Extended state observer based fractional order controller design for integer high order systems. (May 2022)

• Record Type: Journal Article
• Authors: Mansouri, Rachid; Bettayeb, Maamar; Al-Saggaf, Ubaid M; Alsaggaf, Abdulrahman U; Moinuddin, Muhammad
• Is Part Of: Proceedings of the Institution of Mechanical Engineers. Volume 236:Number 10(2022)
• Page Start: 5143
• Page End: 5153
• Publication Date: 2022-05
• Subjects: Fractional order controller -- integer order systems -- linear active disturbance rejection control -- Bode's ideal transfer function -- extended state observer -- robust control; Mechanical engineering -- Periodicals; 621.05
• DOI: 10.1177/09544062211062100
• Languages: English
• ISSNs: 0954-4062

Abstract

In this paper, based on the extended state observer (ESO) and on a fractional order controller (FOC), composed of an integer order PID cascaded with a fractional order filter (FOF), a new control scheme for an n th order integer plant is proposed. The ESO is used to estimate and cancel the unknown internal dynamics and the external disturbance. Afterwards, an FOC is designed to resolve the set-point tracking problem. An analytical and systematic method is proposed to design the FOC. This method is based on the Internal Model Control (IMC) and the Bode's Ideal Transfer Function (BITF). Therefore, the proposed control structure improves the robustness and performance of the traditional linear active disturbance rejection control (LADRC), especially for the open-loop gain variation. In addition, since the system be controlled is an n th order, a general form of the BITF is also proposed. Numerical simulations on a nonlinear model and experimental results on a cart-pendulum system design illustrate the effectiveness of the suggested ESO-PID-FOF scheme for the disturbance rejection, the set-point tracking and robustness. A comparison with the results obtained using the standard LADRC is also presented.