Design and robust performance evaluation of a fractional order PID controller applied to a DC motor

This paper proposes a methodology for the quantitative robustness evaluation of PID controllers employed in a DC motor. The robustness analysis is performed employing a 2 U+00B3 factorial experimental design for a fractional order proportional integral and derivative controller U+0028 FOPID U+0029, integer order proportional integral and derivative controller U+0028 IOPID U+0029 and the Skogestad internal model control controller U+0028 SIMC U+0029. The factors assumed in experiment are the presence of random noise, external disturbances in the system input and variable load. As output variables, the experimental design employs the system step response and the controller action. Practical implementation of FOPID and IOPID controllers uses the MATLAB stateflow toolbox and a NI data acquisition system. Results of the robustness analysis show that the FOPID controller has a better performance and robust stability against the experiment factors.