CCOS边缘效应的小研抛盘修形修正方法

计算机控制光学表面技术(Computer Controlled Optical Surfacing,CCOS)是加工离轴非球面的一项重要技术。小磨头抛光的边缘效应严重制约CCOS技术的加工精度和加工效率。在获得影响边缘效应的关键参数后,结合残余误差等高线的路径规划,对CCOS产生的边缘效应产生的翘边现象进行修正;通过对一块体育场形离轴非球面的加工,获得了全口径光学测量数据,为后续精加工提供面形基础。     

Progressive Type‐II censoring and coherent systems

A new connection between the distribution of component failure times of a coherent system and (adaptive) progressively Type‐II censored order statistics is established. Utilizing this property, we develop inferential procedures when the data is given by all component failures until system failure in two scenarios: In the case of complete information, we assume that the failed component is also observed whereas in the case of incomplete information, we have only information about the failure times but not about the components which have failed. In the first setting, we show that inferential methods for adaptive progressively Type‐II censored data can directly be applied to the problem. For incomplete information, we face the problem that the corresponding censoring plan is not observed and that the available inferential procedures depend on the knowledge of the used censoring plan. To get estimates for distributional parameters, we propose maximum likelihood estimators which can be obtained by solving the likelihood equations directly or via an Expectation‐Maximization‐algorithm type procedure. For an exponential distribution, we discuss also a linear estimator to estimate the mean. Moreover, we establish exact distributions for some estimators in the exponential case which can be used, for example, to construct exact confidence intervals. The results are illustrated by a five component bridge system. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 512–530, 2015     

视觉惯性导航系统初始化方法综述

视觉惯性导航系统通过初始化,对尺度信息、重力向量、速度、惯性传感器偏差等一系列状态估计所需参数进行快速求解,以提升系统后续导航定位与环境感知的准确性。根据传感信息耦合方式,视觉惯性导航系统初始化方法可以分为三类:联合初始化、非联合初始化和半联合初始化。基于现有研究工作,从基础理论、发展与分类、现有方法、性能评估四个方面展开,对目前主流的初始化方法进行综述,并总结视觉惯性导航系统初始化领域未来的发展趋势,有利于对视觉惯性导航系统初始化方法形成总体性了解并把握其发展方向。     

超高精度离子束抛光工具设计与性能分析

为了解决高精度光学修形问题,进行离子束抛光工具的设计与性能分析研究。通过开展离子束抛光工具设计方法的研究、聚焦离子光学系统结构设计和离子束流特性的分析,进行计算机仿真研究和中和器一体化设计;研制聚焦离子光学系统和中和器,并采用15mm和10mm的聚焦离子光学系统进行修形加工实验,将口径150mm的熔石英平面镜从初始面形误差RMS15.58nm修正到RMS0.79nm。结果证明了聚焦离子光学系统设计的有效性,一体化离子束抛光工具具有亚纳米精度的修形能力。     

基于全维PI观测器的混沌系统鲁棒故障检测设计

研究了在干扰存在情况下基于全维PI观测器的混沌系统鲁棒故障检测设计问题。基于一类Sylvester矩阵方程的参数化解,给出了干扰和残差信号解耦的充要条件,并建立了具有鲁棒故障检测功能的全维PI观测器设计的参数化方法。Lorenz混沌系统的数值算例及其计算结果表明：在干扰存在的情况下,基于全维PI观测器的混沌系统鲁棒故障检测设计方法简单有效。     

具有时变通信时延的多智能体系统的一致性

首先,给出一种适用于可连续通信并具有时变通信延迟的有向多智能体系统关于参考状态的一致性算法,基于此算法,各智能体协同变量关于参考状态的一致性问题被转化为一个误差系统的稳定性问题.然后,利用Lyapunov稳定性理论,推导出多智能体系统在该算法作用下达到一致性的充分性判据,并由矩阵不等式的形式描述.结果表明:当时延函数有...     

一类非线性反应扩散控制系统解的整体存在性

研究一类非线性反应扩散控制系统,采用对偶性技巧及Holder不等式方法,得到在Dirichlet边界条件下解的整体存在性.     

基于GIS的陆军野战防空指挥自动化系统分析

从陆军面临的空中威胁目标出发,分析了陆军野战防空的主要特点及对指挥自动化系统的要求,提出了基于地理信息系统(Geographic Information System:GIS)的陆军野战防空指挥自动化系统的设想,并建立了基本的结构模型.最后,根据系统论的思想更深层地说明了陆军野战防空指挥自动化系统建设的重要性.     

Failure profiles of coherent systems

In this paper we first introduce and study the notion of failure profiles which is based on the concepts of paths and cuts in system reliability. The relationship of failure profiles to two notions of component importance is highlighted, and an expression for the density function of the lifetime of a coherent system, with independent and not necessarily identical component lifetimes, is derived. We then demonstrate the way that failure profiles can be used to establish likelihood ratio orderings of lifetimes of two systems. Finally we use failure profiles to obtain bounds, in the likelihood ratio sense, on the lifetimes of coherent systems with independent and not necessarily identical component lifetimes. The bounds are relatively easy to compute and use. © 2004 Wiley Periodicals, Inc. Naval Research Logistics, 2004     

基于信息系统装备指挥运行机制构建研究

着眼装备指挥变革和提高指挥效能的需要,提出了基于信息系统装备指挥运行机制的概念,构建了基于信息系统的要素式装备指挥机构模型,明确了各指挥要素职能及其相互关系,分析了装备指挥信息、决策计划、协调控制的流程,建立了装备指挥效能计算模型,以期为建设新型科学的装备指挥运行机制提供依据．