Showing papers on "Design tool published in 2013"

Finite-Set Model-Based Predictive Control for Flying-Capacitor Converters: Cost Function Design and Efficient FPGA Implementation

Abstract: Recently, there has been an increase in the use of finite-set model-based predictive control (FS-MBPC) for power-electronic converters. However, the computational burden for this control scheme is very high and often restrictive for a good implementation. This means that a suitable technology and design approach should be used. In this paper, the implementation of FS-MBPC for flying-capacitor converters in field-programmable gate arrays (FPGAs) is discussed. The control is fully implemented in programmable digital logic by using a high-level design tool. This allows us to obtain very good performances (both in control quality, speed, and hardware utilization) and have a flexible, modular control configuration. The good performance is obtained by exploiting the FPGA's strong points: parallelism and pipelining. Furthermore, an improved cost function for the voltage control of the flying capacitors is proposed in this paper. Typical cost functions result in tracking control for the flying-capacitor voltages, although this does not correspond with the desired system behavior. The improved cost function offers a capacitor voltage control that corresponds more closely with the desired behavior and adds a limitation on the capacitor voltage deviation. Furthermore, the selection of the weight factor in the cost function becomes less critical.

Definition of a 5MW/61.5m wind turbine blade reference model.

Abstract: A basic structural concept of the blade design that is associated with the frequently utilized %E2%80%9CNREL offshore 5-MW baseline wind turbine%E2%80%9D is needed for studies involving blade structural design and blade structural design tools. The blade structural design documented in this report represents a concept that meets basic design criteria set forth by IEC standards for the onshore turbine. The design documented in this report is not a fully vetted blade design which is ready for manufacture. The intent of the structural concept described by this report is to provide a good starting point for more detailed and targeted investigations such as blade design optimization, blade design tool verification, blade materials and structures investigations, and blade design standards evaluation. This report documents the information used to create the current model as well as the analyses used to verify that the blade structural performance meets reasonable blade design criteria.

Automated Finite Element Analysis of Elastically-Tailored Plates

Abstract: A procedure for analyzing and designing elastically tailored composite laminates using the STAGS finite element solver has been presented. The methodology used to produce the elastic tailoring, namely computer-controlled steering of unidirectionally reinforced composite material tows, has been reduced to a handful of design parameters along with a selection of construction methods. The generality of the tow-steered ply definition provides the user a wide variety of options for laminate design, which can be automatically incorporated with any finite element model that is composed of STAGS shell elements. Furthermore, the variable stiffness parameterization is formulated so that manufacturability can be assessed during the design process, plus new ideas using tow steering concepts can be easily integrated within the general framework of the elastic tailoring definitions. Details for the necessary implementation of the tow-steering definitions within the STAGS hierarchy is provided, and the format of the ply definitions is discussed in detail to provide easy access to the elastic tailoring choices. Integration of the automated STAGS solver with laminate design software has been demonstrated, so that the large design space generated by the tow-steering options can be traversed effectively. Several design problems are presented which confirm the usefulness of the design tool as well as further establish the potential of tow-steered plies for laminate design.

Umi - an urban simulation environment for building

Abstract: 7 8 9 ABSTRACT One widely recognized opportunity to reduce global carbon emissions is to make urban neighborhoods more resource efficient. Significant effort has hence gone into developing computer-based design tools to ensure that individual buildings use less energy. While these tools are increasingly used in practice, they currently do not allow design teams to model groups of dozens or hundreds of buildings effectively, which is why a growing number of research teams are working on dedicated urban modeling tools. Many of these teams concentrate on isolated sustainable performance aspects such as operational building energy use or transportation; however, limited progress has been made on integrating multiple performance aspects into one tool and/or on penetrating urban design education and practice. In this paper a new Rhinoceros-based urban modeling design tool called umi is presented which allows users to carry out operational energy, daylighting and walkability evaluations of complete neighborhoods. The underlying simulation engines are EnergyPlus, Radiance/Daysim as well as a series of Grasshopper and Python scripts. Technical details of umi along with a case study of a mixed use development in Boston are documented.

Q-methodology as a research and design tool for HCI

Abstract: A "discount" version of Q-methodology for HCI, called "HCI-Q", can be used in iterative design cycles to explore, from the point of view of users and other stakeholders, what makes technologies personally significant. Initially, designers critically reflect on their own assumptions about how a design may affect social and individual behavior. Then, designers use these assumptions as stimuli to elicit other people's points of view. This process of critical self-reflection and evaluation helps the designer to assess the fit between a design and its intended social context of use. To demonstrate the utility of HCI-Q for research and design, we use HCI-Q to explore stakeholders' responses to a prototype Alternative and Augmentative Communication (AAC) application called Vid2Speech. We show that our adaptation of Q-methodology is useful for revealing the structure of consensus and conflict among stakeholder perspectives, helping to situate design within the context of relevant value tensions and norms.

Design of Digit-Serial FIR Filters: Algorithms, Architectures, and a CAD Tool

Abstract: In the last two decades, many efficient algorithms and architectures have been introduced for the design of low-complexity bit-parallel multiple constant multiplications (MCM) operation which dominates the complexity of many digital signal processing systems. On the other hand, little attention has been given to the digit-serial MCM design that offers alternative low-complexity MCM operations albeit at the cost of an increased delay. In this paper, we address the problem of optimizing the gate-level area in digit-serial MCM designs and introduce high-level synthesis algorithms, design architectures, and a computer-aided design tool. Experimental results show the efficiency of the proposed optimization algorithms and of the digit-serial MCM architectures in the design of digit-serial MCM operations and finite impulse response filters.

FPGA Implementation for Image Processing Algorithms Using Xilinx System Generator

Abstract: The paper presents information about FPGA implementation for various Image Processing Algorithms using the most efficient tool called Xilinx System Generator (XSG) for Matlab. System Generator is a DSP design tool from Xilinx that enables the use of the Math Works model-based Simulink design environment for FPGA design. In this paper various morphological and intensity image processing algorithms for negatives, image enhancement, threshold,, contrast stretching, Edge detection, boundary extraction for grayscale and color images are explored. Use of Xilinx system generator for image processing effectively reduces intricacy in structural design also provides additional feature for hardware co-simulation

Co-simulation framework for design of time-triggered cyber physical systems

Abstract: Designing cyber-physical systems (CPS) is challenging due to the tight interactions between software, network/platform, and physical components. A co-simulation method is valuable to enable early system evaluation. In this paper, a cosimulation framework that considers interacting CPS components for design of time-triggered (TT) CPS is proposed. Virtual prototyping of CPS is the core of the proposed frame-work. A network/platform model in SystemC forms the backbone of the virtual prototyping, which bridges control software and physical environment. The network/platform model consists of processing elements abstracted by real-time operating systems, communication systems, sensors, and actuators. The framework is also integrated with a model-based design tool to enable rapid prototyping. The framework is validated by comparing simulation results with the results from a hardware-in-the-loop automotive simulator.

PacCAM: material capture and interactive 2D packing for efficient material usage on CNC cutting machines

Abstract: The availability of low-cost digital fabrication devices enables new groups of users to participate in the design and fabrication of things. However, software to assist in the transition from design to actual fabrication is currently overlooked. In this paper, we introduce PacCAM, a system for packing 2D parts within a given source material for fabrication using 2D cutting machines. Our solution combines computer vision to capture the source material shape with a user interface that incorporates 2D rigid body simulation and snapping. A user study demonstrated that participants could make layouts faster with our system compared with using traditional drafting tools. PacCAM caters to a variety of 2D fabrication applications and can contribute to the reduction of material waste.

A parametric investigation of the acoustical performance of contemporary mosques

Abstract: Acoustics is an important factor in mosque prayer halls that had not been given extensive concern during the architectural design stages. Eventually, the importance of speech intelligibility became more important, given the integration of other activities into the prayer halls, such as the holy Quran recitation, speeches, and lectures. Early attempts have been made to control the propagation of sound and to maintain good acoustic quality within the prayer spaces. Architects during the conceptual design stage had barely paid attention to the design issues that affect the acoustic environment inside the prayer zones, which is either due to lack of time during the project development or, in most cases, a lack of simple design guidelines to overcome any drastic acoustical defects arising from the incorrect design, shape, or material selection. The basic guidelines for designers to select the appropriate shape, geometry, size, and finishing materials are an essential design tool. This work examines the three common design topologies of mosques, which differ in size, shape, and finishing materials. In this study, a geometric and material parametric analysis was conducted based on the shape, surface area, volume, and finishing materials of each of the three designs. For the geometric acoustics, a computer model employing the ray tracing theory was employed to investigate the three configurations. Different acoustic treatments were tested relative to the geometric disposition of each design. Finally, basic recommendations and design guidelines were presented.

An automatic physical design tool for clustered column-stores

Abstract: Good database design is typically a very difficult and costly process. As database systems get more complex and as the amount of data under management grows, the stakes increase accordingly. Past research produced a number of design tools capable of automatically selecting secondary indexes and materialized views for a known workload. However, a significant bulk of research on automated database design has been done in the context of row-store DBMSes. While this work has produced effective design tools, new specialized database architectures demand a rethinking of automated design algorithms.In this paper, we present results for an automatic design tool that is aimed at column-oriented DBMSes on OLAP workloads. In particular, we have chosen a commercial column store DBMS that supports data sorting. In this setting, the key problem is selecting proper sort orders and compression schemes for the columns as well as appropriate pre-join views. This paper describes our automatic design algorithms as well as the results of some experiments using it on realistic data sets.

Application of an NVNA-Based System and Load-Independent X-Parameters in Analytical Circuit Design Assisted by an Experimental Search Algorithm

Abstract: Recently, X -parameters have been introduced to model active device nonlinear behavior. In addition to providing a measurement-based tool to numerically predict nonlinear device behavior in computer-aided design, they can also provide the designer of nonlinear circuits an analytical design tool. Exploiting this design tool aspect, this work presents an application that combines the nonlinear vector network analyzer PNA-X and a passive tuner to extract a transistor load-independent X -parameter model, focused around targeted circuit impedances for optimal performance. Furthermore, an experimental search algorithm, based on X-parameters analytical computations and developed by Pelaez-Perez , has been used and experimentally validated in this paper, aimed to speed up the characterization and design process, minimizing the number of load-pull measurements necessary to provide an accurate transistor X-parameter model for use in analytical and/or numerical circuit design.

System design tool for high bit rate terrestrial transmission systems with coherent detection

Abstract: Coherent detection offers the ability to compensate for linear transmission impairments such as fiber chromatic dispersion and polarization-mode dispersion in the digital domain, thereby enabling dispersion-uncompensated optical transmission for high performance and high cost effectiveness. In dispersion-uncompensated transmission systems, the statistics of optical nonlinearity induced distortions have been proven to be essentially Gaussian-distributed, and new physical models have emerged showing profound differences with respect to legacy systems based on direct detection. From such differences stems the need to adapt the design tool to capture these new propagation properties. In that respect, we propose a model for performance prediction, which is used to derive a simple yet effective feasibility parameter to be embedded in the design tool. The feasibility parameter is experimentally validated with real time product transponders, and realistic system configurations: a precision of ±0.5 dB is achieved for 40 Gb/s, 100 Gb/s and 400 Gb/s coherent channels, which represents an improvement of more than 3 dB over the design tool using the nonlinear phase shift as the criterion.

A graphical approach to process synthesis and its application to steam reforming

Abstract: It is common practice in chemical engineering to design processes sequentially. The type of product desired determines the choice of the feed materials that are introduced into the reactor networks. These in turn lead into the separation networks. The flows of heat and work are the final part of the sequence to be considered, with the application of heat exchanger networks, and any deficiency or excess in these flows is usually compensated for with the use of utilities. Although the ongoing research into reactor, separation, and heat exchanger optimization is of indubitable value, an aspect that is often overlooked in conventional research is the question: How do changes to one of the elements in the sequence affect the others? Most process designers do not address such matters until the next optimization of the sequence begins. The result of this sequential approach to design is that processes may contain a few very efficient units, but may also have others that are highly inefficient. A graphical technique that incorporates the flows of heat and work into the design of the process at a very early stage is proposed. The technique can be used to prepare flow sheets that represent a synthesized version of the elements that make up the complete process, rendering each component highly efficient. This new design tool uses the thermodynamic properties of enthalpy (representative of process heat requirements) and Gibbs free energy (representative of process work requirements) to develop process flow sheets that operate as close to reversibly as possible, and can be used as a foundation for more detailed refinements to achieve the best possible result. A case was described in a previous paper in which the graphical technique was applied to gasification. The application of the technique to the production of syngas by the steam reforming of natural gas is detailed. We show that the steam reforming process can be operated with increased reversibility and can actually consume carbon dioxide, thus representing a process with a carbon efficiency of greater than 100%, if the way in which all the process units interact with one another is used to utmost advantage. © 2013 American Institute of Chemical Engineers AIChE J, 59: 3714–3729, 2013

From shape to shell: a design tool to materialize freeform shapes using gridshell structures

Abstract: This paper introduces and explains the design process of a gridshell in composite materials built in Paris in 2011 for the festival Soliday. A brief introduction presents the structural concept and the erection methodology employed. It explains why composite materials are relevant for such applications. Following this practical case, the whole process from 3D-shape to real-shell is then detailed. Firstly, the shape is rationalized and optimized to smooth local curvature concentrations. Secondly, a specific computing tool is used to mesh the surface according to the compass method. This tool allows designers to look for optimal mesh orientations regarding the elements curvature. Finally, a full structural analysis is performed to find the relaxed shape of the grid and check its stability, strength and stiffness under loads. The authors conclude on the overall relevance of such structures.

Wind turbine design using a free-wake vortex method with winglet application

Abstract: Wind turbine blades are traditionally designed with blade element momentum theory (BEMT). This method is incapable of accurately analyzing non-conventional or non-planar blade planforms. Modern wind turbine blade design thus requires non-standard modeling that can effectively analyze the effects of a non-planar blade, such as a blade with a winglet. The free-wake, distributed vorticity element (FW-DVE) method meets these analysis goals. Previous work applied the FW-DVE method to wind turbines, but this work did not include the influence of profile forces and did not include any design applications. The present research focused on developing the FW-DVE method into a design tool for wind turbine design applications and on the validation of this tool. In the research presented in this thesis, the FW-DVE method was modified to include the effect of airfoil profile drag and to account for the effects of stall and a non-linear lift-curve. A design tool was created to aid in using the WindDVE analysis code for trade space exploration. The method was used to analyze and design a winglet for a small-scale wind turbine, which was tested in a wind tunnel at the University of Waterloo where it exhibited a 9% increase in the maximum coefficient of power of the rotor. The performance results from this test have been used to validate the FW-DVE method for wind turbine design, along with an analysis of the National Renewable Energy Laboratory’s Unsteady Aerodynamics Experiment Phase VI wind turbine.

Model-Based Design of a Plug-In Hybrid Electric Vehicle Control Strategy

Abstract: For years the trend in the automotive industry has been toward more complex electronic control systems. The number of electronic control units (ECUs) in vehicles is ever increasing as is the complexity of communication networks among the ECUs. Increasing fuel economy standards and the increasing cost of fuel is driving hybridization and electrification of the automobile. Achieving superior fuel economy with a hybrid powertrain requires an effective and optimized control system. On the other hand, mathematical modeling and simulation tools have become extremely advanced and have turned simulation into a powerful design tool. The combination of increasing control system complexity and simulation technology has led to an industry wide trend toward model based control design. Rather than using models to analyze and validate real world testing data, simulation is now the primary tool used in the design process long before real world testing is possible. Modeling is used in every step from architecture selection to control system validation before on-road testing begins. The Hybrid Electric Vehicle Team (HEVT) of Virginia Tech is participating in the 2011-2014 EcoCAR 2 competition in which the team is tasked with re-engineering the powertrain of a GM donated vehicle. The primary goals of the competition are to reduce well to wheels (WTW) petroleum energy use (PEU) and reduce WTW greenhouse gas (GHG) and criteria emissions while maintaining performance, safety, and consumer acceptability. This paper will present systematic methodology for using model based design techniques for architecture selection, control system design, control strategy optimization, and controller validation to meet the goals of the competition. Simple energy management and efficiency analysis will form the primary basis of architecture selection. Using a novel method, a series-parallel powertrain architecture is selected. The control system architecture and requirements is defined using a systematic approach based around the interactions between control units. Vehicle communication networks are designed to facilitate efficient data flow. Software-in-the-loop (SIL) simulation with Mathworks Simulink is used to refine a control strategy to maximize fuel economy. Finally hardware-in-the-loop (HIL) testing on a dSPACE HIL simulator is demonstrated for performance improvements, as well as for safety critical controller validation. The end product of this design study is a control system that has reached a high level of parameter optimization and validation ready for on-road testing in a vehicle.

Loop program mapping and compact code generation for programmable hardware accelerators

Abstract: We present a novel design methodology for the mapping of nested loops onto programmable hardware accelerators. Key features of our approach are: (1) Design entry in form of a functional programming language and loop parallelization in the polyhedron model, (2) the underlying accelerator architectures consist of lightweight, tightly-coupled, and programmable processor arrays, which can exploit both loop-level parallelism and instruction-level parallelism, (3) support of zero-overhead looping not only for inner most loops but also for arbitrarily nested loops. We implemented the proposed methodology in a prototype design tool and evaluated selected benchmarks by comparing our code generator with the Trimaran compilation framework. As the results show, our approach can reduce the size of the generated processor codes up to 64 % while at the same time achieving a significant higher throughput.

Informing Design through Parametric Integrated Structural Simulation: Iterative structural feedback for design decision support of complex trusses

Abstract: The paper describes the development, testing, and initial findings of a design tool that generates parametrically defined, semi-automatically analyzed, and visualized structural performance of specific truss designs. The prototypical design tool provides structural truss solutions for spans of uniform to non-uniform surface curvatures. Real-time visual structural performance feedback enables the designer to more rapidly develop viable and potentially more efficient designs under user defined load conditions. The research methodology is an example of reinforcing structural learning and intuition within the design process. The research presents findings of the impact of iterative and interactive structural feedback through the development of a parametrically integrated structural truss analysis tool for aiding in design decision support.

Effects of Thinking Style on Design Strategies: Using Bridge Construction Simulation Programs

Abstract: Computer simulation users can freely control operational factors and simulation results, repeat processes, make changes, and learn from simulation environment feedback. The focus of this paper is on simulation-based design tools and their effects on student learning processes in a group of 101 Taiwanese senior high school students. Participants identified as having executive, legislative, judicial, global or local thinking style tendencies were asked to design bridges using WPBD2007 computer simulation freeware. Design strategies and design tool usage were video recorded and analyzed. Results indicate a positive correlation between judicial thinking style and frequency of substantial change in structure and goal strategy; a negative correlation between local thinking style and frequency of component tool list usage; a negative correlation between use of top-down strategies and frequency of using two types of assistance tools; a positive correlation between the use of bottom-up strategies and frequency of using both tool types; a positive correlation between the use of a substantial change strategy and frequency of using the graphical interface only; and positive correlations between total construction costs and the frequencies of using the substantial change strategy and component list tool.

Numerical Manufacturing And Design tool

Abstract: Given the complex geometry of most wind turbine blades, structural modeling using the finite element method is generally performed using a unique model for each particular blade analysis. Development time (often considerable) spent creating a model for one blade may not aid in the development of a model for a different blade. A new software tool, NuMAD, was created in an effort to reduce model development time and increase the usability of advanced finite element analysis capabilities. This discussion reviews some of the improvements and modifications to NuMAD which have occurred in the last year.

Preliminary Design of a Transonic Fan for Low By-Pass Turbofan Engine

Abstract: Design optimization of axial compressors using numerical simulations requires huge computational efforts. Therefore, the design process needs to be started from a reasonable design point. In the current study, a design tool is developed for the preliminary design of transonic compressors using different correlations of cascade experimental data for the shock losses and the deviation angle. A parametric study is performed to select the design parameters for optimum fan performance in terms of efficiency and surge margin. The designed fan is tested during off design operation and simulated numerically using computational fluid dynamics to verify the developed design tool. The numerical simulations of designed fan show good agreement with the preliminary design results.

Design 3D Garments for Scanned Human Bodies

Abstract: In this study we present a 3D garment design method for scanned human bodies. Firstly, a slicing method is proposed to reconstruct a symmetric body from a scanned human body to make it suitable for garment design. Secondly, a sketch modeling method is used to interactively create the garment surface based on the new body. Thirdly, seam lines are drawn on the garment surface, and then a flattening algorithm is employed to design 2D patterns. Finally, a seam line template is used to design the same style for different bodies. Experiments show that the resulted garment well fits the scanned body. Our method provides an efficient design tool for customizing garments in the fashion industry.

Exploiting architecture description language for diverse IP synthesis in heterogeneous MPSoC

Abstract: High Level Synthesis (HLS) and design is gaining traction in commercial and academic circles, as an answer to increasing design complexity and short time-to-market. In this paper, we present a short survey on the HLS landscape and propose modeling concepts to extract and exploit the inherent flexibility for a commercially available high-level design tool, to explore ASIC and CGRA besides native ASIP support. Structural descriptions, representation, flexibility and limitations are discussed. Several case studies help highlight the advantages of the proposed methods, providing a solid framework to aid a broader and faster design space exploration.

Architect and engineer collaboration: the solar decathlon as a pedagogical opportunity

Abstract: While close collaboration between architects and engineers in building design is a wellrecognized necessity, we still educate students in each of these professions separately (and generally in isolation). This paper describes the experience of integrating teams of architecture and engineering students as they progress through the design and construction of a home for the 2013 Solar Decathlon competition. This competition requires that engineering and architecture students, in addition to other disciplines, design, build, and operate a net-zero energy solar house prototype. The Solar Decathlon experience has identified three critical aspects for interdisciplinary collaboration: project logistics, the design process, and the collective values of the design team. Among the three, the design process is the aspect that seems to offer the greatest opportunity for innovation, especially as it relates to information technologies and building information modeling (BIM). BIM, required as a Solar Decathlon deliverable by the U.S. Department of Energy, provides an excellent conceptual framework for organizing teamwork and interdisciplinary collaboration. This paper describes how a BIM management system was used by students as a design tool and how it was used to support a collaborative interdisciplinary team approach. Also described are how the students' design processes were impacted by the use of BIM and how this facilitated an early collaboration with engineers. Our experience shows that the collaborative design process and the effectiveness of the teamwork still depend on conventional design review methods, such as face-to-face interactions, which enable the students to understand and appreciate different professional philosophies and values. Such coordination is greatly augmented by a BIM methodology, which allows the productive participation of different disciplines while ensuring that the responsible team members maintain control of the design in their area of expertise.