Development and implementation of an FPGA based fractional order controller for a DC motor

• A fractional order PI controller for DC motor speed control is proposed.
• We discuss the FPGA implementation issues of robust fractional order PI controllers.
• The advantages of using FPGAs for implementing fractional order PIs are addressed.
• Experimental results show that the proposed solution is robust.

Fractional calculus has been gaining more and more popularity in control engineering in numerous fields, including mechatronic applications. One of the most common applications in all mechatronic domains is the control of DC motors. Several control algorithms have been proposed for such motors, ranging from traditional PID algorithms, to the more sophisticated advanced methods, including fractional order controllers. Nevertheless, very little information regarding the implementation problems of such fractional algorithms exists today. The paper proposes a simple approach for designing a fractional order PI controller for controlling the speed of a DC motor. The resulting controller is implemented on an FPGA target and its performance is compared to other possible benchmarks. The experimental results show the efficiency of the designed fractional order PI controller. Beside the initial DC motor, two other different DC motors are also used in the experiments to demonstrate the robustness of the controller.