虚拟战场中坦克的快速碰撞检测算法

为了使虚拟战场中的坦克仿真运动有较高的真实性,必须处理坦克与场景中的物体及地形的碰撞问题。提出了碰撞检测的简化包围盒算法及地形匹配算法,分别解决这两种碰撞问题。在地形匹配算法中,依据地形平均曲率划定地形范围,地形平缓的地带采用两点匹配法,变化较为剧烈的地带采用三点匹配法。这两种简化的处理方法降低了系统的计算要求,满足了系统仿真的真实性需求。     

交互多模型算法的无人机控制系统故障诊断

交互多模型算法是一种广泛用于各种结构与参数变化的动态系统自适应估计的有效方法.在建立无人机控制系统传感器和执行器的全局故障和局部故障模型的基础上,应用此方法对传感器和执行器的各种软硬故障进行诊断,应用所建立的数学模型与方法,对无人机传感器和执行器的局部与全局故障进行了仿真计算.在仿真过程中发现,与一般的多模型方法相比,此方法能够更加准确可靠地诊断故障,无延迟报警,算法简单.仿真结果验证了该方法的有效性.     

突防过程的组网雷达干扰资源优化分配

以组网雷达融合中心检测概率为目标函数,建立针对组网雷达系统的干扰资源优化分配模型.并进一步指出该模型运用于飞行器突防时,其不足之处在于"以点带面",以飞行器突防过程中某一点的融合中心检测概率代替整个突防过程时,该评估方法损失过程中的大量信息.在此基础上充分利用突防过程的信息,提出以"融合中心检测概率加权积分"为目标函数,建立基于突防过程的干扰资源优化分配模型.仿真结果表明具有一定的指导意义.     

一种基于广义Hough变换的遥感图像船舶横波自动检测与速度估计方法

从Kelvin横波航迹的形成原理出发,详细推导了Kelvin横波波峰模型,提出一种基于广义Hough变换的遥感图像船舶横波自动检测方法,取得了较好的检测效果,并依据检测结果对船舶速度进行了估计。所述方法对海上船舶运输和港口管理等具有重要意义。     

Aircraft routing under the risk of detection

The deterministic problem for finding an aircraft's optimal risk trajectory in a threat environment has been formulated. The threat is associated with the risk of aircraft detection by radars or similar sensors. The model considers an aircraft's trajectory in three‐dimensional (3‐D) space and represents the aircraft by a symmetrical ellipsoid with the axis of symmetry directing the trajectory. Analytical and discrete optimization approaches for routing an aircraft with variable radar cross‐section (RCS) subject to a constraint on the trajectory length have been developed. Through techniques of Calculus of Variations, the analytical approach reduces the original risk optimization problem to a vectorial nonlinear differential equation. In the case of a single detecting installation, a solution to this equation is expressed by a quadrature. A network optimization approach reduces the original problem to the Constrained Shortest Path Problem (CSPP) for a 3‐D network. The CSPP has been solved for various ellipsoid shapes and different length constraints in cases with several radars. The impact of ellipsoid shape on the geometry of an optimal trajectory as well as the impact of variable RCS on the performance of a network optimization algorithm have been analyzed and illustrated by several numerical examples. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006     

DS/PM双模应答机接收信号的快捕技术

提出了一种星用直扩/调相(DS/PM)双模式应答机接收信号快速识别和捕获的算法,并分析了该算法的性能。与传统的处理方式相比,该算法通过对共同处理部件(FFT/IFFT)的复用在提高系统性能的同时优化了系统结构,降低了对硬件规模的要求。解决了高动态、低信噪比和大多普勒频移环境下捕获时间与检测性能的矛盾,对研制星用DS/PM双模式应答机有很好的参考价值。     

高速SpaceFibre总线节点的系统设计

为了实现SpaceFibre总线节点的高效数据传输,针对网络协议中关键问题和技术提出了一种基于现场可编程门阵列(Field Programmable Gate Array,FPGA)的SpaceFibre总线节点系统设计方案。其中,采用了轮询仲裁算法,解决了多路虚拟通道中流量控制字的申请冲突;设计了基于服务质量机制的高效处理状态机,实现了多路虚拟通道的服务质量调度;提出了一种并行的分区存储架构和重发控制算法,实现了基于错误检测隔离恢复机制的错误恢复;采用了不同的数据并行处理方案,实现了多种数据格式的循环冗余校验和伪随机序列的计算。通过ModelSim仿真平台对节点系统进行功能仿真,并在Virtex-6 FPGA上完成了系统验证。结果表明,该设计实现了SpaceFibre总线节点的功能,串行传输速度可达3.125 Gbit/s,能够满足高速数据传输需求。     

Adaptive subspace detection based on two-step dimension reduction in the underwater waveguide

In the underwater waveguide, the conventional adaptive subspace detector (ASD), derived by using the generalized likelihood ratio test (GLRT) theory, suffers from a significant degradation in detection per-formance when the samplings of training data are deficient. This paper proposes a dimension-reduced approach to alleviate this problem. The dimension reduction includes two steps: firstly, the full array is divided into several subarrays; secondly, the test data and the training data at each subarray are transformed into the modal domain from the hydrophone domain. Then the modal-domain test data and training data at each subarray are processed to formulate the subarray statistic by using the GLRT theory. The final test statistic of the dimension-reduced ASD (DR-ASD) is obtained by summing all the subarray statistics. After the dimension reduction, the unknown parameters can be estimated more accurately so the DR-ASD achieves a better detection performance than the ASD. In order to achieve the optimal detection performance, the processing gain of the DR-ASD is deduced to choose a proper number of subarrays. Simulation experiments verify the improved detection performance of the DR-ASD compared with the ASD.     

基于随机有限集理论的多传感器目标联合检测跟踪算法

针对杂波环境中的目标检测跟踪问题,提出一种基于随机有限集理论的多传感器目标联合检测跟踪算法。算法将目标状态和量测描述为随机集合,建立考虑目标出现、目标保持、目标消失等情况的目标状态随机有限集模型,以及考虑漏检和虚警的多传感器量测随机有限集模型。将目标的联合检测跟踪问题构建为目标状态集合的贝叶斯最优估计问题,并基于随机有限集理论对该贝叶斯估计算法的递推表达式进行严格理论推导。采用序贯蒙特卡罗技术实现算法的递推滤波。仿真结果验证了该算法的有效性以及算法相对于传统基于数据关联算法的性能优势。     

水下声探测系统载体振动干扰分析及抑制方法

针对水下探测系统载体振动对目标回波信号的微多普勒特征谱产生干扰的问题,从干扰产生的基本原理出发,推导了干扰的近似乘性表达式。在获取振动干扰数据的条件下,提出了针对乘性干扰的干扰抑制算法,并针对推导干扰乘性表达式时的近似条件,分析了近似算法带来的误差。仿真结果表明,该方法可有效抑制水下探测系统平台振动对目标回波信号的微多普勒特征谱产生的干扰,并且在绝大多数情况下,由算法带来的误差可以忽略不计。