Abstract
New methods are presented for the design of model-reference adaptive control systems. The motivation is in obtaining an adaptive system with faster adapting speed than the conventional systems. The methods of constructing adaptive loops have been given by many authors, but the difference between the outputs of the plant and the model is commonly used as the adaptive criterion. Therefore, the adapting speed has its limit due to the difference of initial conditions.
This obstacle is overcome by using adaptive criteria which do not depend on initial conditions. Two methods proposed here have criteria of that kind. One uses the adjoint system of the model, and the other is based on the substitution of the input and output of the plant to the differential equation of the model.
Adaptive criteria based on these ideas, the relations of these methods to the conventional one, and the constructions of adaptive loops by Lyapunov's second method are given. Finally the possibility for the improvement of the adaptive speed is shown through the simulation results of an example.
