Roundness error evaluation by minimum zone circle via microscope inspection

Utilizing the convex hull theory, a novel minimum zone circle (MZC) method, named improved minimum zone circle (IMZC) was developed in this paper. There were three steps for IMZC to evaluate the roundness error. Firstly, with the convex hull algorithm, data points on the circle contour were categorized into two sets to determine two concentric circles which contained all points of the contour. Secondly, vertexes of the minimum circumscribed circle and the maximum inscribed circle were found out from the previously determined two sets, and then four tangent points for determining the two concentric circles were also found out. Lastly, according to the evaluation using the MZC method, the roundness error was figured out. In this paper, IMZC was used to evaluate roundness errors of some micro parts. The evaluation results showed that the measurement precision using the IMZC method was higher than the least squared circle (LSC) method for the same set of data points, and IMZC had the same accuracy as the traditional MZC but dramatically shortened computation time. The computation time of IMZC was 6.89% of the traditional MZC.     

Autonomous optical navigation for interplanetary exploration based on information of earth-moon

The image elements of earth-center and moon-center are obtained by processing the images of earth and moon, these image elements in combination with the inertial attitude information and the moon ephemeris are utilized to obtain the probe initial position relative to earth, and the Levenberg-Marquardt algorithm is used to determine the accurate probe position relative to earth, and the probe orbit relative to earth is estimated by using the extended Kalman filter. The autonomous optical navigation algorithm is validated using the digital simulation.     

Image matching navigation based on fuzzy information

0　INTRODUCTIONImagematchingalgorithmsplayaveryimportantroleinimagenavigationsystems .Becauseoftheinfluenceofimagingconditionsandimagingdevices ,therearealwaysexistingintensivechangesandgeometricdistortionsbe tweenthereferenceimageandthereal timeimage .Thoughsomemethodscanbeappliedtoimprovethequali tyoftheimagebeforefurtherprocessing ,somecolorandgeometricdistortionmaystillexist,aswellasthenoisedisturbance .Forthesakeofnavigationaccuracy ,itisex pectedthatmatchingalgorithmsshouldbenotonly…     

企业R&D项目组合评价与选择方法

在对国内外R&D项目组合评价与选择研究分析基础上,从实际出发建立了相应的评价指标体系,构建了基于DEA和BSC的评价模型,说明了运用模型进行项目组合评价与选择的过程.运用分枝定界法生成最优项目组合,考虑了项目间资源、收益和输出的相互影响,确定与企业战略相适应的R&D项目组合,为R&D项目组合选择提供了新思路.     

推动军工制造业数控工艺技术发展

党的十六届五中全会指出“国防科技工业要坚持军民结合、寓军于民，健全军民互动合作的协调机制，提高产品的研发和制造水平”、“坚持以信息化带动工业化，广泛应用高新技术和先进适用技术改造提升制造业”、为国防科技工业的发展提出了明确要求。     

Anovel profile error model to calculate contact error

A new profile model based on multi-scale asperities is developed and contact error is calculated.After stratified sampling, the model can get the distribution law of entity points on each cross section.Asperity radius of curvature is estimated by the relationship between circle radius and the section interval. Contact error is related to surface form error. A model equation of contact error plane is calculated through a method based on static equilibrium theory. Three contact asperities which determine the contact error plane on the rough surface are studied. The simulation results show that contact error can be accurately calculated according to the profile error model.     

Remote sensing image compression for deep space based on region of interest

A major limitation for deep space communication is the limited bandwidths available. The downlink rate using X-band with an L2 halo orbit is estimated to be of only 5.35 GB/d. However, the Next Generation Space Telescope (NGST) will produce about 600 GB/d. Clearly the volume of data to downlink must be reduced by at least a factor of 100. One of the resolutions is to encode the data using very low bit rate image compression techniques. An very low bit rate image compression method based on region of interest(ROI) has been proposed for deep space image. The conventional image compression algorithms which encode the original data without any data analysis can maintain very good details and haven't high compression rate while the modern image compressions with semantic organization can have high compression rate even to be hundred and can't maintain too much details. The algorithms based on region of interest inheriting from the two previews algorithms have good semantic features and high fidelity, and is     

一种新的微小型结构件显微图像边缘检测方法

针对目前大多显微图像边缘识别算法的边缘精确识别精度低等问题,提出一种基于工艺匹配思想的微小型结构件边缘识别算法。对不同工艺微小型结构件显微图像进行分析,通过提取不同加工工艺微小型结构件的边缘过渡区,建立边缘过渡区的数学模型,从数学模型中确定边缘点精确位置。建立基于显微视觉检测的边缘图像分形评价模型,分析同类工艺方法边缘图像的相似程度,并以实例进行实验验证。实验结果表明:该方法具有普遍适用性,且边缘检测精度高,能进一步满足精密测量的需要。     

基于兴趣区检测的远距离机场目标识别研究

典型目标的检测识别是精确制导武器的关键技术之一,具有广泛的应用。根据远距离前视红外机场目标图像的特性,文章提出并实现了一种利用边缘线段群特征检测感兴趣机场目标区域,并进一步分割、识别潜在目标的新算法。仿真实验结果证实算法是合理、有效的。本文的算法结构简单、适应性广、适合于实时处理,具有广泛的应用前景。     

基于TOA和TDTOA的增广状态脉冲星组合导航误差抑制方法

脉冲星导航是一种极具潜力的深空自主导航技术,通常采用脉冲到达时间(time of arrival,TOA)作为量测信息.但脉冲星星历误差和星载原子钟误差等系统误差对导航性能有显著影响.为了解决上述问题,提出了一种基于TOA和时间差分TOA (TDTOA)的增广状态脉冲星组合导航误差抑制方法,通过将每个脉冲星的星历误差和...