Finite-time output feedback control for a pneumatic servo system

2016 ◽  
Vol 38 (12) ◽  
pp. 1520-1534 ◽  
Author(s):  
Xiangyu Wang ◽  
Guipu Li ◽  
Shihua Li ◽  
Aiguo Song
Keyword(s):  
Feedback Control ◽  
Output Feedback ◽  
Finite Time ◽  
Tracking Error ◽  
Output Feedback Control ◽  
Feedback Controller ◽  
Nonlinear Observer ◽  
Position Tracking ◽  
Piston Velocity ◽  
Control Scheme

In this paper, the position tracking control problem of pneumatic servo systems is investigated. These systems usually have high nonlinearities and unmeasurable piston velocities. Firstly, by using adding a power integrator technique, a global finite-time state feedback controller is proposed. Secondly, based on homogeneous theory, a nonlinear observer is developed to estimate the piston velocity. Finally, the corresponding output feedback controller is derived, which local finite-time stabilizes the position tracking error system. Compared with the conventional backstepping output feedback control scheme, the developed nonsmooth output feedback control scheme offers a faster convergence rate and a better disturbance rejection property. Numerical simulations illustrate the effectiveness of the proposed control scheme.

Extended state observer–based output feedback control for spacecraft pose tracking with control input saturation

2021 ◽  
pp. 095441002110177
Author(s):  
Kejie Gong ◽  
Ying Liao ◽  
Yafei Mei
Keyword(s):  
Feedback Control ◽  
Output Feedback ◽  
Finite Time ◽  
Output Feedback Control ◽  
State Observer ◽  
Extended State Observer ◽  
Control Input ◽  
Extended State ◽  
Pose Tracking ◽  
Control Scheme

This article proposed an extended state observer (ESO)–based output feedback control scheme for rigid spacecraft pose tracking without velocity feedback, which accounts for inertial uncertainties, external disturbances, and control input constraints. In this research, the 6-DOF tracking error dynamics is described by the exponential coordinates on SE(3). A novel continuous finite-time ESO is proposed to estimate the velocity information and the compound disturbance, and the estimations are utilized in the control law design. The ESO ensures a finite-time uniform ultimately bounded stability of the observation states, which is proved utilizing the homogeneity method. A non-singular finite-time terminal sliding mode controller based on super-twisting technology is proposed, which would drive spacecraft tracking the desired states. The other two observer-based controllers are also proposed for comparison. The superiorities of the proposed control scheme are demonstrated by theory analyses and numerical simulations.

Delayed Output Feedback Control for Nonlinear Systems With Fuzzy Observers

2012 ◽  
Author(s):  
Mansour Karkoub ◽  
Tzu Sung Wu
Keyword(s):  
Feedback Control ◽  
Nonlinear System ◽  
Nonlinear Systems ◽  
Output Feedback ◽  
Tracking Error ◽  
Sufficient Conditions ◽  
Output Feedback Control ◽  
Linear Matrix ◽  
External Disturbances ◽  
Control Scheme

In this paper, the design problem of delayed output feedback control scheme using two-layer interval fuzzy observers for a class of nonlinear systems with state and output delays is investigated. The Takagi-Sugeno type fuzzy linear model with an on-line update law is used to approximate the nonlinear system. Based on the fuzzy model, a two-layer interval fuzzy observer is used to reconstruct the system states according to equal interval output time delay slices. Subsequently, a delayed output feedback adaptive fuzzy controller is developed to override the nonlinearities, time delays, and external disturbances such that the H∞ tracking performance is achieved. The linguistic information is developped by setting the membership functions of the fuzzy logic system and the adaptation parameters to estimate the model uncertainties directly for using linear analytical results instead of estimating nonlinear system functions. The filtered tracking error dynamics are designed to satisfy the Strictly Positive Realness (SPR) condition. Based on the Lyapunov stability criterion and linear matrix inequalities (LMIs), some sufficient conditions are derived so that all states of the system are uniformly ultimately bounded and the effect of the external disturbances on the tracking error can be attenuated to any prescribed level and consequently an H∞ tracking control is achieved. Finally, a numerical example of a two-link robot manipulator is given to illustrate the effectiveness of the proposed control scheme.

scholarly journals Finite-Time Sliding Mode Control Design for Unknown Nonaffine Pure-Feedback Systems

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Jun Zhou ◽  
Xianqiang Li
Keyword(s):  
Feedback Control ◽  
Nonlinear Systems ◽  
Sliding Mode Control ◽  
Output Feedback ◽  
Finite Time ◽  
Sliding Mode ◽  
Output Feedback Control ◽  
Finite Time Convergence ◽  
Mode Control ◽  
Control Scheme

A class of unknown nonaffine pure-feedback nonlinear systems is investigated and a novel output feedback control scheme with low complexity is proposed, based on the sliding mode control theory. The scheme is capable of guaranteeing output tracking error with finite-time convergence and bounded closed loop signals. In this scheme, a novel transformation method is included, which can easily transform the state-feedback control of nonaffine systems into output feedback control of strict-feedback affine systems. Based on the transformed affine systems, a novel finite-time sliding mode control is designed, which is continuous and nonsingular. The control scheme proposed in this work is simple and easy to implement, in which the ‘‘explosion of complexity’’ caused by backstepping-like scheme is completely avoided. And the finite-time convergence is successfully achieved. In addition, the scheme is designed based on output feedback control. And the dynamics of the nonaffine nonlinear systems is unknown in the design process. Thus, the system knowledge needed is reduced.

scholarly journals Finite-Time Output Feedback Control for a Rigid Hydraulic Manipulator System

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Yong-Sheng Hao ◽  
Zhi-Gang Su ◽  
Xiangyu Wang
Keyword(s):  
Output Feedback ◽  
Finite Time ◽  
Tracking Error ◽  
Output Feedback Control ◽  
Feedback Controller ◽  
Finite Time Stability ◽  
Output Feedback Controller ◽  
Analysis Process ◽  
Error System ◽  
Hydraulic Manipulator

The position tracking control problem of a hydraulic manipulator system is investigated. By utilizing homogeneity theory, a finite-time output feedback controller is designed. Firstly, a finite-time state feedback controller is developed based on homogeneity theory. Secondly, a nonlinear state observer is designed to estimate the manipulator’s velocity. A rigorous analysis process is presented to demonstrate the observer’s finite-time stability. Finally, the corresponding output feedback tracking controller is derived, which stabilizes the tracking error system in finite time. Simulations demonstrate the effectiveness of the designed finite-time output feedback controller.

scholarly journals Approximation-Free Output-Feedback Non-Backstepping Controller for Uncertain SISO Nonautonomous Nonlinear Pure-Feedback Systems

Mathematics ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 456 ◽  
Author(s):  
Jang-Hyun Park ◽  
Tae-Sik Park ◽  
Seong-Hwan Kim
Keyword(s):  
Output Feedback ◽  
Finite Time ◽  
Sliding Mode ◽  
Tracking Error ◽  
Feedback Controller ◽  
Feedback Systems ◽  
Fuzzy Logic Systems ◽  
Output Feedback Controller ◽  
Control Scheme ◽  
Exponentially Stable

A novel differentiator-based approximation-free output-feedback controller for uncertain nonautonomous nonlinear pure-feedback systems is proposed. Using high-order sliding mode observer, which is a finite-time exact differentiator, the time-derivatives of the signal generated using tracking error and filtered input are directly estimated. As a result, the proposed non-backstepping control law and stability analysis are drastically simple. The tracking error vector is guaranteed to be exponentially stable in finite time regardless of the nonautonomous property in the considered system. It does not require neural networks or fuzzy logic systems, which are typically adopted to capture unstructured uncertainties intrinsic in the controlled system. As far as the authors know, there are no research results on the output-feedback controller for the uncertain nonautonomous pure-feedback nonlinear systems. The results of the simulation show clearly the performance and compactness of the control scheme proposed.

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