Determination of the optimal positions of window blinds through multi-criteria search

Abstract

Design of building systems should consider trade-offs between conflicting objectives. Multi-criteria search and optimization techniques have been developed for this purpose and these have been successfully applied to many design tasks. One popular approach is Pareto optimization which generates a population of efficient solutions. However, it cannot be used for real time control tasks because the control task requires the identification of a single solution completely autonomously, that is, without human intervention. An algorithm for selecting the best solution that achieves reasonable trade-offs among all the objectives is described in this paper. The algorithm uses two pieces of information for the selection, ordering of objectives according to their importance; and grouping of solutions according to the sensitivity of objective function values. All the solutions that lie within the sensitivity limits of a particular objective are considered to be equivalent. This permits further filtering of solutions according to the importance of objectives. The new algorithm has been applied for the real time control of window blinds. Results from a case study are presented and the advantages of this algorithm are evaluated. © 2011 ASCE.