Design and Experimental Validation of Adaptive Fuzzy PID Controller for a Three Degrees of Freedom Helicopter

Abstract

This paper presents the design of an adaptive fuzzy PID controller to regulate the elevation, pitch and travel angles of a helicopter with three degrees of freedom (3 DOF). A fuzzy system, Mamdani type, adjusts in real time the proportional, integral and derivative constants of a PID controller, according to the value of the error signal and rate of change the error. The fuzzy controller is tuned based on a mathematical model of the system, which is implemented using the tool called Simulink from Matlab; the transient response in closed loop is evaluated for different values of the reference signal, leading to an iterative process that adjusts the rule base and the constants of the controller, with the objective of stabilizing the system, decreasing the overshoot and the settling time. The experimental validation is done using a prototype built by the authors; the transient response of the simulated data is compared against the experimental data, for the three degrees of freedom of the helicopter: elevation, pitch and travel angles, observing that the mathematical model adjusts to the dynamic of the prototype and the conditions of design are fulfilled.