Internal Model Control for Rank Defect Systems based on PSO Algorithm

In this paper, an internal model control method is proposed for rank defect systems with time delays based on particle swarm optimization (PSO) algorithm. The method is obtained by first transform the system with time-delay into a system without time delays by using the pole approximation approach. Then an internal model control is designed to obtain the desired dynamic characteristics of the system. Since the inverse matrix of rank defect system does not exist, the internal model controller is designed by introducing a damping factor. To solve the problem of the choice of the damping factor, PSO algorithm is utilized to improve the accuracy and the feasibility due to its excellent search capability. Furthermore, singular value decomposition is used to analyze steady state performance of the system. Simulations results illustrate that the proposed strategy is not only can guarantee the system stability but also has certain dynamic performance.