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1.
黄静  李长春  延皓  赵旭昌  杨雪松 《兵工学报》2015,36(6):1110-1116
在电液伺服阀的测量和筛选过程中,为进行伺服阀死区和分辨率的测量,需要检查数据序列中的突变点。目前突变点的主要检测方法有Mann-Kendall算法、累积和控制图(CUSUM)算法、最小均方差(MSE)法、小波变换法等,但这些检测方法均有一定的局限性。为此提出了一种多尺度直线拟合法,采用变换拟合尺度逐步逼近的方式来检测突变点。将时间序列按给出的初始长度计算法划分为若干段,每一段用最小二乘拟合的直线代替。比较相邻拟合线段的斜率,其中斜率变化最大的两段线段之内存在突变点。在该两段线段的范围内缩小拟合尺度,继续使用上述方法进行查找,直至拟合尺度收敛为1,此时斜率变化最大的点即是原时间序列的突变点。将该检测方法同其他方法进行比较,并在伺服阀测试系统和故障检测信号中进行实际应用,验证了该方法在查找突变点时的准确性、针对复杂信号时的有效性和计算效率上的优越性。  相似文献   

2.
基于分割模板运动预估的相关跟踪算法   总被引:1,自引:0,他引:1  
为了对常规相关匹配算法实时性能进行提升,提出一种基于分割模板运动预估的相关跟踪算法。采用最小二乘法全区间等距拟合目标运动轨迹,计算出目标当前预估点;将模板图像按块运动估计算法要求分割成宏块;按菱形搜索法在预估点周围区域进行搜索,得到每个宏块的最佳运动矢量;取匹配度最佳的运动矢量对应点为模板的粗匹配点;判断该点所在宏块与搜索区域相对位置关系,决定是否进行精匹配结束搜索,或是按梯度方向建立新的搜索区域。目标跟踪实验证明,该方法比基于全搜索的归一化积相关( NProd)算法其计算时间缩短到3.31倍。  相似文献   

3.
地形匹配制导技术研究   总被引:10,自引:0,他引:10  
陈绍顺  李彦斌  李云 《制导与引信》2003,24(3):17-21,27
指出了匹配系统的性能与地形的选择有很大的关系,给出了地形高程数据的标准差、粗糙度和相关特性等概念,反映了特定区域内地形的总体起伏、局部变化及领域相关性的强弱,对地形匹配区的选择具有重要意义。同时,利用Hausdorff距离作为地形匹配算法的相似性度量,对应最小的Hausdorff距离是最佳匹配。实验结果表明该方法的有效性。  相似文献   

4.
针对SURF算法在构建局部特征描述符阶段耗时过长的问题,提出一种基于BRISK二进制特征描述符的改进SURF算法。应用SURF算法中快速DoH(determinant of hessian)算子检测特征点并确定主方向,采用BRISK描述符进行特征描述,通过匹配阶段采用汉明距离双向匹配和RANSAC算法剔除误匹配,并利用最小二乘法获取精确配准模型完成图像的配准。对比实验结果表明:该算法大幅提高了匹配速度,其匹配性能也超越了原SURF算法,能够较好地完成遥感图像配准。  相似文献   

5.
地形匹配制导技术研究   总被引:1,自引:0,他引:1  
针对地形匹配制导的特点,指出了匹配系统的性能与地形的选择有很大的关系。通过分析,给出了地形高程数据的标准差、粗糙度和相关特性等概念,它们分别反映了特定区域内地形的总体起伏、局部变化及领域相关性的强弱,对地形匹配区的选择具有重要意义。同时,利用Hausdofff距离作为地形匹配算法的相似性度量,对应最小的Hausdorff距离是最佳匹配。实验结果表明该方法的有效性。  相似文献   

6.
运载火箭遥测数据压缩技术研究   总被引:7,自引:1,他引:6  
本研究以CZ-2E运载火箭遥测数据为实例,探讨航天遥测数据的无损压缩的可能性与潜力。道德分析运载火箭一、二级第2、3、4发全部遥则数据的统计特性。广泛研究了常见压缩算法的压缩效果。在此基础邮通道重级玫自适应分区熵编码等改进算法,进行了仿真试验。最后,采用面向对象的编程方法,将研究成果集成为“遥测数据压缩工具包”,为固定帧格式遥测数据的无损压缩研究试验提供了有力的工具,也用于计算机辅助教学(CAI)  相似文献   

7.
基于对应像素距离度量的图像匹配跟踪算法   总被引:3,自引:0,他引:3  
结合最小绝对差度量MAD和Hausdorff距离度量的基本思想,提出了一种新的对应像素距离相似性度量方法的图像匹配算法和自适应模板图像匹配跟踪算法,并对对应像素距离相似性度量方法的图像匹配算法的匹配跟踪性能进行分析.对这2种算法的匹配跟踪性能参数的实验结果进行比较.实验结果表明:对应像素距离相似性度量方法的图像匹配算法具有较强的抗噪、抗畸变能力和稳定性,具有较高的匹配精度和匹配概率.  相似文献   

8.
针对军事侦察或干扰查找环节解决方案较少、已有方案算法速度慢、准确度低的问题,提出一种采用卷积神经网络的无线电信号快速查找方法.该方法将卷积神经网络应用于无线电监测领域,通过数据预处理、参数训练、信号匹配3个步骤实现信号的快速搜索.实验结果表明:该方法查找速度快,精度达到98%,并且有效减少对信号复杂参数的依赖,在无线电信号快速搜索方面的良好性能.  相似文献   

9.
图像压缩技术JPEG与JPEG2000   总被引:2,自引:0,他引:2  
周乐 《四川兵工学报》2002,23(1):21-22,26
JPEG采用基于DCT的有损压缩算法,大大降低了图像的尺寸,使图像压缩技术得到了长足的发展与运用。JPEG2000作为其升级,具有很高的压缩比、能实现渐进传输、支持“感兴趣区域”、支持无损压缩等特性,对医学成像、数码相机等领域的图像压缩具有重要意义。  相似文献   

10.
采用提取图像的尺度不变特征可以获得较好的匹配跟踪效果,但该特征提取方法比较耗时。针对这一问题,提出了一种鲁棒的实时目标跟踪方法。该方法通过提取目标的多尺度平移、旋转特征来构建字典,提高了算法的鲁棒性。利用所构建的字典来表示待跟踪目标集特征,查找与目标模板最近邻的待跟踪目标,即可确定跟踪的最终结果。试验结果表明,这种基于字典学习的实时跟踪算法可以鲁棒实时地跟踪单目标。  相似文献   

11.
Tetraacetyldibenzylhitane (TADBIW) was subjected to debenzylation by nitrosating with inorganic materials available commercially to synthesize tetraacetyldinitrosohexaazaisowurtzitane (TADNSIW). TADNSIW was purified, and its structure was determined by FTIR, 1H NMR, MS and element analysis. The debenzylation reaction of TADBIW gave quantitative benzaldehyde as a by-product. This indicates that the reaction produces an imine cation as an intermediate. Hexanitrohexaazaisowurtzitane (HNIW) was prepared from unpurified TADNSIW with the yield over 96.0 % and the purity more than 98.0 %. And the mechanism of the reaction from TADNSIW to HNIW is proposed to be oxidation of nitroso and nitration of acetyl on the molecule of TADNSIW, This reaction system involved is simple, and the reaction can complete within a short time and under mild conditions. The product can be easily to separate and the waste disposed readily.  相似文献   

12.
The technique of watermarking has been introduced into 2D vector maps for many potential applications such as protecting the copyright of important GIS (geographical information system) data and tracing the data source of military maps. In most previous works, although the validity of the map data could be preserved during the embedding procedure, the shape-distortions of the map elements are usually neglected which would tend to degrade the invisibility of the watermarking schemes. A shape-preserving algorithm for watermarking 2D vector maps is presented in this paper. A 1D distance sequence extracted from the original map is adopted as the cover data instead of 2D coordinates. A watermark bit is represented by changing the distributions of the cover data. The embedding procedure induces lower shape-distortions than in former works. Experimental results indicate better invisibility of the proposed scheme, as well as its robustness to certain attacks such as map simplification, interpolation, additive noise and most geometric transforms.  相似文献   

13.
Open rule-setting method advanced in this paper concentrates on providing designers of engines with a convenient way to express their design innovations and develop the expected prototypes in the early CAD stage, and constitute effective models for the following analysis process of CAE and CAPP. The problems arisen in the process of conceptual design with the traditional experience-based development method are analyzed. Based on those analyses, open rule-setting method is presented and some associated technical problems are discussed. The functional framework of open rule-setting system was built as software engineering methods. The speciality of the engine product as a kind of complex product and the requirement of the engine product based on its structural particularity to rule-setting system are considered carefully. A demonstration is supplied to illustrate how the open rule-setting method enhances the efficiency and quality of the engine conceptual design.  相似文献   

14.
By analyzing the working principle of Linux network device driver, discussing the Linux network driver structure and its key technologies, the general network driver structure and its design methodologies in Linux system are summarized. Through modifying the network device driver of Linux device driver 3rd version snull, c and improving the COW technology, the Zero-Copy technology in Linux (kernel version 2.6.11 ) is implemented. In the end, the success test tells us that the thorough analysis of network device driver is the foundation of many applications, and it also provides a certain improvement to a lot of real applications, even to military application development.  相似文献   

15.
By analyzing the influencing factors of part quality making of sheet alloy of titanium by vibra cutter, the shape of upper reamer is set as cylinder and wedge-shaped form, and the lower reamer as plain and hemicycle form, and its main structural parameters are defined as well. Then it is validated further that such improved vibra cutter reamer can be used to process curve-edged parts of titanium alloy sheet. The experimental result shows that the titanium alloy sheet parts processed by above equipment have no sharpen angles for convex parts and evident crevasse of concave-edged part. In summary, such improvement can eliminate the free-waved edge and improve the manufacture quality of titanium alloy sheet parts greatly.  相似文献   

16.
The initiating behavior of fine-grained explosives by small flyer is studied. The diameter of small flyer in this device is 1 ram. The test results indicate that the granularity of explosives has great effect on its flyer initiating sensitivity.The flyer initiating sensitivity of the fine-grained explosives is higher and the critical initiating energy is lower than that of common explosives. For common explosive, the flyer initiating sensitivity increases as the density is reduced. But for the fine-grained explosive, the test results are exactly opposite.  相似文献   

17.
Multi-laser-target tracking is an important subject in the field of signal processing of laser warners. A clustering method is applied to the measurement of laser warner, and the space-time fusion for measurements in the same cluster is accomplished. Real-time tracking of multi-laser-target and real-time picking of multi-laser-signal are introduced using data fusion of the measurements. A prototype device of the algorithm is built up. The results of experiments show that the algorithm is very effective.  相似文献   

18.
A method to calculate the surface shape error, which is caused by the installing error between the workpiece and the lapping tool in the process of form lapping, is proposed. The mathematical model which the installing translation error influences on the workpiece surface shape error is established. The changing rule of the error is simulated through the calculating example of the paraboloid workpiece. The results indicate that the surface shape error of the workpiece is increasing with the increase of the installing translation error, it is also increasing gradually along the center point of the curve surface to the edge, and the influence is severer to the curve surface with great curvature than that of the small curvature when the translation error is the same.  相似文献   

19.
The paper introduces the performances of magnetostrictive actuators and its applications, discusses the design methods for the structure and internal magnetic circuit of a giant magnetostrictive actuator, and makes tests on the output displacement and force characteristics for an actuator using homemade magnetostrictive material. The experimental result shows that the actuator has satisfactory output precisions and ranges in transient and stable states, and can be used in lowfrequency vibration control system of precise equipment.  相似文献   

20.
The nonlinear dynamic model of spinning ballistic missiles is established during the first boosting phase of the missile. Based on the conventional backstepping sliding mode control and the assumption of a two time-scale separation of missile dynamics, a graded sliding mode controller is designed with two sub-sliding surfaces which have invariability to external disturbances and parameter perturbations, and a matrix which comprises three first order low pass filters is introduced to prevent "explosion of terms". Owing to the upper bounds of the uncertainties are difficult to obtain in advance, adaptive laws are introduced to estimate the values of the uncertainties in real-time. Eventually, the numerical simulation results given to show the proposed controller can ensure the steady flight of missiles.  相似文献   

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