高超声速飞行器的终端滑模姿态控制

针对具有高度非线性、强耦合、含较大不确定性特点的高超声速飞行器,设计了终端滑模控制器,并应用于高超声速飞行器的姿态控制中。对飞行器姿态控制系统的慢回路设计PID控制律,快回路设计终端滑模控制律。终端滑模控制对系统参数的变化不灵敏,具有良好的鲁棒性。并利用李雅普诺夫稳定性理论证明整个闭环系统的稳定性。仿真结果表明,在气动参数大范围摄动的情况下,该控制系统对于高超声速飞行器姿态角信号指令具有良好的跟踪性能。     

不确定参数摄动的高超声速飞行器滑模控制

针对系统内不确定性参数摄动的高超声速飞行器(Hypersonic Vehicles,HV)模型,考虑到传统气动系数简化模型无法真实反映飞行器的气动特性和高超声速下某些不确定性参数摄动的问题,提出了一种改进的气动系数模型,利用改进模型得到准确的气动系数参数,设计了一种基于某些不确定参数的模糊函数逼近的高超声速飞行器滑模控制器。应用模糊函数的强大函数逼近能力对不确定参数进行逼近,应用非线性最小二乘法对改进的气动系数模型进行参数辨识,并与滑模变结构控制结合,提高了系统的鲁棒性,并实现了对系统指令的稳定跟踪控制。仿真结果表明,飞行器在加入速度阶跃指令和高度阶跃指令后,系统能够保持稳定性,并对不确定性参数具有很强的鲁棒性。     

基于扰动观测器的高超声速飞行器递阶滑模控制

针对存在扰动、执行机构死区非线性以及系统不确定性的高超声速飞行器巡航飞行纵向通道模型,提出了带有新型非线性扰动观测器的递阶滑模控制器。递阶滑模控制器采用多层终端滑模面的回归结构,能够保证系统跟踪误差在有限时间内收敛到0. 将执行机构的死区非线性简化为输入的未知扰动,对于系统中存在的由扰动和不确定性产生的复合扰动,设计了新型非线性扰动观测器,补偿作用避免了通过增大系统增益提高控制系统抗扰动性能,同时观测器可以对死区非线性产生的系统扰动进行观测,消除死区非线性对控制系统的影响。理论证明了观测值误差为渐进收敛。基于Lyapunov理论对带有扰动观测器的综合控制系统进行稳定性证明。理论分析和仿真结果表明,该控制策略对高超声速飞行器具有较好的控制作用。     

具有不确定性的高超声速飞行器自适应反演控制

针对飞行器存在气动参数较大的不确定性和外界强干扰的问题,研究了临近空间高超声速飞行器的飞控系统设计问题.首先建立考虑干扰的动力学模型,其次给出一种自适应反演控制律的推导过程,该控制律基于反演思想,并在每一步计算中利用自适应调节函数补偿未知干扰,通过Lyapunov理论对系统稳定性进行证明,最后仿真结果证明了该控制律的有效性和可行性.     

基于向量Lyapunov函数方法的高超声速飞行器着陆段一体化导引与控制律设计

基于向量Lyapunov函数方法,设计了高超声速飞行器着陆段一体化导引与控制律。首先,根据高超声速飞行器着陆段三自由度运动学与动力学模型、阻力加速度动力学模型、姿态动力学方程,在考虑飞行器动力学方程中的不确定因素及可能存在的扰动因素的情况下,推导出制导与控制一体化非线性全耦合模型。然后,将上述非线性全耦合模型抽象为一类具有不确定性和强非线性的MIMO系统,针对该类系统,利用向量Lyapunov函数方法设计鲁棒控制器。最后,通过仿真计算对所提出控制器的有效性进行了检验。     

针对高超声速飞行器的非线性动态逆最优控制

高超声速飞行器具有高度非线性,并且输入输出之间存有耦合.传统控制方案中的线性化处理方法有严重的局限性.采用状态反馈线性化方法对高超声速飞行器纵向模型输入输出线性化,并结合最优控制理论设计控制系统,以求提供满意的非线性解耦控制能力,维持良好的纵向稳定性能.基于某常用的高超声速飞行器模型的仿真研究表明该方案能够使飞行器有效...     

基于自适应滑模控制的高超声速巡航飞行器攻角控制律设计

针对临近空间高超声速巡航飞行器动力系数变化大、攻角要求精确控制的特点,设计了一种自适应滑模变结构攻角控制律。该控制律采用内外环结构,内环通过俯仰角速率反馈提高系统的阻尼、改善动态过程品质,外环控制飞行攻角,用自适应算法调节滑模控制器的控制参数来逼近时变系统参数的上界同时消除外界干扰。仿真研究表明,所设计的攻角控制律响应快、稳态误差小,具有良好的跟踪性能和鲁棒性能。     

基于LADRC的RBCC高超声速飞行器轨迹跟踪

为解决RBCC高超声速飞行器在不确定性强、制导控制量多且相互耦合情况下精确跟踪标称轨迹的难题,从易于工程应用角度出发,提出一种基于线性自抗扰控制的纵向轨迹跟踪制导方法。根据RBCC高超声速飞行器特点建立数学模型。在线性自抗扰控制基本原理的基础上,设计轨迹跟踪制导律。针对自抗扰控制中的Peaking现象,结合比例反馈制导,设计防Peaking制导切换策略。仿真结果表明,相较于传统比例反馈制导,在动态参数扰动和风干扰下,所提方法具有更精确的轨迹跟踪性能,对于各种内外不确定性具有更强的鲁棒性。     

高超声速飞行器鲁棒控制器设计

基于高超声速飞行器高度不确定性的特点。研究了基于H∞理论的高超声速飞行器鲁棒控制器的设计问题。研究了H∞鲁棒控制中的混合灵敏度设计问题，通过选择合适的加权阵，组成广义被控对象，采用Riccati方程求解鲁棒控制器。仿真结果表明：设计出的。控制器能够有效地抵抗飞行过程中存在的多种干扰和飞行参数的摄动，很好地满足了飞行控制系统性能指标。     

吸气式高超声速飞行器制导与控制方法综述

吸气式高超声速飞行器飞行于临近空间环境,飞行速度和高度跨度范围大,气动特性和飞行参数变化剧烈,其动力学模型存在高非线性、强耦合性和不确定性等特点,同时轨迹设计受热流率、动压以及过载等多项约束,给制导和控制系统设计带来挑战,成为当前研究的热点.分析了各种吸气式高超声速飞行器制导和控制方法的特点不足.     

Nitrosation and Nitration of Tetraacetyldibenzylhexaazaisowurtzitane

Tetraacetyldibenzylhitane (TADBIW) was subjected to debenzylation by nitrosating with inorganic materials available commercially to synthesize tetraacetyldinitrosohexaazaisowurtzitane (TADNSIW). TADNSIW was purified, and its structure was determined by FTIR, 1H NMR, MS and element analysis. The debenzylation reaction of TADBIW gave quantitative benzaldehyde as a by-product. This indicates that the reaction produces an imine cation as an intermediate. Hexanitrohexaazaisowurtzitane (HNIW) was prepared from unpurified TADNSIW with the yield over 96.0 % and the purity more than 98.0 %. And the mechanism of the reaction from TADNSIW to HNIW is proposed to be oxidation of nitroso and nitration of acetyl on the molecule of TADNSIW, This reaction system involved is simple, and the reaction can complete within a short time and under mild conditions. The product can be easily to separate and the waste disposed readily.     

A Robust Algorithm for Watermarking 2D Vector Maps with Low Shape-Distortions

The technique of watermarking has been introduced into 2D vector maps for many potential applications such as protecting the copyright of important GIS （geographical information system） data and tracing the data source of military maps. In most previous works, although the validity of the map data could be preserved during the embedding procedure, the shape-distortions of the map elements are usually neglected which would tend to degrade the invisibility of the watermarking schemes. A shape-preserving algorithm for watermarking 2D vector maps is presented in this paper. A 1D distance sequence extracted from the original map is adopted as the cover data instead of 2D coordinates. A watermark bit is represented by changing the distributions of the cover data. The embedding procedure induces lower shape-distortions than in former works. Experimental results indicate better invisibility of the proposed scheme, as well as its robustness to certain attacks such as map simplification, interpolation, additive noise and most geometric transforms.     

Open Rule-setting System Applied to Conceptual Design of Engines

Open rule-setting method advanced in this paper concentrates on providing designers of engines with a convenient way to express their design innovations and develop the expected prototypes in the early CAD stage, and constitute effective models for the following analysis process of CAE and CAPP. The problems arisen in the process of conceptual design with the traditional experience-based development method are analyzed. Based on those analyses, open rule-setting method is presented and some associated technical problems are discussed. The functional framework of open rule-setting system was built as software engineering methods. The speciality of the engine product as a kind of complex product and the requirement of the engine product based on its structural particularity to rule-setting system are considered carefully. A demonstration is supplied to illustrate how the open rule-setting method enhances the efficiency and quality of the engine conceptual design.     

Research on Linux Network Device Driver

By analyzing the working principle of Linux network device driver, discussing the Linux network driver structure and its key technologies, the general network driver structure and its design methodologies in Linux system are summarized. Through modifying the network device driver of Linux device driver 3rd version snull, c and improving the COW technology, the Zero-Copy technology in Linux （kernel version 2.6.11 ） is implemented. In the end, the success test tells us that the thorough analysis of network device driver is the foundation of many applications, and it also provides a certain improvement to a lot of real applications, even to military application development.     

Improvement and Experiment of the Reamer in Vibra Cutter Against Wave Edge of Titanium Sheet Alloy Parts

By analyzing the influencing factors of part quality making of sheet alloy of titanium by vibra cutter, the shape of upper reamer is set as cylinder and wedge-shaped form, and the lower reamer as plain and hemicycle form, and its main structural parameters are defined as well. Then it is validated further that such improved vibra cutter reamer can be used to process curve-edged parts of titanium alloy sheet. The experimental result shows that the titanium alloy sheet parts processed by above equipment have no sharpen angles for convex parts and evident crevasse of concave-edged part. In summary, such improvement can eliminate the free-waved edge and improve the manufacture quality of titanium alloy sheet parts greatly.     

Experimental Study on the Small Flyer Initiating Behavior of Fine-grained Explosives

The initiating behavior of fine-grained explosives by small flyer is studied. The diameter of small flyer in this device is 1 ram. The test results indicate that the granularity of explosives has great effect on its flyer initiating sensitivity.The flyer initiating sensitivity of the fine-grained explosives is higher and the critical initiating energy is lower than that of common explosives. For common explosive, the flyer initiating sensitivity increases as the density is reduced. But for the fine-grained explosive, the test results are exactly opposite.     

Stability of the Third Generation Intensifier under Illumination

The stability under illumination of transmission-mode GaAs photocathode sealed in the third generation intensifier is investigated by use of spectral response testing instruments. The variations of spectral response with the illumination times under weak and intense illumination are compared. The variations of photoemission performance parameters are also characterized. The results show that during initial several weak illuminations photocathode behaves no evident decay and a maximum sensitivity is achieved, while under intense illumination the sensitivity of photocathode begin to decrease largely at the first illumination. The calculated performance parameters show that the variation of surface escape probability with illumination times is a direct cause of instability of photocathode. It is also found that under intense illumination peak wavelength is moved towards short-wave and peak response is decreased, which shows that the ability of long-wave response of photocathode is decreased.     

Algorithm for Multi-laser-target Tracking Based on Clustering Fusion

Multi-laser-target tracking is an important subject in the field of signal processing of laser warners. A clustering method is applied to the measurement of laser warner, and the space-time fusion for measurements in the same cluster is accomplished. Real-time tracking of multi-laser-target and real-time picking of multi-laser-signal are introduced using data fusion of the measurements. A prototype device of the algorithm is built up. The results of experiments show that the algorithm is very effective.     

Robust Graded Sliding Mode Tracking Control for Low Speed Spinning Ballistic Missiles

The nonlinear dynamic model of spinning ballistic missiles is established during the first boosting phase of the missile. Based on the conventional backstepping sliding mode control and the assumption of a two time-scale separation of missile dynamics, a graded sliding mode controller is designed with two sub-sliding surfaces which have invariability to external disturbances and parameter perturbations, and a matrix which comprises three first order low pass filters is introduced to prevent ＂explosion of terms＂. Owing to the upper bounds of the uncertainties are difficult to obtain in advance, adaptive laws are introduced to estimate the values of the uncertainties in real-time. Eventually, the numerical simulation results given to show the proposed controller can ensure the steady flight of missiles.     

A Study on the Estimation of Aeroheating upon the Warhead Nose at Supersonic Speed

An expression for estimating the aeroheating on a warhead nose at different supersonic speeds is proposed by incorporating CFD （computational fluid dynamics） and the least-square method. Compared with the traditional estimation formula, the expression is more accurate, convenient and can be used in the optimized design of warheads. The error from the result obtained in the test of a ball cartridge flight is less than 3 %. It satisfies the engineering requirements.