Feasibility Assessment in Preliminary Design Using Pareto Sets

2005 ◽  
Author(s):  
Ashwin Gurnani ◽  
Scott Ferguson ◽  
Joseph Donndelinger ◽  
Kemper Lewis
Keyword(s):  
Pareto Frontier ◽  
Multidisciplinary Design ◽  
Vehicle Design ◽  
Preliminary Design ◽  
Passenger Vehicle ◽  
Mathematical Methods ◽  
Feasibility Assessment ◽  
Pareto Sets ◽  
Late Model ◽  
Product Specifications

In this paper, we present the development and application of a Technical Feasibility Model (TFM) used in preliminary design to determine whether or not a set of desired product specifications is technically feasible, and the optimality of those specifications with respect to the Pareto frontier. The TFM is developed by integrating the capabilities of a multidisciplinary design framework, a multi-objective design optimization tool, a Pareto set gap analyzer, metamodeling methods, and mathematical methods for feasibility assessment. This tool is then applied to a three objective example problem and to a five objective passenger vehicle design problem by analyzing benchmarking data from 78 late model sedans.

A constraint-based approach to feasibility assessment in preliminary design

2006 ◽  
Vol 20 (4) ◽  
pp. 351-367 ◽  
Author(s):  
ASHWIN GURNANI ◽  
SCOTT FERGUSON ◽  
KEMPER LEWIS ◽  
JOSEPH DONNDELINGER
Keyword(s):  
Design Problem ◽  
Mathematical Problem ◽  
Pareto Frontier ◽  
Vehicle Design ◽  
Preliminary Design ◽  
Passenger Vehicle ◽  
Technical Feasibility ◽  
Feasibility Assessment ◽  
Multiobjective Design ◽  
Product Specifications

In this paper, we present the development and application of a technical feasibility model used in preliminary design to determine whether a set of desired product specifications obtained from marketing is feasible in the engineering domain. This model is developed by integrating the capabilities of a multiobjective design problem, a multicriteria design optimization tool, a Pareto frontier gap analyzer, metamodeling methods, and use of the Pareto frontier as a constraint for feasibility assessment. Although the tools are independent of the domain, their application is illustrated using two examples: a simple three-objective mathematical problem and a five-objective passenger vehicle design problem. The feasibility of the desired product specifications is determined with respect to the problem's Pareto frontier, which is considered to be the necessary constraint to satisfy.

Human Body Size and Passenger Vehicle Design

1956 ◽  
Author(s):  
Ross A. Mcfarland ◽  
Howard W. Stoudt
Keyword(s):  
Body Size ◽  
Human Body ◽  
Vehicle Design ◽  
Passenger Vehicle

scholarly journals Preliminary Sailplane Design Using MDO And Multi-Fidelity Analysis

2021 ◽  
Author(s):  
Chris V. Pilcher
Keyword(s):  
Multidisciplinary Design Optimization ◽  
High Performance ◽  
Vortex Lattice ◽  
Optimization Techniques ◽  
Multidisciplinary Design ◽  
Preliminary Design ◽  
Adaptive Meshing ◽  
Analysis Methods ◽  
And Performance ◽  
Modern Optimization

A multidisciplinary design optimization (MDO) strategy for the preliminary design of a sailplane has been developed. The proposed approach applies MDO techniques and multi-fidelity analysis methods which have seen successful use in many aerospace design applications. A customized genetic algorithm (GA) was developed to control the sailplane optimization that included aerodynamics/stability, structures/weights and balance and, performance/airworthiness disciplinary analysis modules. An adaptive meshing routine was developed to allow for accurate modeling of the aero structural couplinginvolved in wing design, which included a finite element method (FEM) structural solver along with a vortex lattice aerodynamics solver. Empirical equations were used to evaluate basic sailplane performance and airworthiness requirements. This research yielded an optimum design that correlated well with an existing high performance sailplane. The results of this thesis suggest that preliminary sailplane design is a well suited application for modern optimization techniques when coupled with, multi-fidelity analysis methods.

Legibility of Overhead Guide Signs with Encapsulated Versus Microprismatic Retroreflective Sheeting

2003 ◽  
Vol 1844 (1) ◽  
pp. 59-66 ◽  
Author(s):  
Paul J. Carlson ◽  
Gene Hawkins
Keyword(s):  
United States ◽  
Age Groups ◽  
The United States ◽  
Vehicle Design ◽  
Sport Utility Vehicle ◽  
Passenger Car ◽  
Late Model ◽  
The Difference ◽  
Transportation Agencies ◽  
Utility Vehicle

A study was conducted to determine the legibility impacts of freeway guide signs when encapsulated retroreflective sheeting is replaced with microprismatic retroreflective sheeting. The study included freeway guide signs mounted in an overhead position and exclusively illuminated with vehicle headlamps. A total of 60 subjects divided into three age groups participated in this nighttime study. All 60 subjects drove two vehicles, a modern sport utility vehicle (SUV) and a late-model passenger car. The findings show that microprismatic sheeting does provide statistically longer legibility distances than encapsulated sheeting. Overall, the improvement was 53 ft, or 9.5%. However, for the modern SUV, the improvement was much greater (78 ft) compared with the late-model passenger car (28 ft). The main differences are related to the evolution of vehicle design and specifications. Today’s United States citizens prefer large vehicles such as an SUV, pickup, and minivan. These vehicles also meet recently revised headlamp specifications. These two issues inherently reduce the amount of headlamp light retroreflected from the sign back to the driver. Unfortunately, these counterproductive trends show signs of continuing. Considering the increasing proportion of older drivers in the United States, it becomes even more critical that transportation agencies do all they can to increase overhead-sign luminance. The findings show that increasing overhead-sign luminance by switching from encapsulated retroreflective sheeting to microprismatic retro-reflective sheeting results in significantly longer legibility distances. The magnitude of the difference will continue to increase as long as the SUV-like proportion of the U.S. fleet continues to grow and headlamp specifications continue to direct less light toward overhead signs.

Effective Generation of Pareto Sets Using Genetic Programming

2001 ◽  
Author(s):  
John Eddy ◽  
Kemper Lewis
Keyword(s):  
Genetic Programming ◽  
Optimization Problem ◽  
Complete Solution ◽  
Pareto Frontier ◽  
Multi Objective ◽  
Pareto Sets ◽  
Effective Generation ◽  
Final Design ◽  
The Individual ◽  
Measure Of Performance

Abstract Many designers concede that there is typically more than one measure of performance for an artifact. Often, a large system is decomposed into smaller subsystems each having its own set of objectives, constraints, and parameters. The performance of the final design is a function of the performances of the individual subsystems. It then becomes necessary to consider the tradeoffs that occur in a multi-objective design problem. The complete solution to a multi-objective optimization problem is the entire set of non-dominated configurations commonly referred to as the Pareto set. Common methods of generating points along a Pareto frontier involve repeated conversion of multi-objective problems into single objective problems using weights. These methods have been shown to perform poorly when attempting to populate a Pareto frontier. This work presents an efficient means of generating a thorough spread of points along a Pareto frontier using genetic programming.

A Pareto Approach to Aligning Public and Private Objectives in Vehicle Design

2008 ◽  
Author(s):  
Bart Frischknecht ◽  
Panos Papalambros
Keyword(s):  
Public Good ◽  
Pareto Frontier ◽  
Private Good ◽  
Vehicle Design ◽  
Relative Level ◽  
Public And Private ◽  
The Public ◽  
Production And Consumption ◽  
Vehicle Production ◽  
The Government

The quest for producing vehicles friendlier to the environment is often impeded by the fact that a producer private good objective, such as maximum profit, competes with the public good objective of minimizing impact on the environment. Contrary to commercial claims, there may be no defined decision maker in the vehicle production and consumption process who takes ownership of the public good objective, except perhaps the government. One way ecofriendly products could become more successful in the marketplace is if public and private good objectives become more aligned to each other. This paper introduces three metrics for comparing Pareto curves in bi-objective problems in terms of relative level of objective competition. The paper also presents a quantitative way of studying an individual firm’s trade-off between profit and fuel consumption for automotive products, currently undergoing an historic evolution in their design. We show how changes in technology, preferences, competition, and regulatory scenarios lead to Pareto frontier changes, possibly eliminating it altogether.

scholarly journals Multifidelity Multidisciplinary Design Optimization of Integral Solid Propellant Ramjet Supersonic Cruise Vehicles

2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Xiaojian Sun ◽  
Jianquan Ge ◽  
Tao Yang ◽  
Qiangqiang Xu ◽  
Bin Zhang
Keyword(s):  
Design Optimization ◽  
Multidisciplinary Design Optimization ◽  
Solid Propellant ◽  
Multidisciplinary Design ◽  
Preliminary Design ◽  
Flight Trajectory ◽  
Traditional Design ◽  
Study Results ◽  
Optimization Parameters ◽  
Different Levels

Integral solid propellant ramjet (ISPR) supersonic cruise vehicles share the characteristic that they are highly integrated configurations. The traditional design of vehicles cannot achieve a balance between computational expense and accuracy. A multifidelity multidisciplinary design optimization (MDO) platform has been developed in this study. The focus of the platform is on ISPR supersonic cruise vehicles. Firstly, codes of discipline with different levels of fidelity (LoF) were established, such as geometry, aerodynamics, radar cross-section calculations, propulsion, mass, and trajectory discipline codes. Secondly, two MDO frameworks were constructed through discipline codes. A low LoF MDO framework is suitable for conceptual design, and a medium LoF MDO framework is suitable for preliminary design. Finally, taking the optimization problem with the minimum overall detection probability of flight trajectory as an example, the low LoF framework first explores the entire design space to achieve the mission requirements, and then, the medium LoF MDO framework accepts the low LoF framework optimization parameters. Hence, the optimization target is reached with more detailed parameters and higher fidelity. Additionally, an example for a solid propellant missile with minimum total mass is tested by the platform. The study results show that the multifidelity MDO framework not only exploits interactions between the disciplines but also improves the accuracy of optimization results and reduces the iteration time.

scholarly journals Preliminary study on launch vehicle design: Applications of multidisciplinary design optimization methodologies

2017 ◽  
Vol 26 (1) ◽  
pp. 93-103 ◽  
Author(s):  
Loïc Brevault ◽  
Mathieu Balesdent ◽  
Sébastien Defoort
Keyword(s):  
Design Optimization ◽  
Design Process ◽  
Concurrent Engineering ◽  
Multidisciplinary Design Optimization ◽  
Launch Vehicle ◽  
Multidisciplinary Design ◽  
Vehicle Design ◽  
Launch Vehicles ◽  
Data Set ◽  
Launch Vehicle Design

The design of complex systems such as launch vehicles involves different fields of expertise that are interconnected. To perform multidisciplinary studies, concurrent engineering aims at providing a collaborative environment which often relies on data set exchange. In order to efficiently achieve system-level analyses (uncertainty propagation, sensitivity analysis, optimization, etc.), it is necessary to go beyond data set exchange which limits the capabilities of performance assessments. Multidisciplinary design optimization methodologies is a collection of engineering methodologies to optimize systems modelled as a set of coupled disciplinary analyses and is a key enabler to extend concurrent engineering capabilities. This article is focused on several examples of recent developments of multidisciplinary design optimization methodologies (e.g. multidisciplinary design optimization with transversal decomposition of the design process, multidisciplinary design optimization under uncertainty) with applications to launch vehicle design to illustrate the benefices of taking into account the coupling effects between the different physics all along the design process. These methods enable to manage the complexity of the involved physical phenomena and their interactions in order to generate innovative concepts such as reusable launch vehicles beyond existing solutions.

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