A Convex Constraint for Directly Designing a Low-order Controller in Polynomial Approach
Hamid Khatibi, Alireza Karimi · Infoscience (Ecole Polytechnique Fédérale de Lausanne) · 2010
A convex constraint on controller parameters is proposed in order to decrease the controller order in any optimization-based controller design method in polynomial approach for LTI-SISO polytopic systems. It employs rank-deficiency constraint on the controller Sylvester resultant matrix, which is not convex itself. Therefore, an improved convex approximation of the rank deficiency constraint is used that can be represented via LMIs. The effectiveness of the proposed method is shown by appending it to an existing controller design method for polytopic systems in polynomial approach.