Tuning of fractional order PIλDμ controllers with five parameter under strong robustness

In this paper, five parameters tuning method of fractional order controller with strong robust and system open-loop gain changes was presented. In order to enhance the robustness to open-loop gain changes, the method based on the FLATPHASE method adds two constraints to expand the flat range of phase Bode plot of open-loop transfer function for fractional order control system at the crossover frequency. In addition, we use the optimization function FMINCON in MATLAB optimization toolbox to get the five parameters of the fractional order P I^λD^μ controller. Furthermore, we can discrete processing the fractional order P I^λD^μ controller with a direct discrete method called Al-Alaoui+CFE to get Package module and get the simulation results from fractional order control system with Matlab/Simulink. From the simulation results presented, it can be seen that with respect to the traditional integer order control system, fractional order P I^λD^μ control system designed in this paper not only works efficiently, but also has better dynamic performance and stronger robustness.