Achievable performance of decentralized control systems

In this work, an efficient approach for the assessment of achievable performance of decentralized control systems based on a general quadratic performance index involving both system states and inputs is proposed. The performance assessment problem is formulated as an optimization problem subject to constraints in the form of linear/bilinear matrix inequalities which explicitly take the block-diagonal structural constraint on decentralized control systems into account. In order to deal with the block-diagonal constraint, an iterative approach based on the original optimization problem and an equivalent transformation of the original one with parameter space constraint is proposed. The proposed approach solves for both the best achievable performance and the corresponding controller (and observer) gains. The application to one example illustrates the applicability and effectiveness of the proposed approach.