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

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.

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Hailong Niu ◽  
Qinhe Gao ◽  
Zhihao Liu ◽  
Shengjin Tang ◽  
Wenliang Guan

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.


2013 ◽  
Vol 325-326 ◽  
pp. 1229-1232 ◽  
Author(s):  
Ming Chu ◽  
Gang Chen ◽  
Fei Jie Huang ◽  
Qing Xuan Jia

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.


Author(s):  
Sumit Aole ◽  
Irraivan Elamvazuthi ◽  
Laxman Waghmare ◽  
Balasaheb Patre ◽  
Fabrice Meriaudeau

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.


Robotica ◽  
2019 ◽  
Vol 38 (1) ◽  
pp. 118-135 ◽  
Author(s):  
Raouf Fareh ◽  
Mohammad Al-Shabi ◽  
Maamar Bettayeb ◽  
Jawhar Ghommam

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.


Author(s):  
Mario Ramírez-Neria ◽  
Hebertt Sira-Ramírez ◽  
Rubén Garrido-Moctezuma ◽  
Alberto Luviano-Juárez

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.


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