非线性模型下的摄像机自标定

摄像机标定是从二维图像获取三维信息必不可少的步骤，线性（小孔）模型摄像机自标定，目前已成为计算机视觉领域的研究热点之一，对于非线性模型下摄像机的自标定，目前还未见到相关的研究报道，用于线性模型一般不能准确地描述真实像机的几何成像关系，因此对非线性模型摄像机自标定的研究具有十分重要的实际意义，该文主要探索非线性模型摄像机的自标定方法，基本原理是将非线性模型视为线性模型和畸变项的叠加，然后利用线性模型的基本矩阵或单应矩阵，给出非线性模型参数的约束方程，从而实现非线性模型摄像机的自标定，模拟和真实图像实验均表明该文所给的方法是可行的，具有一定的实用价值。     

Robust and non‐linear control of marine system

Robust and non‐linear control theories useful for real marine system are developed and applied to a variety of marine vehicles and equipments. In the thesis, the basic principle of marine control system development is described and advanced robust control algorithm and non‐linear control algorithm applicable for real system are shown. It's effectiveness is confirmed by numerical simulations, tank tests, and sea trial tests. Copyright © 2001 John Wiley & Sons, Ltd.     

基于计算机视觉的飞机燃油非接触式测量系统

为了实现飞机在任意飞行姿态下燃油量的测量,提出了一种新型的飞机燃油测量 系统。首先采用基于计算机视觉的非接触性液位感测技术,测得油箱中油位高度。然后采用 CAD 技术对油箱建模,实现了飞行姿态误差的修正。实现在油箱外对当前液面进行实时观测和 三维重建,无需对油箱内燃油通电,避免了传统测量方式的电磁干扰、电路磨损问题,提升了 燃油系统的安全性和可靠性。实时精确地测量剩余燃油量,对飞机的加输油控制、系统状态监 控、故障诊断隔离等功能具有重要意义。该油量测量方式与传统方式相比具有数字化、智能化 程度高、抗干扰能力强、可靠性高等优点。     

飞机燃油箱无油空间氧气浓度测量系统研究和发展综述

为了降低飞机燃油箱可燃性,绝大部分民用和军用飞机都安装了油箱惰化系统,来控制油箱无油空间的氧气浓度,但却一直没有适用于机载燃油箱的氧浓度实时监测系统。根据多型机油箱惰化系统试飞经验,总结了基于电化学原理和光谱吸收原理测量系统使用中的问题。依据文献分析,认为基于荧光猝灭原理的传感器将成为下一代机载油箱氧浓度测量系统的核心,并详细介绍了荧光猝灭效应的原理、检测方法、受感部和测量系统框架的研究现状。最后,指出测量系统应该向着轻量化、智能化和高可靠性方向发展。     

离散时间多智能体系统一致性的平均驻留时间条件

研究高阶离散时间线性多智能体系统在有向切换信息拓扑下的状态一致性问题。首先通过提出的线性变换将该一致性问题转换为相应离散时间线性切换系统的渐近稳定性问题。然后借助于切换系统稳定性的平均驻留时间方法,分别得到如下两种情形下该一致性问题可解的充分条件：1)信息拓扑集合中的一部分拓扑是可一致的;2)信息拓扑集合中所有信息拓扑是可一致的。最后通过数值仿真验证了所得理论结果的正确性。     

A wireless sensor system for validation of real-time automatic calibration of groundwater transport models

In this paper, we present the use of a wireless sensor network in a lab for subsurface contaminant plume monitoring with the objective of automatic calibration of groundwater transport models. A tank configured to simulate an aquifer was used as a testbed, and a 2D model was created based on the setup. To simulate a contaminant plume, an ion tracer was injected into the tank. Sensor probes capable of detecting the plume were buried inside the tank, and wireless motes used to take readings from the sensors and relay data to a base station. More importantly, a run-time fault detection and diagnosis for abnormal sensor readings is designed and integrated into the data acquisition system. Further, an adaptive data collection technique is integrated that is able to provide evidence about the effectiveness of the groundwater transport model in use. Results from the tracer tests are presented, as well as lessons gained.     

A forecasting system for car fuel consumption using a radial basis function neural network

A predictive system for car fuel consumption using a radial basis function (RBF) neural network is proposed in this paper. The proposed work consists of three parts: information acquisition, fuel consumption forecasting algorithm and performance evaluation. Although there are many factors affecting the fuel consumption of a car in a practical drive procedure, in the present system the relevant factors for fuel consumption are simply decided as make of car, engine style, weight of car, vehicle type and transmission system type which are used as input information for the neural network training and fuel consumption forecasting procedure. In fuel consumption forecasting, to verify the effect of the proposed RBF neural network predictive system, an artificial neural network with a back-propagation (BP) neural network is compared with an RBF neural network for car fuel consumption prediction. The prediction results demonstrated the proposed system using the neural network is effective and the performance is satisfactory in terms of fuel consumption prediction.     

基于电化学原理的飞机燃油箱氧浓度机载测量技术

飞机燃油箱惰化系统属飞机燃油系统设计中重要的分系统，为了准确评估燃油箱惰化系统的功能与性能，需要根据飞机实际使用剖面和惰化系统设计特点确定适用的飞行测试方法。提出了一种基于电化学原理的飞机燃油箱氧浓度机载测量方法，用于飞行实时测量运输类飞机油箱内无油空间或惰化管路的气体氧浓度，并对飞行中的实际影响因素进行模拟分析。经过分析飞行实际环境影响因素、关键传感器匹配性以及原理样机的试验验证等工作，将燃油箱氧浓度机载测量技术转化为专用的飞机燃油箱氧浓度机载测量系统，并通过了飞行实测考验。试飞结果表明，该项技术能够实时准确测量运输类飞机各种状态下的燃油箱氧浓度，满足飞机燃油箱惰化系统的效能评估要求。     

A socio-technical analysis of functional properties in a joint cognitive system: a case study in an aircraft cockpit

Abstract

In a socio-technical work domain, humans, device interfaces and artefacts all affect transformations of information flow. Such transformations, which may involve a change of auditory to visual information & vice versa or alter semantic approximations into spatial proximities from instruments readings, are generally not restricted to solely human cognition. This paper applies a joint cognitive system approach to explore a socio-technical system. A systems ergonomics perspective is achieved by applying a multi-layered division to transformations of information between, and within, human and technical agents. The approach uses the Functional Resonance Analysis Method (FRAM), but abandons the traditional boundary between medium and agent in favour of accepting aircraft systems and artefacts as agents, with their own functional properties and relationships. The joint cognitive system perspective in developing the FRAM model allows an understanding of the effects of task and information propagation, and eventual distributed criticalities, taking advantage of the functional properties of the system, as described in a case study related to the cockpit environment of a DC-9 aircraft.

Practitioner Summary: This research presents the application of one systemic method to understand work systems and performance variability in relation to the transformation of information within a flight deck for a specific phase of flight. By using a joint cognitive systems approach both retrospective and prospective investigation of cockpit challenges will be better understood.

Abbreviations: ATC: air traffic control; ATCO: air traffic controller; ATM: air traffic management; CSE: cognitive systems engineering; DSA: distributed situation awareness; FMS: flight management system; FMV: FRAM model visualize; FRAM: functional resonance analysis method; GF: generalised function; GW: gross weight; HFACS: human factors analysis and classification system; JCS: joint cognitive systems; PF: pilot flying; PNF: pilot not flying; SA: situation awareness; SME: subject matter expert; STAMP: systems theoretic accident model and processes; VBA: visual basic for applications; WAD: work-as-done; WAI: work-as-imagined; ZFW: zero fuel weight     

非规则油箱油量的测量方法

针对采用电容传感器测量油箱中油量的传统测量方法的弊端,提出了非规则油箱的数学模型建立方法及其油量的计算方法,从理论上详细地分析了利用线性电容传感器测量非规则油箱时产生姿态误差的原理,给出了姿态误差的修正方法,最后提出了在姿态误差最小的准则下确定传感器的最佳安装位置;该研究对提高非规则油箱的油量测量精度具有很大的实用价值.     

Minor blind feature based Steganalysis for calibrated JPEG images with cross validation and classification using SVM and SVM-PSO

The spectacular progress of technology related to the information and communication arena throughout the past epoch made the internet a powerful media for faster communication of data. Though this technology is being admired at one side, there equally exists a challenge for safeguarding the data and privacy of information of a personal without any leak in the data and corresponding mistreatment. Hence, the proposed work primarily aims to investigate the internet communication as well as deter any unwanted happenings, which could occur because of the covert communication. The probable presence of hidden messages is inspected in the digital mass media using the technique of steganalysis. The distinctive features are to be identified, chosen and extracted for universal (blind) steganalysis and are decided by the format of image and its transformation. In this paper, the analysis is carried out in JPEG format images and 10% embedding with 10 fold cross validation. The technique of calibration is used to obtain an estimate of the cover image. Four embedded techniques that have been applied for stegananlysis are Least Significant Bit Matching, LSB Replacement, Pixel Value Differencing (PVD) and F5 respectively. Four different sampling like linear, shuffle, stratified and automatic are considered in this paper. The classifiers used for a comparative study are Support Vector Machine (SVM) and SVM- Particle Swarm Optimization (SVM-PSO). Several kernels namely linear, epanechnikov, multi-quadratic, radial, ANOVA and polynomial are used in classification. The classifier is trained to examine every single coefficient as a separate unit for analysis and the outcome of this analysis helps in finding the decision of steganalysis.

     

Development and experimental investigation of an extended Kalman filter for an industrial molten carbonate fuel cell system

Industrial fuel cell stacks only provide very limited measurement information. To overcome this deficit, a state estimator for a molten carbonate fuel cell system is developed in this contribution. The starting point of the work is a rigorous spatially distributed model of the system. From this model, a reduced model is derived by using a Galerkin method and the Karhunen Loève decomposition technique. An extended Kalman filter with a continuous time simulator part and a discrete time corrector part is designed on the basis of the reduced model. The filter is tested in simulations and experimentally.     

加油站储油罐容表自动标定与测量系统

为了能够解决加油站储油罐容表的标定和实时精确测量剩余油量的问题,采用计算机和嵌入式技术设计了容表自动标定与测量系统;系统由计算机、流量计HPLW-80BT和测量终端组成,测量终端采用嵌入式处理器LPC2129作为容表的控制核心,利用液位变送器HGYB-5FY获取油罐内的液位高度;储油罐在投入使用之前,通过流量计预先标定罐内油位高度与储油量的对应关系;根据油位高度实时计算,并修正偏差值ΔV(h)就可以得到精确的测量数据;经过对横截面为椭圆形的储油罐进行数学建模和实验,得出了理论值和偏差值,实现了对储油罐的标定;标定之后,该系统能够在LCD上实时显示油位高度和剩余油量,对加油站的智能化管理起到了积极推进作用。     

A reduction paradigm for output regulation

The goal of this paper is to provide a reduction paradigm for the design of output regulators which can be of interest for nonlinear as well as linear uncertain systems. The main motivation of the work is to provide a systematic design tool to deal with non‐minimum‐phase uncertain systems for which conventional high‐gain stabilization methods are not effective. The contribution of the work is two‐fold. First, this work extends a previous reduction paradigm for output regulation of nonlinear systems. Furthermore, in the case of the uncertain controlled dynamics being linear, we show how the proposed framework leads to a number of systematic design tools of interest for non‐minimum‐phase linear systems affected by severe uncertainties. A numerical control example of a linearized model of an inverted pendulum on a cart is presented. Copyright © 2007 John Wiley & Sons, Ltd.     

发电列车车下燃油箱保温性能CFD仿真

基于CFD理论,应用STAR-CCM+仿真某发电列车车下燃油箱在给定高寒工况下的保温性能.在考虑列车运行时车外流场影响的基础上,耦合分析箱体、保温材料和燃油等的温度分布特性,找出燃油可能发生结蜡的区域.给出相关分析结论和改进建议,为保证燃油箱拥有稳定的工作性能提供可靠的设计参考.     

Analytical and numerical study of the effects of an elastically-linked body on sloshing

In order to investigate the effects of an elastically-linked moving body on liquid sloshing inside a tank, an analytical formulation and a numerical approach were proposed to assess hydrodynamic loads in a partially filled rectangular tank with a body connected to the tank by springs. The analytical approach was developed based on the potential theory to calculate fluid velocity field, and the dynamics of the liquid sloshing coupled to the moving body are described as a mechanical system with two degrees of freedom. The coupling between the fluid and the moving body is given by a damping force calculated based on the body geometry and the fluid velocity field. The proposed numerical approach is based on the Moving Particle Semi-implicit (MPS) method, which is a Lagrangian particle-based method and very effective to model nonlinear hydrodynamics due to fluid–structure interaction. In the numerical approach, the rigid body is modeled as a cluster of particles and the motions are calculated considering its mass, moment of inertia, hydrodynamic loads and springs restoring forces. The elastic link between the body and tank is modeled by applying Hooke’s law. Simple cases of floating body motion were used to validate the numerical method. Finally, analytical and numerical results were compared. Despite its simplicity, the analytical approach proposed in the present work is an efficient approach to provide qualitative understanding and a first estimate of the moving body effects on the sloshing inside the tank. On the other hand, the numerical approach can provide more detailed information about the coupling phenomena, and it is an effective mean for the assessment of the reduction of the sloshing loads due to the moving body with elastic link. Finally, the effectiveness of the concept as a sloshing suppressing device is also investigated.     

主/子惯导标定中挠曲变形误差综合补偿方法

针对挠曲变形对主/子惯导在线标定误差方程多方面影响的问题, 提出一种挠曲变形误差综合补偿方法. 首先, 基于极大似然估计和赤池信息量准则(AIC) 定阶的自回归(AR) 模型对挠曲变形进行建模; 然后, 针对挠曲变形引起的动态杆臂效应问题, 利用机理建模方法建立动态杆臂与挠曲变形角之间的关系模型; 在此基础上, 推导出挠曲变形与动态杆臂误差综合补偿方法; 最后, 将该方法应用于主/子惯导标定滤波器设计. 仿真结果表明, 所提出的综合补偿方法是有效的.

     

Passivity based control of a distributed PEM fuel cell model

This work considers the controlled load change of proton exchange membrane (PEM) fuel cells. Due to the intrinsic nonlinearities of fuel cells, load changes are quite challenging. In the case of a low temperature PEM fuel cell, there is the possibility of undesired liquid water formation. Most available control concepts are heuristic linear controller structures based on a perfectly mixed fuel cell model. In this work a nonlinear controller for one-dimensional spatially distributed model of a PEM fuel cell is presented. The fuel cell model is derived from first principles. The concept of passivity is used to design the controller. A suitable control Lyapunov function is chosen and passivity of the fuel cell is shown. A state-feedback law is derived that can guarantee stability of the closed-loop system over a wide range of operation conditions. In order to make the feedback law applicable to fuel cells with limited measurement information an observer is designed. In a final step the state-feedback law and the observer are combined to an output-feedback controller.     

GRAND — Ground structure based topology optimization for arbitrary 2D domains using MATLAB

The present work describes in detail an implementation of the ground structure method for non–orthogonal unstructured and concave domains written in MATLAB, called GRAND — GRound structure ANalysis and Design. The actual computational implementation is provided, and example problems are given for educational and testing purposes. The problem of ground structure generation is translated into a linear algebra approach, which is inspired by the video–game literature. To prevent the ground structure generation algorithm from creating members within geometric entities that no member should intersect (e.g. holes, passive regions), the concept of “restriction zones” is employed, which is based on collision detection algorithms used in computational geometry and video–games. The aim of the work is to provide an easy–to–use implementation for the optimization of least–weight trusses embedded in any domain geometry.