Practical applications and limitations of adaptive control
Abstract
The practical application and the limitation of the present methods of adaptive control are investigated. This thesis contains three contributions. First, the predictive control of the steam temperature in an electric power plant during start-up is simulated. The model contains two lumped heat exchangers and two stages of water attempering including the spray valve dynamics. A modified temperature ramp yields bounded parameter estimate via persistent excitation. Second, published methods of adaptive control are revealed to have common structures and adaptation algorithms. The composition of the error signal that drives the parameter estimation scheme is shown to be the limitation of adaptive control in terms of robust stability. Third, the robust stability problem of adaptive control is demonstrated on a second order, weakly nonlinear system (a four cylinder pneumatic engine) with measurement noise and unmodelled dynamics. Persistent excitation is shown to be a means of obtaining robust stability for this system.
Degree
Ph.D.
Advisors
Shoureshi, Purdue University.
Subject Area
Mechanical engineering
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