基于自适应遗传算法的小型无人旋翼机系统辨识方法

提出一种基于自适应遗传算法的小型无人旋翼飞行器系统辨识方法.通过机载传感器设备,系统采集小型无人旋翼机的输入信号(舵机的控制信号)和输出信号(飞行器的姿态及速度等信息);经过数据预处理后,利用自适应遗传算法构建小型无人旋翼飞行器高精度动力学模型,并通过仿真和实验对模型的自效性进行验证.实验表明,基于本文提出的动态模型,...     

面向星载操作系统的控制流错误检测方法

空间高能粒子辐射严重影响航天计算的可靠性,必须采取有效措施对其进行加固。相比使用抗辐射器件,使用软加固的商用器件具有性能高、成本低、开发速度快等优势。然而,目前的软加固研究主要适用于应用程序,对操作系统软加固方法的研究还较少。鉴于此,提出了一种面向星载操作系统的控制流错误检测方法。该方法结合星载操作系统自身特点,着眼于线程执行,将每个线程视为一个函数调用序列,通过在函数入口和出口处插入检测语句,监测各线程的执行,实现控制流错误检测。实验结果表明,该方法能将星载操作系统的控制流错误覆盖率提高约25%。     

一种新型车载控制及诊断系统部件设计

新型车载控制及诊断系统部件是高速磁浮窄车体车载控制及诊断系统中的重要单元设备，其功能是将来自车载安全计算机的与安全相关的控制指令发送给车辆子系统，并将子系统发送的状态监视信号反馈给车载安全计算机。为保障控制及诊断系统的安全可靠运行，新型车载控制及诊断系统部件采用冗余架构及模块化设计，形成双重冗余的架构，使设备达到了高度稳定，并且简化了电路设计，还可通过编程及诊断软件进行逻辑功能调试和故障诊断。     

An adaptive vision-based autopilot for mini flying machines guidance,navigation and control

The design of reliable navigation and control systems for Unmanned Aerial Vehicles (UAVs) based only on visual cues and inertial data has many unsolved challenging problems, ranging from hardware and software development to pure control-theoretical issues. This paper addresses these issues by developing and implementing an adaptive vision-based autopilot for navigation and control of small and mini rotorcraft UAVs. The proposed autopilot includes a Visual Odometer (VO) for navigation in GPS-denied environments and a nonlinear control system for flight control and target tracking. The VO estimates the rotorcraft ego-motion by identifying and tracking visual features in the environment, using a single camera mounted on-board the vehicle. The VO has been augmented by an adaptive mechanism that fuses optic flow and inertial measurements to determine the range and to recover the 3D position and velocity of the vehicle. The adaptive VO pose estimates are then exploited by a nonlinear hierarchical controller for achieving various navigational tasks such as take-off, landing, hovering, trajectory tracking, target tracking, etc. Furthermore, the asymptotic stability of the entire closed-loop system has been established using systems in cascade and adaptive control theories. Experimental flight test data over various ranges of the flight envelope illustrate that the proposed vision-based autopilot performs well and allows a mini rotorcraft UAV to achieve autonomously advanced flight behaviours by using vision.     

基于设计模式的星载软件体系结构设计方法

星载软件是整个卫星系统设计和开发的中心,而体系结构是整个软件开发的蓝图,在软件开发中占有十分重要的位置。为了提高星载软件开发效率,降低研制成本,同时满足实时性、可重构和可维护性要求,从体系结构的前3个视图方面采用基于设计模式的方法提出了一种满足要求的星载软件体系结构。     

基于国产平台的虚拟化操作系统架构研究及其实现

高性能计算操作系统面临独特的需求与挑战,这些需求与挑战涵盖并发与高效、系统弹性与容错、异构性、I/O和访存带宽、低噪等诸多方面。传统宏内核操作系统并不能完全满足HPC领域的独特需求,因而需要为HPC定制操作系统。提出虚拟化操作系统架构,该架构主要包含两部分：（1）虚拟机监视器与轻量级内核相结合的虚拟化操作系统架构;（2）支持分时复用虚拟机与空间分割虚拟机相结合的虚拟机监视器架构。在国产平台上设计并实现了一个简单的系统原型Hypervk,说明了上述架构的可行性。初步的实验结果表明,系统具有较好的效率、低噪特性与可行性,在一定程度上可以满足HPC操作系统独特的需求。     

一种星载嵌入式软件安全性测试方法

研究了星载嵌入式软件安全性测试问题.提出一种基于故障注入的安全性测试框架,通过构建全数字仿真测试环境,模拟目标系统输入异常故障及运行态异常故障,可以灵活地实现故障注入.根据软件实际运行结果与预期结果的一致性来评价软件检错、容错能力,进而完成对软件的安全性测试及验证过程.     

Vision-guided tripod material transport system for the packaging industry

A new lightweight parallel kinematic serves as the basis for a material transport system designated for the automated supply of packaging machines with the necessary paper and foil material. The manipulator, a modified Stewart platform, resembles an overhead tripod and is equipped with an air compressor and a PC-based control with a multitasking real-time operating system. It travels on a gantry railway, using on-board visual sensors for the location of the bobbins with packaging material that are to be transported. The intelligent sensors enable the manipulator to locate the proper bobbin in the quasi-disordered arrangement, depalletize it and transfer it to the requesting machine.     

ICARUS: design and deployment of a case-based reasoning system for locomotive diagnostics

Locomotives, like many complex modern machines, are equipped with the capability to generate on-board fault messages indicating the presence of anomalous conditions. Such messages tend to be generated in large quantities, and are difficult and time consuming to interpret manually. This paper presents the design and development of a case-based reasoning system for diagnosing locomotive faults using such fault messages as input. The process of using historical repair data and expert input for case generation and validation is described. An algorithm for case matching is presented, along with some results on pilot data.     

GPS‐denied Indoor and Outdoor Monocular Vision Aided Navigation and Control of Unmanned Aircraft

GPS‐denied closed‐loop autonomous control of unstable Unmanned Aerial Vehicles (UAVs) such as rotorcraft using information from a monocular camera has been an open problem. Most proposed Vision aided Inertial Navigation Systems (V‐INSs) have been too computationally intensive or do not have sufficient integrity for closed‐loop flight. We provide an affirmative answer to the question of whether V‐INSs can be used to sustain prolonged real‐world GPS‐denied flight by presenting a V‐INS that is validated through autonomous flight‐tests over prolonged closed‐loop dynamic operation in both indoor and outdoor GPS‐denied environments with two rotorcraft unmanned aircraft systems (UASs). The architecture efficiently combines visual feature information from a monocular camera with measurements from inertial sensors. Inertial measurements are used to predict frame‐to‐frame transition of online selected feature locations, and the difference between predicted and observed feature locations is used to bind in real‐time the inertial measurement unit drift, estimate its bias, and account for initial misalignment errors. A novel algorithm to manage a library of features online is presented that can add or remove features based on a measure of relative confidence in each feature location. The resulting V‐INS is sufficiently efficient and reliable to enable real‐time implementation on resource‐constrained aerial vehicles. The presented algorithms are validated on multiple platforms in real‐world conditions: through a 16‐min flight test, including an autonomous landing, of a 66 kg rotorcraft UAV operating in an unconctrolled outdoor environment without using GPS and through a Micro‐UAV operating in a cluttered, unmapped, and gusty indoor environment. © 2013 Wiley Periodicals, Inc.     

Development of a Rotorcraft Micro air Vehicle for Indoor Flight Research

Autonomous flight of micro air vehicles (MAVs) in hostile indoor environments poses significant challenges in terms of control and navigation. In order to support navigation and control research for indoor micro air vehicles, a four-wing tail-sitter type rotorcraft MAV weighing less than 350g has been designed in this paper. In an effort to achieve autonomous indoor flight, an embedded integrated avionic system has been developed. The modeling process has been conducted to obtain accurate six degrees of freedom dynamical model for the designed rotorcraft MAV. In addition, aerodynamic coefficients are evaluated from the results of Computational Fluid Dynamics A PI-ADRC double loop controller with inner-loop outer-loop control scheme has been proposed which takes into account the system’s nonlinearities and uncertainties. The proposed flight controller was implemented on the designed rotorcraft MAV that has undergone various simulation and indoor flight tests. Experimental results that demonstrate robustness of the proposed controller with respect to external disturbances and the capabilities of the designed rotorcraft MAV are presented.     

Introduction to SPLM

This is an introduction to, and an overview of, the Space Programming Language Machine (SPLM), which is an architecture for a class of machines designed for efficient execution of on-board, aerospace computation functions. It directly executes software written in the SPLM Language (SPLML), which has been specially constructed as a complete, concise notation for the application area. The goal of the SPLM development effort is to design machines that are smaller, faster and easier to program than currently available aerospace computers. The specific features and characteristics of the SPLM may have general applicability, although this was not a design criterion.     

Heuristics for fault diagnosis when testing from finite state machines

When testing from finite state machines, a failure observed in the implementation under test (IUT) is called a symptom. A symptom could have been caused by an earlier state transfer failure. Transitions that may be used to explain the observed symptoms are called diagnosing candidates. Finding strategies to generate an optimal set of diagnosing candidates that could effectively identify faults in the IUT is of great value in reducing the cost of system development and testing. This paper investigates fault diagnosis when testing from finite state machines and proposes heuristics for fault isolation and identification. The proposed heuristics attempt to lead to a symptom being observed in some shorter test sequences, which helps to reduce the cost of fault isolation and identification. The complexity of the proposed method is analysed. A case study is presented, which shows how the proposed approach assists in fault diagnosis. Copyright © 2006 John Wiley & Sons, Ltd.     

基于特征相关性的牵引系统主回路接地故障诊断

本文针对目前机车、动车牵引系统中主回路接地故障的精确定位问题, 提出了一种基于特征相关性的故障诊断方法. 该方法通过在线计算与故障关联的特征变量, 提取相关故障特征指标, 并考虑各故障特征指标间的相关性, 利用典型相关分析得到残差, 以实现快速故障检测. 进一步, 构建基于残差方向的故障隔离方法, 实现准确地故障定位. 现场实验表明, 与传统基于相关性的故障诊断方法以及实际工程应用方法相比, 在存在较大测量噪声与暂态工况变化时, 本文所提方法能实现更好的故障检测与隔离性能, 具有良好的应用价值.     

基于PHM的特种车辆智能终端设计与实现

针对当前工程车辆在施工过程中故障预测难,发生故障排除故障难的现状,及时进行健康状态管理,针对车辆的整体状况给出全面的检测和评估,及时了解"健康隐患",在故障前给出保养建议及预防策略;针对保障特种车辆健康问题,研制由车载健康管理终端(简称"VPED")和一个架设在公网的远程服务平台构成的智能车载健康管理系统,实现3G、GPS、CanOpen在PHM的理念下无缝结合,对于工程车辆的健康管理和提高施工效率方面有着重要的指导意义.     

机载PHM系统软件设计与验证

针对现有PHM系统软件开发中存在的软件模块规范性差、复用率低和鲁棒性弱等问题,提出了一种基于OSA-CBM标准的构件化机载PHM系统软件设计方法,描述了机载PHM系统软件的构件化模型定义、功能框架、分层体系结构和软件控制流程;设计了机载PHM系统的构件接口和核心功能构件;实现了符合OSA-CBM规范接口的构件化软件。通过原型系统软件验证了构件化机载PHM系统软件设计和开发方法的正确性,表明了该方法能够提升软件的规范性、复用率、鲁棒性和可扩展性。     

基于SysML的航电系统架构安全性评估方法

针对现有系统安全性分析方法中安全性分析与航电系统架构设计过程无法融合的问题,提出基于SysML的航电系统架构安全性评估方法。首先在EA中基于SysML建模语言建立系统架构模型;然后利用XML解析技术从中提取系统关键信息,并建立故障树模型对其失效概率与区域安全性等进行分析,得到安全性评估结果;最后基于SysML语言对IMA架构下的显示系统进行架构设计和安全性评估,评估结果验证了所提出安全性评估方法的有效性。      

An architecture for fault tolerant controllers

A general architecture for fault tolerant control is proposed. The architecture is based on the (primary) YJBK parameterization of all stabilizing compensators and uses the dual YJBK parameterization to quantify the performance of the fault tolerant system. The approach suggested can be applied for additive faults, parametric faults and for system structural changes. The modelling for each of these fault classes is described. The method allows for design of passive as well as for active fault handling. Also, the related design method can be fitted either to guarantee stability or to achieve graceful degradation in the sense of guaranteed degraded performance. A number of fault diagnosis problems, fault tolerant control problems, and feedback control with fault rejection problems are formulated/considered, mainly from a fault modelling point of view. The method is illustrated on a servo example including an additive fault and a parametric fault.     

Concept design of future intelligent Earth observing satellites

This paper presents a concept design of an envisioned future intelligent Earth observing satellite (FIEOS) system. The proposed system is a space-based architecture for the dynamic and comprehensive on-board integration of Earth observing sensors, data processors and communication systems. The architecture and implementation strategies suggest a seamless integration of diverse components into a smart, adaptable and robust Earth observation satellite system. It is intended to enable simultaneous, global measurements and timely analyses of the Earth's environment for a variety of users. In particular, common users would directly access data in a manner similar to selecting a TV channel. We also discuss key technology problems, current technology development, amongst other things. It is concluded that (1) the proposed intelligent Earth observing satellite system is technically feasible; and (2) information technology and real-time information systems, for example multi-layer satellite networks connected with an organic system and on-board data processor capabilities, are crucial for implementation of the intelligent system. This revolutionary concept should dramatically impact on how Earth observing systems develop and conduct missions in the future.