Custom integer optimization method for wire bundle dimensioning

摘要

Automotive wiring harnesses have gained weight and complexity through the last decades due to the increasing number of electrical components, which has raised the interest on its weight optimization. For this purpose, it is essential to know at least the maximum amount of steady current that either single wires or bundles can carry. However, the large amount of combinations of the customer-specific wire harnesses makes it impossible to exhaustively simulate all of the combinations that would allow for a reliable analysis and optimization of the network. The proposed approach consists of achieving accurate predictions of the wire thermal behaviour using fast on-line polynomial functions, which have been created as regression models using data from off-line worst-case finite element simulations. These regression models provide good accuracy for the critical dimensions of wire bundles in a much shorter time than simulations, so that they can be used on-line in optimization algorithms. Two different approaches of optimization are presented here in order to assign discrete values of available wire cross-section to the wire bundles: The first one uses integer linear programming, and the second one consists of a recently created custom algorithm whose objective is to reduce the computation time of the integer linear programming approach. This latter objective is satisfactorily accomplished. Results of both optimization approaches are validated by means of final finite element simulations, and they promisingly fulfill the objectives of this study.