Computer aided identification and design for direct digital control

• Main Author: Bates, M.
• Published: University of Bradford 1979
• Subjects: 629.8
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.449185

This thesis describes a practical application of two CAD packages, CORMAT and CAIAD, for the determination of transfer function models from input/output records and their use in a controller synthesis design. Data records used are taken from PRBS tests applied to a MIMO pilot-scale process running under computer control, while operating in both open and closed loop modes. Both CORMAT and CAIAD are capable of being run within the constraints of a mini computer with backing store and provide, for the SISO and MIMO case; 1) Correlation Model Matching 2) Automatic parameter estimation via Least Squares 3) Model verification via simulation 4) Limited version of 1), 2) and 3) above 5) Automatic model order determination 6) Controller design via conventional PID algorithm 7) Controller synthesis via Block Diagram Algebra (1-3 CORMAT) (4 -7 CAID) Both packages promote user interaction, with final and intermediate results being supplied/displayed in the time-domain. Several 'rules of thumb' have been developed for the application of PRBS tests in the MIMO Case. Identified process models are analysed from open and closed loop tests and used in a controller design. Design is performed using both conventional PID and synthesised controllers.