关于离散时间、时不变系统的可达性与可控性的若干定理

本文对离散时间、时不变系统的可达性与可控性的若干引理、定理及系作出了一个系统的严格的证明。     

Dual-steering mode based on direct yaw moment control for multi-wheel hub motor driven vehicles:Theoretical design and experimental assessment

One of the main challenges for multi-wheel hub motor driven vehicles is the coordination of individual drivetrains to improve mobility and stability in the steering process.This paper proposes a dual-steering mode based on direct yaw moment control for enhancing vehicle steering ability in complex environ-ments.The control system is designed as a hierarchical structure,with a yaw moment decision layer and a driving force distribution layer.In the higher-level layer,the objective optimization function is con-structed to obtain the slip steering ratio,which represents the degree of vehicle slip steering in the dual-steering mode.A yaw moment controller using active disturbance rejection control theory is designed for continuous yaw rate control.When the actual yaw rate of the vehicle deviates from the reference yaw rate obtained by the vehicle reference model and the slip steering ratio,the yaw moment controller is actuated to determine the yaw moment demand for vehicle steering.In the lower-level layer,there is a torque distribution controller based on distribution rules,which meets the requirement of yaw moment demand without affecting the total longitudinal driving force of the vehicle.For verifying the validity and feasibility of the dual-steering mode,simulations were conducted on the hardware-in-loop real-time simulation platform.Additionally,corresponding real vehicle tests were carried out on an eight-wheel prototype vehicle.Test results were generally consistent with the simulation results,thereby demon-strating that the proposed dual-steering mode reduces steering radius and enhances the steering per-formance of the vehicle.     

Effects of module number and firing condition on charge thermal safety in gun chamber

Thermal safety of modular charge which is fed into and retained in the chamber after gun fires consecutively is first investigated with cook-off method.A two-dimensional cook-off model of modular charge in gun chamber is established and the cook-off process of modular charge in gun chamber is numerically simulated.Then the effects of module number and firing condition on charge thermal safety are evaluated by researching the cook-off response characteristics of modules.The results show that,under conditions of different module numbers the cook-off responses all occur on the module closest to the boundary of missile,and the single-base propellants located at the inner surface of cartridge ignite first.When the number of loaded module changes from 1 to 6,the cook-off response temperatures vary little,only in a small range of 478.1 K-482.4 K.The cook-off response times decrease logarithmically in the range of 211.2 s-166.7 s with the increasing length of residual air gap in gun chamber.The simulation results are well matched with the experimental data.Furthermore,different firing conditions have great influence on the cook-off response time,minor influence on the initial response position and little in-fluence on the response temperature.Under the three conditions of consecutive 32 launches with 5 rounds/min,43 launches with 1 round/min,and 41 launches with different firing frequencies,the cook-off response temperatures are 479.2 K,481.1 K and 479.9 K respectively and the response times are 709.2 s,211.2 s and 214.4 s respectively.The response position is near the middle area of the inner cartridge surface in the former condition and near the right area in the latter two conditions.     

多阶段任务系统任务持续能力数学评价模型研究

分析了多阶段任务系统(PMS)及任务可靠度、可信度和任务效能等任务持续能力评价参数。结合实际装备系统大部分属于可用马尔可夫过程进行描述的可修复系统的特点,为简化模型复杂程度提出了一些合理的假设条件。针对两状态PMS,通过分析其状态转移关系,从阶段任务成功概率和阶段任务间转换概率的概念出发,分析给出其计算方法。结合对可信度和任务效能等参数的分析结果,建立其计算模型,从而建立了多阶段任务系统任务持续能力数学评价模型。最后结合常见的“靶场打靶”任务,通过对比仿真结果进行了模型的实例验证。     

基于信息化的国防资源共享机制研究

本文结合我国国防资源信息共享面临的新形势和新要求,对我国国防资源信息共享现状、影响因素及国防资源信息共享的必要性进行了分析,提出推进我国国防资源信息共享的若干措施。     

钛合金材料的等离子弧焊接技术

通过对钛合金管的等离子弧焊接工艺技术探索及分析、试验,掌握了钛合金材料的焊接要点,解决了钛合金在焊接时熔池和高温区的保护措施,改进了保护装置结构和喷嘴尺寸,在合理规范的参数下获得了满意的接头质量。     

美国国防基础研究的政府资助与管理机制研究

本文分析了美国国防基础研究的资助管理体系与国防基础研究的重点领域以及各执行主体的分布情况,总结了美国国防部资助国防基础研究的管理机制及其特点,以期为我国加强国防基础研究的决策与管理提供借鉴。     

浅析军代表处理质量问题的一般程序

本文按照质量问题双归零的原则,从发现问题、分析问题、解决问题三个方面对军品质量问题处理的程序进行了分析,归纳出了六个解决问题的一般步骤,以求为当前军代表处理质量问题提供一些借鉴。     

FAE野外空中爆炸效应实验研究及其一次起爆机理探讨

野外进行1．8kg的FAE静爆实验,采用不同配方的纯固态燃料和液一固混合燃料与等质量的TNT对比分析。实验结果表明,FAE的爆炸效果明显优于等质量的TNT,而纯固态FAE爆炸性能强于液一固混合FAE;FAE爆炸后测到的超压分布呈现单调减趋势,这是由于测量点都分布在云爆区范围之外;FAE的云雾分散效果优于等质量的TNT装药,火焰持续时间也长。通过高速摄影图片看出,合适配方的纯固态无约束的FAE弹体火球的持续时间与有约束的液一固混合FAE弹体相当。分析了纯固态FAE爆炸后超压峰值时刻与火球最大直径时刻不同步的原因,探讨了纯固态FAE一次起爆机理。     

二价阳离子对梭曼的水解作用

实验就4种不同浓度的二价阳离子,研究了它们对梭曼的水解作用和对梭曼水解酶的激活作用．结果表明随着二价钴离子浓度增高,对梭曼催化水解作用增强,其中0．6mmol／L Co^2＋价钴离子对人肝梭曼水解作用最强;18mmol／L Co^2＋对酶的催化水解激活作用最强．