The Study Of The Algorithm Of Self-Tuning PDF Control

Many new equipment and new processes are arising with progress of science and technology today. It's a driving force and also a challenge to control in both theory and technology due to the more and more severe specifications imposing on it. A variety control theory have been developed,however,with limited performance in practical applications,especially in term of the relatively lower response speed when used in those machines which run fast. Therefore,it is necessary to develop a new self-tuning algorithm for fast running plant of uncertainty so as to set theoretical base for controller design.In this thesis,the structure of PDF control of plant up to sixth order is introduced based on PDF control theory. Normally,the order of plant in PDF control is not greater than second,it is necessary to decompose the plant of order higher than second so as to each controller controls a plant of order less than or equal to second. On this base,a self-tuning algorithm of PDF control is presented. The key of the algorithm is identification of plant. Based on analysis and calculation,the thesis presents the theory and method for minimum phase plant identification. The plant with uncertainty can be estimated through plant response to a short-duration step control effort acting directly on the plant so that the PDF control coefficients can be computed. Then the system will be shifted to ordinary PDF control mode immediately. Expanding this algorithm,the thesis studies the possibility to utilize step-response identification in self-tuning control of non-minimum phase plant. Suggestions above are examined by simulation with simulink toolbox in Matlab environment. Numerical examples of self-tuning PDF control running this algorithm are presented to compare the operational performance with the ordinary PDF scheme,showing effectiveness of the algorithm when implemented in practical use.