Research on fractional order two-degrees-of-freedom flight control technology of unmanned air vehicle

In order to satisfy the requirements of flight control system about command tracking performance, disturbance rejection performance and robustness, a fractional order two-degrees-of-freedom PID control technology is introduced in pitch control system design of UAV. A given value filter type fractional order two-degrees-of-freedom PID controller which consists of the given value filter and the fractional order PID (FOPID) controller is proposed. In the fractional order PID controller design, Nelder-Mead´s simplex method is adopted to ensure the control system has the best disturbance rejection performance and robustness, and during the design of the given value filter, a particle swarm optimization (PSO) algorithm is used to make the control system satisfy the requirements of the command tracking performance. The simulation result shows that the designed pitch control system has good control qualities and robustness.