Shape Gene Design For SUV Product Family Driven By Preference

In the era of technical homogenization, the shape design of automobile is becoming an extremely important factor that influences the product competitiveness. The theory of product family shape gene is a popular topic in the design studies for automobiles. It proposes methodology that applies consistent visual features in a series of products, so as to simulate the biological genetic variation effect, and to form a family image. The method will enhance the competitiveness and brand recognition of the products. On the other hand, the aesthetic preference directly influences consumer’s purchase decision. Diversified consumer preferences make automobile manufacturers to take into account the overall consistency and individual differences when they establish the product family image. However, traditional product family design is generally led by industrial designers, which is subject to the designers’ subjective aesthetic feeling and experience, leading possible ambiguities and uncertainties. If the design work is lack of comprehensive planning, differed designs among the series can hardly form a consistent image of the product family. This problem is commonly seen in the modern industrial design area, especially for emerging enterprises without a complete product family strategy. Moreover, the guidelines on SUV, a popular vehicle in global market, is not in place in the academia.In order to solve the abovementioned problems, this paper presents a methodology-"Shape Gene Design for SUV Product Family Driven by Preference". With the application of product family shape gene theory, consumer preference study and evolutionary computation, the methodology builds up a consistent but diversified image for SUV product family, meanwhile, motivates the SUV shape design that fits to consumers’preference. It consists of three stages below:The1st stage extracts and expresses the shape genes of SUV, establishing the gene pool accordingly.(1) Through an Analytic Hierarchy experiment and an investigation on typical SUV families, the shape genes of SUV are extracted and divided into individual gene and inherited gene.(2) The shape gene is expressed with feature wireframes, while the individual gene is expressed with position of hard points and control points on Bezier splines.(3) The shape gene pool is established by extracting and expressing parent generation samples. The individual gene will be involved in the evolution computation and inherited gene will be directly applied in product family design solutions.The2nd stage introduces how preference drives the SUV shape design.(1) Through a Semantic Differential (SD) test and a clustering analysis, the consumers are classified into three groups based on their diversified preferences.(2) A mapping model between preference and design style is established for each consumer group to explain their preference feature. Accordingly, three separate product lines, Cross-country SUV, Business SUV and City Leisure SUV, are defined as the guideline for the design style.(3) A mapping model between preference and shape gene is established under Kansei Engineering theories for each product line, as the preference-driven evolution function for individual gene design.The3rd stage creates the design solution of SUV product family with application of shape genes.(1) The evolution computing is performed on individual gene with genetic algorithm, obtaining optimal genes that fit different consumer groups.(2) The inherited gene is added up to the evolved individual gene, forming a family characteristic among solutions, and generating a series of integral SUV design solutions that are interconnected and meet the diversified prereferences among consumers.(3) Through an evaluation, the design solutions obtain good assessment from consumers. It verifies the feasibility and effectiveness of the proposed methodology. Based on the methodology, a Computer-Aid Conceptual Design System for SUV Product Family is developed. Through simple input and selection, users can generate a series of conceptual design solutions and successfully establish product family image among them, verifing the practicability and correctness of the proposed methodology.In the end, a conceptual conclusion is made to indicate further steps of research theoretically and practically.