Digital Modeling and Digital Redesign of Analog Uncertain Systems Using Genetic Algorithms

Genetic algorithms (GAs) are utilized to e nd the equivalent discrete-time uncertain model of a continuoustime uncertain system for digital simulation and digital design of the continuous-time uncertain system. The developed digitalinterval model providesless conservativeresults than thoseobtained by the conventionalbilinear transform method. Also, the global optimization searching technique provided in the GAs is used to determine the digital control law, taking into account the intersample behavior and implementation errors, for digital control of continuous-time parametric uncertain systems. The developed digitally redesigned control law is able to optimally match the states of the analogously controlled uncertain system and those of the digitally controlled sampleddata uncertain system. Moreover, it produces less conservative results than those obtained by the existing interval method. An illustrative example is included to demonstrate the proposed method.