Identification of a control-oriented energy model for a system of fan coil units

In recent years, application of advanced control, fault detection and diagnosis algorithms for building heating and cooling systems has been intensively investigated with the aim to improve their energy efficiency and bring the buildings sector into the smart city arena. Hindering the trend, hysteresis and proportional–integral–derivative controllers are still a common practice for temperature control in buildings with Fan Coil Units (FCUs). Introduction of more sophisticated controllers for additional savings requires a cost-effective approach for identification of an energy model which accurately resembles thermal and hydraulic performance of a system of FCUs. In the present work, the control-oriented energy model of a system of FCUs is developed and accompanied with replicable, robust and simple methodologies for its identification derived by consolidating the advantages of physical modelling, identification methods and manufacturer’s catalogue data. The validity of the developed approach is tested on the 248-office living-lab. The introduced simple and accurate dynamic characterization of energy transmitted from a FCU to zone air fills the gap between thermal and energy management for buildings. This enables implementation of predictive building controls and unleashes significant energy and cost-saving potentials of a smart building in a smart city.     

Closed-loop control of a SCR system using a NOx sensor cross-sensitive to NH3

This paper proposes a control strategy for an automotive selective catalytic reduction (SCR) system using a NO_x sensor in a feedback loop. As is representative of real world applications, the employed NO_x sensor is cross-sensitive to NH₃, which induces several complexities. In particular the ambiguity of the measurements could be detrimental to the closed loop response, as it generates multiple equilibrium points (artefacts), besides the point of practical interest. A study of the closed-loop dynamics is performed in the vicinity of each point, which shows that the closed loop system naturally converges to the point of interest not to the artefacts. Experimental results obtained after a detailed calibration method illustrate the relevance and performance of the proposed approach.     

Control-oriented model for integrated diesel engine and aftertreatment systems thermal management

In order to perform effective real-time active thermal management, control-oriented thermal models for the integrated Diesel engine and aftertreatment systems are required. The purpose of this study is to develop a control-oriented temperature dynamic model for a modern Diesel engine equipped with a complete set of aftertreatment systems including Diesel oxidation catalyst (DOC), Diesel particulate filter (DPF), and urea-based selective catalytic reduction (SCR) system. In specific, the influences of in-cylinder post injection (fuel injection rate and injection timing) on the temperature dynamics were investigated. Several engine experiments were conducted to validate the proposed model in various operating scenarios. Experimental results show that the developed model can well capture the thermal behaviors of the aftertreatment systems with and without post injections.     

Estimation and adaptive nonlinear model predictive control of selective catalytic reduction systems in automotive applications

The demands of high NO_x conversion efficiency and low tailpipe ammonia slip for urea-based selective catalytic reduction (SCR) systems have been substantially increased in the past decade, as NO_x emission legislations for Diesel engines are becoming more stringent than ever before. Since catalyst aging has a significant impact on SCR performance, robust and adaptive SCR control has been preferred for degraded SCR systems to realize emission control objectives. The purpose of this paper is twofold. Firstly, a robust ammonia coverage ratio observer was designed for estimating the ammonia coverage ratio reference for catalysts with different aging levels. An ammonia storage capacity observer was developed for estimating the actual ammonia storage capacity which can be reduced due to catalyst aging. An adaptive ammonia coverage ratio reference design was then developed to estimate the desired ammonia coverage ratio ranges at each instantaneous engine operating point for both single-cell and two-cell SCR systems at different aging levels based on a singular perturbation method. Secondly, to ensure the estimated ammonia coverage ratio falls in the desired ranges for most of engine operating conditions, robust nonlinear model predictive control (NMPC) algorithms were designed for both single-cell and two-cell SCR systems. Experimental data over US06 cycle were collected from a Diesel engine and aftertreatment system platform for controller verification. Simulation results under US06 test cycle demonstrate that the proposed NMPC algorithms were capable of consistently achieving high NO_x conversion efficiency (>95.6%) and constrained tailpipe ammonia slip (<10 ppm on average and <12 ppm on the peak) for both fresh catalyst and aged catalyst with 30% loss of ammonia storage capacity.     

Development of an experimental system for a snake-like gliding model

A snake, which has a simple shape without limbs, can move over rough terrain, climb a wall or tree, swim, and glide through the air. It is difficult to understand the gliding flight of a snake in aerodynamics assuming a static model, because a snake undulates its body trunk and turns in air. This paper presents an experimental system for investigation of the relationship between the shape of the gliding snake model and gliding characteristics. Results of a gliding experiment confirm a sufficiently high reproducibility of the experiment.     

Simulation model for a vanpooling system

Vanpooling programs have recently generated interest as a mode of transporting people to and from work. The vanpooling service can help in decreasing transportation cost, solving parking problems, easing traffic congestion, reducing air pollution, etc.

The implementation and success of a vanpooling program usually depends on the service schedule and economic considerations. Costs have been worked out such that each monthly payment covers all costs of acquiring, maintaining, operating, and replacement of the vans.

This paper will discuss the design, modeling, and simulation of a vanpooling service system. The paper will cover the simulation program that was developed, and an application of this model.

The study demonstrated that the cost per participant is approximately half the cost that is involved in private transportation.     

区域地震速度模型分析与应用系统的实现

为有效地管理地震速度数据,方便灵活地进行模型分析,并直观地以模型的形式反映地震速度在各个区域内的分布情况,“区域地震速度模型分析与应用系统”基于MapGIS-TDE平台的三维建模技术,应用属性建模和结构建模两种方式,使用插件技术完成地震速度数据的录入、管理、输出和三维可视化分析功能,该系统提供了方便快捷的地震速度模型（包括层速度模型和叠加速度模型）的分析功能和高效的地震速度数据管理功能。     

Development of a framework system for tool integration in a product information archive

The described framework system has the goal of providing an integration platform for engineering tools to interact. Engineering tools exchange information via the data repository of the framework system. In the European research project ESPRIT EP6896 Concurrent/Simultaneous Engineering System (CONSENS), a Product Information Archive (PIA) is being developed based on the object-oriented database system of the framework, the Object Management System. The Product model is based on a STEP compliant schema. This has been achieved by developing an Application Resource Model (ARM) for the required product information according to a user requirements analysis. The ARM then was mapped to the Integrated Resource Models of STEP which resulted in an object-oriented STEP compliant model. The main objective of PIA is the integration of the product information flows between parallel teams using the framework for product development. This is provided by an interface consisting of a library of functions that enable tools within and external to the framework to access PIA and exchange up-to-date product information. Additionally an X Motif based interface provides human users with direct access possibilities. The framework has been tested by the integration of various tools which support product development.     

Development of an information model for composites design data

Material properties data, particularly those of advanced composite materials such as fiber-reinforced plastics, provides a very complex domain which is difficult to computerize. As a foundational activity supporting the development of material property databases, we have examined and modeled the data contained within this large, diverse, and intricate domain. Our primary objective was to gain a better understanding of the data involved in this system and their transformation and use. We examined the life cycle of a fiber-reinforced composite material, from a raw material to a manufactured product, focusing on the various applications which require and/or supply materials data and the types of materials data which must be included. A high-level information model was created to illustrate the overall picture of composite materials data which emerged from this analysis. This model provides a global view of the data encompassed in the domain of composite materials, and forms the basis of a formal conceptual model from which databases may be developed.     

土石方开挖数学模型和仿真系统的设计与研究

建立了土石方开挖数学模型,将开挖过程简化为相应的数学问题,利用数学理论进行分析和研究,为土石方分区分层分块开挖原则提供了科学的方法和理论的指导。讨论了土石方开挖仿真系统的组成、统一建模语言（Unified Modeling Language,UML）的建模机制,提出了一种基于UML土石方开挖仿真系统的建模方法,并利用Rational Rose工具对其进行面向对象的可视化建模,详细阐述了系统用例模型、静态模型和动态模型的建模过程。实例分析说明了土石方开挖数学模型、UML建模机制是有效的、可行的。     

Development of fault tree for reliability studies of a data-processing system

In this paper a systematic approach is developed for generating the fault-tree logic, which is the basic requirement in any reliability studies of large complex systems using Monte Carlo simulation or deterministic approaches. The entire network is decomposed into sub-networks, each sub-network involving several loops, and it becomes quite easy to determine failure logic for these loops and thus for the subnetworks. Failure of such subnetworks between the source and the sink node leads to a major system failure and therefore this successive development results in a fault tree for the whole network.These loops can be automatically generated.

The failure event for each node in such an approach can also be accounted for. The advantage of the present methodology is that the fault-tree logic is automatically developed, which can be directly used as a sub-programme on a computer for various reliability studies of the system.     

Development of a feature-based and object-oriented concurrent engineering system

Product information modeling is critical to the integration of mechanical CAD/CAM systems and to the implementation of a concurrent engineering system. This paper presents a recent development of a feature-based and object-oriented concurrent engineering system with its focus on a product information modeling technique implemented in the system. The technique was developed to capture product definition data including form features and their spatial relationships and to store them as an object-oriented information model during the design process. The paper also describes the implementation of the information modeling technique and its application to manufacturing process planning in an object-oriented environment.     

网络坦克作战系统仿真方法及模型研究

网络坦克作战系统是一个分布式复杂适应系统.对复杂系统仿真建模有诸多平台与方法,分布式交互仿真更能反映系统的真实特性.提出了网络坦克作战系统的基本体系结构,对其常用的两种仿真方法HLA方法和MAS方法进行了比较,并依据作战系统的特征选择MAS方法,提出了其概念模型,设计了基于Swarm平台的仿真模型.     

Dynamic model of a stair-climbing mobility system and its experimental validation

The use of Electric-Powered Wheelchairs (EPWs) implies a dramatic improvement for people with physical disabilities, thus enabling them to lead more independent lives and to interact in society. Although numerous modifications have been made in recent years to improve access to transportation services and public buildings, the problem of a standard EPW dealing with certain architectural barriers has not yet been satisfactorily resolved. In order to contribute toward solving some of these problems, a stair-climbing mobility system (SCMS) which is capable of negotiating architectural barriers such as curbs, ramps, and staircases was developed in previous works. In this paper, is presented a novel dynamics model of a SCMS based on Newton formulation. It is characterized by the definition of a solely point mass located in the center of mass of the system and the assumption of quasistatic conditions. Additionally, taking into account that the SCMS adopt different mechanical configurations, the dynamics model incorporates relations between all the different actuators involved in each configuration of the SCMS and its generalized coordinates allowing different dynamic control strategies to be addressed. Finally, encouraging experimental results have been reported which confirm a high reliability of the model-experiment of the SCMS as it ascends a staircase.     

一种应用于地球系统模式的通用插值算法模型

地球系统模式的现有插值算法误差较大、网格适用性差,无法满足其未来的发展需求。提出了一种插值算法分类方法,根据此方法设计了一个通用插值算法模型。该模型基于复合算法的思想,既可表示现有算法,还可通过选择适当的两个算法灵活构造出局部的高精度的新算法。根据此模型并利用径向基函数良好的插值效果提出了两个新的插值算法。基于球面Voronoi图的搜索算法可有效优化插值算法的实现。实验结果表明新算法具有良好的插值效果。     

一种新型喷氨嘴布置优化设计方法

我国SCR脱硝技术仅有25年应用历史,在对原有火电机组进行SCR脱硝工程改造时,存在因空间受限导致的还原剂混合距离过短,有时没有空间安装用于保证催化剂入口氨浓度分布一致性的混合格栅,导致氨逃逸浓度和脱硝效率难以达到设计指标.针对这些问题,提出了一种适用于空间受限烟气脱硝装置的新型喷氨嘴布置优化设计方法.具体地,采用计算...     

多起重机节能混杂系统模型及其仿真*

为了保证多起重机节能系统中设备的正常运行并取得较好节能效果,构造多起重机节能系统的等效电路,针对系统复杂难以建模问题,引入混杂系统理论,建立基于混杂自动机的电网整流装置模型,将离散事件活动周期图建模方法推广至混杂系统构建受控功率源的活动周期图模型,从而得到系统整体模型。仿真研究了系统直流母线的功率和电压,验证了所建模型的合理性。为更深入地开展多电机节能系统的研究提供仿真平台。     

鼓式燃气换热器简化CFD模型开发及其试验验证

针对鼓式燃气换热器(drum gas heater,DGH)建模过程中存在的化学反应复杂和冷热流耦合计算困难等问题,基于计算流体力学(computational fluid dynamics,CFD)技术,采用k-ω湍流模型、Eddy-Dissipation模型和Discrete Ordinates辐射换热模型建立DG...     

数字图书馆主题搜索引擎的设计与实现*

提出构建数字图书馆主题搜索引擎的总体系统设计。利用一个预处理系统尽量选择高质量的种子站点,从而产生Web主题定义数据;在系统控制器的协调下,各主题爬行器同步地采集爬行器所推荐的Web资源,对下载的资源进行文本分类与主题识别;将已经下载的Web资源按学科分类存储在Web主题资源库中,通过全局信息库建立索引,接入通用接口进行依主题检索。依赖数字图书馆各方面特点,提出支持多线程主题爬行器的设计,并提出一种新颖的URL主题相关性剪切算法EPR,为实现数字图书馆主题搜索引擎原型提供重要的设计。基于开源Lucene平