OPTIMAL DISCRETE-TIME DYNAMIC OUTPUT-FEEDBACK DESIGN - A W-DOMAIN APPROACH

An alternative method for optimal digital control design is described in this paper. The method is based on the usage of the w-transform and has many attractive design features. One of these is its immediate co nnection with frequency loop-shaping techniques that are now popular a nd effective for multivariable control synthesis in the continuous-tim e domain. Furthermore, any design algorithms originally developed for continuous-time systems can now be immediately extended to the discret e-time domain. The main results presented in this paper are the exact problem formulation and solution of an optimal discrete-time dynamic o utput-feedback design in the w domain involving a quadratic performanc e index to random disturbances. In addition, necessary conditions for optimality are obtained for the numerical solution of the optimal outp ut-feedback compensator design. A numerical example is presented illus trating its application to the design of a low-order dynamic compensat or in a stability augmentation system of a commercial transport.