Design and performance of non-linear fuzzy logic PI controller for line of sight stabilized platform

Instead of conventional proportional integral (PI) controller, non-linear fuzzy proportional integral (NLFPI) controller is proposed to control an inertially stabilized platform. The strategy is to start with a tuned, conventional PI controller that achieve a certain desired performance, replace it with an equivalent linear fuzzy proportional integral (LFPI) controller, and finally convert the linear fuzzy controller to nonlinear fuzzy controller. The system performance and robustness are investigated. Simulation results demonstrate the effectiveness of the designed controller, which offers an excellent performance and robustness in the presence of uncertainty and nonlinearity.