scholarly journals Active Disturbance Rejection Control for Position Tracking of Electro-Hydraulic Servo Systems under Modeling Uncertainty and External Load

Actuators ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 20
Author(s):  
Manh Hung Nguyen ◽  
Hoang Vu Dao ◽  
Kyoung Kwan Ahn
Keyword(s):  
Angular Velocity ◽  
Disturbance Rejection ◽  
Lyapunov Theory ◽  
Tracking Performance ◽  
System Stability ◽  
Position Tracking ◽  
Parametric Uncertainties ◽  
Active Disturbance Rejection Control ◽  
Active Disturbance Rejection ◽  
Disturbance Rejection Control

In this paper, an active disturbance rejection control is designed to improve the position tracking performance of an electro-hydraulic actuation system in the presence of parametric uncertainties, non-parametric uncertainties, and external disturbances as well. The disturbance observers (Dos) are proposed to estimate not only the matched lumped uncertainties but also mismatched disturbance. Without the velocity measurement, the unmeasurable angular velocity is robustly calculated based on the high-order Levant’s exact differentiator. These disturbances and angular velocity are integrated into the control design system based on the backstepping framework which guarantees high-accuracy tracking performance. The system stability analysis is analyzed by using the Lyapunov theory. Simulations based on an electro-hydraulic rotary actuator are conducted to verify the effectiveness of the proposed control method.

Robust Active Disturbance Rejection Control For Flexible Link Manipulator

Robotica ◽  
2019 ◽  
Vol 38 (1) ◽  
pp. 118-135 ◽  
Author(s):  
Raouf Fareh ◽  
Mohammad Al-Shabi ◽  
Maamar Bettayeb ◽  
Jawhar Ghommam
Keyword(s):  
Disturbance Rejection ◽  
Sliding Mode ◽  
Lyapunov Theory ◽  
Control Law ◽  
Active Disturbance Rejection Control ◽  
Flexible Link ◽  
Estimation Errors ◽  
Disturbance Estimation ◽  
Active Disturbance Rejection ◽  
Disturbance Rejection Control

SummaryThis paper presents an advanced robust active disturbance rejection control (ADRC) for flexible link manipulator (FLM) to track desired trajectories in the joint space and minimize the link’s vibrations. It has been shown that the ADRC technique has a very good disturbance rejection capability. Both the internal dynamics and the external disturbances can be estimated and compensated in real time. The proposed robust ADRC control law is developed to solve the problems existing in the original version of the ADRC related to the disturbance estimation errors and the variation of the parameters. Indeed, these parameters cannot be included in the existing disturbances and then be estimated by the extended state observer. The proposed control law is based on the sliding mode technique, which considers the uncertainties in the control gains and disturbance estimation errors. Lyapunov theory is used to prove the closed-loop stability of the system. The proposed control strategy is simulated and tested experimentally on one FLM. The effect of the observer bandwidth on the system performance is simulated and studied to select the best values of the bandwidth frequency. The simulation and experimental results show that the proposed robust ADRC has better performance than the traditional ADRC.

Trajectory Tracking Control for a Robotic Manipulator Using Nonlinear Active Disturbance Rejection Control

2017 ◽  
Author(s):  
Mohammed Ali ◽  
Charles K. Alexander
Keyword(s):  
Disturbance Rejection ◽  
Control Method ◽  
Robot Manipulator ◽  
Tracking Performance ◽  
Active Disturbance Rejection Control ◽  
Parameter Uncertainties ◽  
External Disturbances ◽  
Trajectory Tracking Control ◽  
Active Disturbance Rejection ◽  
Disturbance Rejection Control

The tracking performance of a robot manipulator is controlled using nonlinear active disturbance rejection control (ADRC). The proposed method does not require the complete knowledge of the plant’s parameters, and external disturbances since it is based on the rejection and estimation of the unknown internal dynamics and external disturbances. The proposed method is simple and has minimal tuning parameters. The robustness of the proposed method is discussed against parameter uncertainties and disturbances. First, the mathematical model of the manipulator is developed. ADRC theory is explained. The manipulator is represented in ADRC form. ADRC’s tracking performance for the joints and end-effector is compared to the tracking performance of the robust passivity (RP) control. The simulations prove that the proposed control method achieves good tracking performance compared to RP control. It is shown that ADRC has a lower energy consumption compared to RP control by calculating the power in the input signals.

Optimal power tracking control of a hydraulic wind turbine based on active disturbance rejection control methodology

2020 ◽  
Vol 44 (3) ◽  
pp. 461-470 ◽  
Author(s):  
Chao Ai ◽  
Chao Wu ◽  
Fan Zhao ◽  
Xiangdong Kong
Keyword(s):  
Wind Turbine ◽  
Disturbance Rejection ◽  
Input Power ◽  
System Stability ◽  
Active Disturbance Rejection Control ◽  
Pump Speed ◽  
Wind Speeds ◽  
Active Disturbance Rejection ◽  
Disturbance Rejection Control ◽  
Displacement Pump

Power point tracking (PPT) is one of the necessary functions of the wind turbine to optimize the use of wind energy. PPT is a condition that needs to be completed after the grid is connected, which can be achieved by tracking the optimal rotation speed of the output of the wind turbine and the optimum torque and power output of the hydraulic system. Based on a fixed displacement pump speed control, an optimal PPT strategy with the active disturbance rejection control (ADRC) method is proposed, and the control objective is to maximize the energy conversion of the system. This paper sets out to (i) establish a hydraulic wind turbine grid-connected affine nonlinear mathematical model, based on the ADRC method and a fixed displacement pump speed output control, (ii) design a nonlinear tracking differentiator and extended state observer and nonlinear state error feedback control law, and (iii) achieve optimal PPT under different wind speeds. Simulations were model by MATLAB/Simulink, where the system inputs signals of different wind speeds and analyses control system stability and robustness. Simulation results show that the input power was greater with a fixed displacement pump speed .

scholarly journals Analysis and Tuning for Active Disturbance Rejection Control

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Fan Wang ◽  
Ran-Jun Wang ◽  
En-Hai Liu
Keyword(s):  
Disturbance Rejection ◽  
Parameter Tuning ◽  
Open Loop ◽  
Internal Model Control ◽  
System Stability ◽  
Theoretical Principle ◽  
Active Disturbance Rejection Control ◽  
Active Disturbance Rejection ◽  
Disturbance Rejection Control ◽  
Model Control

The linear active disturbance rejection control (LADRC) method is investigated in this paper. Firstly, the integral effect of the ADRC is analyzed under the premise that ADRC was transformed into a new form. Then, ADRC is changed into an internal model control (IMC) framework, and an almost necessary and sufficient condition for stability and tracking performance of the ADRC system are proposed on this basis. In addition, some useful corollaries are proposed so that the traditional open-loop frequency-domain analysis method can be applied to ADRC system stability analysis. It also provides a theoretical principle and theoretical guidance for some parameter tuning. To improve the performance of ADRC, an approximate integral gain is treated as a separated adjustable parameter according to the new structure. Furthermore, tuning of some parameters is discussed to enhance system performance. Finally, simulations are used to verify the effectiveness of proposed methods.

scholarly journals Active Disturbance Rejection Control for Double-Pump Direct-Driven Hydraulics

Proceedings ◽  
2020 ◽  
Vol 64 (1) ◽  
pp. 14
Author(s):  
Shuzhong Zhang ◽  
Angen Wu ◽  
Fuquan Dai
Keyword(s):  
Mathematical Model ◽  
State Space ◽  
Disturbance Rejection ◽  
Control Method ◽  
External Disturbance ◽  
Position Tracking ◽  
Active Disturbance Rejection Control ◽  
Active Disturbance Rejection ◽  
Disturbance Rejection Control ◽  
Space Equation

As a result of the energy crisis and further development of the electro-hydraulic actuator, double-pump direct driven hydraulics (DDH) was brought forward, which mainly comprises a servo motor, double fixed displacement pumps, a differential cylinder, a low-pressurized tank and auxiliary valves. To address the problems caused by uncertain parameters and unknown external disturbances of DDH, this paper proposed a control method adopting active disturbance rejection control (ADRC). Firstly, a mathematical model, including a DDH unit and a micro-crane, was created and modelled in MATLAB/Simulink. Further, the model was verified by measurement. After that, the state-space equation model of the system was derived based on its mathematical model and a third-order ADRC was designed using the constructed system state-space equation. Additionally, tracking-differentiator (TD) was employed to process the input signal transiently to avoid unnecessary oscillations, and the extended state observer (ESO) was used to accurately estimate the influence of the uncertainty and compensate by nonlinear feedback control law (NFCL). Moreover, the proposed ADRC or Proportional–Integral–Differential (PID) control was combined with the mathematical model of a micro-crane. Finally, the simulations were performed under varying loads, and the system position tracking performance were analyzed and compared. The results show that the ADRC can sufficiently suppress the unknown external disturbance, has the advantages of robustness, and improves the position tracking precision.

Active Disturbance Rejection Control of a 2D MEMS Micromirror with Sidewall Electrodes

2016 ◽  
Vol 04 (01) ◽  
pp. 35-40
Author(s):  
Ping Liu ◽  
Weijie Sun ◽  
Zhendong Sun
Keyword(s):  
Angular Velocity ◽  
Disturbance Rejection ◽  
Position Control ◽  
External Disturbance ◽  
Main Idea ◽  
Active Disturbance Rejection Control ◽  
Active Disturbance Rejection ◽  
Disturbance Rejection Control ◽  
Control Scheme ◽  
Torsional Micromirror

This study proposes the active disturbance rejection control (ADRC) for a second degree of freedom (2D) electrostatic torsional micromirror with sidewall electrodes. The main idea is to use the linear extended state observer (LESO) to estimate the external disturbance and the angular velocity of the micromirror, and a feedback controller is further applied to achieve the position control of the micromirror. The effectiveness of the LESO in the estimation of the external disturbance and angular velocity is demonstrated. The proposed novel control scheme provides the micromirror with high positioning accuracy and disturbance rejection.

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