Adaptive Control and Rejection of Persistent Disturbances

2003 ◽  
Author(s):  
Mark Balas ◽  
Robert Fuentes ◽  
Eric Mehiel
Keyword(s):  
Adaptive Control ◽  
Persistent Disturbances

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.

A New Robustness Theorem for the Adaptive Control of Nonlinear Systems

2011 ◽  
Author(s):  
Mark J. Balas ◽  
James P. Nelson
Keyword(s):  
Adaptive Control ◽  
Nonlinear Systems ◽  
Adaptive Controller ◽  
Output Regulation ◽  
Bounded Perturbations ◽  
Persistent Disturbances

Many systems must operate in the presence of bounded perturbations. In this paper we present a new robustness result for nonlinear systems. We use this result to show that for bounded perturbations, a simple adaptive controller with leakage can produce output regulation to a neighborhood with radius dependent upon the size of the perturbation. This regulation occurs in the presence of persistent disturbances and the convergence is exponential.

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.

Augmented Adaptive Control of Flexible Structures Using Residual Mode Filters

2010 ◽  
Author(s):  
Mark Balas ◽  
Susan A. Frost
Keyword(s):  
Adaptive Control ◽  
Flexible Structures ◽  
Adaptive Controller ◽  
Operating Conditions ◽  
Control Approach ◽  
Control Techniques ◽  
Direct Adaptive Control ◽  
Positive Realness ◽  
Persistent Disturbances ◽  
Theoretical Results

Flexible structures containing a large number of modes can benefit from adaptive control techniques which are well suited to applications that have unknown modeling parameters and poorly known operating conditions. In this paper, we focus on a direct adaptive control approach that has been extended to adaptively reject persistent disturbances. This theory will be extended to accommodate troublesome modal subsystems of a plant that might inhibit the adaptive controller. In some cases the plant in does not satisfy the adaptive controller requirements of Almost Strict Positive Realness. Instead, there maybe be a modal subsystem that inhibits this property. In this paper we will modify the adaptive controller with a Residual Mode Filter (RMF) to compensate for the troublesome modal subsystem, or the Q modes. This paper addresses leakage, or propagation, of the disturbances into the Q modes. We will apply the above theoretical results to a flexible structure example to illustrate the behavior with and without the residual mode filter.

Sign in / Sign up

Export Citation Format

Share Document