Abstract: Wire harness connection graph (WHCG), consisting of wire harness segments, is a connected acyclic graph generated from wire harness drawing after removing the wire harness connectors. WHCG, the main component of automatic layout of wire harness drawing, represents the connection of wire harness connectors and determines the layout skeleton of wire harness drawing. The paper introduces the force-directed layout models and algorithms from the undirected graph layout theory into automobile WHCG’s automatic layout, the trunk search algorithm for WHCG and constrained symmetrical layout of wire harness branches are given, based on which the WHCG’s layout is formulated, providing the effective methods and techniques for automatic layout of automobile wire harness drawing.

Key words: engineering graphics, drawing layout, wire harness connection graph, force-directed algorithm, constraint symmetry