System Identification and Design of Genetic-Algorithm-Based Optimal Vibration Controller for a Smart Fin

A solution to the problem of identification and control of smart structures is presented in this paper. Smart structures with build-in sensors and actuators can actively and adaptively change their physical geometry and properties. As a particular example, a representative dynamic model of a typical fighter vertical tail, identified as the smart fin, is considered. Piezoelectric patches, which are mounted on the vertical tail, are employed as actuator in the model. The Frequency Response Function (FRF) of the smart fin is obtained from experiment. The corresponding transfer function is then derived using classic system identification (ID) techniques, using MATLAB® system identification toolbox, which is verified with the experimental data. The model obtained using system ID is then used to tune an optimal PID controller to reduce the vibration of the smart structure. To this end, several cost functions are defined and optimized by a genetic algorithm. Next, the obtained controllers are compared with each other and a suitable one is chosen as the system’s controller. Finally, It is shown in simulations that the designed controller is able to reduce the vibration of the smart fin very well.