Parameter space design of robust control systems

Find a state or output feedback with fixed gains such that nice stability (defined by a region in the eigenvalue plane) is robust with respect to large plant parameter variations, sensor failures, and quantization effects in the controller. Keep the required magnitude of control inputs small in this design. A tool for tackling such problems by design in the controller parameter spaceKis introduced. Pole placement is formulated as an affine map from the spacePof characteristic polynomial coefficients to theKspace. This allows determining the regions in theKspace, which place all eigenvalues in the desired region in the eigenvalue plane. Then tradeoffs among a variety of different design specifications can be made inKspace. The use of this tool is illustrated by the design of a crane control system. Several open research problems result from this approach: graphical computer-aided design of robust systems, algebraic robustness conditions, and algorithms for iterative design of robust control systems.     

嵌入式系统软硬件协调设计环境构造与实现方法

文章研究嵌入式系统协调设计方法,重点讨论一个完整的嵌入式系统协调设计环境———BitCoDesign构造,把嵌入式系统设计分解为系统功能描述和划分阶段、软硬件设计阶段、协同模拟阶段和软硬件综合阶段。具体阐述各设计阶段功能的实现方法,使嵌入式系统在设计初期,通过协同模拟手段验证系统的设计正确性,避免设计反复,降低开发成本,缩短开发周期     

嵌入式TCP/IP协议的内存管理技术

开发嵌入式系统的TCP/IP协议,内存管理的设计和实现是第一步,也是对整个协议栈性能有重要影响的一步。由于嵌入式系统的系统资源有限,内存管理既要节约系统资源,又要提高系统的性能,同时也要降低系统开发的难度。本文针对TCP/IP协议的实现,以及一些常用的嵌入式TCP/IP协议的实现,分析了相关的设计思路和方法,总结出在特定环境下内存管理系统设计实现的原则和方法,便于更好地实现嵌入式系统的网络功能。     

Multiobjective evolutionary optimization of DNA sequences for reliable DNA computing

DNA computing relies on biochemical reactions of DNA molecules and may result in incorrect or undesirable computations. Therefore, much work has focused on designing the DNA sequences to make the molecular computation more reliable. Sequence design involves with a number of heterogeneous and conflicting design criteria and traditional optimization methods may face difficulties. In this paper, we formulate the DNA sequence design as a multiobjective optimization problem and solve it using a constrained multiobjective evolutionary algorithm (EA). The method is implemented into the DNA sequence design system, NACST/Seq, with a suite of sequence-analysis tools to help choose the best solutions among many alternatives. The performance of NACST/Seq is compared with other sequence design methods, and analyzed on a traveling salesman problem solved by bio-lab experiments. Our experimental results show that the evolutionary sequence design by NACST/Seq outperforms in its reliability the existing sequence design techniques such as conventional EAs, simulated annealing, and specialized heuristic methods.     

Neural networks and response surface polynomials for design of vehicle joints

Typically, design of a complex system starts by setting targets for its performance characteristics. Then, design engineers cascade these targets to the components and design the components to meet these targets. It is important to have efficient tools that check if a set of performance targets for a component corresponds to a feasible design and determine the dimensions and mass of this design. This paper describes a method to develop tools that relate response parameters that describe the performance of a component to the physical design variables that specify its geometry. Neural networks and response surface polynomials are used to rapidly predict the performance characteristics of the components given the component dimensions. The method is demonstrated on design of an automotive joint. The paper compares neural networks and response surface polynomials and shows that they are almost equally accurate for the problem considered.     

A CAD-based design parameterization for shape optimization of elastic solids

In this paper a CAD-based design sensitivity analysis (DSA) and optimization method using Pro/ENGINEER for shape design of structural components is presented. The CAD-based design model is critically important for multidisciplinary shape design optimization. Only when each discipline can compute the design sensitivity coefficients of the CAD-based design model, can a true multidisciplinary what-if study, trade-off analysis, and design optimization be carried out. The proposed method will allow the design engineer to compute design sensitivity coefficients of structural performance measures such. as stress and displacement, evaluated using existing finite element analysis (FEA) tools, both h- and p-versions, with respect to design variables defined in the parameterized CAD model. The proposed method consists of (i) a CAD-based design parameterization technique that ties the structural DSA and optimization to a CAD tool; (ii) a design velocity field computation that defines material point movement due to design change in CAD geometry, satisfies linearity and regularity requirements, and supports both hand p-version FEA meshed using existing mesh generators; and (iii) a design optimization method that supports structural geometric and finite element model updates in Pro/ENGINEER during the optimization process.     

Control System Design Automation for Mechanical Systems

In this paper, a user-friendly and comprehensive control system design package called Control System Design Automation (CSDA) is described. The system consists of five main blocks: a requirement interpretation block, a modeling block, an analysis/design block, a database management and knowledge base block, and a verification block. The requirement interpretation block transforms the specifications in terms of the application to those in terms of control. The analysis/design block selects an optimal control structure and determines the controller parameters. In addition to the conventional design methods, CSDA also contains the more recent design methods such as the LMI design approach and the Kessler/Manabe method. The LMI approach can obtain a controller which satisfies multiple specification items at the same time. The configuration of the system as well as the analysis/design block are described in detail in this paper.     

基于uC/OS的网络PDA总体结构设计与实现

叙述了基于 u C/ OS 的一款网络 PDA的总体结构设计 ,阐述了本 PDA的软件设计 ,包括实时操作系统 u C/ OS 、开源 TCP/ IP协议栈 L WIP的选择、移植以及一些功能模块的设计实现。本 PDA系统的设计、开发 ,为以后嵌入式系统应用开发积累了丰富的经验。     

Application of design parameters space search for belt conveyor design

Belt conveyor design is examined as an application of a proposed Design Parameters Space Search technique. First, the main characteristics of the belt-conveyor design process are presented as they appear in the current literature. Furthermore, a proposed general knowledge-representation platform is described, and its ability to house the relevant conveyor design knowledge is also shown.

Next, the extended search technique of the design space is discussed, and an integrated example of a belt-conveyor design is presented, based on the proposed representation platform and the extended search technique. Finally, it is shown that the design of belt conveyors according to the proposed approach presents the following significant advantages:

• • Due to the knowledge-representation scheme adopted, both qualitative and quantitative knowledge can be used within the same platform.

• • Multiple solutions can be easily produced through user-defined design criteria. These solutions can be further modified and/or evaluated to produce more-specific designs.

• • The required for user-input data is kept to a minimum. Due to the applied extended search method, semiautomatic design can be achieved. As a consequence, the design process is completed in less time than that required by the conventional methods.

     

Development of a comprehensive industrial work design model

An overview of the conceptual, theoretical, and interdisciplinary approaches to industrial work design is presented. Five existing models in the area of industrial work design are reviewed. A thorough understanding of the various factors affecting industrial work design is necessary for improving worker productivity, job satisfaction, safety, health, and well-being. With this objective in mind, a comprehensive model of industrial work design is developed. The model depicts the relationship among a great many factors that affect the design of industrial work: human, machine, job, workspace, and work design factors—social, psychological, physical/physiological, organizational, and economical. The subfactors are also identified. The model shows the expected work design attributes and outcomes. Hitherto, no other work design model has included so many relevant factors/subfactors as possible into a single model. © 1999 John Wiley & Sons, Inc.     

Telerobot-enabled HUB-CI model for collaborative lifecycle management of design and prototyping

The HUB-CI model is investigated in a telerobotic system in a client/server network to manage the lifecycle of engineering design and prototyping. The purpose of this platform is to support collaborative engineering design and proof of concept to enhance distributed team collaboration and resource utilization. The suggested platform is exemplified in two collaboration support tools and a physical prototyping platform. Structured Co-Insight Management is developed to support innovative idea exchanges and the consensus decision-making during the design process. Conflict/error detection management helps preventing conflicts and errors during the lifecycle of design and development. Physical collaboration over the network occurs when a team controls the telerobot operation during prototyping and testing in design cycles. A pilot system is implemented with a group project for the design of an electronic circuit (including both hardware and software designs). The functional assessment method is used to compare this platform to other collaborative design tools. The system presented offers unique qualitative advantages as an integrated collaboration support system.     

A glance of technology efforts for design-for-manufacturing in nano-scale CMOS processes

This paper overviews design for manufacturing （DFM） for IC design in nano-CMOS technologies. Process/device issues relevant to the manufacturability of ICs in advanced CMOS technologies will be presented first before an exploration on process/device modeling for DFM is done. The discussion also covers a brief introduction of DFM-aware of design flow and EDA efforts to better handle the design-manufacturing interface in very large scale IC design environment.     

Applications of an interaction,process, integration and intelligence (IPII) design approach for ergonomics solutions

This paper first reviews current ergonomics design approaches in delivering digital solutions to achieve a unified experience from interaction and business process design perspectives. Then, it analyses the opportunities that new technologies may bring in for enhancing current ergonomics design approaches from integration and intelligence design perspectives. To address the challenges in today’s ergonomics practices in delivering digital solutions, an interaction, process, integration and intelligence (IPII) design approach is proposed. A case study is presented that implemented the IPII approach. The quantitative data gathered from the case study demonstrates that the IPII approach has achieved significant advantages in reaching the goal of a unified experience and operational benefits for delivering digital solutions. The IPII approach also demonstrates improvements compared to today’s ergonomics design approaches, such as user-centred design, for digital solutions. Finally, the paper highlights the contributions of the IPII approach for future ergonomics practices in delivering digital solutions.

Practitioner Summary: In addition to the interaction design for the UI of digital solutions, as is the case in current typical ergonomics practice, the IPII adds three additional design components: process, integration and intelligence design. The case study demonstrates the advantages of the IPII, providing an enhanced approach for designing digital solutions.

Abbreviations: IPII: interaction, process, integration and intelligence; IEA: International Ergonomics; Association; HFE: human factors/ ergonomics; HCD: human-centred design; UX: user experience; UI: user interface; ISO: International Organization for Standardization; UCD: user-centred design; ERP: enterprise resource planning; E2E experience: end-to-end experience; UXD: user experience design; AI: artificial intelligence; ML: machine learning; HCI: human-computer interaction; IaaS: infrastructure as a service; PaaS: platform as a service; SaaS: software as a service; CRM: customer relation management; SCM: supply chain management; HCM: human capability management; BI: business intelligence; BOMA: Bill of Materials Application; POC: proof of concept; TCM: transition change management; SMEs: subject matter experts; PMO: program management office; UAT: user acceptance test; iBPMS: intelligent business process management suite     

基于FPGA的UART设计与应用

针对通用异步收发器(UART)的特点,提出一种基于FPGA芯片的嵌入式设计算法,其中包括状态机设计技术和层次设计方法,实现了数据传输的全双工收/发功能,设计了UART的功能测试电路。结果表明,该设计具有可编程收/发数据位数和提供功能扩展等优点。     

Assessing the Changeability of two Object-Oriented Design Alternatives--a Controlled Experiment

An important motivation for the object-oriented paradigm is to improve the changeability of the software, thereby reducing lifetime development costs. This paper describes the results of controlled experiments assessing the changeability of a given responsibility-driven (RD) design versus an alternative control-oriented mainframe (MF) design. According to Coad and Yourdon's OO design quality principles, the RD design represents a good design. The MF design represents a bad design. To investigate which of the designs have better changeability, we conducted two controlled experiments--a pilot experiment and a main experiment. In both experiments, the subjects were divided in two groups in which the individuals designed, coded and tested several identical changes on one of the two design alternatives.The results clearly indicate that the good RD design requires significantly more change effort for the given set of changes than the alternative bad MF design. This difference in change effort is primarily due to the difference in effort required to understand how to solve the change tasks. Consequently, reducing class-level coupling and increasing class cohesion may actually increase the cognitive complexity of a design. With regards to correctness and learning curve, we found no significant differences between the twodesigns. However, we found that structural attributes change less for the RD design than for the MF design. Thus, the RD design may be less prone to structural deterioration. A challenging issue raised in this paper is therefore the tradeoff between change effort and structural stability.     

Effect of load/unload process on friction/stiction and durability of head-disk interface

 Effect of various operating parameters viz. load/unload speed, disk speed, ramp height, and disk dynamics on load/unload performance, friction/stiction and durability of a head-disk interface (HDI) were studied. Load/unload performance was evaluated using acoustic emission signals and friction force measurements. The load/unload performance was found to be better for higher load/unload durations, lower disk speeds and higher ramp heights. The effect of ramp height was studied for two different slider suspension designs. A slider suspension with `A' type suspension design performed well for higher ramp heights. The slider with `B' suspension design was not affected by a change in ramp height. Disk dynamics studies indicated how strongly HDI can be affected by disk vibrations and supported the effect seen by varying ramp heights. Durability tests revealed that the HDI deteriorated faster for lower ramp heights for a slider with `A' type suspension design than for the slider with `B' type suspension design. Received: 22 February 2002/Accepted: 20 June 2002     

基于系统级FPGA/CPLD的SoPC嵌入式开发研究

针对基于系统级FPGA／CPLD的SoPC嵌入式设计特点，介绍采用SoPC Builder设计工具有选择地将处理器、存储器、I／O等系统设计所需的IP组件集成到PLD器件上，也可以通过自定义用户逻辑集成到PLD器件上的开发方法，构建高效SoC。文中分析了嵌入式处理器Nios软核的特性，并给出了基于Nios内核的SoPC软硬件开发流程和白定义用户逻辑的软硬件设计过程。     

A knowledge-based standards processor for structural component design

This paper presents a design strategy in which structural components are designed automatically by applying three types of knowledge: knowledge in a design standard; textbook knowledge of structural, material, and geometrical relationships; and knowledge representing designer-dependent design expertise. The design strategy selects from the designer-dependent knowledge source the behavior limitations—limit states of an object in a given stress state—to consider, translates the behavior limitations into a subset of corresponding standard requirements, generates a set of constraints from the requirements and the relations in the knowledge-base of textbook relationships, satisfies the constraints, and then checks the satisfaction of all remaining applicable requirements. By using this design strategy, it is possible to construct a knowledge-based design strategy that is standard independent, so that the same design process can be performed regardless of which design standard is explicitly represented.The design strategy described has been implemented in a prototype knowledge-based system, SPEX, which has a blackboard architecture similar to, but much simpler than, that of HEARSAY. The blackboard represents the level of abstraction through which a component design progresses. The knowledge-base in SPEX consists of several knowledge sources that perform portions of the component design task. Control of the design process knowledge sources in SPEX is rule-based.     

CACSD using the state-space L∞ theory-adesign example

The L^∞ optimal control theory is used to achieve singular value loop-shaping design objectives in a multivariable aircraft pitch-axis control design example involving an unstable nonminimum phase plant. Comparison to the frequency-weighted LQG (Linear quadratic Gaussian) design shows that the L^∞ theory easily produced a superior design having both higher bandwidth and greater stability margin, with no need for designer interaction for iterative adjustment of weights, than LQG. The design example provides a vivid illustration of how the all-pass property of the L^∞ theory enables precise shaping of closed-loop singular-value Bode plots to conform pointwise to prespecified weighting functions     

基于．NET平台的B／S系统开发框架的研究

微软提供的．NET平台是一个高效的中小型系统的开发平台，但是它没有像J2EE那样提供一个应用系统架构的开发标准。为了给大家提供一个统一的参考模型，文中通过对NET平台下的B／S结构软件系统开发框架的研究，对框架化的BAS系统设计模式和其中的业务逻辑组织进行了详细的论述，最后介绍该开发框架在一个校务管理系统的实际应用来说明用．NET平台构建系统的解决方案。