Optimum design of multistep gearbox, since many high-performance power transmission applications (e.g., automotive, space industry) require compact volume, has become an important interest area. This design application includes more complicated problems that are not taken into account while designing single stage gear drives. Design applications are generally made by trial and error methods depending on the experience and the intuition of the designer. In this study, using Visual Basic 6.0, an interactive program is developed for designing multistep involute standard and nonstandard spur gearbox according to the American Gear Manufacturers Association (AGMA) Standards 218.01 and 2001- B88. All the equations for calculating the pitting resistance geometry factor I, and the bending strength geometry factor J, are valid for external spur gears that are generated by rack-type tools (rack cutters or hobs). The program is made for twostage to six-stage gear drives, which are commonly used in the industry. Compactness of gear pairs and gearbox, and equality of factor of safety against bending failure is taken as the design objective. By considering the total required gear ratio, the number of reduction stages is input by the user. Gear ratios of every stage is distributed to the stages according to the total gear ratio that satisfies the required precision (from &plusmn / 0.1 to &plusmn / 0.00001 on overall gear ratio) depending on the user selected constraints (unequal gear ratio for every stage, noninteger gear ratio e.g.). Dimensional design is determined by considering bending stress, pitting stress, and involute interference constraints. These steps are carried out iteratively until a desirable solution is acquired. The necessary parameters for configuration design such as number of teeth, module, addendum modification coefficient, are selected from previously determined gear pairs that satisfies the constraints by user interaction considering the performance criterion from the developed program. The positions of gears and shafts are determined automatically in order to keep the volume of gearbox as minimum while satisfying the nonlinear spatial constraints (center distance constraint for proper meshing of gear pairs, face distance constraint for proper assembly of pinion and gear having same shaft, gear interference constraint for preventing interferences between gears, shaft interference constraint for preventing interferences between gears and shafts) by using DLL (Dynamic Link Library) technology of Lingo 8.0 optimization software together with Visual Basic 6.0. If shaft interference constraint is removed then cantilevered mounting of gear pairs would also be possible, otherwise the gears should be mounted between bearings. Visual output of assembly is made by using Autodesk Inventor 7.0, automatically by the program.

The HVAC system configuration is a conceptual design of the HVAC system, including the employed components, the topology of the airflow network, and the control strategy with set points. Selection of HVAC system configuration is normally done in the early stage of the design process. The configuration design, however, has significant impacts on the performance of the final system. This thesis describes the development of the design synthesis of optimal HVAC system configurations by Evolutionary Algorithm. In this research, the HVAC system configuration design synthesis has been formulated as an optimisation problem, in which, the component set of the configuration, the topology of the airflow network, and the control set points for the assumed supervisory control strategy, are the optimisation variables. Psychrometrics-based configuration model has been developed in order to evaluate the optimisation objective of minimising the annual energy consumption of the HVAC system. The optimisation is also subjected to a number of design constraints, including the connectivity of the topology, the performance limitations of the components, and the design requirements for the air-conditioned zones. The configuration synthesis problem is a multi-level optimisation problem. The topology depends on the set of selected components, whereas the search space of the control set points changes with the different components and topology. On the other hand, the performance of the configuration is assessed with its optimum operation; therefore the control set points have to be optimised for each configuration solution, before the optimum configuration can be identified. In this research, a simultaneous evolutionary approach has been developed. All optimisation variables of the configuration have been enwded into an integrated genotypic data structure. Evolutionary operators have also been developed to search the topological space (for the optimum topology) and parametric space (for the optimal control set points) at the same time. The performance of the developed approach has been validated with example optimisation problems. It is concluded that the implemented evolutionary algorithm has been able to find (near) optimum solutions for various design problems, though multiple trials may be required. The limitations of this approach and the direction of future development have been discussed.

Désormais, les clients ne se satisfont plus seulement d’une offre diversifiée de produits mais ils demandent à être partie prenante pendant les processus de développement et de configuration afin d’obtenir des produits le plus personnalisés possible en regard de leurs attentes. La contribution des clients à ces processus conduit à des changements dans l’organisation de la conception, dans le modèle de gestion de l'entreprise, la définition du produit. Tout d'abord, nous présentons le modèle de conception en configuration personnalisée nommé Auser. Nous décrivons tout d’abord les fondamentaux théoriques du modèle de conception en configuration pour personnalisation orientée utilisateur. Dans le deuxième chapitre, la méthode de conception est étudiée, y compris la description formelle des entités décrivant le produit, la construction de l'ontologie ainsi que la modélisation par fonctions, composants et services. Le troisième chapitre présente la configuration de modèle de produit personnalisé par l'utilisateur final du robot industriel. Ces utilisateurs peuvent spécifier les objectifs et contraintes de la mise en œuvre des robots industriels par le biais des paramètres et attributs. / In today's market, obtaining a variety of products through configuration design has become increasingly common. However, with the development of the market, customers have not only satisfied the company offering a variety of products, and more demands on participating in the process of configuration design by themselves, so that they can obtain fully personalized products. Customer participation leads to the changes of design process, company's management model, etc. Based on the above problem, this thesis takes industrial robot as an example, and studies the management issues related to the customer involved in the design, in order to address the contradiction between product diversification, personalized requirements and the long design cycle and high manufacturing costs. Firstly, Auser-customized configuration design pattern is presented. The theory source of user-customized configuration design pattern is introduced, and then the related concepts are expounded. The corresponding business mode of user-customized configuration design pattern is given, and the key technologies to realize business mode is studied. System dynamics models were established for user-customized configuration design business mode and for traditional business mode of industrial robots by Anylogic simulation software. Secondly, the component-based theory and method are studied, including the formal description of things, ontology representation, componentization and servitization. On this basis, the componentization description model is established for the product parts. And the model is represented as service-component. Next, the formation process and extension method of service-component are introduced. An example of industrial robot components modeling is analyzed, includingestablishing industrial robot domain ontology by protégé, describing, instantiating and extensing components. Thirdly, the industrial robot user-customized configuration design template is constructed, and users can obtain the industrial robot meeting constraints through parameters setting; The kinematics and dynamics analysis on template is taken by Simscape model, and the dynamic parameters is analyzed, and the finite element analysis on template is taken by ANSYS, including statics analysis and modal analysis. The parameters flow process in template is analyzed. Then taking industrial robot user-customized configuration design using configuration template as an example, the configuration template is analyzed in application. Fourthly, the internal algorithm of user-customized configuration design is researched. Platform-based and user-leading user-customized configuration design process is constructed, and then the internal algorithm to keep the design running smoothly is studied, including the degree of freedom determination, fuzzy demand calculation, and service-component configuration and the configuration program evaluation. A case analysis is also taken for the internal algorithm Finally, on the basis of the previous section, the prototype system design of the open design platform is taken. Based on system requirements analysis and system design, the main pages of the platform are designed, and the key functions are introduced .

Design fixation is a phenomenon experienced by professional designers and engineering design students that stifles creativity and innovation through discouraging ideational productivity, fluency and diversity. During the design idea and concept generation phase of the design process, a reliance on perceptual surface feature similarities between design artefacts increases the likelihood of design fixation leading to design duplication. Psychologists, educators and designers have become increasingly interested in creative idea generation processes that encourage innovation and entrepreneurial outcomes. However, there is a notable lack of collaborative research between psychology, education and engineering design particularly on inductive reasoning of undergraduate engineering students in higher education. The data gathered and analysed for this study provides an insight into property inference decision-making preferences and decision switching (SWITCH) patterns of engineering undergraduates under similarity-based inductive judgements [SIM] and category-based inductive judgements [CAT]. For this psychology experiment, property induction tasks were devised using abstract shapes in a triad configuration. Participants (N = 180), on an undergraduate engineering programme in London, observed a triad of shapes with a target shape more similar-looking to one of two given shapes. Factors manipulated for this experiment included category alignment, category group, property type and target shape. Despite the cognitive development and maturation stage of undergraduate engineers (adults) in higher education, this study identified similarity-based inductive judgements [SIM] to play a significant role during inductive reasoning relative to the strength of category-based inductive judgements [CAT]. In addition to revealing the property inference decision-making preferences of a sample of undergraduate engineers (N = 180), two types of switch classification and two types of non-switch classification (SWITCH) were found and named SIM_NCC, SIM-Salient, Reverse_CAT and CAT_Switching. These different classifications for property inference switching and non-switching presented a more complex pattern of decision-making driven by the relative strength between similarity-based inductive judgements [SIM] and category-based inductive judgements [CAT]. The conditions that encouraged CAT_Switching is of particular interest to design because it corresponds to inference decision switching that affirms the sharing of properties between dissimilar-looking shapes designated as category members, i.e., in a conflicting category alignment condition (CoC). For CAT_Switching, this study found a significant interaction between a particular set of conditions that significantly increased the likelihood of property inference decisions switching to affirm the sharing of properties between dissimilar-looking shapes. Stimuli conditions that combined a conflicting category alignment condition (where dissimilar-looking shapes belong to the same category) with category specificity, a causal property and a target shape with merged (or blended) perceptual surface features significantly increased the likelihood of a property inference decision switching. CAT_Switching has important implications for greater ideational productivity, fluency and diversity to discourage design fixation within the conceptual design space. CAT_Switching conditions could encourage more creative design transformations with alternative design functions through inductive inferences that generalise between dissimilar artefact designs. The findings from this study led to proposing a Cartesian view of the concept design space to represent the possibilities for greater movements through flexible and expanding category boundaries to encourage conceptual combinations, greater ideational fluency and greater ideational diversity within a configuration design space. This study has also created a platform for further research into property inference decision-making, ideational diversity and category boundary flexibility under stimuli conditions that encourage designers and design students to make inductive generalisations between dissimilar domains of knowledge through a greater emphasis on causal relations and semantic networks.