一种宽带多维雷达信号设计

设计了一种宽带多维雷达信号,在宽带噪声调频信号中通过频率捷变的方式融合非线性调频信号,将探测信号隐匿于宽带噪声调频信号中,对敌方雷达进行干扰的同时实现对目标的探测。仿真表明该信号具有较好的隐蔽性,且兼具探测与干扰的双重功能。     

基于分形滤波的能量检测方法

能量检测是认知无线电频谱感知的有效方法,但在低信噪比情况下检测概率明显下降。提出了基于分形滤波的频谱感知能量检测方法。基于分形滤波可以有效抑制噪声的特点,该方法先对接收信号进行分形滤波,以其能量值作为检测统计量,进行能量检测。仿真结果表明,通过基于分形滤波的能量检测和直接进行能量检测方法对比,滤波后信噪比在下降7 d B时仍然满足90%以上的检测概率。此外,该方法对不同调制信号均具有较好的适用性,在噪声不确定情况下仍然具有较高的检测概率。     

Research on simultaneous localization and mapping for AUV by an improved method: Variance reduction FastSLAM with simulated annealing

At present, simultaneous localization and mapping (SLAM) for an autonomous underwater vehicle (AUV) is a research hotspot. Aiming at the problem of non-linear model and non-Gaussian noise in AUV motion, an improved method of variance reduction fast simultaneous localization and mapping (FastSLAM) with simulated annealing is proposed to solve the problems of particle degradation, particle depletion and particle loss in traditional FastSLAM, which lead to the reduction of AUV location estimation accuracy. The adaptive exponential fading factor is generated by the anneal function of simulated annealing algorithm to improve the effective particle number and replace resampling. By increasing the weight of small particles and decreasing the weight of large particles, the variance of particle weight can be reduced, the number of effective particles can be increased, and the accuracy of AUV location and feature location estimation can be improved to some extent by retaining more information carried by particles. The experimental results based on trial data show that the proposed simulated annealing variance reduction FastSLAM method avoids particle degradation, maintains the diversity of particles, weakened the degeneracy and improves the accuracy and stability of AUV navigation and localization system.     

An infrared target intrusion detection method based on feature fusion and enhancement

Infrared target intrusion detection has significant applications in the fields of military defence and intelligent warning. In view of the characteristics of intrusion targets as well as inspection difficulties, an infrared target intrusion detection algorithm based on feature fusion and enhancement was proposed. This algorithm combines static target mode analysis and dynamic multi-frame correlation detection to extract infrared target features at different levels. Among them, LBP texture analysis can be used to effectively identify the posterior feature patterns which have been contained in the target library, while motion frame difference method can detect the moving regions of the image, improve the integrity of target regions such as camouflage, sheltering and deformation. In order to integrate the advantages of the two methods, the enhanced convolutional neural network was designed and the feature images obtained by the two methods were fused and enhanced. The enhancement module of the network strengthened and screened the targets, and realized the background suppression of infrared images. Based on the experiments, the effect of the proposed method and the comparison method on the background suppression and detection performance was evaluated, and the results showed that the SCRG and BSF values of the method in this paper had a better performance in multiple data sets, and it’s detection performance was far better than the comparison algorithm. The experiment results indicated that, compared with traditional infrared target detection methods, the proposed method could detect the infrared invasion target more accurately, and suppress the background noise more effectively.     

一种新的活塞式磁通压缩发电机设计方案

介绍了磁通压缩发电机 (MFCG)作为高功率脉冲电源的特性 ,针对国外MFCG方案中遇到的烧蚀问题 ,提出了一种活塞式双螺旋绕组MFCG的新设计方案 ,给出了该方案的设计结构 ,分析了该种方案的原理、工作过程及特点     

核电磁脉冲对单片机系统的辐照效应研究

核爆炸产生的电磁脉冲的“杀伤”范围极广,它可使距离爆心投影点几千公里的电气设备、电子装备和系统的工作失灵甚至破坏。为了研究它对单片机的各种效应,利用GTEM室产生的模拟核电磁脉冲,对单片机系统进行了辐照效应实验。实验表明,单片机系统在核电磁脉冲作用下,会出现“死机”、重启动、控制状态的改变、通讯错误和外部RAM内容改变以及数据采集误差增大等现象。在实验基础上,研究了单片机系统的各种效应产生的原因。     

神经网络技术及其在机器耳监测仪中的应用

介绍了利用GAL算法对装备产生的声音信号进行处理,改进完善了基于竞争学习的GAL神经网络。测试结果表明,基于GAL算法的智能耳诊断系统的识别精度和自学习方面优于传统算法。     

蓄电池注水装置水位控制原理研究与实现

研究设计了由电磁式液位传感器、隔离开关、单片机控制器及报警系统组成的潜艇蓄电池注水装置,确保了各蓄电池液面误差不大于5mm.给出了该装置结构及工作原理,分析了液位传感器和单片机控制电路.经使用证明,该装置对控制注水高度及缩短注水时间有良好效果.     

具有镀铬层的铁磁材料和零件的裂纹检测

阐述了具有镀铬层铁磁性零件的裂纹漏磁检测机理,探讨了基于循环搜索逼近的裂纹定量检测的基本方法。实测结果证明漏磁法检测具有镀铬层工件的缺陷是可靠的。     

电发火系统感应电流测试方法研究

对电发火系统在电磁环境下的感应电流测量采用一种新型的白光干涉型光纤测温仪。通过测量电发火系统中电火工品桥丝在电磁环境下温度的变化,利用桥丝温度和感应电流的关系,测量出桥丝上的感应电流,进而对弹箭系统进行电磁环境效应评估。