scholarly journals Decreasing the Value of Specified Cost Function by Adaptive Controller Based on Modified ACLF for a Class of Nonlinear Systems

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Keizo Okano ◽  
Kojiro Hagino ◽  
Hidetoshi Oya
Keyword(s):  
Adaptive Control ◽  
Nonlinear Systems ◽  
Cost Function ◽  
Design Method ◽  
Adaptive Controller ◽  
Control Law ◽  
Control Lyapunov Function ◽  
Nonlinear Adaptive Control ◽  
Hamilton Jacobi Bellman ◽  
Adaptive Control Law

A new nonlinear adaptive control law for a class of uncertain nonlinear systems is proposed. The proposed control law is designed by a modified adaptive control Lyapunov function (ACLF) which satisfies a Hamilton-Jacobi-Bellman (HJB) equation. The modified ACLF is derived from transformation of an ACLF. The proposed control law is different from the inverse optimal one in decreasing the value of a cost function specified by a designer. In this paper, we show a transformation coefficient for an ACLF and a design method of a nonlinear adaptive controller. Finally, it is shown by a numerical simulation that the proposed control law decreases the value of a given cost function and achieves the desirable trajectory.

Robust Adaptive Control of Mildly Nonlinear Systems With Time Varying Input/Output Delays

2012 ◽  
Author(s):  
James P. Nelson ◽  
Mark J. Balas ◽  
Richard S. Erwin
Keyword(s):  
Adaptive Control ◽  
Nonlinear Systems ◽  
Adaptive Controller ◽  
Robust Adaptive Control ◽  
Control Law ◽  
Time Varying ◽  
Robust Adaptive ◽  
Input Delays ◽  
Persistent Disturbances ◽  
Adaptive Control Law

Many systems must operate in the presence of delays both internal to the system and in its inputs and outputs. In this paper we present a robustness result for mildly nonlinear systems. We use this result to show that, for small unknown time varying input delays, a simple adaptive controller can produce output regulation to a neighborhood with radius dependent upon the size of an upper bound on the delay. This regulation occurs in the presence of persistent disturbances and the convergence is exponential. We conclude with an example to illustrate the behavior of this adaptive control law.

Robust Adaptive Control of Nonlinear Systems With Input/Output Delays

2010 ◽  
Author(s):  
Mark J. Balas ◽  
Suraj Gajendar
Keyword(s):  
Adaptive Control ◽  
Nonlinear Systems ◽  
Adaptive Controller ◽  
Output Regulation ◽  
Robust Adaptive Control ◽  
Control Law ◽  
Robust Adaptive ◽  
Input Delays ◽  
Persistent Disturbances ◽  
Adaptive Control Law

Many systems must operate in the presence of delays both internal to the system and in its inputs and outputs. In this paper we present a robustness result for mildly nonlinear systems. We use this result to show that for small unknown input delays, a simple adaptive controller can produce output regulation to a neighborhood with radius dependent upon the size of the delay. This regulation occurs in the presence of persistent disturbances and the convergence is exponential. We conclude with an example to illustrate the behavior of this adaptive control law.

A Design Method of LS-SVM Based Stable Adaptive Controller for a Class of Nonlinear Systems

2011 ◽  
Vol 48-49 ◽  
pp. 17-20
Author(s):  
Chun Li Xie ◽  
Tao Zhang ◽  
Dan Dan Zhao ◽  
Cheng Shao
Keyword(s):  
Nonlinear Systems ◽  
Design Method ◽  
Nonlinear Function ◽  
Lyapunov Stability Theory ◽  
Adaptive Controller ◽  
Control Law ◽  
Continuous Systems ◽  
Control Schemes ◽  
Closed Systems ◽  
Simulation Results

A design method of LS-SVM based stable adaptive controller is proposed for a class of nonlinear continuous systems with unknown nonlinear function in this paper. Due to the fact that the control law is derived based on the Lyapunov stability theory, the scheme can not only solve the tracking problem of this class of nonlinear systems, but also it can guarantee the asymptotic stability of the closed systems, which is superior to many LS-SVM based control schemes. The effectiveness of the proposed scheme is demonstrated by simulation results.

Contribution to the Adaptive Control of Multiple Compliant Manipulation of Dynamic Environments

Robotica ◽  
1999 ◽  
Vol 17 (1) ◽  
pp. 97-109 ◽  
Author(s):  
M. Vukobratovic ◽  
A. Tuneski
Keyword(s):  
Adaptive Control ◽  
Inverse Dynamics ◽  
Adaptive Controller ◽  
Control Law ◽  
Multiple Robots ◽  
Constrained Motion ◽  
Parameter Update Law ◽  
Physical Effects ◽  
Multiple Robot ◽  
Adaptive Control Law

An adaptive control of multiple robot compliant manipulation of a dynamical environment is synthesized. It may be implemented when: (i) there is no good understanding of all physical effects incorporated in the multiple robots/object/environment system to be controlled; (ii) the parameters of the system are not precisely known, (iii) the system parameters do vary in a known region about their nominal values. The proposed adaptive control law has the inverse dynamics controller structure and is composed of an identification part (parameter update law), and a control law part. It is proved that the proposed adaptive controller is asymptotically stable. The simulation results verify the proposed approach to coordinated adaptive control of multiple robot manipulators in constrained motion tasks. They also verify that the multiple robots/object/environment system can track a step parameter change.

Adaptive Control of Robot Manipulators Using a Popov Hyperstability Approach

1995 ◽  
Vol 209 (2) ◽  
pp. 93-100
Author(s):  
H Yu
Keyword(s):  
Adaptive Control ◽  
Robot Manipulators ◽  
Adaptive Controller ◽  
Control Law ◽  
Control Laws ◽  
Performance Simulation ◽  
Control Approach ◽  
Adaptive Parameters ◽  
Hyperstability Theory ◽  
Adaptive Control Law

A general adaptive control approach of robot manipulators using Popov hyperstability is proposed in this paper. The manipulator adaptive control problem is first formulated in a form suitable for the application of hyperstability theory. The adaptive control law is general, and most of the adaptive control laws that have been proposed are special forms of this adaptive control law. The adaptive controller takes advantage of the flexibility in the choice of the adaptive parameters and the controller structure. The adaptive controller guarantees globally asymptotic stability in the hyperstability sense. For input disturbances, the control law, with little modification, maintains satisfactory system performance. Simulation results are presented to evaluate the performance of the adaptive controller for a two link manipulator.

Adaptive Backstepping Stabilization of Uncertain Switched Nonlinear Systems in Parametric Strict-Feedback Form

2010 ◽  
Author(s):  
Arash Haghpanah ◽  
Mohammad Eghtesad ◽  
Mohammad Rahim Hematiyan ◽  
Alireza Khayatian
Keyword(s):  
Nonlinear Systems ◽  
Design Method ◽  
Adaptive Controller ◽  
Control Input ◽  
Switched Nonlinear Systems ◽  
Adaptive Backstepping ◽  
Feedback Form ◽  
Control Lyapunov Function ◽  
Globally Asymptotically Stable ◽  
Strict Feedback

This paper considers the stabilization problem for a class of parametric switched nonlinear systems under arbitrary switching and parameter uncertainty. A parametric strict-feedback form is adopted in order to represent the switched system. Using the adaptive backstepping approach a common control Lyapunov function under simultaneous domination assumption is constructed and then a control input is designed such that the system is globally asymptotically stable. The design method is developed in a recursive manner and results in an overparametrized adaptive controller. The procedure is illustrated by a descriptive example and the simulation results verify the effectiveness of the designed controller in the system performance.

An Improved Multi-Level Adaptive Control Algorithm Based on Parameters Self-Tuning for a Class of SISO Nonlinear Systems

2015 ◽  
Vol 740 ◽  
pp. 247-250
Author(s):  
Feng Qiao ◽  
Zhi Zhen Liu
Keyword(s):  
Adaptive Control ◽  
Nonlinear Systems ◽  
Partial Derivative ◽  
Control Algorithm ◽  
Control Law ◽  
Self Tuning ◽  
On Line ◽  
Multi Level ◽  
Adaptive Control Algorithm ◽  
Adaptive Control Law

In this paper, a multi-level adaptive control algorithm using parameters self-tuning is proposed for improving the tracking performance of a class of SISO nonlinear systems. This scheme is comprised of the pseudo partial derivative estimation law and the adaptive control law. The adaptive control law is derived from a novel higher order weighted one-step-ahead criterion function which exploits more previous control information. In order to identify the laws’ penalty factors which partly imply the dynamics of the system, an approach of parameters self-tuning is proposed with on-line recursive gradient algorithm. This design is model free and depends directly on the pseudo partial derivative updating on-line with the input and output data Simulation examples are provided to illustrate the effectiveness of the proposed method.

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