TITLE:
Adaptive Control for a Class of Systems with Output Deadzone Nonlinearity
AUTHORS:
Nizar J. Ahmad, Ebraheem K. Sultan, Mohammed Q. Qasem, Hameed K. Ebraheem, Jasem M. Alostad
KEYWORDS:
Adaptive Inverse Control, Output Deadzone, Hard Nonlinearity
JOURNAL NAME:
Intelligent Control and Automation,
Vol.6 No.4,
November
4,
2015
ABSTRACT: This paper presents a continuous-time
adaptive control scheme for systems with uncertain non-symmetrical deadzone
nonlinearity located at the output of a plant. An adaptive inverse function is developed
and used in conjunction with a robust adaptive controller to reduce the effect
of deadzone nonlinearity. The deadzone inverse function is also implemented in
continuous time, and an adaptive update law is designed to estimate the
deadzone parameters. The adaptive output deadzone inverse controller is
smoothly differentiable and is combined with a robust adaptive nonlinear
controller to ensure robustness and boundedness of all the states of the system
as well as the output signal. The mismatch between the ideal deadzone inverse
function and our proposed implantation is treated as a disturbance that can be
upper bounded by a polynomial in the system states. The overall stability of
the closed-loop system is proven by using Lyapunov method, and simulations
confirm the efficacy of the control methodology.