Model Reference Adaptive Control Scheme for Retuning Method-Based Fractional-Order PID Control with Disturbance Rejection Applied to Closed-Loop Control of a Magnetic Levitation System

Abstract

This study demonstrates the utilization of model reference adaptive control (MRAC) for closed-loop fractional-order PID (FOPID) control of a magnetic levitation (ML) system. Design specifications of ML transportation systems require robust performance in the presence of environmental disturbances. Numerical and experimental results demonstrate that incorporation of MRAC and FOPID control can improve the disturbance rejection control performance of ML systems. The proposed multiloop MRAC–FOPID control structure is composed of two hierarchical loops which are working in conjunction to improve robust control performance of the system in case of disturbances and faults. In this multiloop approach, an inner loop performs a regular closed-loop FOPID control, and the outer loop performs MRAC based on Massachusetts Institute of Technology (MIT) rule. These loops are integrated by means of the input-shaping technique and therefore no modification of any parameter of the existing closed-loop control system is necessary. This property provides a straightforward design solution that allows for independent design of each loop. To implement FOPID control of the ML system, a retuning technique is used which allows transforming an existing PID control loop into an FOPID control loop. This paper presents the simulation and experimental results and discusses possible contributions of multiloop MRAC–FOPID structure to disturbance rejection control of the ML system.

Multi-loop Model Reference Adaptive PID Control for Fault-Tolerance

“…Thus, a change in control performance of inner loop can be easily detected by observing model error signal and then this mismatch can be tolerated by contributions of the MIT rule. Multi-loop control architectures have been addressed previously to improve certain weaknesses of conventional PID systems, and related works indicates potentials of multi-loop control structures to improve control performance [28][29][30][31][32]. Majority of these studies aim retuning of PID controller coefficients according to the model mismatch error.…”

Multi-Loop Model Reference Proportional Integral Derivative Controls: Design and Performance Evaluations

“…The topic of multi-loop control involves a wide variety of control systems that employ multi-loop control structures, including cascaded control loops [11,12], multi-input multi-output control systems [13], use of additional control loops for performance improvements [14,15], direct model reference control based on output matching [16,17], direct model reference adaptive control with online controller tuning [5][6][7][8][9][10], model reference adaptive control based on Massachusetts Institute of Technology (MIT) rule [18][19][20][21][22][23], backstepping-based adaptive PID control [24], and hierarchical ML-MR adaptive control [25][26][27][28]. The current study investigates several configurations of hierarchical ML-MR adaptive control structures.…”

“…Hierarchical ML-MR adaptive PID control has been investigated, and certain benefits of this structure related to fault tolerance [25] and disturbance rejection [26] have been discussed. This structure can be easily applied to the existing closed loop PID control systems, thus transforming the PID control systems into model reference adaptive PID control systems.…”

“…This presents a significant potential to improve the robust control performance of industrial PID control systems without largely modifying the existing PID loops. Although a growing research trend has been initiated for the use of ML-MR adaptive PID structures to improve the control performance of the closed loop PID control family [25][26][27], this control structure is still in the early stages of development. There is a need for further research efforts to establish design methodologies and reveal some practical benefits and drawbacks.…”

PIDA Denetçilerin Bozucu Dışlama Performansının Teorik İncelenmesi

“…Bu yayında önerilen bozucu dışlayıcı kontrol yapısı, gürültülerin denetçi performansı üzerindeki olumsuz etkilerini azaltan bir denetçi tasarımını hedeflemektedir. Günümüze kadar PID denetçilerin bozucu dışlama kapasitesi üzerine çeşitli çalışmalar yapılagelmiş ve birçok öneriler ileri sürülmüştür [5][6][7][8][9][10][11][12][13][14][15]. Kapalı çevrim kontrol sistemlerinde RDR ile bozucu dışlama kapasitesinin belirlenmesi, kontrol sistemlerinin bozucu dışlama performansı açısından önemlidir [5][6][7].…”