AN INTEGRATED SYSTEMS ENGINEERING METHODOLOGY FOR DESIGN OF VEHICLE HANDLING DYNAMICS

The primary objective of this research is to develop an integrated system engineering methodology for the conceptual design of vehicle handling dynamics early on in the product development process. A systems engineering-based simulation framework is developed that connects subjective, customer-relevant handling expectations and manufacturers\u27 brand attributes to higher-level objective vehicle engineering targets and consequently breaks these targets down into subsystem-level requirements and component-level design specifications. Such an integrated systems engineering approach will guide the engineering development process and provide insight into the compromises involved in the vehicle-handling layout, ultimately saving product development time and costs and helping to achieve a higher level of product maturity early on in the design phase. The proposed simulation-based design methodology for the conceptual design of vehicle handling characteristics is implemented using decomposition-based Analytical Target Cascading (ATC) techniques and evolutionary, multi-objective optimization algorithms coupled within the systems engineering framework. The framework is utilized in a two-layer optimization schedule. The first layer is used to derive subsystem-level requirements from overall vehicle-level targets. These subsystem-level requirements are passed on as targets to the second layer of optimization, and the second layer derives component-level specifications from the subsystem-level requirements obtained from the first step. The second layer optimization utilizes component-level design variables and analysis models to minimize the difference between the targets transferred from the vehicle level and responses generated from the component-level analysis. An iterative loop is set up with an objective to minimize the target/response consistency constraints (i.e., the targets at the vehicle level are constantly rebalanced to achieve a consistent and feasible solution). Genetic Algorithms (GAs) are used at each layer of the framework. This work has contributed towards development of a unique approach to integrate market research into the vehicle handling design process. The framework developed for this dissertation uses Original Equipment Manufacturer\u27s (OEM\u27s) brand essence information derived from market research for the derivation and balancing of vehicle-level targets, and guides the chassis design direction using relative brand attribute weights. Other contributions from this research include development of empirical relationships between key customer-relevant vehicle handling attributes selected from market survey and the various scenarios and objective metrics of vehicle handling, development of a goal programming based approach for the selection of the best solution from a set of Pareto-optimal solutions obtained from genetic algorithms and development of Vehicle Handling Bandwidth Diagrams

Multi-objective optimization model in the vehicle suspension system development process

U cilju unapređenja konceptualne faze razvoja vozila, ovo istraživanje je usmjereno na razvoj novog višekriterijskog optimizacijskog modela za određivanje optimalnih parametara ovjesa vozila. U ovom istraživanju naglasak je na razvoju ovjesa vozila promatrano kroz dinamičko ponašanje kompletnog vozila. Novi optimizacijski model temelji se na integraciji brzih simulacijskih alata s zadovoljavajućom razinom točnosti za analizu kinematike ovjesa i dinamiku vozila unutar okruženja za višekriterijsko optimiranje. Nužni koraci koji prethode razvoju optimizacijskog modela su identifikacija utjecajnih parametara, definiranje kriterija za ocjenu dinamičkih karakteristika vozila u različitim ispitnim procedurama i odabir višekriterijskih optimizacijskih algoritama, prvenstveno suvremenih evolucijskih algoritama. Usporedba optimizacijskih algoritama pokazala je da se najbolji rezultati u pogledu konvergencije, broja mogućih rješenja, trajanja računanja i približavanja Pareto fronti postižu s FMOGA-II algoritmom.In order to improve conceptual phase of vehicle development, this research is focused on development of new multi-objective optimization model for determining the optimal parameters of the suspension system. In this research emphasis is on the development of suspension system from the viewpoint of full vehicle dynamics behaviour. The new optimization model consists of the integration of fast simulation tools with a suitable degree of accuracy for analysis of suspension system kinematics and analysis of vehicle dynamics into multi-objective optimization environment. The necessary steps that proceed to development of optimization model are identification of influence parameters, definition of criteria for the evaluation of vehicle dynamic characteristics in different test procedures and selection of multi-objective optimization algorithms, primarily contemporary evolutionary algorithms. In comparison of the algorithms, the best results in terms of convergence, number of solutions, short computing time and Pareto front approximation were achieved with the FMOGA-II algorithm

Development Environment for Optimized Locomotion System of Planetary Rovers

This paper addresses the first steps that have been undergone to set up the development environement w.r.t optimization and to modelling and simulation of overall dynamics of the rover driving behaviour under all critical surface terrains, like soft and hard soils, slippage, bulldozing effect and digging in soft soil. Optimization is based on MOPS (Multi-Objective Prameter Synthesis), that is capable for handling several objective functions such as mass reduction, motor power reduction, increase of traction forces, rover stability guarantee, and more. The tool interferes with Matlab/Simulink and with Modelica/Dymola for dynamics model implementation. For modelling and simulation of the overall rover dynamics and terramechanical behaviour in all kind of soils we apply a Matlab based tool that takes advantage of the multibody dynamics tool Simpack. First results of very promising rover optimizations 6 wheels are presented that improve ExoMars rover type wheel suspension systems. Performance of driveability behaviour in different soils is presented as well. The next steps are discusses in order to achieve the planned overall development environment

Conceptual design optimization study

The feasibility of applying multilevel functional decomposition and optimization techniques to conceptual design of advanced fighter aircraft was investigated. Applying the functional decomposition techniques to the conceptual design phase appears to be feasible. The initial implementation of the modified design process will optimize wing design variables. A hybrid approach, combining functional decomposition techniques for generation of aerodynamic and mass properties linear sensitivity derivatives with existing techniques for sizing mission performance and optimization, is proposed

ADAPTS: An Intelligent Sustainable Conceptual Framework for Engineering Projects

This paper presents a conceptual framework for the optimization of environmental sustainability in engineering projects, both for products and industrial facilities or processes. The main objective of this work is to propose a conceptual framework to help researchers to approach optimization under the criteria of sustainability of engineering projects, making use of current Machine Learning techniques. For the development of this conceptual framework, a bibliographic search has been carried out on the Web of Science. From the selected documents and through a hermeneutic procedure the texts have been analyzed and the conceptual framework has been carried out. A graphic representation pyramid shape is shown to clearly define the variables of the proposed conceptual framework and their relationships. The conceptual framework consists of 5 dimensions; its acronym is ADAPTS. In the base are: (1) the Application to which it is intended, (2) the available DAta, (3) the APproach under which it is operated, and (4) the machine learning Tool used. At the top of the pyramid, (5) the necessary Sensing. A study case is proposed to show its applicability. This work is part of a broader line of research, in terms of optimization under sustainability criteria.Telefónica Chair “Intelligence in Networks” of the University of Seville (Spain

Applications of structural optimization methods to fixed-wing aircraft and spacecraft in the 1980s

This report is the summary of a technical survey on the applications of structural optimization in the U.S. aerospace industry through the 1980s. Since applications to rotary wing aircraft will be covered by other literature, applications to fixed-wing aircraft and spacecraft were considered. It became clear that very significant progress has been made during this decade, indicating this technology is about to become one of the practical tools in computer aided structural design

Aircraft Analysis Using the Layered and Extensible Aircraft Performance System (LEAPS)

The Layered and Extensible Aircraft Performance System (LEAPS) is a new air- craft analysis tool being developed by members of the Aeronautics Systems Analysis Branch (ASAB) and the Vehicle Analysis Branch (VAB) at NASA Langley Research Center. LEAPS will enable the analysis of advanced aircraft concepts and architec- tures that include electric and hybrid-electric propulsion systems. The development of LEAPS is motivated by the analysis gaps found in traditional aircraft analysis tools such as the Flight Optimization System (FLOPS). FLOPS has been the tool of choice of the ASAB for over 30 years and has proven to be a reliable analysis tool for conventional aircraft. However, FLOPS is not suitable to analyze the cur- rent unconventional vehicles that are of interest to industry, government agencies, and academia. In contrast, LEAPS is being developed with a flexible architecture that leverages new analysis methodologies that will enable the analysis of unconven- tional aircraft. This paper presents the first complete working version of LEAPS by showing the analysi at include fuel-based and hybrid-electric conceptual aircraft

Multiobjective optimization as a decision aid for managing build-to-order supply chains

This paper provides an overview of multiobjective optimization (MOO) as a decision aid in build-to-order supply chains (BTO-SC). The main features of BTO-SCs are discussed along with capabilities of MOO to enhance decision making at different points along the chain. Key decision points across a typical BTO-SC are identified and potential applications of MOO are discussed. A sample application is presented and future avenues for further research highlighted

Decision support for build-to-order supply chain management through multiobjective optimization

This paper aims to identify the gaps in decision-making support based on multiobjective optimization for build-to-order supply chain management (BTOSCM). To this end, it reviews the literature available on modelling build-to-order supply chains (BTO-SC) with the focus on adopting multiobjective optimization (MOO) techniques as a decision support tool. The literature has been classified based on the nature of the decisions in different part of the supply chain, and the key decision areas across a typical BTO-SC are discussed in detail. Available software packages suitable for supporting decision making in BTO supply chains are also identified and their related solutions are outlined. The gap between the modelling and optimization techniques developed in the literature and the decision support needed in practice are highlighted and future research directions to better exploit the decision support capabilities of MOO are proposed