Stabilization of time-delay systems by nonconvex optimization techniques

In this thesis, both centralized and decentralized controller design for linear time-invariant time-delay systems is considered. The main objective is to design a controller which strongly stabilizes the given time-delay system. In this respect, the centralized controller design method, which uses nonsmooth and nonconvex optimization based fixed-order controller design approach, is introduced. Regarding the nonconvexity, an initialization procedure is proposed as a novel contribution of this thesis. Then, the centralized controller design algorithm, which uses this initialization procedure and applies nonsmooth optimization algorithms, is given. After that, considering the recently developed stabilizability conditions of decentralized time-delay systems, a decentralized controller design algorithm, based on decentralized pole assignment algorithm, is proposed. Also, a new MATLAB based software package, named as DCD-TDS, is introduced. Finally, by using DCD-TDS, the design methods are applied to numerical examples.