Multicriteria and Discrete Configuration and Design Optimization with Applications for Satellites

Abstract

Typical, numerical structural optimization is well established in improving structural design in its final design phase. The overall product topology is then already defined and structural optimization is “only” used to improve shape and size parameters, which have no influence on the global mechanical topology. Significant decisions have been made already in earlier development stages. However, it is desirable to expand this optimization capabilities to CAE based support for the definition and preliminary design of the general layout, geometrical and structural architecture, equipment configuration and functional requirements. For satellites such a support can be defined as follows: Finding the conceptual geometrical architecture of a satellite satisfying the basic geometrical, mechanical and thermal requirements within an automated optimization process. This includes mainly the (a) topology and geometry of the basic structural components, (b) placements of basic components and equipment and (c) preliminary concept evaluation (e.g. FEM, etc.) Intentionally, the satellite design engineering team should be supplied with a set of feasible or nearly feasible satellite configurations (satisfying the main geometric, mechanical and thermal requirements) serving as a good starting basis for satellite configuration development in early design phases. The design engineers investigate these preliminary conceptual satellite designs for the remaining, typically more specific and more locally acting requirements (e.g. fastening, piping, etc...). In this way the main basic effects guiding satellite design can be taken into account at the very early development stages and, moreover, can be compared with alternative designs to find the best tradeoff. This is a great advantage and progress compared to the traditional design process. Optimization now starts to enter the early and important design phases, the real significant design decisions can now be made by support of optimization techniques. It should be further noted, that our system is not proposed to substitute the design engineers, but to supplement and to enlarge the potentials of the design branch to reach a better design in a shorter time conforming to concurrent engineering issues. In this paper our approach for an automated satellite conceptual design method will be presented, and emphasis is put on demonstration and verification by the satellite GammaBus 1 (the carrier of the Galileo system) as well as other real space applications. Further some main aspects regarding discrete-continuous optimization for structural configuration tasks from an algorithmic point of view are discussed to round out this paper