scholarly journals Improved Linear Active Disturbance Rejection Control for Lever-Type Electric Erection System with Varying Loads and Low-Resolution Encoder

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Hailong Niu ◽  
Qinhe Gao ◽  
Zhihao Liu ◽  
Shengjin Tang ◽  
Wenliang Guan
Keyword(s):  
Trajectory Tracking ◽  
Disturbance Rejection ◽  
Approximate Model ◽  
Control Mode ◽  
Active Disturbance Rejection Control ◽  
Tracking Accuracy ◽  
Low Resolution ◽  
Reduced Order ◽  
Active Disturbance Rejection ◽  
Disturbance Rejection Control

The lever-type electric erection system is a novel kind of erection system and the experimental platform in this paper operates with varying loads and low-resolution encoder. For high accuracy trajectory tracking, linear active disturbance rejection control (LADRC) is introduced. An approximate model, consisting of the servo system configured at velocity control mode and the lever-type erection mechanism, is built by means of system identification and curve fitting. Reduced-order LADRC based on the further simplified model is proposed to improve tracking accuracy and robustness. As comparisons, traditional LADRC and PID with high-gain tracking differentiator (HGTD) are designed. Simulation and experimental results indicate that reduced-order LADRC can realize higher trajectory tracking accuracy with low-resolution encoder and has better robustness to variation in erection loads, compared with traditional LADRC and PID with HGTD.

scholarly journals Linear Active Disturbance Rejection Control for Lever-Type Electric Erection System Based on Approximate Model

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Hailong Niu ◽  
Qinhe Gao ◽  
Shengjin Tang ◽  
Wenliang Guan
Keyword(s):  
Trajectory Tracking ◽  
Disturbance Rejection ◽  
Approximate Model ◽  
Control Law ◽  
Active Disturbance Rejection Control ◽  
Tracking Accuracy ◽  
Servo Drive ◽  
Active Disturbance Rejection ◽  
Disturbance Rejection Control ◽  
Servo Drive System

Linear active disturbance rejection control (LADRC) algorithm is proposed to realize accurate trajectory tracking for the lever-type electric erection system. By means of system identification and curve fitting, the approximate model is built, which is consisting of the servo drive system with velocity closed-loop and the lever-type erection mechanism. The proportional control law with velocity feedforward is designed to improve the trajectory tracking performance. The experimental results verify that, based on approximate model, LADRC has better tracking accuracy and stronger robustness to the disturbance caused by the change of intrinsic parameters compared with PI controller.

Active Disturbance Rejection Control for Trajectory Tracking of Manipulator Joint with Flexibility and Friction

2013 ◽  
Vol 325-326 ◽  
pp. 1229-1232 ◽  
Author(s):  
Ming Chu ◽  
Gang Chen ◽  
Fei Jie Huang ◽  
Qing Xuan Jia
Keyword(s):  
Trajectory Tracking ◽  
Disturbance Rejection ◽  
External Disturbance ◽  
Active Disturbance Rejection Control ◽  
Tracking Accuracy ◽  
Active Disturbance Rejection ◽  
State Observers ◽  
Disturbance Rejection Control ◽  
In Series ◽  
Time Observation

For high-accuracy trajectory tracking of manipulator joint, the more realistic dynamic equations, considering reducer flexibility, nonlinear friction and external disturbance, are established and then decomposed into two subsystems in series. A double closed-loop controller, which is mainly used to compensate the flexibility, is designed by using active disturbance rejection control (ADRC) technology. The extended state observers are applied for real-time observation and compensation of the nonlinear terms. Simulation results indicate that the flexibility and friction are simultaneously overcomed, and the proposed controller can greatly improve the tracking accuracy.

Non-linear active disturbance rejection control for upper limb rehabilitation exoskeleton

2020 ◽  
pp. 095965182095457
Author(s):  
Sumit Aole ◽  
Irraivan Elamvazuthi ◽  
Laxman Waghmare ◽  
Balasaheb Patre ◽  
Fabrice Meriaudeau
Keyword(s):  
Upper Limb ◽  
Trajectory Tracking ◽  
Disturbance Rejection ◽  
Active Disturbance Rejection Control ◽  
Upper Limb Rehabilitation ◽  
Active Disturbance Rejection ◽  
Disturbance Rejection Control ◽  
Flexion Extension ◽  
Non Linear ◽  
Limb Rehabilitation

Trajectory tracking in upper limb rehabilitation exercises is utilized for repeatability of joint movement to improve the patient’s recovery in the early stages of rehabilitation. In this article, non-linear active disturbance rejection control as a combination of non-linear extended-state observer and non-linear state error feedback is used for the sinusoidal trajectory tracking control of the two-link model of an upper limb rehabilitation exoskeleton. The two links represent movements like flexion/extension for both the shoulder joint and the elbow joint in the sagittal plane. The Euler–Lagrange method was employed to acquire a dynamic model of an upper limb rehabilitation exoskeleton. To examine the efficacy and robustness of the proposed method, four disturbances cases in simulation studies with 20% parameter variation were applied. It was found that the non-linear active disturbance rejection control is robust against disturbances and achieves better tracking as compared to proportional–integral–derivative and existing conventional active disturbance rejection control method.

On the Linear Control of Underactuated Nonlinear Systems Via Tangent Flatness and Active Disturbance Rejection Control: The Case of the Ball and Beam System

2016 ◽  
Vol 138 (10) ◽  
Author(s):  
Mario Ramírez-Neria ◽  
Hebertt Sira-Ramírez ◽  
Rubén Garrido-Moctezuma ◽  
Alberto Luviano-Juárez
Keyword(s):  
Equilibrium Point ◽  
Trajectory Tracking ◽  
Disturbance Rejection ◽  
Observer Design ◽  
Active Disturbance Rejection Control ◽  
Tracking Tasks ◽  
Active Disturbance Rejection ◽  
Beam System ◽  
Disturbance Rejection Control ◽  
Ball And Beam System

In this paper, a systematic procedure for controller design is proposed for a class of nonlinear underactuated systems (UAS), which are non-feedback linearizable but exhibit a controllable (flat) tangent linearization around an equilibrium point. Linear extended state observer (LESO)-based active disturbance rejection control (ADRC) is shown to allow for trajectory tracking tasks involving significantly far excursions from the equilibrium point. This is due to local approximate estimation and compensation of the nonlinearities neglected by the linearization process. The approach is typically robust with respect to other endogenous and exogenous uncertainties and disturbances. The flatness of the tangent model provides a unique structural property that results in an advantageous low-order cascade decomposition of the LESO design, vastly improving the attenuation of noisy and peaking components found in the traditional full order, high gain, observer design. The popular ball and beam system (BBS) is taken as an application example. Experimental results show the effectiveness of the proposed approach in stabilization, as well as in perturbed trajectory tracking tasks.

scholarly journals Load Frequency Active Disturbance Rejection Control for Multi-Source Power System Based on Soft Actor-Critic

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4804
Author(s):  
Yuemin Zheng ◽  
Jin Tao ◽  
Hao Sun ◽  
Qinglin Sun ◽  
Zengqiang Chen ◽  
...  
Keyword(s):  
Power System ◽  
Disturbance Rejection ◽  
Load Frequency Control ◽  
Control Mode ◽  
Active Disturbance Rejection Control ◽  
Source Power ◽  
Load Frequency ◽  
Active Disturbance Rejection ◽  
Disturbance Rejection Control ◽  
Tie Line

To ensure the safe operation of an interconnected power system, it is necessary to maintain the stability of the frequency and the tie-line exchanged power. This is one of the hottest issues in the power system field and is usually called load frequency control. To overcome the influences of load disturbances on multi-source power systems containing thermal power plants, hydropower plants, and gas turbine plants, we design a linear active disturbance rejection control (LADRC) based on the tie-line bias control mode. For LADRC, the parameter selection of the controller directly affects the response performance of the entire system, and it is usually not feasible to manually adjust parameters. Therefore, to obtain the optimal controller parameters, we use the Soft Actor-Critic algorithm in reinforcement learning to obtain the controller parameters in real time, and we design the reward function according to the needs of the power system. We carry out simulation experiments to verify the effectiveness of the proposed method. Compared with the results of other proportional–integral–derivative control techniques using optimization algorithms and LADRC with constant parameters, the proposed method shows significant advantages in terms of overshoot, undershoot, and settling time. In addition, by adding different disturbances to different areas of the multi-source power system, we demonstrate the robustness of the proposed control strategy.

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