In order to meet the requirements of wind tunnel test for some large-scale models,a five-degree-of-freedom manipulator should be designed in a specific wind tunnel environment to support the test model to carry out wind tunnel test.By analyzing the gravity and aerodynamic load of the model,the installation and use space of the manipulator and the index requirements,the series-parallel structure is adopted to realize the design of the five-degree-of-freedom manipulator in the specific wind tunnel environment.The results of finite element analysis show that the manipulator meets the requirements of stiffness,strength,accuracy and stroke,and can meet the requirements of wind tunnel test for a kind of model,which is of great value.
In order to solve the problems of difficult development and poor maintainability of display and control logic simulation software of avionics system in current flight training simulator,a modular and loosely coupled display and control system function simulation idea is proposed,in which the display and control logic judgment and display picture simulation are designed independently.The display and control logic simulation module is constructed based on the finite state machine(FSM)theory according to the interactive,multiple input and multiple output temporal logic decision-making characteristics of the display and control system,and is implemented by Simulink/Stateflow.The results show that the design idea and structure are reasonable,the development process is intuitive,and the program is easy to maintain and transplant,which is conducive to improving the display and control logic simulation and development efficiency.
In order to realize convenient and efficient workflow aided design and parameter optimization,the object-oriented type and graphical editing interface for parameter configuration of graphic elements such as arrow lines and nodes are designed for the activity-on-arrow network diagram,which can automatically generate the relationship model of graphic elements while the user edits the network graph.Topology traversal is used to automatically determine the standardization of the network diagram,calculate the critical path and time parameters,and provide a convenient tool for users to optimize the workflow.The results show that the design can provide assistance for multi-domain workflow optimization.
In order to study the secondary engraving problem caused by the unequal rifling height between the revolver bushing and the barrel bushing of revolver automata,a finite element model reflecting the rifling height difference was established to analyze the secondary engraving process of the belt.Through numerical simulation,the stress,deformation and temperature were obtained when the belt was completely squeezed into the revolver bushing and the barrel bushing.The simulation results were in good agreement with the notch of the belt recovered in live firing,which indicated that the established finite element model had a certain credibility.The simulation results show that the unequal height of the bore liner and the barrel liner has a significant effect on the belt squeezing process.The half-height bore liner can make the belt squeeze into the bore liner more smoothly,but the belt will produce stronger impact when it squeezes into the barrel liner for the second time;Full-height rifling is more difficult when the belt is squeezed into the revolver liner,but it is smoother when the belt is squeezed into the barrel liner twice.
Aiming at the problems of machining errors and installation errors in the production process of a certain type of solid material propellant,a compensation strategy for positioning position errors was proposed.By Using the DH method which is commonly used in the field of robotics,the kinematics modeling is carried out,the modeling parameter error is regarded as a variable that changes with the drive command,and the coordinate measuring machine is used as a measuring tool to identify the actual axis equation of the linear axis and the rotary axis,and then the state matrix of the actual coordinate system of each link is re-established.The relationship curve between the errors of the elements of the actual homogeneous coordinate transformation matrix and the given driving instructions is fitted,and the ideal homogeneous coordinate transformation matrix is compensated.Simulation results show that the position error is reduced by about 40%after compensation,which verifies the effectiveness of the method.
Aiming at the problem of domestic CPU chip substitution,combined with the technical requirements of CAN communication,the domestic chip substitution scheme is designed,and the implementation and performance test of the hardware and software improvement scheme of chip universality are carried out.The application results show that the design verifies the substitutability of the selected domestic chips and the correctness of CAN bus optimization.
In order to meet the actual needs of combat,based on the improved particle swarm optimization(PSO)algorithm,the β algorithm and the oscillation value theory are proposed as constraints to build a mathematical model to establish the time and space coordination relationship between missiles in multi-position and multi-direction assault water surface ship operations.The results show that the model has fast convergence speed and can effectively solve the problem of missile route planning in joint action.
Conduct an analysis of operational evaluation methods for the six stages of the US military joint objective work cycle.The main steps for the US military to conduct operational evaluation are analyzed from four aspects:operational damage assessment methods,collateral damage assessment methods,ammunition efficiency assessment methods,and re attack suggestions.Suggestions are proposed to strengthen theoretical research on operational evaluation,improve operational mechanisms for operational evaluation,strengthen the talent team for operational evaluation,and enhance the level of information technology construction in operational evaluation.The results indicate that this analysis can provide reference and guidance for our military's organizational combat evaluation.
Since it is difficult to measure the comprehensive camouflage effect of adaptive camouflage targets in multiple backgrounds by using the camouflage evaluation method in a single background,a method for evaluating the optical camouflage effect of adaptive camouflage targets in multiple backgrounds is proposed.Selecting several typical backgrounds,evaluating the optical camouflage effect of the target under each background,classifying the ground objects in the target activity area according to the satellite-borne hyperspectral image,and determining the area proportion of each typical background in the area;The proportion of each background is taken as the proportion of the evaluation results in the comprehensive evaluation under the background,and the evaluation results of each typical background are weighted to obtain the comprehensive evaluation results under the complex background.The experimental results show that the method quantifies the comprehensive camouflage effect under multiple backgrounds,and its evaluation results are more objective and comprehensive than the traditional evaluation,which is more in line with the actual situation of the target's activities in multiple backgrounds.
Aiming at the problem that the long range rocket artillery strike platform will face the battle test in the multi battlefield environment in the future,an evaluation method using cloud model is proposed.On the basis of building the operational effectiveness evaluation index system of the long-range rocket artillery strike platform,the operational effectiveness of the long-range rocket artillery strike platform in different battlefield environments is evaluated;Experiments show that the complex battlefield environment has an impact on the operational effectiveness of the long-range rocket artillery attack platform.The experimental results show that this method can provide support for finding out the base of the combat capability of the long-range rocket artillery attack platform in different battlefield environments,improving the equipment development of the long-range rocket artillery attack platform and the targeted application practice of the army.
The destruction of waste ammunition is of great significance to eliminate the hidden dangers of explosion accidents.Based on the safety requirements of blasting destruction of various waste ammunition found in civil construction,a small shaped charge destruction device is designed by using the principle of impact detonation of shaped charge to shelled charge.Considering the requirements of size,power and field adaptability,the structural parameters of the destruction device are optimized and determined,and the static armor-piercing and impact detonation simulation projectile body tests are carried out.The test results show that the destruction device has strong impact detonation ability,high reliability for common waste ammunition,and is easy to set up and use,which can provide a reference for the design of similar devices.
In order to solve the problems of traditional manufacturing enterprises,such as the lack of digital capability construction and the lack of effective underlying software support for the monitoring and scientific management of workshop operation status,the research and implementation of digital twin workshop based on real-time data acquisition and storage analysis are carried out.Establish the digital model of the key elements of the production workshop,such as human,machine,material,method and environment;realize the process management and control of the whole life cycle of production and manufacturing through the establishment of production plan management module and production execution management module;realize the acquisition,storage,analysis and monitoring of real-time data in the manufacturing site through the establishment of data acquisition and monitoring system;Establish quality management and analysis through the binding of quality data and products.The results show that the research and implementation process of digital twin workshop completes the collection,integration and monitoring of workshop production and manufacturing data,and realizes the digital transformation and intelligent promotion of manufacturing workshop.
In order to analyze the damage caused by the delayed firing fault to the external energy source automatic machine,a three-dimensional model of the automatic machine at the time of locking and firing was established.Based on the contact finite element theory,the nonlinear structural dynamic model of the automatic breech mechanism was established according to different breech opening times.The explicit time integration method was used to simulate the firing process,and the stress and failure of the main components of the automatic breech mechanism under the late firing state were analyzed,and the stress changes of the dangerous section and the damage of the cartridge case under the chamber pressure were obtained.The results show that the locking tooth root and the contact surface are damaged,the bottom of the cartridge case is broken,and the damage degree of the automatic mechanism is different under different delay time.The damage analysis of the late firing fault is consistent with the experimental results,which can provide a basis for the design of the late firing safety mechanism.
In order to solve the problem of polygon effect in the chain rotating structure of chain rotating magazine,a rotary automatic magazine with the projectile vertical placed is designed.The method of multiple chain links corresponding to one ammunition storage cylinder is adopted to reduce the pitch of the chain links used in the conveying chain,so as to reduce the polygon effect and dynamic load of the rotating magazine and improve the stability and accuracy of projectile transmission;Under two different conditions of low-speed rotation and high-speed rotation,the dynamic simulation of the movement process of a round of projectile conveyed by the vertical projectile rotating magazine is carried out.The results show that the lateral motion error of the projectile is small,and the longitudinal runout is small,which meets the requirements of stable motion and reliable transmission.
In order to improve the long-range attack capability of our amphibious assault ship,the adaptability of foreign ships and aircraft is analyzed.This paper analyzes the technology status of foreign short/vertical takeoff and landing(SVTOL)aircraft,analyzes the compatibility of warship and aircraft from the perspective of warship overall design,and puts forward the key technologies.Combined with the large amphibious ships of the United States,Japan and Italy,the refitting project of carrier-based aircraft on board is analyzed.The results show that the analysis can provide a reference for scientific research and production in related fields in China.
In order to improve the prediction accuracy of nitrogen oxides(NOx)mass concentration at the inlet of denitration system,a combination algorithm prediction model of principal component analysis(PCA)and an extreme learning machine(ELM)with multi-layer self-coding structure based on mutual information is proposed.The selection of input variables is improved,and the network structure of the prediction algorithm is optimized by adding the historical NOx mass concentration.The experimental results show that compared with other prediction algorithm models,the proposed model has higher prediction efficiency and higher prediction accuracy under different working conditions,and shows good anti-noise ability and generalization ability.
In order to solve the problem of firing deviation caused by the roll of a recoilless gun,a coordinate system method for shoulder-firing was proposed.This paper describes the gun attitude change,establishes the calculation model of firing deviation under the state of roll,and analyzes the influence of roll on the gun firing accuracy,so as to improve the firing accuracy and damage effect of the gun.The results show that the method can provide reference for fire control to correct firing deviation.
针对当前在役考核评估困难的问题,提出一种基于直觉梯形模糊多属性决策的综合评估方法.构建在役考核概念模型,阐述其基本内涵及评估指标;构建在役综合能力评价矩阵,利用直觉梯形模糊数将语言评价矩阵转换为标准评估矩阵;利用AHP与熵权法计算各指标组合权重,采用TOPSIS法进行综合评估,得到装备在役综合能力评估结果.仿真结果表明,该方法在装备在役考核综合能力评估应用中合理有效.
为回答轻武器射表是什么、有什么用和怎么用的问题,提出一套完整的轻武器射表实战应用方法.针对实战中需要应用射表的典型案例进行解析,分析弹道偏差产生机理,并以射表数据为基础,给出射击诸元解算及修正方法.结果表明,该方法为提升步兵战斗人员射击技能提供有效易行的解决方案.
针对快速随机树(rapidly-exploring random tree,RRT)算法盲目生成搜算节点、扩展无方向性和路径曲折不光滑等问题,对传统RRT算法进行改进.通过引入概率值,减少生成的随机点;采用目标偏置策略,引导随机树向目标点生长,利用变步长减少目标点附近的震荡;对路径进行简化并通过3次B样条曲线对初始路径进行优化.仿真结果表明:改进的R RT算法能有效缩短路径长度,减少转折次数,提高路径的平滑性,具有良好的有效性.
