1969.  doi:10.3969/j.issn.1000-1093.2020.10.005

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In order to obtain the thermochemical reaction properties of PTFE/Al reactive materials, the thermochemical reaction experiments of PTFE/Al reactive materials with different aluminum particle sizes were carried out at different heating rates. The PTFE/Al active materials with 50 nm and 10 μm aluminum particle sizes were prepared by wet mixing process, and their thermochemical reaction behaviors at heating rates of 10 ℃/min, 15 ℃/min, 20 ℃/min and 30 ℃/min were analyzed by differential scanning calorimetry (DSC) and thermogravimetry (TG). The results show that, at the heating rate from 10 ℃/min to 30 ℃/min, all the PTFE/Al samples containing nano Al particles are exothermic, while the PTFE/Al samples containing micro Al particles do not react with the decomposition products of PTFE at a temperature lower than 900 ℃; in addition, the addition of Al particles plays a catalytic role in the thermal decomposition of PTFE. For PTFE/Al active materials with aluminum particle size of 50 nm, the peak temperature of reaction exothermic peak moves to high temperature zone with the increase in heating rate, from 578.2 ℃ to 608.5 ℃. The unit heat release increases from 331.6 J/g to 641.3 J/g. The research results have important reference value for the engineering application of PTFE/Al reactive materials.

Cook-off Characteristics of Solid Rocket Motor with Star-configuration Propellant Charge

YE Qing， YU Yonggang

2020, 41(10):  1970-1978.  doi:10.3969/j.issn.1000-1093.2020.10.006

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The thermal security of a solid rocket motor with ammonium perchlorate /hydroxyl-terminated polybutadiene (AP/HTPB) is studied. A 3D cook-off model of a rocket motor with star-configuration propellant is established. The reaction kinetic for cook-off is two-step global chemical mechanism. Numerical predictions of cook-off behavior are conducted at fast heating rates, medium heating rates and slow heating rates, respectively. The results show that the heating rate has a certain influence on the ignition temperature and delay period, and has a great impact on the ignition position, shape and size. At fast heating rate of 0.55-1.45 K/s, the ignition is closer to the right end face and the radial section area increases as the heating rate is higher. At medium heating rates of 0.005-0.011 K/s, the ignition zone is distributed with discontinuous point-like rings. The ignition center is located in the midline of wing groove, and the radial section area becomes larger with the increase in heating rate; at slow heating rate of 2.4-3.3 K/h, the ignition positions are symmetrically distributed on the centerline of wing groove. The ignition temperature has a quadratic function relationship with the heating rate, namely, T_i= 516.659 36- 1.267 8k+7.479 4k².

Response Characteristics of Hypervelocity Ogive-nose Projectile Penetrating into Mortar Target

GAO Fei, ZHANG Guokai, JI Yuguo, CHEN Jianyu

2020, 41(10):  1979-1987.  doi:10.3969/j.issn.1000-1093.2020.10.007

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To study the damage effects of mortar targets subjected to hypervelocity impact of kinetic-energy projectiles, the ogive-nose steel rods launched from a two-stage light gas gun were experimentally penetrated into mortar targets at 1 200-2 400 m/s. The linear dependences of cratering diameter and depth on the initial impact velocity are found from the experimental results. The penetration depth increases linearly first and then decreases sharply, and again increases slowly with the increase in impact velocity. Three penetration mechanisims, i.e., rigid penetration, semi-fracture penetration and fracture penetration, were observed,respectively, with the increase in impact velocity. A calculation model based on the internal friction penetration theory, in which the mass loss function of projectile is considered, is developed for predicting the penetration depths of rigid penetration and semi-fracture penetration. The calculated results were compared with the experimental results. The results indicate that the calculated results of the proposed model are in well agreement with the experimental results in terms of non-dimensional penetration depth. The special phenomenon of penetration depth reduction in the process of hypervelocity penetration is explained, and the inherent mechanism of variation law of penetration depth is further revealed.

Multi-stage Cooperative Trajectory Optimization of Dual-pulse Missile Based on Decentralized Parallel Pseudospectral-neuralNetwork Algorithm

LIU Chaoyue， ZHANG Cheng

2020, 41(10):  1988-2000.  doi:10.3969/j.issn.1000-1093.2020.10.008

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A decentralized parallel algorithm based on Gauss pseudospectral method and artificial neural network is presented for the multi-stage cooperative trajectory optimization problem of dual-pulse missiles, in which considers dropping the detached engine shell to a safe area. According to the characteristic of two-stage pulse, the entire trajectory of dual-pulse missile is divided into four flight stages, such as launching, climb, endurance and attack. In order to predict the landing position of the detached engine shell, a range prediction function is established and is fitted off-line by artificial neural network to improve the prediction speed. In the decentralized parallel algorithm, each missile independently solves its optimal trajectory in parallel. The lower bound constraint of flight time is introduced to ensure the flight time consistency of missiles. The decentralized parallel algorithm is compared with the centralized algorithm by two simulation examples. The simulated results show that the decentralized parallel algorithm proposed in this paper can be used to obtain better performance index and higher solution efficiency for solving the multi-stage cooperative trajectory optimization problem of dual-pulse missiles.

Propagation Properties of Shock Wave in Aluminum Powder/rubber Composites under Explosion Loading

LI Junbao, LI Weibing, WANG Heng, YUAN Shuqiang, WANG Xiaoming, HONG Xiaowen, XU Heyang

2020, 41(10):  2001-2007.  doi:10.3969/j.issn.1000-1093.2020.10.009

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The explosion loading test were carried out to investigate the propagation of explosion shock wave in aluminum powder/rubber composites containing 30-60 vol% Al. The shock wave pressures ranged from 6.50 to 14.25 GPa were measured using a manganin gauge, and the attenuation mechanism of shock wave was revealed by observing the mesostructure of the composites. The results show that the shock wave pressure at 15 mm propagation distance decreases first and then increases with the increase in the aluminum powder content under the same charge characteristics; the composites containing 50 vol% Al presents the strongest attenuation behavior to the shock wave, which is related to its viscous constitutive behavior, and the pressure attenuation coefficient of 0.066 8 was obtained by fitting the test results.

Strapdown Inertial Integrated Navigation Algorithm under Short-term Failure of Information Sources

ZHANG Mengde, LI Kailong, HU Baiqing, L Xu

2020, 41(10):  2008-2015.  doi:10.3969/j.issn.1000-1093.2020.10.010

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In strapdown inertial integrated navigation, the short-term failure of auxiliary information source may lead to the reduction of integrated navigation accuracy. To solve this problem, a Gaussian process regression aided strapdown inertial navigation algorithm is proposed. In the proposed algorithm, the output speed of strapdown inertial navigation sysytem corrected by integrated navigation closed-loop is used as the training input set of Gaussian process regression, and the speed output of auxiliary information source is used as the training output set. Gaussian process regression is trained whithout failure of auxiliary information source. When the auxiliary information source fails, Gaussian process regression is used to predict the output of auxiliary information source to realize the measurement update of combined filter. In the experiment, the attitude, position and gyro constant drift estimated by the proposed algorithm are compared with those of the traditional algorithm in the case of failure by using the low precision MEMS/GPS integrated vehicle data. The results show that, in the case of 60 s short-term failure, the proposed algorithm improves the effects of pitch, roll and position estimations by about 90%, the effect of yaw estimation by 70.7%, and the effects of east and north gyro drift estimations by 10.3% and 10.8%, respectively. The results show that the proposed algorithm can effectively solve the problem of short-term failure of auxiliary information sources in integrated navigation.

Initial Alignment for Rotating SINS Based on On-line Compensation of Size Effect

CHANG Zhenjun, ZHANG Zhili, ZHOU Zhaofa, XU Zhihao, GUO Qi

2020, 41(10):  2016-2022.  doi:10.3969/j.issn.1000-1093.2020.10.011

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In initial alignment of rotating strapdown inertial navigation system (SINS), the acceleration error due to size effect will reduce the accuracy of alignment.A rotation-modulation initial alignment method based on the on-line estimation and compensation of size effect is proposed to compensate the size effect error. An optimal estimation model of rotation modulation initial alignment is established, and the error suppression mechanism of initial alignment by rotation modulation is elaborated. Model of size effect error is deduced by analyzing the influence of size effect error on the output of accelerometer. The length parameter of inside lever arm is put into the state space of initial alignment, and estimated in the process of optimal estimation. The size effect error is compensated in a filtering model. The experimental results show that the length of inside lever arm is estimated on-line, and the accuracy of rotation modulation initial alignment is enhanced by compensating the size effect error.

Emitter Signal Modulation Recognition Based on Stacked Dimension Reduction and Dictionary Learning

LI Dongjin， YANG Ruijuan， LI Xiaobai， ZHU Shengkun， FEI Taiyong

2020, 41(10):  2023-2032.  doi:10.3969/j.issn.1000-1093.2020.10.012

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A classification and recognition system based on time-frequency features, stacked dimension reduction and dictionary learning is proposed for the problems about low accuracy and timeliness of modulation recognition of emitter signal in a low signal-to-noise ratio environment. The system performs time-frequency transformation and sparse domain noise reduction on the time-domain signals to obtain the two-dimensional time-frequency features and reduce the noise interference. Then it extracts the low-dimensional non-linear features based on unsupervised stacked dimension reduction networks to reduce the feature redundancy. In addition, it improves the timeliness of subsequent processing. Based on multiple discriminant constraints and regular constraints, the discriminative ability and classification timeliness of the dictionary are enhanced to realize the modulation recognition. The simulated results verify the effectiveness and feasibility of the proposed method. The overall average recoghition rate of 7 types of emitter signals, such as single carrier frequency modulation (SCFM) signal, binary frequency shift keying (BPSK) signal, quadrature frequency shift keying (QFSK) signal, linear frequency modulation (LFM) signal, binary phase shift keying (BPSK) signal, quadrature phase shift keying (QPSK) signal, Frank signal, is 95.93% at -8 dB, which has strong robustness and timeliness.

Edge Detection Method of Multiple Magnetic Sources under the Condition of Oblique Magnetization

LI Jinpeng, FANG Hongbo, ZHANG Yingtang, LI Zhining, YIN Gang

2020, 41(10):  2033-2044.  doi:10.3969/j.issn.1000-1093.2020.10.013

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The traditional edge detection method has poor recognition ability for multi-magnetic source targets under the condition of oblique magnetization. An edge detection method of multiple magnetic sources under the condition of oblique magnetization is proposed. The components of magnetic field are transformed into total magnitude anomaly and direction cosines according to vector composition principle, and an improved K singular value decomposition denoising model is proposed to reconstruct the magnetic data. The magnetization direction of each magnetic source is estimated by correlation between normalized magnetic source strength and a general phase transformation of the total magnetic intensity. The magnetic gradient tensor is transformed into the tensor data, which would be produced by the same sources with vertical magnetization. The horizontal edges of multiple magnetic sources are estimated from the ratio of the sum of the absolute values of the matrix eigenvalues of the transformed magnetic gradient tensor to the gradient component of magnetic field component along the direction of z axis in the direction of z axis. The method is tested both on synthetic magnetic data and real magnetic data. The results show that the proposed method considerably reduces the effects of oblique magnetization, and has a good ability to resist noise.

Airport Runway Detection Agorithm Based on Accurate Regression of Typical Geometric Shapes

LIANG Jie, REN Jun, LI Lei, QI Hang, ZHOU Hongli

2020, 41(10):  2045-2054.  doi:10.3969/j.issn.1000-1093.2020.10.014

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In the field of remote sensing detection, it is of great significance to achieve accurate detection of ground runway targets and contours under complex environmental conditions. The mainstream deep learning algorithm represented by YOLOv3 has achieved remarkable results in the field of target detection, but this algorithm can only give the approximate position of target in a rectangular frame, the detection result has a certain background area and cannot accurately get corner position. For the above problems, an airport runway detection algorithm based on the exact regression of typical geometric shape is proposed. Through the utilization of the typical quadrilateral corner regression strategy, the quadrilateral anchor frame mechanism, the quadrilateral non-maximum suppression module, the target geometric topological relationship, and the lightweight design of the network and model compression, the proposed algorithm can realize to learn the imaging characteristics of target under affine distortion, quickly predict the corner coordinates of target, and finally give its position with the quadrilateral contour of target. Experimental results show that the proposed algorithm has the functions of airport runway target type discrimination and contour extraction, which effectively solves the problem of accurate target positioning in practical applications, and doubles the detection speed without losing accuracy, and greatly improve the accuracy and efficiency of automatic target recognition.

Radiation Characteristics of Rotating Magnetic Dipole Super-low Frequency Transmitting Antenna

WANG Xiaoyu, ZHANG Wenhou, ZHOU Xin, CAO Zhenxin, QUAN Xin

2020, 41(10):  2055-2062.  doi:10.3969/j.issn.1000-1093.2020.10.015

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Super-low frequency electromagnetic wave (30-300 Hz) has a small path loss in water and soil, so it plays an irreplaceable role in submarine, mine emergency, earthquake prediction and military fields. The radiation characteristics of moving magnetic dipoles were studied to realize the miniaturized and low-power comsumption ultralow frequency mechanical antenna. To explore the radiation characteristics of a moving magnetic dipole, an alternating magnetic field and super-low frequency electromagnetic waves are generated by controlling the rotation of permanent magnet. The rotating permanent magnet is equivalent to its surface ampere current. According to Faraday's law of electromagnetic induction, the parameters of the permanent magnet and the measured distance are introduced to establish a radiation power analytical model based on the ampere current model. The relationship between the influencing factors and the radiated power of rotating permanent magnet is studied, and the binary digital frequency (2FSK) signal modulation is used for communication experiments. The experimental results show that the radiation power of rotating permanent magnet in space is proportional to the square of magnetic remanence of permanent magnet and the third power of its volume, and is inversely proportional to the fourth power of test distance; the super-low frequency communication is realized by real-time control of speed and time-frequency domain transformation of signal.

Combined Pressure-resistant Co-vibrating Vector Hydrophone for Underwater Glider Platform

SUN Qindong， ZHANG Xiaochuan， HAN Mei， WANG Wenlong

2020, 41(10):  2063-2070.  doi:10.3969/j.issn.1000-1093.2020.10.016

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A combined pressure-resistant co-vibrating vector hydrophone for underwater glider platform was designed to meet the needs of developing a combined small size and pressure-resistant co-vibrating vector hydrophone for underwater glider prototype. The sound pressure and vector channels are designed acoustically according to the working principle of vector hydrophone. The pressure-resistant characteristics of piezoelectric ceramic elements and thin-walled aluminum alloy shell are simulated and analyzed. The pressure-resistant capacity and electro-acoustic parameters of the vector hydrophone were tested, and the vector hydrophone was integrated into the underwater acoustic glider. Sea trial was carried out in a sea area in the South China Sea. The information of underwater acoustic field in the range of 100- 3 000 Hz was collected during the sea trial, the changing curves of different frequency noise levels with time were given, and the change of nose level at different frequency points was got when a surface ship passed. Results show that the vector hydrophone can reliably work in the depths of 1 200 meters and the different frequency noise level changes, the design of the vector hydrophone can meet the demand of application of underwater acoustic glider prototype.

Multi-objective Optimization of Inlet Duct of Water-jet Propulsion Based on Response Surface Method

ZHANG Fuyi, WU Qin, ZHAO Xiaoyang, LIU Ying, WANG Guoyu

2020, 41(10):  2071-2080.  doi:10.3969/j.issn.1000-1093.2020.10.017

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The key structural parameters of inlet duct are optimized to improve the flow performance of inlet duct of water-jet propulsion. The inclination angle α and radius R_T are optimized for higher efficiency η of inlet duct, higher weighted average angle θ of outlet velocity and non-uniformity coefficient ξ of lower outlet velocity in the cases of given diameter D, height H, and overall length L of inlet duct. There are 35 sets of sample points in design space selected by using central composite design and Latin hypercube sampling design method. Quadratic polynomials are employed to construct a response surface model based on the sample points, which reflects the relationship between design and target variables. The Pareto optimal solution set is obtained by the multi-objective genetic algorithm during the optimization process. Good optimization was obtained.The research results show that the efficiency of duct is increased from 91.2% to 94.1%, the outlet velocity weighted average angle is increased from 82.5° to 87.1°, and the non-uniformity coefficient of outlet velocity is decreased from 0.152 to 0.068.

A Foam Interlayer Method for Improving on the Acoustic Reflection Capability of Underwater Corner Reflector

LUO Yi， WANG Jieya， XIE Taotao

2020, 41(10):  2081-2087.  doi:10.3969/j.issn.1000-1093.2020.10.018

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For the unsatisfactory acoustic target strength and scattering stability of common underwater metal corner reflector, a method for improving the acoustic reflection performance of corner reflector by using low impedance foam interlayer was proposed according to the principle of water-reflector layer acoustic impedance mismatch, and a polyurethane foam interlayer plate was designed. Its acoustic reflectance was calculated, and was compared with that of monolayer metal plate in terms of frequency and incident angle. Based on this, a new polyurethane foam interlayer corner reflector is constructed. Considering the concave shape and submerged thin-wall structure of the underwater corner reflector, the acoustic scattering characteristics of the underwater foam interlayer corner reflector and the metal plate corner reflector are simulated and compared by using the finite element software ANSYS combined with the acoustic software SYSNOISE. Finally, the contrast experiments of the two kind corner reflectors were carried out in anechoic pool. The results show that the polyurethane foam interlayer corner reflector has better acoustic reflection performance than the metal plate corner reflector, and its target strength and scattering stability are better under the condition of the same side length.

Maneuvering Active Decoying Method Based on Joint TOA-DOA Localization

TANG Jianlong， GUO Libo, DONG Yangyang

2020, 41(10):  2088-2095.  doi:10.3969/j.issn.1000-1093.2020.10.019

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The active decoying system is one of the main measures for ground-based radar against anti-radiation missile (ARM). The decoying effect of the existing decoying system is unreliable since the decoy cannot obtain the real-time position information of ARM in the decoying process, and ARM has inertial navigation error. A new method of single-maneuvering decoy against ARM based on single station location is proposed to solve the problem above. The method of the decoying system positioning ARM after the shutdown of radar transmitter is proposed based on the maneuvering active decoying principle, and the systematic error of the positioning method is deduced. The possible landing area of ARM is analyzed in the comprehensive consideration of the inertial navigation error, and then the appropriate shutdown time of the decoy is determined to improve the reliability of the decoying system. The numerically simulated results show that the decoying system can effectively locate ARM and successfully control the bait to decoy ARM, which effectively guarantees the safety of radar and decoys.

Obstacle Avoidance Algorithm for Autonomous Wheeled Vehicle in Unstructured Environments

DU Guangze， ZHANG Xudong， ZOU Yuan， ZHENG Zhuangzhuang

2020, 41(10):  2096-2105.  doi:10.3969/j.issn.1000-1093.2020.10.020

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An obstacle avoidance algorithm based on model prediction control is proposed for the obstacle avoidance task of autonomous ground vehicle in unstructured environments. The trajectory of vehicle, steering angle and reference acceleration can be generated by using optimization method without the offline map and the reference trajectory in unstructured environments, and the result satisfies the vehicle motion constraint in passable area. Obstacle avoidance problem is divided into multi-phrases optimal control problem by using the environment perception results according to unstructured road scenarios. The vehicle constraints and cost function for each phrase of the optimal control problem are clarified. The constraints are transformed into the formulation related to vehicle longitudinal and lateral control. Then the optimal control problem is solved by mathematical method. The results of real vehicle tests show that the proposed algorithm can generate trajectory in unstructured environments. It is also shown that the algorithm is capable for obstacle avoidance and keeps vehicle under the limits of constraint.

Path Planning of Mobile Robots Based on Improved Potential Field Algorithm

SUN Pengyao， HUANG Yanyan， PAN Yao

2020, 41(10):  2106-2121.  doi:10.3969/j.issn.1000-1093.2020.10.021

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In view of the problems existing in the traditional potential field algorithm (PFA), such as unrecognized path, local minimal trap and oscillation, a potential field algorithm combining multi-behavior strategy and obstacles variable affected range, and the path planning of robots suitable for the complex obstacle environment is proposed. The obstacles affected range can be changed to eliminate the common necessary conditions of the above problems, so as to avoid unrecognized path, oscillation caused by multiple obstacles and local minimal trap caused by multiple obstacles in advance. Based on the new classification method for step-by-step and oscillation, the multi-behavior strategy is designed with the exact starting and ending conditions. The behaviors are switched by predicting the common expression of problems and the connection of starting and ending conditions, thus avoiding the local minimum trap caused by single obstacle and the oscillation caused by single obstacle in advance. The simulated results based on MATLAB verify the effectiveness and stability of the proposed method in the complex battlefield obstacle environment, and the proposed method has the feasibility for path planning compared with potential field algorithm, dynamic window approach, A-star algorithm and rapid-exploration random tree algorithm.

Real-time Detection of Parts by Assembly Robot Based on Deep Learning Framework

YU Yongwei， PENG Xi， DU Liuqing， CHEN Tianhao

2020, 41(10):  2122-2130.  doi:10.3969/j.issn.1000-1093.2020.10.022

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For the problems about low accuracy and poor robustness under complex conditions such as adhesion, stacking, illumination change and environmental factors, a part real-time detection method based on improved YOLOv3 deep learning framework is proposed. The CFE module is embedded in each residual network of Darknet-53 basic feature extraction network. A deep feature extraction network CFE-Darknet53 that combines CFE module and Darknet-53 is constructed. A real-time part detection model based on CFE-Darknet53 under the YOLOv3 deep learning framework is established, which improves the feature extraction ability of the detection network in complex environment. An improved K-means algorithm is designed to predict the bounding box. The data sets of parts are clustered to select the optimal number and size of anchor frames, which further improves the detection accuracy. The experimental results show that the detection accuracy of the improved YOLOv3 algorithm for multi class parts with high similarity can reach 91.6% under complex conditions. Compared with the YOLOv3 algorithm, the improved YOLOv3 algorithm improves the detection accuracy by more than 10%. The detection time is 43 ms, so the improved method achieves real-time detection of parts at the video transmission frame rate of 24 frames/s.

Comprehensive Review

A Review on Power Source Technology of Unmanned Ground Vehicles

ZOU Yuan, JIAO Feixiang, CUI Xing, ZHANG Xudong, ZHANG Bin

2020, 41(10):  2131-2144.  doi:10.3969/j.issn.1000-1093.2020.10.023

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The power source is a core component of ground unmanned vehicle and has direct effect on its manoeuvrability and combat performance. According to the development status of power source technology for unmanned ground platforms at home and abroad, the characteristics and applied range of the four types of power sources, such as internal combustion engine power source, pure electric drive system power source, fuel cell system power source, and hybrid power system power source, are analyzed. The key technologies and development trends of the power source are summarized from the aspects of engine-generator set technology, battery pack technology, power electronics integration technology, and energy management and control system technology. Finally, the main problems, research direction and research focus of the power source are prospected.