Disturbance Observer Based Discrete Time Sliding Mode Control for a Continuous Stirred Tank Reactor

Ma, Lifeng; Zhao, Dongya; Spurgeon, Sarah K.

doi:10.1109/vss.2018.8460344

Cited by 8 publications

(2 citation statements)

References 24 publications

(24 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The SMC is known as one of the variable structure controls where high-speed switching action is carried out to eliminate the initial errors for excellent robustness in achieving an offset-free tracking approach [6]. From the study of SMC by Ma, Zhao and Spurgeon, the SMC algorithms in discrete form is discovered to reduce the chattering effect caused by the infinite switching frequency [7]. Furthermore, the elimination of the external disturbance effects is also considered by adding a disturbance observer to measure the control input required to mitigate its deviation.…”

Section: Sliding Mode Controlmentioning

confidence: 99%

Model Predictive Control – Sliding Mode Control of a pH system

Ooi

Hermansson

Lim

2022

IOP Conf. Ser.: Mater. Sci. Eng.

View full text Add to dashboard Cite

This paper studies the feasibility of using discrete sliding mode controller (SMC) to achieve offset-free control of nonlinear processes in the presence of disturbances. The performance of the SMC is compared to a multiple model predictive controller (MMPC) studying the ability of set-point tracking using the pH system as a case study. The results presented from the comparison show that SMC can perform offset-free control of a pH system, with the major drawback being slow response as well as oscillation at some pH values. Finally, a design of a combination between MMPC and SMC (MMPC-SMC) is proposed, with MMPC carrying out basic control response while the SMC fulfils the role of eliminating the offset. However, the inaccurate reading in the MATLAB simulation model does not generate the expected results on the pH control. Therefore, the modification on the MATLAB models is required to achieve the improved control system on the offset-free behaviour for the set-point tracking.

show abstract

Section: Sliding Mode Controlmentioning

confidence: 99%

Model Predictive Control – Sliding Mode Control of a pH system

Ooi

Hermansson

Lim

2022

IOP Conf. Ser.: Mater. Sci. Eng.

View full text Add to dashboard Cite

show abstract

“…A DSMC method combined with a decoupled disturbance compensator (DDC) has been developed to recover the loss of stability for SMC in discrete-time systems [24], [25]. It can be shown that the DDC has the same structure as the conventional DOB [26], and the DSMC with DOB methods have been successfully implemented in industrial applications [27]- [29]. However, these works assumed that the control inputs are unconstrained, and they lose stability when control saturation occurs.…”

mentioning

confidence: 99%

Effective Disturbance Compensation Method Under Control Saturation in Discrete-Time Sliding Mode Control

Han

Kim

et al. 2020

IEEE Trans. Ind. Electron.

View full text Add to dashboard Cite

This article presents a novel method of dealing with disturbances and control saturation in the framework of discrete-time sliding mode control (DSMC). A DSMC with decoupled disturbance compensator (DDC) was developed for SMC to recover the loss of stability in the discrete-time domain. However, windup phenomena occur in both the switching function and the disturbance estimate when control saturation occurs, and the method cannot guarantee stability. The article develops a new method for maintaining stability under both disturbances and control saturation by incorporating a novel auxiliary state into the DSMC with DDC method. The auxiliary state prevents the windup phenomena, and the developed new method preserves the asymptotic convergence property of the disturbance estimation error dynamics and the stability of the sliding mode dynamics. Also, the error states are stable under bounded disturbances and control saturation. Simulations and experiments are performed on a commonly used industrial servo system to demonstrate the effectiveness of the proposed method. Index Terms-Discrete-time systems, sliding mode control (SMC), servosystems. I. INTRODUCTIONS LIDING mode control (SMC) is a special kind of variable structure control and is one of the most successful approaches in general control systems with bounded and matched disturbances. SMC drives the state variables to a predesigned sliding surface in a finite time and then keeps them on the sliding surface in the presence of the bounded disturbance. Therefore,

show abstract