In complicated land warfare environments, image classification techniques is an important tool to quickly distinguish armored vehicle targets. To address the problem that the existing mainstream classification algorithms based on Convolutional Neural Network (CNN) have high requirements for the number and quality of training samples and perform with insufficient accuracy in the image classification task of newly equipped armored vehicles, a transfer learning method that integrates two CNNs based on different learning strategies is proposed. Specifically, one CNN is pre-trained on an old-fashioned armored vehicle image dataset whose samples can be easily obtained and have sufficient quantity to learn local detail features. The other CNN is pre-trained on the dataset of virtual images of the newly equipped armored vehicles with a low image quality to learn the global features. The pre-trained CNNs are all fine-tuned according to different strategies using a limited number of real samples of newly equipped armored vehicles to improve the characterization capability. A self-learning model integration mechanism based on the Optuna hyperparametric optimization framework is designed, which can autonomously weight the outputs of the two CNNs for optimization and further improve the classification accuracy of the algorithm. The experimental results show that the accuracy of the proposed algorithm is improved by 7% in the image classification task of newly equipped armored vehicles compared with the same model trained from scratch, which effectively alleviates the problem of insufficient training samples.

To explore the effects of multimodal warning on the response of armored vehicle occupants regarding the direction of enemy vehicles under different cognitive load levels, 20 adult males were recruited to take two-factor ergonomic experiments on the warning type and cognitive load level. The experiments were based on a virtual simulated armored vehicle occupant task platform designed for a hypothetical operational task for armored vehicle occupants and warned the occupants under different cognitive load levels about enemy vehicle directions. Results show that multimodal warning with haptics was easier for occupants to understand the situation and more in line with their cognitive state than visual warning. This type of warning significantly reduced their reaction time, annihilation time, and response error rate. Occupants with a high cognitive load level showed a significant decrease in information comprehension and a significant increase in reaction time, annihilation time, and response error rate compared to those with a lower load. The findings suggest that multimodal warning can be used to speed up occupant reaction and improve combat performance when the visual channel is overloaded or the cognitive load is high. This study provides a theoretical basis for designing multimodal human-computer interaction warnings in armored vehicle compartments.

The power quality and stability of an on-board DC microgrid are related to whether the electrical equipment in the vehicle can work safely and reliably. Aiming at the problem of bus voltage oscillation and instability of on-board DC microgrids under large disturbances, a large-disturbance model of an on-board DC microgrid that considers constant power load and engine-generator is established. Based on the mixed potential theory, the stability criterion of the on-board microgrid is obtained, solving the problem that existing large-disturbance analysis methods are not suitable for on-board microgrids. The influence of important parameters on the response speed and stability of the microgrid are also analyzed. Finally, the stability criterion and the accuracy of the analysis results are verified by hardware-in-the-loop simulation and bench experiments. The results show that the system satisfying the criterion can operate stably under large disturbances.

The system evaluation method for systems engineering is used for distributing the basic reliability index of armored equipment. For a characteristic parameter testing system as an example，a system hierarchy analysis model is established，the distribution weights of the unit in the system are determined，and the calculation process is adopted by checking calculation.The results show that the system engineering method can be used to reasonably allocate the basic reliability indexes of armored equipment.

In order to refine the specifications and processes on the overall design of armored vehicles，the main concepts concerned on the system architecture of armored vehicles，such as the vehicle architecture of five object levels，six design categories，four-layers Work-Breakdown criteria and assemblies trade-off methods，are proposed based on the design theories in Refs. \[9-12\].The V-mode workflow and the conceptual design process from needs to solutions are defined，and the concept of set-based design(SBD) is introduced into the overall design of armored vehicles.The polices of intergraded portfolio development management are summarized.

The situational awareness level of armored vehicle crew significantly affects the combat effectiveness of the vehicle, and the situational awareness of crew members is affected by working memory, attention distribution and other factors. In order to explore the effects of crew’s long-term working memory and attention distribution on their situational awareness, 24 subjects were recruited to carry out the evaluation experiment of crew’s situational awareness. The experiment was based on the virtual simulation experiment system of a hypothetical armored vehicle crew task. The results showed that: in the aspect of long-term working memory, the situational awareness level of skilled people was significantly higher than that of beginners; in terms of attention distribution, the situational awareness level under the high-saliency condition was significantly higher than that under the low-saliency condition; the frequency of abnormal information, however, had little effect on situational awareness. Further analysis showed that indices such as 3D-SART, SAGAT, abnormal information response time, percentage of eyelid coverage of the eye, proportion of gaze time on the instrument area, SDNN and PNN50 are more sensitive to the change of situational awareness level. This study can provide some design basis for the design of human-computer interaction interface of armored vehicles.

Due to its high strength, high hardness, high toughness and high viscosity, SiC/GFRP laminated composite armor after molding has considerable difficulty in hole drilling. Damages such as laminat interface failure, ceramic chipping, and fiber tearing tend to occur during hole drilling. The novel thin-walled diamond core drill prepared by the hybrid process of sintering and brazing was used. Combined with rotary ultrasonic vibration technology assisting with hole machining, the kinematic model of a single abrasive particle was established, the core drill and the workpiece were separated by contact periodically during ultrasonic vibration drilling, and the discontinuous cutting characteristic is conducive to reducing the axial force. The hole-drilling experiments on SiC/GFRP laminated composite armor were conducted. The change law of the axial force and the hole quality in conventional machining and ultrasonic vibration-assisted machining were analyzed. The results showed that: compared with conventional sleeve grinding, the axial force in the case of ultrasonic vibration-assisted sleeve grinding was significantly reduced, with a maximum decrease of 31.8%; the bonding at the laminate interface during ultrasonic machining was tight and no serious ceramic breaking occurred; defects featuring irregular bulges and large bulge height in holes by conventional machining were effectively avoided, and the maximum reduction of bulge height was 61.03%, which significantly improved the surface quality of the holes and reduced the degree of hole damage. The results provide theoretical reference for the continuous hole machining in SiC/GFRP laminated composite armor with high efficiency and low damage.

The ballistic performance of ceramic armor systems with different structures is studied to optimize the structural design of the armor. The FEM-SPH coupling calculation model is verified through ballistic experiments and numerical simulations. The process of a long-rod projectile impacting a ceramic-metal composite armor is then simulated, and the influence of different thickness ratios of ceramic to the metal back plate on interface breakdown analyzed. The results show two main protective mechanisms of the ceramic composite armor. When the projectile velocity's is less than 1 000 m/s and the ceramic thickness is increased from 15 mm to 25 mm for a bi-layer ceramic composite armor with a total thickness of 30 mm, the dwell time of the composite armor would be more than doubled, and the maximum energy consumption of the projectile body can reach 50%. When the velocity of the projectile exceeds 1 000 m/s,the energy consumption is dominant in the penetration phase, and the maximum energy absorption during penetration is 85%. When the composite armor has a metal to ceramic thickness ratio of 2∶1, the missile body stays longer on the interface and achieves a relatively high ballistic protection efficiency. Our results can be used as a reference for the design of armor structures.

Large-caliber anti-armor weapons are playing an increasingly important role in the battlefield，and higher requirements are put forward for the armor materials and structure design. In order to explore the bulllet-proof mechanisms and performance of ceramic composite armor penetrated by 14.5 mm armor-piercing projectile，an armor structure with ceramic/fiber/metal/flexible material/metal layup configuration was designed，and the influences of thickness matching，bottom plate material and flexible material on the ballistic performance were discussed through experiments.The results show that the thickness of ceramic plate has an influence on the bullet-proof performance significantly，and when the thickness of ceramic plate is 1.38 times of the core diameter，the targets have excellent bullet-proof performance. For the similar surface density and the constant ceramic thickness，the dimension matching of the composite rear plates has little influence on the bullet-proof performance when changing in a certain range.For the similar surface density，the thickness of the bottom plate should be larger when the armored aluminum is selected，and the anti-penetration performance is better. The flexible material can not only decrease the damage area，but also make the projectile yawed and change the incidence angle of projectile，thus improving the protective performance of the composite armor.

Broadband and high-amplitude electromagnetic interference exists in the working process of an electric drive system，posing a significant threat to the system itself and other electronic and electrical equipment. This paper proposes an innovative method for modeling the three-phase synchronous motor while taking the parasitic effect of interference into consideration. The method can help researchers analyze EMI risks and improve the system.First，the frequency domain characteristics of the common-mode and differential-mode impedance of the motor's three-phase port are obtained upon tests.Then，the characteristics of the single-phase common-mode and differential-mode impedance of the motor are obtained upon mathematical derivation，and high-frequency equivalent circuit models of the single-phase port of the motor are developed through vector fitting. Finally，a complete three-phase circuit model of the motor is constructed based on star connection of single-phase equivalent circuits. Based on this method，an equivalent model of a 140 kW permanent magnet synchronous motor is built，and the accuracy of the model is validated by tests.Results show that this method is compatible with a wide frequency range and has good convergence and high accuracy，and can be cascaded with other electronic and electrical modules to form a complete electric drive system model.The innovative and practical approach can effectively support fast analysis and prediction of system-level EMI and electromagnetic sensitivity.

A specific type of armored steel with high yield strength has been widely used in China to improve the protection performance of armored vehicles. To numerically simulate the dynamic properties of the material，the material’s dynamic constitutive parameters based on the Johnson-Cook constitutive model are calibrated and verified through experiments. First，quasi-static mechanical properties of the armor steel are systematically measured using a universal material testing machine under temperatures ranging from room temperature to 550 ℃.The compression properties of the material are further measured at various strain rates using a separated Hopkinson pressure bar system. Second，based on the Johnson-Cook constitutive model，the measured dynamic properties of the armor steel are fitted to obtain the material’s constitutive parameters. Finally，a monolithic beam made of the armor steel is impacted by a aluminum foam projectile launched from a light-gas gun，and the test results are compared with finite element simulation results obtained using the constitutive parameters and the ideal elastic-plastic constitutive model. The results show that the armor steel demonstrates strong strain rate strengthening effect and thermal softening effect. The relative error between the peak deflection values of the monolithic beam obtained from J-C constitutive model simulation and experimental study is 1.7%-6.1%，and that for residual deflection is 0.6%-7.6%.

The predictive effect of the big-data-driven prediction model on the consumption demand of equipment maintenance materials with small sample size is not ideal. A data simulation expansion algorithm is proposed. The AP clustering algorithm is improved by taking the accumulated equipment consumption at different time stages as similarity measure, and the data at different time stages are clustered by iteration. Each relative equipment consumption in the report stage, in which the data are clustered as the same category, is considered as normally distributed data. The normal distribution characteristics of each component of a vector to be predicted are calculated, and a large number of random samples are generated by using mathematical software as the simulation training samples of the data-driven prediction model. The numerical results show that the simulation training samples generated by this method can effectively improve the predictive effect of the big-data-driven prediction model with few samples, and with the increase in the number of simulation sample data, the predicted results of different prediction models are stable near the same predicted value, which effectively improves the credibility of the predicted results of the data-driven model.

For the problem of accuratedistance measurement of tank reactive armor in complex environment with low extension trajectory，a tank target detection method based on capacitance/magnetic combination is proposed， in which the distance is accurately determined through the capacitance detection，and the ferromagnetic target is identified through the magnetic detection. The composite system is used to solve the interference problem of the complex background environment of the low extension trajectory. The principle of capacitance detection is theoretically analyzed. The electrode distribution of the dual-electrode capacitance detection model is optimized through COMSOL simulation，which effectively improves the accuracy of capacitance detection. The calculation formula of tank magnetic field is theoretically deduced，and the change curve of the magnetic field intensity around the tank target is simulated. The tunnel magnetoresistance is used to design a magnetic detection circuit，which is verified by experiment. A capacitive/magnetic composite target detection and recognition method based on the state machine method is proposed，and the multiple feature quantities are used to improve the target recognition accuracy of fuze. The experimental verification of prototype was made. The result shows that the composite detection method can realize the accurate recognition of ferromagnetic target and meet the fixed distance requirements. At the same time，for the problem of insufficient detection range of the latest reactive armors，a single-electrode detection model is proposed，which can effectively increase the detection range to 2 m through simulation analysis.

In order to effectively damage an armored target with explosive reactive armor(ERA)，it is necessary to study how to avoid the explosive field of ERA.A calculation model for the operating range of proximity fuze based on the low trajectory of tank gun is established on account of the structure and action principle of ERA and high explosive antitank (HEAT) projectile. According to the geometrical relationship of the proposed calculation model，the limiting intersection position of HEAT projectile and ERA as well as the proper operating range of the first-stage proximity fuze can be worked out. The theoretically calculated value of limiting position and the relationship between the operating range of the first-stage proximity fuze and the velocity of HEAT projectile were derived by taking a HEAT projectile as an example.Experimental results show that the critical value of limiting intersection position of HEAT projectile and ERA is approximately equal to its theoretically calculated value，and the theoretical value of this calculation model has higher accuracy and has guiding significance for the actual project design.

A bus voltage control strategy of armored vehicle with electric transmission is proposed for the fluctuating voltage arising in the process of sudden acceleration and deacceleration. A small signal model including the super capacitor and motor loads is developed based on the topological structure of vehicular integrated power system of 8×8 armored vehicle. The causes of two kinds of bus voltage fluctuations are analyzed. A dual-channel compensation control strategy is proposed based on power feedforward control strategy and the negative impedance characteristics of motor loads. The effect of the control strategy is evaluated by hardware-in-loop simulation and prototype vehicle test. The results show that the bus voltage fluctuations caused by sudden acceleration and deceleration are well restrained by using power feedforward control strategy, but it has no influence on the voltage fluctuation caused by negative impedance characteristics. The bus voltage fluctuations are effectively restrained by the dual-channel compensation control strategy, which also improves the anti-interference ability of the system.

A combined power prediction method based on improved grey Markov chain is proposed to solve the problem of low accuracy of demand power prediction for electric drive armored vehicles. The improved grey prediction method and Markov chain prediction method are used to predict the main power and residual power in the load demand power. The predicted results of demand and residual powers at each prediction moment are algebraically added to establish an improved grey Markov chain combination prediction method. The simulated results show that，compared with the traditional prediction method，the proposed demand power combination prediction method can better predict the strong randomness of load power and accurately predict the variation trend of demand power，and the prediction accuracy is increased by 16.49%，which can provide effective reference information for the energy management strategy.

A direct yaw and torque vector control method for 8×8 distributed electric drive armored vehicles is proposed to improve the vehicle's driving stability and take advantage of the hub motor drive.A linear 2-DOF model of vehicle is established to calculate the desired yaw rate and the sideslip angle.A hierarchical controller is designed based on this model. The upper controller is to coordinate the yaw rate and the sideslip angle. The control outputs of the two variables are calculated by using sliding mode control，and the weight function is designed to obtain the yaw torque output. The lower controller divides the eight wheels into four groups according to the axis. Then the torque of each wheel can be obtained according to the yaw moment and longitudinal force by the torque vector synthesis. The real-time simulated results show that the proposed control method can distribute the wheel torque reasonably，control the yaw rate effectively，and improve the vehicle's driving stability.

A dynamic modeling and analysis method considering the coupling effect of drive motor and planetary transmission mechanism is proposed to obtain the electromechanical dynamic characteristics of wheel hub driving system. Based on the spatial electromagnetic force model of driving motor，the radial force，tangential force and torque ripple of the motor are calculated as the dynamic excitation of mechanical system of electric driving wheel. A dynamic model of planetary gear mechanism with flexible shell is established for the electromechanical coupling dynamic simulation of driving motor and planetary gear mechanism.The result shows that the low-order modal of the wheel hub driving system is mainly the global modal， and the high-order modal is mainly the local modal of the planetary transmission system. For the vibration response of the system，the high-order electromagnetic excitation is the main cause in the low speed region，while the low-order electromagnetic excitation is the main cause in the high speed region.

A test research on the wind drag coefficient of tracked armored vehicles is carried out for the problem about the inaccurate wind drag coefficient of high-speed tracked vehicles affecting the calculation of maneuverability. Based on the similarity theory, a series of wind tunnel tests were made for the miniature scale models of armored vehicles. The wind drag coefficient values of different types of tracked armored vehicles were obtained by processing the test data. The results show that, in the aerodynamic design, the wind drag coefficient of 0.92 can be selected for the main battle tank, 0.99 can be selected for self-propelled artillery vehicles, and 0.83 can be selected for infantry fighting vehicles. The test results provide engineering guidance for the precise calculation of vehicle maneuverability.

To solve the problem of easily losing the targets when tracking multiple targets by the current video target tracking algorithms，an improved tracking-learning-detection (TLD) algorithm is presented for multi-target detection and tracking by taking armored vehicles and aircrafts in videos as the research objects.For the lost targets，the trajectories of typical targets in video are tracked by using the prediction function of Kalman filtering algorithm，and the tracked trajectories are used to compensate for the lost parts of TLD algorithm so as to obtain the complete trajectories of typical targets in videos，which is beneficial to improve the accuracy of video multi-target tracking.For the poorer accuracy of the existing trajectory prediction methods，a video target trajectory prediction algorithm based on social long short term memory (Social-LSTM) network is proposed. The algorithm integrates the contextual environment information and the interaction relationship among multiple target trajectories into Social-LSTM network and predicts the trajectories of the typical targets to be detected. Simulation experimental results show the trajectory prediction algorithm is superior to the traditional LSTM algorithm，hidden Markov model (HMM) algorithm，and Gaussian mixture model (GMM) algorithm，which is helpful to improve the accuracy of trajectory prediction for typical video targets.

Rational intelligent and information design of armored vehicles is of great significance to reduce the mental workload and improve the effectiveness of armored vehicle occupants. In order to investigate the influences of intelligent design and complexity of information processing modality on occupant mental workload, and based on a new armored vehicle simulation platform, 20 subjects were selected to carry out a comprehensive experiment on the influencing factors of occupant mental workload according to the typical operational task of armored vehicle commander. The test results show that the NASA-TLX rating scale score, alpha band absolute power and task false operation rate under the condition of high-intelligent task are lower than those under the condition of low-intelligent task, and the saccade average peak speed under the condition of high-intelligent task is higher than that under the condition of low-intelligent task; in the audio-visual dual modalities task, higher NASA-TLX rating scale score, theta band absolute power and average pupil diameter are observed compared with the single visual modality task. The occupant mental workload under the condition of high-intelligent design is significantly lower than that under the condition of low-intelligent design, and the automation operation and intelligent human-computer interaction mode can effectively reduce the occupant workload of occupant under the high demand for information. The occupant mental workload under the condition of audio-visual dual modalities task is significantly increased compared with the single visual modality task, while the use of dual audio-visual modalities information processing mode is conducive to ensure a better performance under multi-task demands. In addition, the different physiological measurement indices have distinguished sensitivity and diagnostic ability to the influencing factors of mental workload.

The theoretical conditions of detonation capability, separation timing and penetration ability of tandem EFP were proposed for the design of tandem explosively formed projectile (EFP) used for anti-explosive reactive armor (ERA). The ERA detonation criterion, EFP velocity decay theory and penetration theory are used to analyze the influences of shape, mass ratio and velocity gradient on detonation capability, separation timing and penetration ability. For the typical ERA of which interference time τ_e is less than or equal to 1 500 μs, the necessary conditions ofthe tandem EFP forming characteristics for distance H≤1 000 ( is charge diameter) are obtained, where 1) for the shape of sphericity-rod combination, the front and rear EFP diameter ratio d_f/d_r≤1.09, the ratio of front EFP mass to total mass is 0.17_{f/m≤0.40, and the front and rear EFP velocity gradient Δv is larger than or equal to 150 m/s; 2) for the shape of rod-rod combination, df/dr≤1.09，0.20≤mf/m≤0.65，Δv≥166 m/s. An EFP warhead that could form the sphericity-rod tandem EFP was designed and processed. The countering ERA linkage experiment was carried out. The process of EFP separating flight, front EFP detonating ERA, and rear EFP penetrating into target were observed by using the high speed photographic system. The experiments verified the correctness of the theory and the necessary conditions.}

The technical status and the lastest research progress of active suspension structure technology for military vehicles are introduced, and the structure and characteristics of electro-hydraulic and electromechanical active suspensions are introduced in detail.The bottleneck problems of active suspension structure for military vehicles are analyzed from the test results of electro-hydraulic and electromechainical active suspensions. The requirements of military vehicle active suspension for structural performance and the key bottleneck technologies are summarized, which are high power density, high reliability and low hysteresis actuator technology. A clear research idea of new active suspension structure is put forward: the innovative introduction of electro-hydraulic composite actuator can not only avoid the large time delay of electro-hydraulic active suspension and the inertial impact of electromechanical active suspension, but also realize the active suspension control.

The current armored equipment for the troops generally present the problem of its bottom out-of-gauge during railway transportation. For the problem above, the loading position of armored equipment is increased to the bottom gauge of Chinese railways by a heightening solution, and the maximum gauge width in the middle of railway is fully utilized in order to achieve the goal of not exceeding the gauge of armored equipment. The expression of determining whether the calculation points are out-of-gauge is derived by establishing a coordinate system, and the calculation points are determined. Then the value range of the elevated height Δh of equipment withoutout-of-gauge is calculated according to the constraints of the overrun equipment, the contour size of load, the boundary outline of railway limit, and the high center of gravity of heavy truck. The feasibility of the heightening solution to solve the problem of out-of-gauge railway transportation of armored equipment is verified.

The normal penetration of explosively formed penetrator (EFP) into armor steel is test and simulated to obtain the origin and axial position of behind-armor debris (BAD) with bigger kinetic energy. The axial distribution of velocity and mass of BAD generated during the normal penetration of EFP into armor steel under the conditions of different thicknesses of target (30-70 mm) and different impact velocities of EFP (1 650-1 860 m/s) were analyzed by the simulation method. The results indicate that the velocities of BAD from target and EFP increase approximately linearly with its axial position, the slope of envelope line is also constant when the target thickness or impact velocity of EFP is constant, and the intercept of envelope lines is affected weakly by debris origin (generated by target or EFP); the heavy (>10 g) BADs from target are in the middle of BAD cloud or close to target, and the heavy (>10 g) BADs from EFP are far from target; and the BADs with bigger kinetic energy are generated by EFP and far from target. Key

An ergonomic test platform of armored vehicle information system is designed and developed to meet the requirement of ergonomic experiment of crew information operation in armored vehicles. The system scheme of test platform is analyzed, including main control system, simulation and test system, and data processing system. Test cabin and console, operation simulator, integrated test device were designed according to the real vehicle situation. Main control, information terminal and fire simulation software were developed. Embedded test method is used to embed the performance test function into the process of operation simulation. The effectiveness and practicality of test platform are demonstrated by a specific example. The results show that the test platform can realize the whole-course test of information operation performance, and the integrated test of cognitive ability, mental workload and physiological parameters. The influences of relative factors on crew information operation performance can be discriminated effectively. Key

In order to get the speed characteristic of engine in misfiring condition, a measuring method for instantaneous speed of engine is researched. The tests are taken on an armored vehicle to simulate the misfire faults in the way of cutting off the fuel, and the instantaneous speed signals are measured in the conditions of normal work, incomplete combustion and misfire. In order to clear the signal noise, the original speed signal is translated into “0-1” series. Fourier analysis is done to show the irregular change of engine speed when engine cylinder is cut out. Furthermore the complexity of the speed signal is analyzed, and K［,C］ complexity is extracted. The result shows that engine cylinder cut out can be recognized by analyzing the complexity of speed.

In allusion to the problem that contribution rate evaluation of weapon equipment system has highly complexity and great difficulty due to multitudinous relation factors, a research framework is proposed based on the systematic analysis of contribution rate conception. For the contribution rate evaluation of a new intelligent armoured combat system, an evaluation index system is established from the viewpoints of functional completeness, architecture optimization, operational capability enhancement and technological progress. The contribution rate evaluation of a new intelligent armoured combat system is systematically studied by using an evidential reasoning approach based on the belief rule base. The result shows that the contribution rate of weapon equipment system is a comprehensive characteristic parameter describing the position and function of weapon equipment system, its evaluation must be systematically studied from multiviewpoints and multilevels, and the evidential reasoning approach based on the belief rule base is an effective, scientific and practical method for solving the contribution rate evaluation of weapon equipment system. Key

The anti-penetration experiments of composite targets with different structures were carried out to study the influence of the arrangement of armored steel in multi-layer heterogeneous composite target on the microscopic mechanism and force state of plastic deformation. The microscopic mechanism of plastic deformation of bullet holes in armor steel is studied based on the theory of metal materials science. The surface hardness distribution and microstructure evolution of armored steel craters are analyzed. The internal relation between the mechanical behavior and deformation mechanism of projectile penetrating into the armored steel is studied through numerical simulation. The results show that the wave impedance matchingis from high to low, the stress wave generated by projectile impact is reflected from the interface between the layers, resulting in the formation of a tensile wave and the crack propagation to reduce the projectile penetration resistance; the internal structure of adiabatic shear zone is affected by temperature andextrusion load, producing high-hardness martensite grains and hindering continued plastic deformation; and the higher the strength and stiffness of armored steel backplanes are, the more is the dislocation movement caused by plastic deformation of armor steel hindered, which is conducive to improve the penetration resistance of target plate. Key

The experiment of stretched rod copper explosion formed projectile (EFP) formed by the shaped charge penetrating into main target add-on typical explosive reactive armor（ERA）with different oblique angle were conducted to reveal the effect of sandwich ERA on penetration efficiency of EFP. The pulsed X-ray photographs of the interaction between ERA and EFP were obtained by flash X-ray experiment, together with residual depth of penetration (RDOP) of residual EFP. The results show that RDOP has a nonlinear decreasing tendency as oblique angle raises. The drop of penetration depth of EFP passing through ERA exponentially increases with ERA oblique angle. When the oblique angles of ERA are 0° and 30°, RDOP and drop of penetration depth keep stabile. But when it grows from 30° to 60°, RDOP declines from 0.50 D to 0.19 D, and the drop of penetration depth grows rapidly from 41% to 77%. On the other hand, the increment of layer thickness results in a heavier reduction in RDOP and the increase in the drop of penetration depth. ERA with 0.027 D layer thickness makes the drop of penetration depth higher 8% on average than it with 0.018 D. The reason for RDOP reduction is analyzed for researching the mechanism of action of EFP and ERA. Key

As the natural fault samples are insufficient in the field test and the evaluated result of the laboratory test is superior to the real testability level of the equipment, a scientific evaluation method of testability is lack for armored vehicles in final stage. For this reason, the test predictive model of testability is modified according to the definition of conditional probability, and the relationship between the test result and the test evaluation mode is studied. A comprehensive test method of testability based on the three test modes,including field test, laboratory test, and analysis and evaluation, ispresented, and a calculation model of test result credibility and a comprehensive evaluation model of testability, which determines the weight of different test results according to credibility, are established. The proposed method and models are validated via applied examples. Results show that the comprehensive testability evaluation method based on the credibility of the test results solves the problem that the samples of field test are insufficient andimproves the practicability of test operation and the scientificalness of evaluation conclusion. Key

A multi-algorithm-based power flow control strategy is established for a kind of power source of series hybrid drive system,in which the disparate control objectives are realized by using different algorithms. The wavelet transform is used to separate the highand low frequency components of the load demand power. The frequency values are distributed to the super capacitor and the power sources with low output cutoff frequency to realize the matching of load frequency characteristic and power source output characteristic. The fuzzy controller is used to realize the optimal control of battery state of charge. A secondaryallocation strategy is designed to control optimally the instantaneous efficiency of system when the low frequency component of optimal load demand power is allocated between battery and engine-generatorset. The simulation analysis and vehicle test results show that the proposed power flow control algorithm can be used for the multiobjective optimization control of multi-power source system, and it is suitable for power flow control of armored vehicle hybrid power system.Key

In order to investigate the penetration resistance of steel fiber reinforced concrete (SFRC), 12.7 mm armor-piercing projectiles and long rod projectiles are used to penetrate a high strength fiber reinforced concrete backed by armor steel in high speed impact test. The penetration resistance of composite target is evaluated using protection factor according to the penetration depth of rear target. The lattice discrete particle model (LDPM) is introduced to model fiber reinforced concrete, and the elastic-plastic model and Johnson-Cook criterion are used to describe the projectile and armor steel. A numerical simulation model for penetration into concrete target is established. The feasibility of numerical model for simulation of penetration into fiber reinforced concrete is validated in terms of penetration depth and concrete target damage mode. The effects of internal gap and fiber content of composite target on penetration response in 3 typical penetration tests are simulated and analyzed. The numerical results show that, for the composite target without gap, the residual penetration depth of rear target can be effectively reduced, and the fiber reinforcement has no effect on the penetration depth but affects the concrete damage mode significantly. Further numerical analyses of fiber reinforced concrete target perforated by 12.7 mm armor-piercing projectiles indicate that the perforation velocity of projectile tends to converge if the diameter of cylindrical target is 30 times larger than projectile diameter, and the residual velocity approximates a linear relationship with impact velocity with the decrease in target thickness. Key

Integrated electronic information system, which is the basis and core to fulfill the informatization of tanks and armed vehicles, has direct impacts on the platform informatization level and tactical capabilities. The development of integrated electronic information system has been constrained to some extent due to lack of clear understanding on its double role as general informatization unit and vetronics function system. The essential meaning of vetronics system is illustrated, and it is concluded that the electronic information system of tanks and armored vehicles relies on system integration. The history and development process of vetronics technology are reviewed and analyzed, and the important technique points of sensor integration, display and control integration, seat role integration, processing and information integration are discussed and summarized. The key technology, as well as the general design process and modeling simulation method of vetronics system are proposed, which could be considered to provide some useful directions for the evolution of the integrated electronic information system of tanks and armored vehicles. Key

A target detection method based on hierarchical multi-scale convolution feature extraction is proposed for the image detection of tank and armored targets. The idea of transfer learning is used to mo-difyand fine-tune the structure and parameters of VGG-16 network according to the target detection task, and the region proposal network and the detection sub-network are combined to realize the accurate detection of targets. For the region proposal network, the multi-scale proposals are extracted from the convolution feature maps of different resolutions to enhance the detection capability of small targets. For the object detection sub-network, the feature maps with high-resolution convolution are used to extract the targets, and an upsampling layer is added to enhance the resolution of the feature maps. With the help of multi-scale training and hard negative sample mining, the proposed method achieves the excellent results in the tank and armored target data set, and its detection accuracyand speed are better than the those of current mainstream detection methods. Key

Three different composite armor systems with 50 mm width or no interspace between different parts were designed to simulate sandwich bulkhead, in which 5 mm-thick steel plate and 10 mm-thick steel plate are used as front and back plates, respectively, and the para-aramid fiber-reinforced plate (AFRP) with areal density of about 60 kg/m² is used as sandwich core. Ballistic experiments are carried out to study the anti-penetration performance of the three para-aramid fiber-reinforced composite armor systems subjected to normal impact by 40 g cylindrical fragments at about 1 630 m/s. The failure modes of surface plate and sandwich core of the composite armor system are presented, the anti-penetration mechanisms of the composite armor systems are analyzed, and the anti-penetration performances of the three composite armor systems are compared. The experimental results show that interspace between different parts has significant effect on the failure modes of AFRP and anti-penetration performance of composite armor system. Key

The vertical ammunition cabin possesses the functions of ammunition storage, recognition and automatic selection. The ammunition vertically placed in the cabin is circularly dragged along the optimum ammunition trajectory by the drive chain. In order to analyze the dynamic properties of drive chain and the stability of ammunition, all links of drive chain and the double-row rollers of ammunition rack are simplified as spring-damper elements. The full dynamics models of drive chain and the stability model of ammunition are established by use of multi-body dynamics and kineto-elastodynamics methods. A numerical simulation of the full dynamics models is performed by adopting Matlab software. The stability modelof ammunition is solved. Simulated results show that the velocity and acceleration of drive chain fluctuate within a small range. The dynamic response and drastic characteristic of centrifugal forces are dominated by the shape feature of the trajectory. The normal stability of ammunition is influenced by the drastic characteristic. The tangential stability is determined by the inertia forces of ammunition and the dynamic parameters of drive chain. The analysis shows that the ammunition has high normal and tangential stability. The tangential accelerations of chain and the normal accelerations of ammunition rack are measured. It can be found that the measured data are consistent with the simulated results. Key

Solid-state phase transformation has significant effect on the evolution and magnitude of welding residual stress for armour steel during welding thermal cycle, while the current constitutive model can not take solid-state phase transformation into account. Based on heat transfer theory, solid-state phase transformation theory and continuum mechanics, a thermo-metallurgical-mechanical coupling constitutive model in which the effects of volumetric change, yield strength change and transformation induced plasticity(TRIP) on residual stresses due to solid-state phase transformation on welding residual stress are considered is established. The constitutive model is inserted into a general purpose implicit finite element program via user material subroutine UMAT. The change rules of temperature, microstructure and residual stresses are obtained for a butt welding of armour steel plates. The research results show that longitudinal residual stresses obtained from the coupling constitutive model are in good agreement with experimental results measured by X-ray diffraction perpendicular to weld centerline on the upper surface of the weldment. The correctness of developed computational method is confirmed, and TRIP has certain effects on the evolution of longitudinal residual stresses. For the magnitude of longitudinal residual stresses in the vicinity of weld zone, the fully-transformed region is less than partially-transformed region, and the partially-transformed region is less than untransformed region. Key

The accurate prediction of operation time is essential to study the operating state of crew in armored vehicle, and is important to improve the operational effectiveness of the man-machine system. In view of a basic trend that the operation type gradually changes into information processing，the information input task is studied，and the operate-units and cognitive process are systematically analyzed. A predictive operation time model is built based on crew’s control and cognitive characteristics. The predictive operation time model is verified through experiment, with an aim to solve the prediction problem of crew’s information processing time under the condition of emergency. The test results show that the proposed model could describe the whole cognitive process of crew’s information input task and predict the reaction times of operate-units accurately. The model has high prediction accuracy and reusability.Key

A simulated equivalent target of passenger compartment of the typical armored personnel carrier is built to investigate the damage effect of shock wave on the advanced armor target. The tests of shock wave in closed cabin were carried out in the conditions of SC static penetration and the static explosion of detonator in cabin. The results indicate that the shaped charge jet can produce a certain damage effect when penetrating the armored cabin; and the test waveforms differ greatly due tocabin vibration, test position, wall reflection and installation methods of sensors when the bulkhead is penetrated by shaped charge jet. Compared with the static explosion of bare charge in cabin, the shock waves produced by shaped charge explosion and jet penetration are more complex, therefore the effective waveform is beneficial to obtain by using the test method of removing the simulated cabin bottom. Key