Classical control design in delta domain by optimal generalised moment matching using genetic algorithm

摘要

In this paper the concept of optimal generalised delta time moment (OGDTM) is introduced for controller design problem in a model matching framework. A reference model transfer function is developed in the complex delta domain from time, frequency and complex domain specifications such that the over all closed loop controlled system match this reference model. The design philosophy adopts Truxal method in an approximate sense and uses a set of optimal generalised time-moments in complex delta domain. The method uses Genetic algorithm search technique to select optimal real frequency points to obtain generalised time moments and yield simple low order rational controllers using output feedback. The method is applied to design rational, discrete-time controller for single-input single-output (SISO), multi-input multi-output (MIMO) systems. The design method further converges to its continuous-time counterpart from its discrete-time description at high sampling frequency highlighting the advantage of using delta parameterisation in modelling and control. Examples are included to illustrate the efficacy of the method.