Fractional-order proportional integral controller based on Al-Alaoui operator for resonant optical gyro

The first-and second-order fractional-order proportional integral (FOPI) controllers based on the Al-Alaoui operator and the continued fraction expansion method are designed and applied to the closed-loop control system of a resonant optical gyro. The phase margin method is used to tune the control parameters. The characteristics of the unit step responses of the integer order proportional integral (IOPI) and the FOPI controllers are calculated and compared. Responses to perturbations at different positions of the closed-loop control system are simulated. Results show that for the resonant optical gyro, the FOPI closed-loop control system has much better unit-step-response performance and noise-resistance ability than the IOPI control system, which is important for improving the dynamic response characteristics and the robustness of the gyro's feedback system and enhancing the detection ability of the gyro. Experiments on a resonant optical gyro experimental system also verify the advantages of the FOPI controller in step response and bias stability. (C) 2019 Society of Photo-Optical Instrumentation Engineers (SPIE)