Genetic algorithm enabled computer-automated design of QFT control systems

This paper first reviews existing Quantitative Feedback Theory (QFT) based design techniques and difficulties that a designer encounters. Based on this analysis and taking into account practical constraints, an evolutionary computation enabled automatic design procedure is developed. It can be employed to provide an initial controller quickly on which to base manual loop-shaping and refinements, or be used to further tune existing controllers or start from scratch. A design example against a MATLAB QFT Toolbox benchmark problem shows that this methodology not only automates loop-shaping but also improves design quality and, most usefully, improves the quality with a reduced order controller. The entire design is targeted towards global optimisation, including the prefilter selection.