Trajectory tracking guidance of interceptor via prescribed performance integral sliding mode with neural network disturbance observer

This paper investigates interception missiles’trajectory tracking guidance problem under wind field and external disturbances in the boost phase.Indeed,the velocity control in such trajectory tracking guidance systems of missiles is challenging.As our contribution,the velocity control channel is designed to deal with the intractable velocity problem and improve tracking accuracy.The global prescribed performance function,which guarantees the tracking error within the set range and the global convergence of the tracking guidance system,is first proposed based on the traditional PPF.Then,a tracking guidance strategy is derived using the integral sliding mode control techniques to make the sliding manifold and tracking errors converge to zero and avoid singularities.Meanwhile,an improved switching control law is introduced into the designed tracking guidance algorithm to deal with the chattering problem.A back propagation neural network(BPNN)extended state observer(BPNNESO)is employed in the inner loop to identify disturbances.The obtained results indicate that the proposed tracking guidance approach achieves the trajectory tracking guidance objective without and with disturbances and outperforms the existing tracking guidance schemes with the lowest tracking errors,convergence times,and overshoots.

Time-varying fault-tolerant formation tracking based cooperative control and guidance for multiple cruise missile systems under actuator failures and directed topologies

This paper studies time-varying fault-tolerant formation tracking problems for the multiple cruise missile system under directed topologies subjected to actuator failures. Firstly, the timevarying fault-tolerant formation tracking process for the multiple cruise missile system is divided into the guidance loop and the control loop. Then protocols are constructed to accomplish distributed fault-tolerant formation tracking in the guidance loop with the adaptive updating mechanism, in the condition where neither the knowledge about actuator malfunctions nor any global information of the communication topology remains available. Moreover, sufficient conditions to accomplish formation tracking are presented, and it is shown that the multiple cruise missile system can carry on the predefined time-varying fault-tolerant control (FTC) formation tracking through the active disturbances rejection controller (ADRC) and the proportion integration (PI) controller by the way of the fault-tolerant protocol utilizing the designed strategies, in the event of actuator failures. At last, numerical analysis and simulation are designed to verify the theoretical results.

Consecutive tracking for ballistic missile based on bearings-only during boost phase

This paper proposes a modified centralized shifted Rayleigh filter（MCSRF） algorithm for tracking boost phase of ballistic missile（BM） trajectory with a highly nonlinear dynamical model based on bearings-only.This paper contributes three folds.Firstly,the mathematical model of an MCSRF for multiple passive sensors is derived.Then,minimum entropy based onedimensional optimization search to adaptively adjust the probability of the different filters for real time state estimation is deployed.Finally,the unscented transform（UT） is introduced to resolve the asymmetric state estimation problem.Simulation results show that the proposed algorithm can consecutively track the BM precisely during the boost phase.In comparison with the unscented Kalman filter（UKF） algorithm,the proposed algorithm effectively reduces the tracking position and velocity root mean square（RMS） errors,which will make more sense for early precision interception.

Multi-target tracking algorithm of boost-phase ballistic missile defense

Considering the problem of multiple ballistic missiles tracking of boost-phase ballistic missile defense, a boost-phase tracking algorithm based on multiple hypotheses tracking （MHT） concept is proposed. This paper focuses on the tracking algo- rithm for hypothesis generation, hypothesis probability calculation, hypotheses reduction and pruning and other sectors. From an engineering point of view, a technique called the linear assignment problem （LAP） used in the implementation of M-best feasible hypotheses generation, the number of the hypotheses is relatively small compared with the total number that may exist in each scan, also the N-scan back pruning is used, the algorithm＇s efficiency and practicality have been improved. Monte Carlo simulation results show that the proposed algorithm can track the boost phase of multiple ballistic missiles and it has a good tracking performance compared with joint probability data association （JPDA）.

Three-Dimensional Discrete Observability Analysis for Air-to-Air Missile Target Tracking

The interception information of infrared（ IR）-guided air-to-air missiles（ AAM） is mainly estimated only using the basic bearing measurements. In order to intercept highly maneuverable targets,it is essential to study the system observability to improve the target tracking system performance.The uniqueness of this paper is that the observability analysis is derived based on a discrete three-dimensional （3D） system model. During the maneuvering scenario,the system is approximated by a segment-by-segment system. The relationship between missile-target motion and observability is given by direct and dual approaches. Meanwhile sufficient observability conditions are derived. Moreover,a numerical simulation is conducted and an alternate method is provided to reinforce the proposed observability analysis results.

Study on video intelligent early warning and tracking system based on ARM

The protrusion of the planning of numerical intelligent early-warning and tracking system in this study which can ease triggerman's work strength,lay the next generation intelligence supervision system foundation and expand effectively the video resources use etc. In the numerical intelligent early-warning matrix sub-system,the authors have designed a kind dual-core system which includes both ARM and DSP,and designed detailedly traffic dynamics affairs early-warning arithmetic which bases on that system. And then,this system will carry quickly on fixing the right position of license plate,correcting the inclination degree of license plate,and thinning it to get the number of this license and severity grade. Secondly,in the rotated dome camera sub-system,the authors have designed three-dimensional trajectory mathematical model which makes use of a fuzzy PID controller to achieve the high- speed track. At last,Simulation shows that the proposed control method has high profile tracking precision,accuracy and robustness of the disturbance.

Target-tracked prioritization to surveille ballistic missiles

The missile-tracked priority assessment for the early warning system monitoring multi-missile very well, is the first task to defend them and useful to perform optimally the sensor-to-missile assignment. The problem of the missile-tracked priority assessment is of incomplete information, of multi-attribute and dynamic. To solve the dificult problem, the index system, which includes six classification indices, is established by means of reducing the target＇s primary information which the early warning system focuses on. The lack of some attributes values, which is caused by the incomplete information, is handled by the approach： first classifying each attribute as unknown one or known one, and then subdividing the latter, last using the expectation and the information entropy if the attribute is known but uncertain. With a view of reality, nine qualitative evaluation criteria are given. Based on them each index is quantified by the eigenvector method. And then based on the improved technique for order preference by similarity to ideal solution （TOPSIS）, the targets-tracked priorities are assessed and sorted by an evaluation function from three aspects： 1） the quantity of the available information, 2） the affirmative or accurate degree of the available information, 3） the classification or trait of the available information.

Real-time lane departure warning system based on principal component analysis of grayscale distribution and risk evaluation model

A technology for unintended lane departure warning was proposed. As crucial information, lane boundaries were detected based on principal component analysis of grayscale distribution in search bars of given number and then each search bar was tracked using Kalman filter between frames. The lane detection performance was evaluated and demonstrated in ways of receiver operating characteristic, dice similarity coefficient and real-time performance. For lane departure detection, a lane departure risk evaluation model based on lasting time and frequency was effectively executed on the ARM-based platform. Experimental results indicate that the algorithm generates satisfactory lane detection results under different traffic and lighting conditions, and the proposed warning mechanism sends effective warning signals, avoiding most false warning.

复杂多方向威胁下的导弹预警雷达优化部署方法

针对现有导弹预警雷达部署相对独立、协同困难,难以满足大规模对抗场景的现状,从远程预警雷达、跟踪识别雷达、机动式预警雷达不同的任务特点出发,建立应对复杂多方向威胁的多型导弹预警雷达优化部署模型,在满足最优覆盖、协同交接、目标识别等任务约束下,解决雷达协同部署问题。针对所提模型设计了一种基于云自适应的分区优化离散粒子群(CPBPSO)算法,通过设计分区编码策略缩减算法求解空间、加入云自适应变异算子提高算法全局寻优和局部跳出能力,使算法更适用于导弹预警雷达部署问题的处理。实例验证了所提模型在求解单方向、多方向威胁场景部署问题的可行性,对比分析了CPBPSO算法的有效性,基本满足导弹预警雷达最优化协同部署的需求。

医院传染病实时监控、预警和追踪管理系统的研发及应用效果追踪评价

目的通过研发“医院传染病实时监控、预警和追踪管理系统”,实现实时监测预警,生成报告卡,形成传染病个案追踪管理、全程闭环管理。方法选取2020年4月—2022年10月传染病报告22185例,与2022年11月—2024年5月传染病报告33640例,对比新的传染病预警管理系统上线前后19个月时间与上线前原传统传染病报告管理方式传染病报告管理情况,对比传染病报告率、传染病报告准确率、传染病报告及时性(时间)、传染病追踪成效、临床医务人员传染病报告满意度进行对比分析。结果新的医院传染病预警和追踪管理系统使用后,对传染病报告率、传染病报告准确率、传染病报告及时性、传染病追踪成效和临床医务人员传染病报告满意度成效对比差异均有统计学意义(P<0.05)。结论研发“医院传染病实时监控、预警和追踪管理系统”在传染病报告率、传染病报告准确率、传染病报告及时性、传染病追踪成效和临床医务人员传染病报告满意度成效均显著提高,具有实时、高效、准确的特点,预警和追踪管理效果良好,具有很好的推广价值。

油气行业作业人员不安全行为智能预警方法探讨

油气行业涉及领域广,从业人员在作业过程中通常面临复杂的生产工艺、恶劣的工作环境及高强度的工作状态等,油气行业事故发生率常年居高不下,其中人为失误等事故原因所占比例超过70%。实现油气行业作业人员不安全行为的智能预警,对于减少油气行业事故的发生具有重要意义。油气行业作业人员的不安全行为主要包括错误行为与安全隐患行为。针对作业人员的不安全行为识别和预警,目前主要采用人员检查、事后分析及视频监控等方法,但是上述方法分别存在无法实时识别作业人员的错误行为,无法识别和预警作业人员的安全隐患行为等。视线追踪技术是通过捕捉作业人员的注视点与注视时间的变化过程,从而判断作业人员当前工作状态的一项技术。该技术具有反应灵敏、准确度高、无死角与可穿戴等特点,在医疗健康、交通安全、心理学等领域均已有较好的应用。利用视线追踪技术在人员状态监测等方面的优势,将其引入到油气行业作业人员不安全行为的识别或预警方法研究,用以探讨在该领域实现作业人员不安全行为智能预警的可行性。

基于节点重要性和改进效能环的防空反导预警体系能力评估

针对防空反导预警体系能力评估中存在的现实性较弱、考虑异质特性较少和能力计算不够全面等问题,提出基于节点重要性和改进效能环的体系能力评估方法。依托超网络模型对体系结构进行抽象建模,给出具有现实意义的效能环模型。从网络全局和局部节点的重要性出发,根据节点之间相互影响关系对效能边进行分析,并结合节点的重要性和可靠性提出体系的能力期望,从而改进基于效能环的体系能力评估方法。反导预警作战的案例仿真分析结果表明:新方法具有可行性与合理性,充分考虑了防空反导预警体系的现实特性和装备的异质特征,能够较全面地评估体系作战能力,为体系的能力评估和结构优化提供理论支撑。

强跟踪容积卡尔曼滤波在空空导弹制导中的应用

针对传统滤波算法在处理目标复杂机动时非线性逼近能力不足、跟踪精度下降等问题,提出一种强跟踪容积卡尔曼滤波(STCKF)方法。首先,根据战斗机规避空空导弹的机动特征,建立了蛇形机动和桶滚机动两种目标运动模型;其次,引入强跟踪滤波(STF)以增强容积卡尔曼滤波(CKF)对系统状态突变等不确定因素的能力;然后,将STCKF应用于导弹末制导目标运动参数估计中,并通过与CKF、无迹卡尔曼滤波(UKF)和粒子滤波(PF)的对比仿真分析验证了该方法的有效性。仿真结果表明,STCKF具有较强的鲁棒性和系统自适应能力,尤其在目标机动突变时其跟踪误差相比CKF减小约10%,能够满足空空导弹末制导高精度和快速响应要求。

基于载机视觉信息的改进视线制导律设计

针对无人机机载武器低成本精确打击的需求,提出利用机载光电吊舱获取制导信息、采用视线制导法进行制导律设计的方案。通过分析载机、导弹和目标的运动关系,建立了系统状态空间模型,基于反步法和滑模控制设计了改进视线制导律。对制导律中无法由载机获取的参数进行了讨论,采用跟踪微分器提取视线角并估计视线角速度信息。数值仿真结果表明,在视线角存在噪声且导弹矢径拉偏的情况下,改进视线制导律仍可保证对地面目标的精准打击。与传统视线制导律相比,载机的运动方向不受限制,可在发射导弹后远离目标以免受到威胁,符合现实需求。

江苏沿海台风风暴潮特征分析

收集了1950—2022年影响江苏沿海的历史台风风暴潮过程资料,对引起江苏沿海台风风暴潮的台风路径进行了分类和分析,开展了江苏沿海台风风暴潮的月际分布和年际变化研究,提出了不同路径台风风暴潮的预报要点。结果表明:引起江苏沿海台风风暴潮次数最多的是外海转向型台风,占比高达44.3%,而正面登陆型台风最少,占比只有5.4%,但引起的增水量值最大;江苏沿海台风风暴潮在6—10月均有出现,8月出现次数最多;风暴潮强度等级为Ⅴ级(增水50~100 cm)的过程占比最多,为42.7%,而高潮位超警戒程度等级为Ⅳ级(超警戒30 cm之内或达到黄色警戒潮位值)的占比最多,为45.0%;风暴潮发生次数在近几年呈上升趋势,尤其是增水为50~100 cm的过程,高潮位超警戒或达到黄色警戒潮位值以上的过程在近20年只出现3次;在江苏沿海台风风暴潮的预报和应对中,需要重视可能正面登陆的和9—10月的外海转向型台风;8月和9月是江苏沿海出现风暴潮灾害可能性较高的月份,若这两个月的天文高潮与风暴增水叠加合适,极有可能出现达到黄色警戒潮位以上的高潮位。

首要教学原理下反导预警雷达探测技术课程教学改革

针对反导预警雷达探测技术课程教学中存在的基础衔接不流畅、高阶挑战有差距、理实一体落实差问题,以“为战育人”为核心导向,引入首要教学原理,提出了课程的“聚焦问题-激活旧知-示证新知-应用新知-融会贯通”五步教学方法.教学实践表明,该教学方法用于反导预警雷达探测技术课程教学改善效果明显.

基于STK的反导预警雷达作战场景仿真分析方法

针对有先验信息的类弹道导弹发射活动,提出了一种基于卫星工具软件(STK)的反导预警雷达作战场景仿真分析方法,利用STK软件可视化设计的优势,对反导预警雷达拦截搜索屏进行设计,并对搜索屏的拦截效果进行评估.这对进行雷达总体设计的相关人员,具有一定的实用价值.

基于特征融合的轻量化巡飞弹目标跟踪算法

针对巡飞弹平台上的视觉目标跟踪算法,开始引入深度学习思想,但是受到硬件平台算力限制的影响,提出一种轻量化的基于深度学习的孪生网络框架,在较低计算量的情况下保证巡飞弹的跟踪性能。根据IOU质量评估分支和回归分支结构,提出了一种新的特征融合方式。通过1×1卷积调整特征层通道数,控制通道数比例,对不同特征层的通道按比例进行深浅层特征拼接,用于后续的特征融合模块。在特征拼接前,引入特征合并的方法来获得有不同感受野的融合特征,进一步提高特征分辨率。将提出的新特征融合方式和特征合并方式进行纵向与横向的特征融合,充分利用特征属性,提高算法性能。根据巡飞弹硬件平台的属性限制,框架采用轻量化的AlexNet网络作为骨干网络。在OTB100、GOT-10K、UAV123三个数据集上测试,框架整体以160 fps的帧率保证了较高准确度和成功率。在满足巡飞弹特殊工作环境的基础上,实现了较为先进的跟踪性能。整体框架相对简单且性能较高,有较好的跟踪实时性,可加入其他模块来进一步提升跟踪性能。

面向机动目标的分布式弹群在线协同定位方法

机动目标的高精度协同定位是协同打击的关键,通过分布式弹群来实现协同定位是目前研究的热点。提出了一种分布式弹群在线协同定位的策略,解决弹群通信受限条件下协同定位的实时性问题;针对目标状态估计中模型非线性、噪声非高斯分布等特点,提出了容积卡尔曼粒子滤波算法;设计了自适应转弯速率的匀速转弯模型,并将现有的二维匀速转弯模型扩展至三维,解决了现有匀速转弯模型先验转弯速率固定,导致定位精度不高的问题;设计了自适应模型转移概率的交互多模型方法,实时修正马尔可夫转移概率,解决了单模型滤波定位精度不高的问题。通过仿真验证了所提策略和方法的有效性和准确性。

红外预警机对弹道导弹中段弹头探测能力研究

文中着眼发挥预警机的灵活性、拓展弹道导弹防御层次,对红外预警机探测弹道导弹中段弹头的能力进行研究。从红外传感器作用距离影响因素入手分析了中段弹头红外辐射特性及其红外背景,借助大气传输软件MODTRAN分析了大气透过率随观测天顶角的变化情况,进而建立了机载红外传感器对中段弹头的最大作用距离模型。结合弹道导弹运动特性分析了地球曲率、预警机与目标直线距离等条件对探测能力的约束,以2500km射程导弹为例仿真分析了预警机不同配置位置下对中段弹头的探测能力,所得结论可为弹道导弹防御作战中预警兵力配置提供参考。