Abstract: “In this paper particle swarm optimization(PSO)has been applied for the design of the optimal robust controllers for third order systems . The controller design problem is posed as constrained nonlinear optimization problem. The parameters of the chosen controller are obtained solving the nonlinear constrained optimization problem.The performance index which has been used in the design is integral square error(ISE).The constraints are frequency domain performances related with robust stability .”

Keywords: PSO, ISE, nonlinear optimization, optimal robust controller