Robust adaptive fuzzy control application to uncertain non-linear systems in robotics

In this paper the problem of tracking of a non-linear system in the presence of external disturbances is analysed. An adaptive fuzzy controller is proposed to improve performance of an H∞ tracking problem. The proposed approach benefits from the high performance of H∞ on the one hand, and the intuitive ‘smart’ approach of fuzzy control on the other. An example of a two-link manipulator is used for illustration.

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Observer-Based Robust Adaptive Fuzzy Control for MIMO Nonlinear Uncertain Systems with Delayed Output

Mathematical Problems in Engineering ◽

10.1155/2013/215201 ◽

2013 ◽

Vol 2013 ◽

pp. 1-12 ◽

Cited By ~ 2

Author(s):

Chiang Cheng Chiang

Keyword(s):

Nonlinear System ◽

Fuzzy Control ◽

Robust Stability ◽

Uncertain Systems ◽

Fuzzy Controller ◽

Adaptive Fuzzy Control ◽

Controlled System ◽

Adaptive Fuzzy ◽

Nonlinear Uncertain Systems ◽

Robust Adaptive

An observer-based robust adaptive fuzzy control scheme is presented to tackle the problem of the robust stability and the tracking control for a class of multiinput multioutput (MIMO) nonlinear uncertain systems with delayed output. Because the nonlinear system functions and the uncertainties of the controlled system including structural uncertainties are supposed to be unknown, fuzzy logic systems are utilized to approximate these nonlinear system functions and the upper bounded functions of the uncertainties. Moreover, the upper bound of uncertainties caused by these fuzzy modeling errors is also estimated. In addition, the state observer based on state variable filters is designed to estimate all states which are not available for measurement in the controlled system. By constructing an appropriate Lyapunov function and using strictly positive-real (SPR) stability theorem, the proposed robust adaptive fuzzy controller not only guarantees the robust stability of a class of multivariable nonlinear uncertain systems with delayed output but also maintains a good tracking performance. Finally, some simulation results are illustrated to verify the effectiveness of the proposed control approach.

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Research of Robust Adaptive Fuzzy Control in Manipulator

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.317-319.713 ◽

2011 ◽

Vol 317-319 ◽

pp. 713-717

Author(s):

Hong Lin Li ◽

Peng Bing Zhao

Keyword(s):

Fuzzy Control ◽

Influencing Factors ◽

Fuzzy Controller ◽

Adaptive Fuzzy Control ◽

Random Disturbance ◽

State Variables ◽

Adaptive Fuzzy Controller ◽

Adaptive Fuzzy ◽

Load Variation ◽

Robust Adaptive

There are friction characteristics, random disturbance, load variation and other nonlinear influencing factors in the multi-joint manipulator system generally. According to the problem that the traditional PID and fuzzy control are difficult to achieve rapid and high-precision control for this kind of system, a kind of robust adaptive fuzzy controller was designed based on fuzzy compensation under the circumstances that the fuzzy information can be known and all the state variables can be measured. Simultaneously, in order to reduce the computational load of fuzzy approximation and improve the efficiency of mathematical operation, a method that distinguishing different disturbance compensatory terms and approximating each of them respectively was adopted. The simulation results show that the robust adaptive fuzzy controller based on fuzzy compensation can restrain friction, disturbance, load variation and other nonlinear influencing factors.

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