Output Feedback Adaptive Robust Control of Linear Motors With Negligible Electrical Dynamics

2000 ◽  
Author(s):  
Li Xu ◽  
Bin Yao
Keyword(s):  
High Performance ◽  
Adaptive Robust Control ◽  
Tracking Accuracy ◽  
Initial State ◽  
Robust Controller ◽  
Estimation Errors ◽  
Parameter Adaptation ◽  
Linear Motors ◽  
Disturbance Estimation ◽  
Extended Filter

Abstract This paper studies high performance robust motion control of linear motors that have a negligible electrical dynamics. A discontinuous projection based adaptive robust controller (ARC) is constructed. Since only output signal is available for measurement, an observer is designed to provide exponentially convergent estimates of the unmeasurable states. This observer has an extended filter structure so that online parameter adaptation can be utilized to reduce the effect of the possible large nominal disturbance. Estimation errors that come from initial state estimates and uncompensated disturbances are effectively dealt with via certain robust feedback at each step of the ARC backstepping design. Theoretically the resulting controller achieves a guaranteed transient performance and a prescribed final tracking accuracy. In the presence of parametric uncertainties only, asymptotic output tracking is also achieved. This scheme is implemented on an epoxy core linear motor. Extensive experimental results are presented to illustrate the effectiveness and the achievable control performance of the proposed scheme.

Adaptive Robust Control for Hydraulic Actuators With Disturbance Estimation

2015 ◽  
Author(s):  
Z. B. Xu ◽  
J. Y. Yao ◽  
Z. L. Dong ◽  
Y. Zheng
Keyword(s):  
Robust Control ◽  
Finite Time ◽  
Disturbance Observer ◽  
High Performance ◽  
Adaptive Robust Control ◽  
Parametric Uncertainties ◽  
Tracking Accuracy ◽  
Robust Controller ◽  
Hydraulic Actuators ◽  
Disturbance Estimation

In this paper, an adaptive robust control for hydraulic actuators with disturbance estimation is proposed for a hydraulic system with mismatched generalized uncertainties (e.g., parameter derivations, external disturbances, and/or unmodeled dynamics), in which a finite time disturbance observer and an adaptive robust controller are synthesized via backstepping method. The finite time disturbance observer is designed to estimate the mismatched generalized uncertainties. The adaptive robust controller is designed to handle parametric uncertainties and stabilize the closed loop system. The proposed controller accounts for not only the parametric uncertainties, but also the mismatched generalized uncertainties. Furthermore, the controller theoretically guarantees a prescribed tracking transient performance and final tracking accuracy while achieving asymptotic tracking performance after a finite time T0, which is very important for high accuracy tracking control of hydraulic servo systems. Simulation results are obtained to verify the high performance nature of the proposed control strategy.

Adaptive robust control of machining force and contour error with tool deflection using global task coordinate frame

2016 ◽  
Vol 232 (1) ◽  
pp. 40-50 ◽  
Author(s):  
Tyler A Davis ◽  
Yung C Shin ◽  
Bin Yao
Keyword(s):  
High Performance ◽  
Milling Process ◽  
Adaptive Robust Control ◽  
Contour Error ◽  
Coordinate Frame ◽  
Tool Deflection ◽  
Peripheral Milling ◽  
Robust Controller ◽  
Control Approach ◽  
Machining Force

Peripheral milling process productivity or quality can be improved by controlling either cutting force or contour error. While each means for improvement is often addressed individually, efforts to control both aspects simultaneously are less common in the literature. This article describes an approach to control both the contour error and force using an adaptive robust controller. The axes dynamic behavior and tool deflection are considered as the two major sources of error expressly considered in the control design and are embedded in a global task coordinate frame representation of contour error. The adaptive control component maintains high-performance control of both force and contour error in the presence of significant model error or external disturbances. The control approach is implemented on a three-axis machine tool for validation. Experimental results indicate that significant improvements to both contour error and force regulation have been achieved.

Suppression of nonlinear aeroelastic vibration of a wing/store under gust effects using an adaptive-robust controller

2016 ◽  
Vol 23 (7) ◽  
pp. 1206-1217 ◽  
Author(s):  
SA Fazelzadeh ◽  
M Azadi ◽  
E Azadi
Keyword(s):  
Parameter Uncertainty ◽  
High Performance ◽  
Equations Of Motion ◽  
Adaptive Robust Control ◽  
Elastic Model ◽  
Governing Equations ◽  
Robust Controller ◽  
Control Scheme ◽  
Piezoelectric Wafer ◽  
Disturbance Model

In this paper, a nonlinear active control scheme is applied to suppress the flutter vibration of a wing/store. The system is considered as a two dimensional airfoil with attached store. The nonlinear aero-servo-elastic model of the system is obtained based on the Lagrange's formulation. The proposed active pylon involves the piezoelectric wafer strut as the actuator. The aero loads are modeled using Theodorsen function. A gust disturbance model is also added to the system governing equations of motion. An adaptive-robust control scheme is used to suppress the flutter vibration of the wing/store system. The proposed adaptive-robust controller is a composition of the adaptive and robust controllers and so can be considered as a useful controller in presence of unknown parameter uncertainty and disturbances. Finally, the system is simulated and the controller is applied to the system to control the flutter vibrations. The results illustrate the high performance and effectiveness of the controller.

scholarly journals Simplified Adaptive Robust Motion Control with Varying Boundary Discontinuous Projection of Hydraulic Actuator

2014 ◽  
Vol 2014 ◽  
pp. 1-10
Author(s):  
Cungui Yu ◽  
Xianwei Qi
Keyword(s):  
Robust Control ◽  
Motion Control ◽  
High Performance ◽  
Simple Algorithm ◽  
Adaptive Robust Control ◽  
Hydraulic Systems ◽  
Hydraulic Actuator ◽  
Tracking Accuracy ◽  
Rotary Actuator ◽  
Robust Motion Control

This paper deals with the high performance adaptive robust motion control of electrohydraulic servo system driven by dual vane hydraulic rotary actuator. The recently developed adaptive robust control theory is used to handle the nonlinearities and modelling uncertainties in hydraulic systems. Aside from the difficulty of handling parametric variations, the traditional adaptive robust controller (ARC) is also a little complicated in practice. To address these challenging issues, a simplified adaptive robust control with varying boundary discontinuous projection is developed to enhance the robustness of the closed-loop system, based on the features of hydraulic rotary actuator. Compared with previous ARC controller, the resulting controller has a simple algorithm for more suitable implementation and can handle parametric variations via nonlinear robust design. The controller theoretically achieves a guaranteed transient performance and final tracking accuracy in the presence of both parametric uncertainties and uncertain nonlinearities. Extensive simulation results are obtained for a hydraulic rotary actuator to verify the high performance nature of proposed control strategy.

Regularized error function-based extended Kalman filter for estimating the cancer chemotherapy dosage: impact of improved grey wolf optimization

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Utkarsha L. Mohite ◽  
Hirenkumar G. Patel
Keyword(s):  
Tumor Cells ◽  
Error Function ◽  
Drug Dosage ◽  
Parameters Estimation ◽  
Gray Wolf ◽  
Robust Performance ◽  
Parameter Uncertainties ◽  
Initial State ◽  
Robust Controller ◽  
Fine Tune

AbstractObjectivesThe main aim of this work is to introduce a robust controller for controlling the drug dosage.MethodsThe presented work establishes a novel robust controller that controls the drug dosage and it also carried out parameters estimation. Along with this, a Regularized Error Function-based EKF (REF-EKF) is introduced for estimating the tumor cells that could be adapted for different conditions. It also assists in solving the overfitting problems, which occur during the drug dosage estimation. Moreover, the performance of the adopted controller is compared over other conventional schemes, and the attained outcomes reveal the appropriate impact of drug dosage injection on immune, normal, and tumor cells. It is also ensured that the presented controller does a robust performance on the parameter uncertainties. Moreover, to enhance the performance of the proposed system and for fast convergence, it is aimed to fine-tune the initial state of EKF optimally using a new Improved Gray Wolf Optimization (GWO) termed as Adaptive GWO (AGWO). Finally, analysis is held to validate the betterment of the presented model.ResultsThe outcomes, the proposed method has accomplished a minimal value of error with an increase in time, when evaluated over the compared models.ConclusionsThus, the improvement of the proposed REF-EKF-AGWO model is proved from the attained results.

scholarly journals Sliding Mode Robot Control with Friction and Payload Estimation

2004 ◽  
Vol 8 (5) ◽  
pp. 553-561 ◽  
Author(s):  
Lörinc Márton ◽  
◽  
Béla Lantos ◽  
Keyword(s):  
Robot Control ◽  
Control Algorithm ◽  
Lyapunov Method ◽  
Sliding Mode ◽  
Robot Arm ◽  
Tracking Accuracy ◽  
Parameter Adaptation ◽  
Robust Parameter ◽  
Payload Mass ◽  
Friction Parameters

The paper deals with robust motion control of robotic systems with unknown friction parameters and payload mass. The parameters of the robot arm were considered known with a given precision. To solve the control of the robot with unknown payload mass and friction parameters, sliding mode control algorithm was proposed combined with robust parameter adaptation techniques. Using Lyapunov method it was shown that the resulting controller achieves a guaranteed final tracking accuracy. Simulation results are presented to illustrate the effectiveness and achievable control performance of the proposed scheme.

scholarly journals A New Linear Motor Force Ripple Compensation Method Based on Inverse Model Iterative Learning and Robust Disturbance Observer

Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-19
Author(s):  
Xuewei Fu ◽  
Xiaofeng Yang ◽  
Zhenyu Chen
Keyword(s):  
Iterative Learning Control ◽  
Disturbance Observer ◽  
Learning Control ◽  
Inverse Model ◽  
Iterative Learning ◽  
Compensation Method ◽  
Tracking Accuracy ◽  
Linear Motors ◽  
Learning Speed ◽  
Force Ripple

Permanent magnet linear motors (PMLMs) are gaining increasing interest in ultra-precision and long stroke motion stage, such as reticle and wafer stage of scanner for semiconductor lithography. However, the performances of PMLM are greatly affected by inherent force ripple. A number of compensation methods have been studied to solve its influence to the system precision. However, aiming at some application, the system characteristics limit the design of controller. In this paper, a new compensation strategy based on the inverse model iterative learning control and robust disturbance observer is proposed to suppress the influence of force ripple. The proposed compensation method makes fully use of not only achievable high tracking accuracy of the inverse model iterative learning control but also the higher robustness and better iterative learning speed by using robust disturbance observer. Simulation and experiments verify effectiveness and superiority of the proposed 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.

Uniform robust exact differentiator based adaptive robust control for a class of nonlinear systems

2017 ◽  
Vol 40 (9) ◽  
pp. 2901-2911 ◽  
Author(s):  
Zhangbao Xu ◽  
Dawei Ma ◽  
Jianyong Yao
Keyword(s):  
Robust Control ◽  
Nonlinear Systems ◽  
Closed Loop ◽  
Lyapunov Method ◽  
Adaptive Robust Control ◽  
Experimental Results ◽  
Closed Loop System ◽  
Robust Controller ◽  
Performance Simulation ◽  
The Stability

In this paper, an adaptive robust controller with uniform robust exact differentiator has been proposed for a class of nonlinear systems with structured and unstructured uncertainties. The adaptive robust controller is integrated with an uniform robust differentiator to handle the problem of the incalculable part of the derivative of virtual controls and the differential explosion happened in backstepping techniques. The stability of the closed loop system is demonstrated via Lyapunov method ensuring a prescribed transient and tracking performance. Simulation and experimental results are carried out to verify the advantages of the proposed method.

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