Extension of Analytical Target Cascading using Augmented Lagrangian Coordination for Multidisciplinary Design Optimization

Analytical target cascading (ATC) is a method originally developed for translating system-level design targetsto design specifications for the elements comprising the system. ATC has also been shown to be usefulfor coordinating distributed design optimization of hierarchical, multilevel systems. The traditional ATC formulationuses a hierarchically decomposed problem structure, in which coordination is performed by communicatingtarget and response values between parents and children. This paper presents two extensions of theATC formulation to allow non-hierarchical target-response coupling between subproblems and to introducesystem-wide constraints that depend on local variables of two or more subproblems. The ATC formulationwith these extensions belongs to a subclass of augmented Lagrangian coordination, and has thus convergeproperties under the usual convexity and continuity assumptions. A supersonic business jet design problemreported earlier in the literature is used to illustrate these extensions.