Time delay is a natural component of dynamic processes in many engineering fields. Also in most industrial systems, the parameters of the system are uncertain. Thus, the control problem of uncertain dynamical systems with time delays is of great importance. In this thesis, output feedback model reference adaptive control of linear plants with state delays is discussed. For this purpose, a method is studied in which, a feedforward control component is used in addition to an output feedback. The feedforward component is formed by adaptively adjusted prefilters as a function of the delayed states of the reference model. The output feedback is designed as the plant is without delay, but applied to the plant with time delay. This two component controller structure makes it possible to solve the problem of adaptive asymptotic output tracking for the case which the relative degree of the transfer function of system without delay is one. In this thesis, the mentioned method is extended for the relative degrees two and the closed loop stability has been proved using a new Lyapunove-Krasovskii functional. In some systems, the actuators may fail during the system operation. In this research, an output feedback adaptive controller is designed for systems with actuator failures. The two component controller structure can also be used for large scale systems with state delays in the subsystems and in the interconnections.
