State Feedback Controllers Synthesis Using Bmi Optimisation for Large Scale Web Handling Systems

In web transport systems, the main concern is to control independently speed and tension in spite of perturbations such as radius variations and changes of set point. In this paper we present multivariable H2 controllers, with and without integrator, applied to winding systems. Different controller structures are considered: a centralized and a semidecentralized controller with or without overlapping. The use of decentralized control leads to performance deterioration as compared to centralized control, but brings other advantages: on one hand, it allows for a local implementation close to each actuator, on the other, sensor or actuator failures create only local disturbances. Our approach consists in designing state feedback control, with bilinear matrix inequality (BMI) optimisation. Simulation results are given based on a nonlinear model for a web handling system, identified on an experimental bench. Copyright © 2005 IFAC