A KBE Application for Automatic Aircraft Wire Harness Routing

Abstract

Wire harness design is an increasingly complex task. Knowledge Based Engineering (KBE) and optimization techniques can be used to support designers in handling this complexity. The wire harness design process can be divided in three main parts, namely electrical design, configuration design and geometrical routing. This paper describes the latest progress in the development of a KBE application aiming at the automation of the routing phase. Discrete optimization techniques are used to design shortest path harnesses, while complying with different type of constraints. Some preliminary results have been presented in a previous paper, where only geometrical constraints were addressed. However, wire harness design is affected also by other types of rules and constraints, which need to be accounted to obtain more realistic design results from the optimization process. This paper describes some new developments in the routing application to account for the presence of critical zones inside the aircraft. As study case, the presence of heat sources inside the airframe is considered, which either force the harness to be routed elsewhere, or require the use of wire protections, with obvious consequences on weight and manufacturing. First, some mathematic transformation techniques are used to model the presence of heat sources inside the routing environment. Then the A* algorithm is used for compute the 3D routing, aiming at minimum wire harness weight. The main architecture of the routing application is presented and its functionality is demonstrated with samples of wire harness routing inside a wing. The results show that the proposed KBE application can automate the routing of wire harness while taking into account different rules and constraints. The modeling approach for a heat source can be generalized and extended to address other criticality such as abrasion, electromagnetic interference, corrosion, etc. The achieved level of automation relieves designers from the repetitive work associated with the frequent changes affecting the design environment.