scholarly journals Investigation of the Hydraulic Servo System of the Rolling Mill Using Nonsingular Terminal Sliding Mode-Active Disturbance Rejection Control

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Jining Guo ◽  
Haoyu Zhang ◽  
Desheng Liu
Keyword(s):  
Disturbance Rejection ◽  
Sliding Mode ◽  
State Observer ◽  
Active Disturbance Rejection Control ◽  
Tracking Accuracy ◽  
Terminal Sliding Mode ◽  
Active Disturbance Rejection ◽  
Disturbance Rejection Control ◽  
Nonsingular Terminal Sliding Mode ◽  
Hydraulic Servo

In order to improve the disturbance rejection ability and tracking accuracy of the hydraulic servo system of the rolling mill, this study combines nonsingular terminal sliding mode control (NTSMC) with active disturbance rejection control (ADRC). A fourth-order extended state observer was designed to estimate the disturbance of the system in real time. The stability of the control system was tested using the Lyapunov method. System effectiveness was verified through simulation experiments. Simulation results showed that the designed state observer can estimate the total disturbance of the system in real time and that the chattering of the control input can be eliminated by the introduction of a state observer. In terms of uncertainty in the system model caused by load changes and external interference signals, the nonsingular terminal sliding mode-active disturbance rejection control method exhibited better disturbance rejection capacity and a higher tracking accuracy than NTSMC.

scholarly journals Integral Nonsingular Terminal Sliding Mode Control of Hydraulic Servo Actuator Based on Extended State Observer

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Zhenshuai Wan ◽  
Yu Fu
Keyword(s):  
Sliding Mode ◽  
State Observer ◽  
Extended State Observer ◽  
Extended State ◽  
Tracking Accuracy ◽  
Terminal Sliding Mode ◽  
Motion Trajectories ◽  
Nonsingular Terminal Sliding Mode ◽  
Servo Actuator ◽  
Hydraulic Servo

Hydraulic servo actuator always suffers from various disturbance and uncertainties, which makes it difficult to design a higher performance controller. In this paper, an integral nonsingular terminal sliding mode controller based on extended state observer (ESO-INTSM) is proposed to improve the robust performance of hydraulic servo actuator. The ESO is designed to estimate not only the parametric uncertainties but also the model disturbance. Based on the observed states of ESO, the proposed controllers could enable hydraulic servo actuator to track the desired motion trajectories. The stability of the synthesized controller is proved via Lyapunov analysis, which is very important for high-accuracy tracking control of hydraulic servo actuator. Simulation and experimental results demonstrate that the proposed control strategy can effectively attenuate the adverse influence caused by the uncertainties and apparently improve the tracking accuracy.

Adaptive output-feedback robust active disturbance rejection control for uncertain quadrotor with unknown disturbances

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Nigar Ahmed ◽  
Syed Awais Ali Shah
Keyword(s):  
Output Feedback ◽  
Disturbance Rejection ◽  
Sliding Mode ◽  
The State ◽  
Active Disturbance Rejection Control ◽  
State Variables ◽  
Content Type ◽  
Active Disturbance Rejection ◽  
Disturbance Rejection Control ◽  
Attitude Model

PurposeIn this research paper, an adaptive output-feedback robust active disturbance rejection control (RADRC) is designed for the multiple input multiple output (MIMO) quadrotor attitude model subject to unwanted uncertainties and disturbances (UUDs).Design/methodology/approachIn order to achieve the desired control objectives in the presence of UUDs, the low pass filter (LPF) and extended high gain observer (EHGO) methods are used for the estimation of matched and mismatched UUDs, respectively. Furthermore, for solving the chattering incurred in the standard sliding mode control (SMC), a multilayer sliding mode surface is constructed. For formulating the adaptive output-feedback RADRC algorithm, the EHGO, LPF and SMC schemes are combined using the separation principle.FindingsThe findings of this research work include the design of an adaptive output-feedback RADRC with the ability to negate the UUDs as well as estimate the unknown states of the quadrotor attitude model. In addition, the chattering problem is addressed by designing a modified SMC scheme based on the multilayer sliding mode surface obtained by utilizing the estimated state variables. This sliding mode surface is also used to obtain the adaptive criteria for the switching design gain parameters involved in the SMC. Moreover, the requirement of high design gain parameters in the EHGO is solved by combining it with the LPF.Originality/valueDesigning the flight control techniques while assuming that the state variables are available is a common practice. In addition, to obtain robustness, the SMC technique is widely used. However, in practice, the state variables might not be available due to unknown parameters and uncertainties, as well as the chattering due to SMC reduces the performances of the actuators. Hence, in this paper, an adaptive output-feedback RADRC technique is designed to solve the problems of UUDs and chattering.

scholarly journals High-Order Sliding Mode-Based Fixed-Time Active Disturbance Rejection Control for Quadrotor Attitude System

Electronics ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 357 ◽  
Author(s):  
Chunlin Song ◽  
Changzhu Wei ◽  
Feng Yang ◽  
Naigang Cui
Keyword(s):  
Disturbance Rejection ◽  
Sliding Mode ◽  
Fixed Time ◽  
High Order ◽  
Extended State Observer ◽  
Active Disturbance Rejection Control ◽  
Extended State ◽  
Active Disturbance Rejection ◽  
Disturbance Rejection Control ◽  
Control Scheme

This article presents a fixed-time active disturbance rejection control approach for the attitude control problem of quadrotor unmanned aerial vehicle in the presence of dynamic wind, mass eccentricity and an actuator fault. The control scheme applies the feedback linearization technique and enhances the performance of the traditional active disturbance rejection control (ADRC) based on the fixed-time high-order sliding mode method. A switching-type uniformly convergent differentiator is used to improve the extended state observer for estimating and attenuating the lumped disturbance more accurately. A multivariable high-order sliding mode feedback law is derived to achieve fixed time convergence. The timely convergence of the designed extended state observer and the feedback law is proved theoretically. Mathematical simulations with detailed actuator models and real time experiments are performed to demonstrate the robustness and practicability of the proposed control scheme.

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