Control System in Missiles for Whole-Trajectory-Controlled Trajectory Correction Projectile Based on DSP

A control system for correction mechanisms through the whole trajectory is proposed based on the principle of one-dimensional trajectory correction projectile. Digital signal processing （DSP） is utilized as the core controller and gobal positioning system （GPS） is used to measure trajectory parameters to meet the requirements of calculating ballistics and system functions. Firstly, the hardware, mainly including communication module, ballistic calculation module, boosting ＆ detonating module and data storage module, is designed. Secondly, the supporting software is developed based on the communication protocols of GPS and the workflow of control system. Finally, the feasibility and the reliability of the control system are verified through dynamic tests in a car and live firing experiments. The system lays a foundation for the research on trajectory correction projectile for the whole trajectory.     

Adapitive waveform design for distributed OFDM MIMO radar system in multi-target scenario

In order to improve detection and estimation performance of distributed Orthogonal-Frequency-Division Multiplexing (OFDM) Multiple-Input Multiple-Output (MIMO) radar system in multi-target scene, we propose a novel approach of Adaptive Waveform Design (AWD) based on a constrained Multi-Objective Optimization (MOO). The sparse measurement model of this radar system is derived, and the method based on decomposed Dantzig selectors is applied for the sparse recovery according to the block structures of the sparse vector and the system matrix. An AWD approach is proposed, which optimizes two objective functions, namely minimizing the upper bound of the recovery error and maximizing the weakest-target return, by adjusting the complex weights of the emitting waveform amplitudes. Several numerical simulations are provided and their results show that the detection and estimation performance of the radar system is improved significantly when this MOO-based AWD approach is applied to the distributed OFDM MIMO radar system. Especially, we verify the effectiveness of our AWD approach when the available samples are reduced severally and the technique of compressed sensing is introduced.     

基于贝叶斯方法的HPRF雷达跟踪解距离模糊方法(英文)

高脉冲重复频率(HPRF)雷达目标跟踪需要解决距离模糊问题。本文通过把脉冲间隔数和脉冲间隔变化量作为目标的离散状态,目标的距离和径向速度作为目标的连续状态,将HPRF雷达的跟踪和解距离模糊问题转换为贝叶斯框架下的混合估计问题并且利用粒子滤波方法实现。仿真结果表明本文方法在脉冲间隔数变化时仍可以正确地解距离模糊,并且跟踪精度比多假设方法高。     

一种基于多模分布的SAR图像分割算法

SAR图像目标、背景、阴影的不同散射机理使得这三部分具有不同的统计特性.分析SAR图像三部分统计性质分别建立统计模型,并给出了一种基于这三种模型组合的多模分布的SAR图像分割算法,对于目标分割和阴影分割分别采用不同的预处理方法,分别提出了快速Otsu分割算法分割目标和基于背景均值保留的冲击滤波算法分割阴影.分割结果表明,这种基于多模分布的SAR图像分割算法与传统的基于单模分割算法相比,能最佳地利用各部分统计特性的差异,得到准确的分割结果.     

数据链航迹延迟与 ESM点迹间断融合跟踪

数据链与电子支援措施(Electronic Supporting Measures,ESM)融合跟踪是 1种典型的异类多传感器信息融合。针对数据链航迹存在延迟和 ESM点迹间断情况下的数据链航迹与 ESM点迹融合跟踪,提出了复杂情况下的数据链与 ESM融合跟踪方法,并对融合跟踪的精度进行分析研究。首先,对数据进行时间对准,保证数据链和 ESM数据率一致;然后,通过构造基于不敏变换(Unscented Transformation,UT)的非线性量测转换和误差估计方法,将数据链数据对准到 ESM数据;最后,通过引入随机补偿机制对数据链延迟进行补偿,并与 ESM数据进行关联融合。实验结果表明,有延迟补偿时的融合跟踪精度取决于延迟补偿均值与实际延迟的贴近程度。结果可为信息综合处理装备的发展和设计提供借鉴。     

A novel target detection approach based on adaptive radar waveform design

To resolve problems of complicated clutter, fast-varying scenes, and low signal-clutterratio (SCR) in application of target detection on sea for space-based radar (SBR), a target detection approach based on adaptive waveform design is proposed in this paper. Firstly, complicated sea clutter is modeled as compound Gaussian process, and a target is modeled as some scatterers with Gaussian reflectivity. Secondly, every dwell duration of radar is divided into several sub-dwells. Regular linear frequency modulated pulses are transmitted at Sub-dwell 1, and the received signal at this sub-dwell is used to estimate clutter covariance matrices and pre-detection. Estimated matrices are updated at every following sub-dwell by multiple particle filtering to cope with fast-varying clutter scenes of SBR. Furthermore, waveform of every following sub-dwell is designed adaptively according to mean square optimization technique. Finally, principal component analysis and generalized likelihood ratio test is used for mitigation of colored interference and property of constant false alarm rate, respectively. Simulation results show that, considering configuration of SBR and condition of complicated clutter, 9 dB is reduced for SCR which reliable detection requires by this target detection approach. Therefore, the work in this paper can markedly improve radar detection performance for weak targets.     

基于3DES算法的SRAM工艺FPGA加密设计

本文提出了一种基于3DES算法的SRAM工艺FPGA加密设计方法,并详细描述了3DES加密算法的模型以及其硬件设计过程,最后给出3DES加密算法的硬件实现仿真时序图以及在FPGA中的实现结果.     

ADS-B用于高精度雷达标定的方法

为了更好地解决高精度雷达标定的问题,提出了基于广播式自动相关监视系统(ADS-B)固定误差及目标回波中心动态修正的雷达标定新方法。首先分析了ADS-B位置数据误差的来源、类型及在雷达坐标系下的特征,同时对民航目标回波中心的变化作了分析建模,在此基础上进一步通过对雷达数据与ADS-B数据之差作动态联合修正,最终估算出雷达系统误差,提高了雷达系统误差标定的精度和稳定性。并利用多批次的实测数据对该标定新方法与其他方法进行了对比验证,结果表明,该方法有效提高了标定的精度和稳定性,并已成功应用于雷达标定设备中。     

认知雷达系统概念和体系架构研究

认知雷达作为一种全新的智能化雷达概念,可以有效提升雷达在复杂地理和电磁环境中的探测性能,被认为是未来雷达发展的方向。针对认知的基本概念,探讨了认知雷达的基本内涵和概念,并提出了层次化的知识体系和处理流程,给出了认知雷达的系统架构。     

LPP低污染燃烧室两相喷雾燃烧性能数值研究

采用Fluent软件对贫油预混预蒸发(LPP)低污染燃烧室两相喷雾燃烧流场、温度场和污染排放性能进行数值计算.在副模结构保持不变时,LPP低污染燃烧室头部在相同工况下,数值研究不同的主模旋流角度对燃烧流场、温度场以及污染排放的影响.采用标准的k-ε模型对湍流黏性进行模拟,采用离散相模型对油珠颗粒的运动轨迹进行追踪,采用非预混平衡化学反应模型来模拟化学反应速率.数值计算结果表明:①在LPP低污染燃烧室头部存在明显的中心回流区、角回流区和唇口回流区;②中心回流区外形呈橄榄形状,并且回流区长度都较长,随着主模旋流角度的增大,中心回流区逐渐变胖且变短,角回流区则逐渐变小;③随着主模旋流角度增大,压力损失也随之增大;④热力型NOx生成的速率与燃烧温度超过1950K区域的面积大小和最高的燃气温度有直接的关系,在副模和主模火焰锋面附近,由于燃烧温度高,是热力型NOx的集中分布区域;⑤出口温度分布系数随着主模旋流角度的增加呈现出先减少后增加的趋势,且主模旋流角度为45°(C方案)时出口温度分布系数最小,即C方案的出口温度分布最均匀;⑥在相同的工况下,C方案燃烧性能相对最优.