Exploring Mass Trade-Offs in Preliminary Vehicle Design Using Pareto Sets

2006 ◽  
Author(s):  
Joseph Donndelinger ◽  
Scott Ferguson ◽  
Kemper Lewis
Keyword(s):  
Vehicle Design ◽  
Trade Offs ◽  
Pareto Sets

scholarly journals Multiobjective Monotonicity Analysis: Pareto Set Dependency and Tradeoffs Causality in Configuration Design

2021 ◽  
pp. 1-18
Author(s):  
Nökkvi S. Sigurdarson ◽  
Tobias Eifler ◽  
Martin Ebro ◽  
Panos Y. Papalambros
Keyword(s):  
Oral Drug Delivery ◽  
Pareto Set ◽  
Oral Drug ◽  
Configuration Design ◽  
Analysis Process ◽  
Trade Offs ◽  
Design Changes ◽  
Pareto Sets ◽  
Multiobjective Design ◽  
Monotonicity Analysis

Abstract Multiobjective design optimization studies typically derive Pareto sets or use a scalar substitute function to capture design trade-offs, leaving it up to the designer's intuition to use this information for design refinements and decision making. Understanding the causality of trade-offs more deeply, beyond simple post-optimality parametric studies, would be particularly valuable in configuration design problems to guide configuration redesign. This paper presents the method of Multiobjective Monotonicity Analysis to identify root causes for the existence of trade-offs and the particular shape of Pareto sets. This analysis process involves reducing optimization models through constraint activity identification to a point where dependencies specific to the Pareto set and the constraints that cause them are revealed. The insights gained can then be used to target configuration design changes. We demonstrate the proposed approach in the preliminary design of a medical device for oral drug delivery

scholarly journals A Unified Framework for Aerocapture Systems Analysis

2019 ◽  
Author(s):  
Athul Pradeepkumar Girija
Keyword(s):  
Systems Analysis ◽  
Mission Design ◽  
Vehicle Design ◽  
Trajectory Design ◽  
Unified Framework ◽  
Trade Offs ◽  
Subsystem Level ◽  
Interplanetary Trajectory ◽  
Level Analysis ◽  
Systems Studies

A unified framework for aerocapture systems analysis studies is presented, taking into account the interconnected nature of interplanetary trajectory design and vehicle design. One of the limitations of previous aerocapture systems studies is their focus on a single interplanetary trajectory for detailed subsystem level analysis. The proposed framework and aerocapture feasibility charts enable a mission designer to perform rapid trajectory and vehicle design trade-offs, and is illustrated with its application to a Neptune mission. The approach can be applied to other atmosphere-bearing Solar System destinations. The framework can be be implemented in an aerocapture software suite to enable rapid mission design studies.

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.

Platform Selection Under Performance Loss Constraints in Optimal Design of Product Families

2002 ◽  
Author(s):  
Ryan Fellini ◽  
Michael Kokkolaras ◽  
Panos Y. Papalambros ◽  
Alexis Perez-Duarte
Keyword(s):  
Optimal Design ◽  
Design Problem ◽  
Product Family ◽  
Individual Performance ◽  
Optimal Design Problem ◽  
Product Families ◽  
Performance Loss ◽  
Trade Offs ◽  
Pareto Sets ◽  
Different Levels

Designing a family of product variants that share some components usually entails a performance loss relative to the individually optimized variants due to the commonality constraints. Choosing components for sharing may depend on what performance losses can be tolerated. This article presents a methodology for making commonality decisions while controlling individual performance losses. Previous work focused on evaluating individual performance losses due to pre-specified sharing. Trade-offs were identified for different platforms (i.e., the sets of components shared among products) by means of Pareto sets. In the present work an optimal design problem is formulated to choose product components to be shared without exceeding a user-specified performance loss tolerance. This enables the designer to control trade-offs and obtain optimal product family designs for different levels of performance losses in an attempt to maximize commonality. A family of automotive side frames is used to demonstrate the approach.

Vehicle Design, Simplifying the CAD Process

2005 ◽  
Author(s):  
Craig Tucker ◽  
Robert D. Brown
Keyword(s):  
Graphical Representation ◽  
Representation Learning ◽  
Vehicle Design ◽  
Considerable Time ◽  
Design Time ◽  
Trade Offs ◽  
Military Vehicle ◽  
Vehicle Components ◽  
User Friendly

It is a feature of several courses that students undertake a military vehicle design and costing exercise. Many of the students do not have engineering or technical backgrounds and are unfamiliar with conventional engineering techniques of graphical representation. Learning a complex CAD package solely for this exercise is inappropriate, it would require considerable time to be found in the timetable and it is highly unlikely that the student would use this skill again. As a result Cranfield University has developed a user friendly design package which allows the students to design and build their vehicle by selecting suitable vehicle components from a drop down menu and arranging them on the workspace. In summary, this design package has greatly reduced the design time. It has helped students to appreciate the problems related to accommodating major subassemblies and their packaging and has allowed compromises and trade-offs to be understood and addressed rapidly.

An Example Performance Trade-Off Evaluation Using the Integration Framework for Architecture Development (IFAD) for Conceptual Vehicle Design

2005 ◽  
Author(s):  
Xiaoyu Gu ◽  
Peter A. Fenyes
Keyword(s):  
Genetic Algorithm ◽  
Vehicle Design ◽  
Vehicle Performance ◽  
Integration Framework ◽  
Trade Offs ◽  
Design Variables ◽  
Design Changes ◽  
High Level ◽  
Architecture Development ◽  
Geometrical Dimensions

The Integration Framework for Architecture Development (IFAD) is an integrated framework that provides fast and consistent discipline analysis results and identifies discipline consequences corresponding to vehicle design changes. This information is valuable for balancing and integration in the early design phase. In this paper, the IFAD framework is utilized to conduct an example multi-objective multi-disciplinary optimization to evaluate vehicle performance trade-offs for a hypothetical vehicle. We consider design changes on high-level geometrical dimensions including front overhang, rear overhang and vehicle width at rocker. We also study vehicle configurations including choice of materials and tires and choice of powertrains. A commonly used multi-objective genetic algorithm (MOGA) technique, Non-dominated Sorting Genetic Algorithm (NSGAII [1]) is chosen because of the mixed types of design variables involved (i.e., continuous design variables representing high-level geometrical dimensions and discrete design variables representing vehicle configurations such as powertrain selection and material choice). Vehicle performance analyses in a range of disciplines such as geometry, aerodynamics and energy are carried out automatically through IFAD. The use of response surface modeling (RSM) is desired due to the large number of evaluations typical for a MOGA application. A comparison of the engineering performance trade-offs based on two different sets of performance objectives is presented.

scholarly journals Proceedings of the Resource Efficient Vehicles Conference - 2021 (rev2021)

2021 ◽  
Author(s):  
Malte Rothhämel
Keyword(s):  
Early Stage ◽  
Panel Discussion ◽  
Vehicle Design ◽  
Public Agencies ◽  
Stage Design ◽  
Trade Offs ◽  
Institute Of Technology ◽  
Early Stage Design ◽  
Multidisciplinary Conference ◽  
Resolving Functional

rev2021 was the first edition of the conference on Resource Efficient Vehicles, held online on 14-16 June 2021. This vehicle-centric conference aims to bring together participants from academia, industry and public agencies to discuss research from all relevant fields connected to resource efficiency in all motorised modes of transport and interdependent surrounding systems. The theme of this multidisciplinary conference is Resolving Functional Conflicts in Vehicle Design, a theme explored through topics including modelling for multifunctional design; making trade-offs; efficient use of materials and space; integrating new solutions; transforming the product system; transforming the vehicle-transport system; sustainable design; and early-stage design. The 2021 edition of the conference consisted of 40 selected papers for presentation at the conference, complemented with four workshops, five keynote lectures from invited speakers, and a concluding panel discussion with four invited participants. It was organised by the Centre for ECO2 Vehicle Design at KTH Royal Institute of Technology in Stockholm.

Vehicle Design for Fire Safety and Evaluation of Design Trade-Offs

2007 ◽  
Author(s):  
Leland E. Shields ◽  
Robert R. Scheibe ◽  
Terry Thomas
Keyword(s):  
Fire Safety ◽  
Vehicle Design ◽  
Trade Offs

Novel players fine-tune plant trade-offs

2015 ◽  
Vol 58 ◽  
pp. 83-100 ◽  
Author(s):  
Selena Gimenez-Ibanez ◽  
Marta Boter ◽  
Roberto Solano
Keyword(s):  
Ubiquitin Ligase ◽  
Feedback Loop ◽  
Molecular Level ◽  
26S Proteasome ◽  
Signalling Molecules ◽  
Transcriptional Reprogramming ◽  
Trade Offs ◽  
Jaz Proteins ◽  
Regulatory Feedback Loop ◽  
Fine Tune

Jasmonates (JAs) are essential signalling molecules that co-ordinate the plant response to biotic and abiotic challenges, as well as co-ordinating several developmental processes. Huge progress has been made over the last decade in understanding the components and mechanisms that govern JA perception and signalling. The bioactive form of the hormone, (+)-7-iso-jasmonyl-l-isoleucine (JA-Ile), is perceived by the COI1–JAZ co-receptor complex. JASMONATE ZIM DOMAIN (JAZ) proteins also act as direct repressors of transcriptional activators such as MYC2. In the emerging picture of JA-Ile perception and signalling, COI1 operates as an E3 ubiquitin ligase that upon binding of JA-Ile targets JAZ repressors for degradation by the 26S proteasome, thereby derepressing transcription factors such as MYC2, which in turn activate JA-Ile-dependent transcriptional reprogramming. It is noteworthy that MYCs and different spliced variants of the JAZ proteins are involved in a negative regulatory feedback loop, which suggests a model that rapidly turns the transcriptional JA-Ile responses on and off and thereby avoids a detrimental overactivation of the pathway. This chapter highlights the most recent advances in our understanding of JA-Ile signalling, focusing on the latest repertoire of new targets of JAZ proteins to control different sets of JA-Ile-mediated responses, novel mechanisms of negative regulation of JA-Ile signalling, and hormonal cross-talk at the molecular level that ultimately determines plant adaptability and survival.

Dual Goals for Speed and Accuracy on the Same Performance Task

2012 ◽  
Vol 11 (3) ◽  
pp. 118-126 ◽  
Author(s):  
Olive Emil Wetter ◽  
Jürgen Wegge ◽  
Klaus Jonas ◽  
Klaus-Helmut Schmidt
Keyword(s):  
Memory Scanning ◽  
Performance Task ◽  
Performance Tasks ◽  
Trade Off ◽  
Test Experiment ◽  
Trade Offs ◽  
New Finding ◽  
Sternberg Paradigm ◽  
Speed Accuracy ◽  
Speed And Accuracy

In most work contexts, several performance goals coexist, and conflicts between them and trade-offs can occur. Our paper is the first to contrast a dual goal for speed and accuracy with a single goal for speed on the same task. The Sternberg paradigm (Experiment 1, n = 57) and the d2 test (Experiment 2, n = 19) were used as performance tasks. Speed measures and errors revealed in both experiments that dual as well as single goals increase performance by enhancing memory scanning. However, the single speed goal triggered a speed-accuracy trade-off, favoring speed over accuracy, whereas this was not the case with the dual goal. In difficult trials, dual goals slowed down scanning processes again so that errors could be prevented. This new finding is particularly relevant for security domains, where both aspects have to be managed simultaneously.

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