Intelligent Support for Knitwear Design

Communication between different members of a design team often poses difficulties. The knitwear design process is shared by the designers, who plan the visual and tactile appearance of the garments, and the technicians, who have to realise the garment on a knitting machine and assemble it. This thesis reports a detailed empirical study of over' twenty companies in Britain and Germany, which shows that the communication problem constitutes a major bottleneck. Designers specify their designs inaccurately, incompletely and inconsistently; the technicians interpret these specifications according to their previous experience of similar designs, and produce garments very different from the designers' original intention. Knitwear is inherently difficult to describe, as no simple and complete notation exists for knitted structures; and the relationship between visual appearance and structure and technical properties of knitted fabric is subtle and complex. At the same time the interaction between designers and technicians is badly managed in many companies. This thesis argues that this communication bottleneck can be overcome by enabling designers to produce accurate specifications of technically correct designs, through the help. of an intelligent computer support system that corrects inconsistent input and proposes design suggestions that the user can edit. In this thesis this proposal is elaborated for one aspect of knitwear design: garment shape construction. Garment shapes are modelled using Bezier curves generated using design heuristics drawn from industrial practice, to create curves that look right to a designer and can be easily edited. The development of the garment shape models presented in this thesis involved the solution of unusual problems in numerical analysis. The thesis shows how the mathematical models can be integrated into an intelligent CAD system, and discusses die benefits of such a system could have for the design process.