助推-滑翔式导弹中段弹道方案的初步分析

建立了助推—滑翔式弹道中段的无量纲运动方程。采用非线性规划方法实现弹道优化。首先求解不同初始速度、速度倾角和最大升阻比的最大射程弹道,然后考虑驻点热流、过载约束,求解总气动加热最小和射程最大的最优弹道。基于前者的计算结果分析了初始条件对最大射程弹道的影响。将考虑约束的再入滑翔弹道与弹道式再入的特征参数比较,表明再入滑翔弹道的峰值热流较小,而总气动加热增加,但再入滑翔飞行时间在一般锥形体再入机动飞行器的热防护系统可承受的时间范围内。     

基于NFxPEM算法的调制气流声源的非线性补偿研究

针对调制气流声源存在较强的谐波畸变,将声源系统等效为Hammerstein非线性模型,利用该模型下的预失真技术对声源进行非线性补偿研究。根据辨识的Hammerstein模型中静态非线性部分带有直流分量的特点,给出了考虑直流分量补偿的预失真算法,并用数值仿真验证了算法的准确性和直流分量补偿的必要性。在非线性补偿实验中,根据单频信号辨识得到Hammerstein模型参数,采用NFxPEM算法求得对应的预失真Wiener模型参数和预失真波形。实验结果表明,与直接发射相比,补偿发射后声波的功率谱中谐波能量有所下降,而基频能量有小幅度的上升,说明了研究思路的正确性。     

空间光通信粗瞄系统的扰动估计与补偿

粗瞄系统以直流力矩电机驱动二维转台为执行机构,通过粗瞄控制器对其进行控制。对系统受到的扰动进行分析,应用了最速跟踪微分器提取速度信号;以二维转台的方位轴为控制对象,在其位置环、速度环采用级联线性自抗扰控制器,通过线性扩张状态观测器主动补偿扰动,达到内外环双重隔离扰动的目的,提高跟踪精度;之后进行了实验分析。分析结果表明:在加入同样的模拟扰动信号,输入2 Hz,5 Hz和8 Hz的正弦信号时,与比例、微分、积分控制器相比,跟踪误差的标准差约降低50%;验证了线性扩张状态观测器具有扰动补偿效果;在输入不同频率正弦信号时,自抗扰控制器对输入信号频率的变化不敏感,仍能保证较高的跟踪精度。     

基于小波的信噪分离方法

本文在 Ｄｏｎｏｈｏ 提出的从噪声中恢复信号的非线性小波方法的基本原理的基础上, 并针对非线性小波方法的核心问题——浮动阈值的设定提出了新的算法。通过算例证明, 所设计的浮动阈值在实际应用中效果较好, 特别在低信噪比时信号恢复效果明显优于现常用的浮动阈值设计方法。     

疲劳裂纹闭合的非线性超声在线测量

建立了外部载荷作用下用非线性振动-声场调制指数表征裂纹尺寸的数学模型。根据对外载荷与塑性致闭应力共同作用下裂纹面的开闭响应的分析,提出了裂纹张开和闭合应力的在线测量方法。在一块含中心穿透裂纹的铝合金薄板试件上进行了裂纹闭合参数的测量实验,实验结果表明,使用振动-声场调制技术在线测量裂纹闭合参数是可行且有效的,且该方法还能用于分析小裂纹的特殊开闭行为。     

Optimal motion planning in rapid‐fire combat situations with attacker uncertainty

This article provides a modeling framework for quantifying cost and optimizing motion plans in combat situations with rapid weapon fire, multiple agents, and attacker uncertainty characterized by uncertain parameters. Recent developments in numerical optimal control enable the efficient computation of numerical solutions for optimization problems with multiple agents, nonlinear dynamics, and a broad class of objectives. This facilitates the application of more realistic, equipment‐based combat models, which track both more realistic models, which track both agent motion and dynamic equipment capabilities. We present such a framework, along with a described algorithm for finding numerical solutions, and a numerical example.     

谈公安边防部队处置边境地区暴（骚）乱事件中的组织指挥

针对当前边境地区日趋复杂的暴（骚）乱事件的特点,就公安边防部队处置边境暴（骚）乱事件的有效方式、组织指挥进行研究探讨,提出建立警民一体联合指挥机构、运用信息手段、正确运用战法等相应对策。     

Integrated guidance and control of guided projectile with multiple constraints based on fuzzy adaptive and dynamic surface

Based on fuzzy adaptive and dynamic surface (FADS), an integrated guidance and control (IGC) approach was proposed for large caliber naval gun guided projectile, which was robust to target maneuver, canard dynamic characteristics, and multiple constraints, such as impact angle, limited measurement of line of sight (LOS) angle rate and nonlinear saturation of canard deflection. Initially, a strict feedback cascade model of IGC in longitudinal plane was established, and extended state observer (ESO) was designed to estimate LOS angle rate and uncertain disturbances with unknown boundary inside and outside of system, including aerodynamic parameters perturbation, target maneuver and model errors. Secondly, aiming at zeroing LOS angle tracking error and LOS angle rate in finite time, a nonsingular terminal sliding mode (NTSM) was designed with adaptive exponential reaching law. Furthermore, combining with dynamic surface, which prevented the complex differential of virtual control laws, the fuzzy adaptive systems were designed to approximate observation errors of uncertain disturbances and to reduce chatter of control law. Finally, the adaptive Nussbaum gain function was introduced to compensate nonlinear saturation of canard deflection. The LOS angle tracking error and LOS angle rate were convergent in finite time and whole system states were uniform ultimately bounded, rigorously proven by Lyapunov stability theory. Hardware-in-the-loop simulation (HILS) and digital simulation experiments both showed FADS provided guided projectile with good guidance performance while striking targets with different maneuvering forms.     

考虑非线性退化与随机失效阈值的剩余寿命预测

针对广泛存在的非线性退化设备,现有方法尚未考虑随机失效阈值对剩余寿命预测结果的影响。因此,通过对设备性能退化过程进行分析,提出了一种综合考虑非线性退化与随机失效阈值的剩余寿命预测方法。基于Wiener过程构建了考虑个体差异与测量误差的非线性退化模型;基于卡尔曼滤波算法建立状态空间模型以实现对退化状态的在线更新;基于极大似然法估计失效阈值分布系数估计方法,得到随机失效阈值的概率分布;基于随机失效阈值推导出剩余寿命的概率分布,实现对剩余寿命的在线预测。算例研究表明,所提方法可以有效地提升剩余寿命预测的准确性,具备一定工程应用价值。     

超连续谱激光光源研究进展

高非线性光纤制造技术的成熟和光纤激光器性能的提升,极大地促进了超连续谱光源的快速发展,以光纤为非线性介质的超连续谱的产生成为当前研究热点。从可见光、近红外和中红外3个不同波段,综述了超连续谱产生的技术方案与最新进展。当前,可见光和近红外波段的超连续谱光源输出功率已经突破百瓦量级,并出现了多芯光子晶体光纤、光纤放大器和随机光纤激光器产生超连续谱等众多新方案;以氟化物光纤和亚碲酸盐光纤为非线性介质的中红外超连续谱,输出功率也突破了十瓦量级;在光谱拓展方面,以硫系光纤为非线性介质的超连续谱,输出光谱已扩展到12μm以上。