Feedback controllers for a wind tunnel model involving a delay: A numerical simulation

This paper summarizes the results of a numerical simulation of a closed loop performance of four alternative controllers for a wind tunnel model with delay described in a previous (1982) CDC paper [10]. The proposed feedback controllers involve a linear combination of state variables and weighted integrals of some of the state variables over a period equal to the time delay. An extensive numerical simulation of the closed loop performance showed that the proposed feedback gives a substantial reduction of the settling time as compared to previous designs and also is very easy to adjust to parameter changes. Several other nice features of the feedback law have been demonstrated. In particular, it was shown that without significant loss of accuracy the integral term in the feedback can be replaced by a linear combination of the present and delayed state variables. The design was based on the finite spectrum assignment method for time delay systems.