Design Of Reference Model Research Articles

Observer design for exhaust gas recirculation rate estimation in a variable-geometry turbocharger diesel engine using a model reference identification scheme

Exhaust gas recirculation systems are used in diesel engines to reduce nitrogen oxide emissions. Since excessive recirculation in the cylinders may lead to an increase in generation of particulate matter and to unstable combustion, the exhaust gas recirculation rate should be measured correctly and should be controlled precisely. Unfortunately, the harsh conditions of the exhaust gas recirculation path make it difficult to measure the exhaust gas recirculation mass flow rate directly by using the relevant sensors. Therefore, precise control of the exhaust gas recirculation system depends on accurate estimation of the exhaust gas recirculation rate. To estimate accurately the exhaust gas recirculation rate in a turbocharged diesel engine, we propose an observer based on a model reference identification scheme. A linear parameter-varying model of the intake manifold pressure was derived to serve as the observer’s reference model. An update rule of the observer was designed with the model reference identification scheme. The intake and exhaust temperature models were developed through an empirical approach. Convergence of the proposed observer was proven in terms of the Lyapunov stability criterion. The proposed observer was implemented on a real-time embedded system and validated successfully through experiments on the engine.

A model-free design of reduced-order controllers and application to a DC servomotor

This paper presents a new model-free technique to design fixed-structure controllers for linear unknown systems. In the current control design approaches, measured data are used to first identify a model of the plant, then a controller is designed based on the identified model. Due to errors associated with the identification process, degradation in the controller performance is expected. Hence, we use the measured data to directly design the controller without the need for model identification. Our objective here is to design measurement-based controllers for stable and unstable systems, even when the closed-loop architecture is unknown. This proposed method can be very useful for many industrial applications. The proposed control methodology is a reference model design approach which aims at finding suitable parameter values of a fixed-order controller so that the closed-loop frequency response matches a desired frequency response. This reference model design problem is formulated as a nonlinear programming problem using the concept of bounded error, which can then be solved to find suitable values of the controller parameters. In addition to the well-known advantages of data-based control methods, the main features of our proposed approach are: (1) the error is guaranteed to be bounded, (2) it enables us to avoid issues related to the use of minimization methods, (3) it can be applied to stable and unstable plants and does not require any knowledge about the closed-loop architecture, and (4) the controller structure can be selected a priori, which means that low-order controllers can be designed. The proposed technique is experimentally validated through a real position control problem of a DC servomotor, where the results demonstrate the efficacy of the proposed method.

Tuning Nonlinear Controllers with the Virtual Reference Approach

Virtual Reference Feedback Tuning (VRFT) is a well established method for data-driven tuning of linear controllers. In VRFT the design is performed in “one-shot”, that is, with only one batch of input-output data, without the need of iterative data collection procedures. Its core concept consists in treating input-output data collected from the plant to be controlled as if they had been obtained from a virtual experiment , in which a particular reference signal - the virtual reference - would have been applied to the closed-loop system. A key feature of the VRFT method is that it greatly simplifies the design procedure with respect to standard model reference design: for linear and linearly parametrized controllers, it results in convexification of the design, so that its solution can be found by a single least squares method. In this paper this paradigm is applied to the tuning of nonlinear controllers. We propose specific design procedures for two classes of nonlinear plants: rational plants and plants of the Wiener type. Statistical properties of the controllers thus designed in noisy environments are also illustrated.

Based on Model Reference Design of Lead Sheets Servo Winder Tension Control System of Electro-Hydraulic Design Simulation and Analysis

In this paper,for the precision of tension control affects the products quality and performance of the device. In the coiling process while the tension control of the lead plate coiling machine is not stable, it will cause uneven thickness of lead sheet, affect the winding quality of lead sheets, and impact electrolysis efficiency. In this paper, according to the requirements of electrolytic process and the lead sheet winder actual working process, designing a tension control system in order to improve the precision of tension control.

Based on Model Reference Design of Lead Sheets Servo Winder Tension Control System of Electro-Hydraulic Design Simulation and Analysis

Based on Model Reference Design of Lead Sheets Servo Winder Tension Control System of Electro-Hydraulic Design Simulation and Analysis

Design of Reference Model for Complex Embedded Software Testing

As information telecommunication industry develops and systems get integrated gradually, the importance of complex embedded software testing is growing significantly. On the contrary, the reliability of complex embedded software testing has worsened. Accordingly, testing of software is an essential part in designing and building up embedded system and the volume of testing required is immense. This paper elaborates on design and testing reference model for complex embedded software testing, providing guidelines to collect requirements for complex embedded software testing.

Key characteristics-based sensor distribution in multi-station assembly processes

This paper presents a novel approach for optimal key characteristics-based sensor distribution in a multi-station assembly process, for the purpose of diagnosing variation sources responsible for product quality defects in a timely manner. Current approaches for sensor distribution are based on the assumption that measurement points can be allocated at arbitrary locations on the part or subassembly. This not only presents challenges in the implementation of these approaches but additionally does not allow required product assurance and quality control standards to be integrated with them, due to lack of explicit relations between measured features and geometric dimensioning and tolerancing (GD&T). Furthermore, it causes difficulty in calibration of measurement system and increases the likelihood of measurement error due to the introduction of measurement points not defined in GD&T. In the proposed approach, we develop methodology for optimal sensor allocation for 6-sigma root cause analysis that maximizes the number of measurement points placed at critical design features called Key Characteristics (KCs) which are classified into: Key Product Characteristics and Key Control Characteristics and represent critical product and process design features, respectively. In particular, KCs have defined dimensional and geometric tolerances which provides necessary design reference model for process control and diagnosis of product 6-sigma variation faults. The proposed approach allows obtaining minimum required production system 6-sigma diagnosability. A feature-based procedure is proposed which includes Genetic Algorithm-based approach (allowing pre-defined KCs as the measurement points) and state-of-the-art approaches (unrestricted location of measurement points) to iteratively include arbitrary measurement points together with KCs in the final sensor layout. A case study of automotive assembly processes is used to illustrate the proposed feature-based approach.

A New Method for Volumetric Evaluation of Gingival Recessions: A Feasibility Study

This preliminary in vitro study, presented at the General Session of the International and American Association for Dental Research in 2010 (Barcelona, Spain), evaluates whether three-dimensional (3D) optical scanning and subsequent superimposing procedures could be used for reproducible volumetric evaluation of gingival recession. Silicone impressions were taken of mandibular and maxillary master casts, and eight stone replicas of each master cast were produced. Each replica was scanned 10 times with a 3D optical system, and 3D datasets representing the computer-aided design reference models were calculated using a triangulation method. Marks designating gingival recession were scratched into the anterior segments of the replicas. The modified replicas were then scanned 10 times, and 3D datasets were calculated and subsequently superimposed. Differences in the volume of the gingival recession were recorded with reference to the initial data. The determination of gingival recession volume was highly reproducible. For all replicas, the 3D optical method showed small standard deviations and intraclass correlation coefficients between 0.997 and 0.999. This new method allows the reproducible volumetric evaluation of gingival recession marks on stone replicas. Additional clinical trials are necessary to confirm these in vitro findings. This method allows the operator to control the volumetric progression of periodontal soft tissue, for example, after root coverage procedures and to detect relapses at an early stage.

Schedulability Analysis for Hard Network Lifetime Wireless Sensor Networks With High Energy First Clustering

Network lifetime predictability is an essential system requirement for the type of wireless sensor network (WSN) used in safety-critical and highly-reliable applications. All sensor nodes in these time-critical WSNs should meet the lifetime constraint at any time instance, else it may cause severe consequences that involve economic losses, or even fatalities. In the literature, clustering sensors into groups is a popular strategy to maximize the network lifetime, but none of the clustering algorithms address the predictability issue for time-critical WSNs. In this paper, the High Energy First (HEF) clustering algorithm is chosen as a design reference model, which is proved in this paper to be an optimal clustering policy under certain ideal conditions. To address network lifetime predictability in practice, the network lifetime bounds and feasibility test for the HEF are developed via the worst case energy consumption analysis. The network simulator 2 (NS2) is used to verify the proposed network lifetime predictability model, and the results show that the derived bounds of the predictability provide accurate estimations of the system lifetime.

Predictive Control Allocation for a Thermal Management System Based on an Inner Loop Reference Model—Design, Analysis, and Experimental Results

This paper addresses the challenge of controlling an overactuated engine thermal management system where two actuators, with different dynamic authorities and saturation limits, are used to obtain tight temperature regulation. A modular control strategy is proposed that combines model predictive control allocation (MPCA) with the use of an inner loop reference model. This results in an inner loop controller that closely matches a dynamic specification for input-output performance while addressing actuator dynamics and saturation constraints. This paper presents the design and implementation strategy and illustrates the effectiveness of the proposed solution through real-time simulation and experimental results.

Correlations between the evolution of contradictions and the law of identity increase

TRIZ literature largely claims the efficiency of Altshuller's Laws of Engineering System Evolution (LESE) as a means for producing technology forecasts. Besides, all the instruments and the procedures proposed so far suffer from poor repeatability, thus limiting the adoption of TRIZ instruments as reliable means for the analysis of emerging technologies and their potential impact. In a previous work [1,2] the authors have presented their modelling approach based on a combination of well known TRIZ techniques and traditional engineering design reference models. The outcome is a Network of Evolutionary Trends which supports decision making by positioning alternative technologies and technical solutions according to the LESE. The choice of the favourite strategic direction is still assigned to the beneficiaries of the forecast, since decisions will be taken also based on their mission and values. Besides, it is necessary providing further means of judgement to the decision makers. According to this purpose, it is useful to assess the maturity level of the analyzed technologies. The present work is a study about the correlations existing between the evolution of contradictions and the Law of Ideality increase, as a means to estimate the stage of development of a Technical System. The paper details the method proposed to make a systematic comparison of the contradictions related to each technology. The approach is clarified by means of a case study related to the production of tablets in the pharmaceutical manufacturing sector.

Design and Development of an e-Platform for Supporting Liquid Food Supply Chain Monitoring and Traceability

In this paper, the deliverables of a research project are presented, which aims at the development of a webbased platform capable of supporting the traceability of liquid products like milk, wine and olive oil. First, it includes the design of a supply chain reference model and the identification of the data required for the efficient operation of the traceability system. The main elements of the proposed model defined in this paper are the entities, stages, events, and processes. The reference model consists of three distinct phases that represent stages of real-life supply chains. Each of these phases is defined by certain interactions between the above basic elements. Additionally, the proposed e-platform is based on the above reference model aiming to follow and register the production and distribution processes of the raw materials, semi-finals, and final products that are used in the examined industry.

A user-centric approach for information modelling in arable farming

Agriculture and farmers face a great challenge in effectively manage information both internally and externally in order to improve the economic and operational efficiency of operations, reduce environmental impact and comply with various documentation requirements. As a part of meeting this challenge, the flow of information between decisions processes defined as realizing a decision must be analyzed and modelled as a prerequisite for the subsequent design, construction and implementation of information systems. This paper defines the actors, their role and communication specifics associated with the various decision and control processes in farmers’ information management. Core-task analysis and core task demands from earlier research are utilised as premises for the modelling of information flow from the farmers’ point of view. A user-friendly generic FMIS design reference model is the primary objective for the study in which planning, execution and evaluation measures have been incorporated. A user-centric approach to model the information flows for targeted field operations is presented. The information models are centred around the farmer as the principal decision maker and involves external entities as well as mobile unit entities as the main information producers. This is a detailed approach to information modelling that will enable the generation of a Farm Management Information System in crop production.

Preservation Planning in the OAIS Model

The OAIS model has gained widespread acceptance as the fundamental design reference model for an archival system by the digital library community. One of its core entities is Preservation Planning, for which central functional entities are given yet without every detail breaking down into activities requirements. The Planets Preservation Planning approach addresses this by providing a way to make informed and accountable decisions on which preservation strategy to implement in order to most suitably preserve digital objects for a given preservation context. It allows the explicit definition of requirements and goals and offers a systematic way to evaluate preservation strategies. This paper shows the implementation of the Develop Preservation Strategies and Standards function of the OAIS model through the Planets Preservation Planning approach. Moreover, the paper examines the information flows within the OAIS Preservation Planning entity and with other functional entities with respect to the Planets model.

디지털 도서관 상호운영성 기술요소에 기반한 기술 참조 모델 설계에 관한 연구

본 연구에서는 디지털 도서관의 상호운영성 및 통합 관리 문제를 해결하기 위해 상호운영성을 위한 핵심 기술 및 디지털 도서관의 기능, 서비스를 분석하여 정보기술아키텍처의 기술참조모델을 설계하였다. 제시된 디지털 도서관의 정보기술아키텍처의 영역은 1)Metadata Management, 2)Library Services, 3)Service Integration 4)Service Management, 5)Open Interface, 6)Network, 7)Architecture 등 총 7개의 영역으로 구분되며, 20개의 세부 기술 영역으로 하였다. 이러한 연구결과는 정보시스템간의 상호운영성 및 호환성을 확보하기 위한 핵심 기술을 식별함으로서 디지털 도서관의 체계적인 구축과 효율성을 제고하기 위한 틀을 제공할 수 있을 것이다.

Performance Metric Portfolios: A Framework and Empirical Analysis

The widespread adoption of supply chain management principles suggests that managers recognize the importance of evaluating operational decisions holistically. However, it is often difficult to link specific operational practices to strategic level outcomes and in turn to corporate financial results. This presents problems for both managers and academic researchers attempting to justify the often high cost of operational improvement initiatives in terms of objective accounting metrics. This study provides evidence that it is possible to demonstrate linkages between carefully chosen portfolios of tactical, strategic, and financial metrics. Survey data from 118 manufacturers are used to evaluate hypotheses linking multilevel metrics of performance across three well‐established strategic foci. We present portfolios of metrics drawn from the literature and from the Supply Chain Counciľs supply‐chain operations reference model and related design and customer chain models. Our analysis suggests that metric portfolios in which tactical metrics are designed to match strategic‐level metrics, based on alignment with a specific strategic focus, provide clearer mechanisms for understanding performance linkages.

A two‐degree‐of‐freedom ℋ︁∞ control design method for robust model matching

AbstractWe propose an ℋ︁∞ controller design method which achieves a closed‐loop transfer function equal or otherwise sensibly close to a desired transfer function, viz. a model reference design. The proposed controller design method inherits the model reference feature of the internal model control design method and incorporates the weighting scheme of the ℋ︁∞ loop‐shaping. It utilizes Youla–Kucera parameterization in a two‐degree‐of‐freedom scheme to achieve robust model reference and high performance design while ensuring a sensible robust stability margin, and can be readily applied to the generic class of LTI systems (SISO, MIMO, stable, unstable). Copyright © 2006 John Wiley & Sons, Ltd.

An On-Chip IP Address Lookup Algorithm

This paper proposes a new data compression algorithm to store the routing table in a tree structure using very little memory. This data structure is tailored to a hardware design reference model presented in this paper. By exploiting the low memory access latency and high bandwidth of on-chip memory, high-speed packet forwarding can be achieved using this data structure. With the addition of pipeline in the hardware, IP address lookup can only be limited by the memory access speed. The algorithm is also flexible for different implementation. Experimental analysis shows that, given the memory width of 144 bits, our algorithm needs only 400kb memory for storing a 20k entries IPv4 routing table and five memory accesses for a search. For a 1M entries IPv4 routing table, 9Mb memory and seven memory accesses are needed. With memory width of 1,068 bits, we estimate that we need 100Mb memory and six memory accesses for a routing table with 1M IPv6 prefixes.

Perceptual factors underlying user preferences toward product form of mobile phones

This study examined the relationship between user preference perception of mobile phones and their form design elements. Subjects were asked to judge 26 mobile phone designs by using a user preference rating scale for 11 image words. The determining factors for user preference, including image words for design trends and product design elements, were specified through the semantic differential method. It was found that users prefer mobile phone designs with soft and compact images. Design reference models composed of relative weights of design elements were then proposed for specific design trends. In accordance with the design reference model, optimal solutions for preference and design trends of “soft” and “compact” were obtained through a specific algorithm. Concrete examples were illustrated and verified. The user's preference database can serve as the styling benchmark to help designers adopt a proper design and development perspective for the intended end users. Relevance to industry Important design elements and design trends related to the user's preference for mobile phones were extracted from the study. The optimal design solutions obtained from the database can serve as the styling benchmark for designers and managers in making design strategy, by which the time and cost of product development can be reduced.

905 遺伝的アルゴリズムによるモデル規範多変数ロバストモデル規範形制御の設計(機械力学・計測制御VIII)

905 遺伝的アルゴリズムによるモデル規範多変数ロバストモデル規範形制御の設計(機械力学・計測制御VIII)