Research On Automatic Layout Of Automobile Wire Harness Drawings

Automobile wire harness drawings represent component arrangements and wire harness connection relations and thus are the important data in wire harness technology design and manufacture. To improve the layout aesthetically and adjust the layout according to various practical needs, force-directed layout model and algorithm are introduced to automatic layout of wire harness drawings. Based on the thorough analysis on the characteristics of wire harness presentation and layout, the heuristic laws are combined with force-directed layout algorithms to produce an aesthetical-pleasing and practical layout. The main research work is listed as follows:(1) Put forward parameter-based multi-connection graph to represent wire harness drawings. The connection relation of wire harness is modeled on graph theory by parameterizing wire harness segment with connection information. The presentation and inner logical connections are effectively separated, and influence domain caused by drawing modification is sharply decreased.(2) Introduced force-directed layout algorithms into automobile connection graph's automatic layout. First, the wire harness trunk is defined and the trunk search algorithm for wire harness drawings is given, based on which the wire harness trunk layout is formulated. Second, the wire harness branches connected to the trunk are grouped hierarchically, which are then arranged using force-directed algorithm in a bottom-up way.(3) Proposed the method for wire harness connector and accessory layout based on heuristic rules and a kind of force-directed algorithm called spring algorithm. For connector layout, the initial positions of connectors and accessories are firstly determined by rules after the layout of wire harness connection graph; secondly, springs are simulated between every two relevant connectors and the movement path of every connector is heuristically formulated; finally, the spring layout algorithm is executed to fulfill the layout of connectors. And the accessory's layout is completely achieved by means of man-set rules.