Integrated Modified Repetitive Control With Disturbance Observer of Piezoelectric Nanopositioning Stages for High-Speed and Precision Motion

2019 ◽  
Vol 141 (8) ◽  
Author(s):  
Zhao Feng ◽  
Jie Ling ◽  
Min Ming ◽  
Xiaohui Xiao
Keyword(s):  
Disturbance Observer ◽  
High Speed ◽  
External Disturbance ◽  
Repetitive Control ◽  
Optimization Procedure ◽  
Tracking Performance ◽  
Hysteresis Nonlinearity ◽  
Control Scheme ◽  
The Stability ◽  
Precision Motion

The tracking performance of piezoelectric nanopositioning stages is vital in many applications, such as scanning probe microscopes (SPMs). Although modified repetitive control (MRC) can improve tracking performance for commonly used periodic reference input, it is sensitive to unexpected disturbances that deteriorate tracking precision, especially for high-speed motion. In order to achieve high-speed and precision motion, in this paper, a new composite control scheme by integrating MRC with disturbance observer (DOB) is developed. To simplify controller implementation, the hysteresis nonlinearity is treated as external disturbance and the proposed method is designed in frequency domain. The stability and robust stability are analyzed, and an optimization procedure to calculate the controller parameters is employed to enhance the performance to the maximum extent. To validate the effectiveness of the proposed method, comparative experiments are performed on a piezoelectric nanopositioning stage. Experimental results indicate that the hysteresis is suppressed effectively and the proposed method achieves high-speed and precision tracking with triangular waves references up to 25 Hz and improves the disturbance rejection ability with disturbances under different frequencies and robustness to model uncertainty through comparing with feedback controllers and MRC, respectively.

Opto-electronic platform tracking control of multi-rotor unmanned aerial vehicles based on composite disturbance compensation

2019 ◽  
Vol 233 (12) ◽  
pp. 4410-4420 ◽  
Author(s):  
Rijun Wang ◽  
Yue Bai ◽  
Zhiqiang Zeng ◽  
Junyuan Wang ◽  
Wenhua Du ◽  
...  
Keyword(s):  
Disturbance Observer ◽  
Adaptive Fuzzy Control ◽  
Tracking Performance ◽  
Velocity Signal ◽  
Control Precision ◽  
Control Scheme ◽  
Vehicle Systems ◽  
Aerial Vehicle ◽  
Series Of Experiments ◽  
The Stability

Airborne opto-electronic platforms are very important in unmanned aerial vehicle systems. The stability and tracking performance of airborne opto-electronic platforms are easily affected by disturbance factors, making compensating for those disturbances a very prominent issue. In this paper, compared to the traditional disturbance observer, an improved velocity signal based disturbance observer (IVDOB) is particularly designed to compensate for the disturbance. Then its capability, robustness, and stability are discussed. For improving the stabilization accuracy and tracking performance of airborne opto-electronic platforms, the universal approximation property of fuzzy systems is used to compensate the disturbance further and an adaptive fuzzy control system based on IVDOBs is proposed. To validate the scheme, a series of experiments were carried out. The results show that the proposed control scheme can achieve reliable control precision and satisfy the requirements of airborne opto-electronic platform tasks.

scholarly journals Adaptive Neural Output Feedback Control for Uncertain Robot Manipulators with Input Saturation

Complexity ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Rong Mei ◽  
ChengJiang Yu
Keyword(s):  
Feedback Control ◽  
Output Feedback ◽  
Disturbance Observer ◽  
Robot Manipulators ◽  
External Disturbance ◽  
Input Saturation ◽  
Output Feedback Control ◽  
System State ◽  
Control Scheme ◽  
Uncertain Robot

This paper presents an adaptive neural output feedback control scheme for uncertain robot manipulators with input saturation using the radial basis function neural network (RBFNN) and disturbance observer. First, the RBFNN is used to approximate the system uncertainty, and the unknown approximation error of the RBFNN and the time-varying unknown external disturbance of robot manipulators are integrated as a compounded disturbance. Then, the state observer and the disturbance observer are proposed to estimate the unmeasured system state and the unknown compounded disturbance based on RBFNN. At the same time, the adaptation technique is employed to tackle the control input saturation problem. Utilizing the estimate outputs of the RBFNN, the state observer, and the disturbance observer, the adaptive neural output feedback control scheme is developed for robot manipulators using the backstepping technique. The convergence of all closed-loop signals is rigorously proved via Lyapunov analysis and the asymptotically convergent tracking error is obtained under the integrated effect of the system uncertainty, the unmeasured system state, the unknown external disturbance, and the input saturation. Finally, numerical simulation results are presented to illustrate the effectiveness of the proposed adaptive neural output feedback control scheme for uncertain robot manipulators.

A force reflecting control scheme for telemanipulators with high reduction ratio joint

Robotica ◽  
2002 ◽  
Vol 20 (1) ◽  
pp. 69-79 ◽  
Author(s):  
Sung-Ho Ahn ◽  
Ji-Sup Yoon ◽  
Sang-Jeong Lee
Keyword(s):  
Input Saturation ◽  
High Ratio ◽  
Reduction Ratio ◽  
Tracking Performance ◽  
Position Tracking ◽  
Control Input ◽  
Slow Dynamics ◽  
Control Scheme ◽  
High Reduction ◽  
The Stability

Since a slave manipulator with a high reduction ratio joint generally has slow dynamics in comparison with a master manipulator in telemanipulation systems, its control input is likely to be saturated resulting in poor position tracking performance and deteriorated stability. This paper proposes a force reflecting control scheme for telemanipulators with a high reduction ratio joint, which can effectively compensate the control input saturation caused by the high ratio gear reducer at its joint. The proposed scheme is also shown to guarantee the stability and provides an excellent position tracking performance regardless of the saturation.

scholarly journals A composite controller based on nonlinear H_∞ and nonlinear disturbance observer for attitude stabilization of a flying robot

2021 ◽  
Vol 22 (1) ◽  
pp. 270
Author(s):  
Vahid Razmavar ◽  
Heidar Ali Talebi ◽  
Farzaneh Abdollahi
Keyword(s):  
Attitude Control ◽  
Disturbance Observer ◽  
External Disturbance ◽  
Parametric Uncertainty ◽  
Control Technique ◽  
Robust Controller ◽  
Nonlinear Disturbance Observer ◽  
Control Scheme ◽  
Nonlinear Disturbance ◽  
Flying Robot

<span>In this article a novel composite control technique is introduced. We added a nonlinear disturbance observer to a nonlinear H_∞ control to form this composite controller. The quadrotor kinematics and dynamics is formulated using euler angles and parameters. After that, this nonlinear robust controller is developed for this flying robot attitude control for the outdoor conditions. Because under these conditions the flying robot, experiences both external disturbance and parametric uncertainty. Stability analysis is also presented to show the global asymptotical stability using a Lyapunov function. The simulation results showed that the suggested composite controller had a better performance in comparison with a nonlinear H_∞ control scheme.</span>

Enhanced disturbance observer-based robust yaw servo control for ROVs with multi-vector propulsion

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yihui Gong ◽  
Lin Li ◽  
Shengbo Qi ◽  
Changbin Wang ◽  
Dalei Song
Keyword(s):  
Attitude Control ◽  
Disturbance Observer ◽  
External Disturbance ◽  
Proportional Integral Derivative ◽  
Content Type ◽  
Proportional Integral ◽  
Control Scheme ◽  
Yaw Attitude ◽  
Nonlinear Hydrodynamics ◽  
Parameters Perturbation

Purpose A novel proportional integral derivative-extended state disturbance observer-based control (PID-ESDOBC) algorithm is proposed to solve the nonlinear hydrodynamics, parameters perturbation and external disturbance in yaw control of remote operated vehicles (ROVs). The effectiveness of PID-ESDOBC is verified through the experiments and the results indicate that the proposed method can effectively track the desired attitude and attenuate the external disturbance. Design/methodology/approach This study fully investigates the hydrodynamic model of ROVs and proposes a control-oriented hydrodynamic state space model of ROVs in yaw direction. Based on this, this study designs the PID-ESDOBC controller, whose stability is also analyzed through Kharitonov theorem and Mikhailov criterion. The conventional proportional-integral-derivative (PID) and active disturbance rejection control (ADRC) are compared with our method in our experiment. Findings In this paper, the authors address the nonlinear hydrodynamics, parameters perturbation and external disturbance problems of ROVs with multi-vector propulsion by using PID-ESDOBC control scheme. The advantage is that the nonlinearities and external disturbance can be estimated accurately and attenuate promptly without requiring the precise model of ROVs. Compared to PID and ADRC, both in overshoot and settling time, the improvement is 2X on average compared to conventional PID and ADRC in the pool experiment. Research limitations/implications The delays occurred in the control process can be solved in the future work. Practical implications The attitude control is a kernel problem for ROVs. A precise kinematic and dynamic model for ROVs and an advanced control system are the key factors to obtain the better maneuverability in attitude control. The PID-ESDOBC method proposed in this paper can effectively attenuate nonlinearities and external disturbance, which leads to a quick response and good tracking performance to baseline controller. Social implications The PID-ESDOBC algorithm proposed in this paper can be ensure the precise and fast maneuverability in attitude control of ROVs or other underwater equipment operating in the complex underwater environment. In this way, the robot can better perform undersea work and tasks. Originality/value The dynamics of the ROV and the nominal control model are investigated. A novel control scheme PID-ESDOBC is proposed to achieve rapidly yaw attitude tracking and effectively reject the external disturbance. The robustness of the controller is also analyzed which provides parameters tuning guidelines. The effectiveness of the proposed controller is experimental verified with a comparison by conventional PID, ADRC.

A Robust Anti-Swing Trajectory Control of Overhead Cranes With High-Speed Load Hoisting: Simulation Study

2009 ◽  
Author(s):  
Ho-Hoon Lee
Keyword(s):  
High Speed ◽  
Trajectory Control ◽  
Design Tool ◽  
Sliding Surface ◽  
Tracking Errors ◽  
New Approach ◽  
Overhead Cranes ◽  
Control Scheme ◽  
The Stability ◽  
Load Swing

This paper proposes a new approach for the anti-swing trajectory control of overhead cranes that allows simultaneous high-speed load hoisting. The objective of this study is to design an anti-swing trajectory control scheme that is robust to unavoidable mechanical inaccuracies and installation errors such as locally sloped trolley rails. First, a coupled sliding surface is defined based on the load-swing dynamics, and then the stability of the coupled sliding surface is shown to be equivalent to that of trolley tracking errors. Next, a robust anti-swing trajectory control scheme, minimizing the coupled sliding surface asymptotically to zero, is designed based on the trolley and load-hoisting dynamics. Finally, the proposed control is extended to an adaptive scheme. In this study, the Lyapunov stability theorem is used as a mathematical design tool. The proposed control guarantees asymptotic stability of the anti-swing trajectory control while keeping all internal signals bounded. The proposed control provides a practical solution for the robustness problem caused by the usual mechanical inaccuracies and installation errors in application. The proposed control also provides clear gain-tuning criteria for easy application. The validity of the theoretical results is shown by computer simulation.

Adaptive Control of a Surface Ship at High Speed Using Neural Networks

2012 ◽  
Vol 571 ◽  
pp. 518-523
Author(s):  
Li Dong Guo ◽  
Li Xin Yang
Keyword(s):  
Adaptive Control ◽  
High Speed ◽  
Synthesis Method ◽  
Control Synthesis ◽  
Lyapunov Theorem ◽  
Nonlinear Characteristics ◽  
Surface Ship ◽  
Hydrodynamic Damping ◽  
Control Scheme ◽  
The Stability

An adaptive control synthesis method is considered, which forces a surface ship at high speed to track a desired path. The nonlinear characteristics of the hydrodynamic damping can never be neglected in high speed maneuvering situation. Since the hydrodynamic coefficients of the surface ship at high speed are very difficult to be accurately estimated as a prior, the unknown part of the tracking dynamics system is approximated by neural network. The stability analysis will be given by Lyapunov theorem. Numerical simulations illustrate the excellent tracking performance of the surface ship at high speed under the proposed control scheme.

Disturbance observer-based model prediction control with real-time modified reference for a piezo-actuated nanopositioning stage

2019 ◽  
Vol 42 (4) ◽  
pp. 813-822
Author(s):  
Min Ming ◽  
Zhao Feng ◽  
Jie Ling ◽  
Xiaohui Xiao
Keyword(s):  
Real Time ◽  
Model Prediction ◽  
Disturbance Observer ◽  
Nonlinear Effects ◽  
Tracking Performance ◽  
Experimental Investigations ◽  
Nominal Model ◽  
Model Prediction Control ◽  
Hysteresis Nonlinearity ◽  
Prediction Control

Piezo-actuated micro-/nanopositioning systems have been widely employed in diverse high-precision positioning applications. However, the inherent hysteresis nonlinearity seriously deteriorates the tracking performance of piezo-actuated stages. This paper presents the design, analysis, and validation of a novel control scheme termed model prediction control (MPC) with real-time modified reference based on disturbance observer (DOB) to suppress the hysteresis nonlinearity and model uncertainty, in which the nonlinear effects are treated as an unknown disturbance to the system. In order to remove the most of the interference and diminish the effect of noise, a DOB is designed for the non-minimum phase (NMP) system. Then the difference between the actual displacement and the output of the nominal model termed the residual error is estimated and used to modify the reference in real time for a better performance. By the proposed method, the model of the inherent hysteresis is not required and the controller is established based on the identified nominal model. Its effectiveness is validated through experimental investigations on a commercial nanopositioner. Experimental results show that the proposed method can improve the tracking performance of the piezo-actuated stage, as compared with the traditional MPC and DOB-based MPC.

scholarly journals Backstepping Control of an Unmanned Helicopter Subjected to External Disturbance and Model Uncertainty

2021 ◽  
Vol 11 (12) ◽  
pp. 5331
Author(s):  
Wenlong Zhao ◽  
Zhijun Meng ◽  
Kaipeng Wang ◽  
Haoyu Zhang
Keyword(s):  
External Disturbance ◽  
Flight Test ◽  
Lyapunov Theory ◽  
Outdoor Environment ◽  
Wind Gust ◽  
External Disturbances ◽  
Attitude Tracking ◽  
Control Scheme ◽  
Highly Nonlinear ◽  
The Stability

A helicopter is a highly nonlinear system. Its mathematical model is difficult to establish accurately, especially the complicated flapping dynamics. In addition, the forces and moments exerted on the fuselage are very vulnerable to external disturbances like wind gust when flying in the outdoor environment. This paper proposes a composite control scheme which consists of a nonlinear backstepping controller and an extended state observer (ESO) to handle the above problems. The stability of the closed-loop system can be guaranteed based on Lyapunov theory. The external disturbances and model nonlinearities are treated as a lumped disturbance. Meanwhile, the ESO is employed to compensate the influence by estimating the lumped disturbance in real-time. Numerical simulation results are presented to demonstrate that the algorithm can achieve accurate and agile attitude tracking under the external wind gust disturbances even with model uncertainties. When coming to the flight test, a block dropping device was designed to generate a quantifiable and replicable disturbance, and the experimental results indicate that the algorithm introduced above can reject the external disturbance rapidly and track the given attitude command precisely.

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