Adaptive control scheme achieving smooth control input in the presence of input saturation

In this paper, the main attention is focused on transient property of control input signal, we propose a novel model reference adaptive control scheme for time-continuous single-input single-output linear systems with input saturation. To improve a control performance, a novel estimator using an observer for the output tracking error signal is proposed. Using the estimator, it is shown theoretically that the tracking error between the controlled object output and the reference model output can converge to zero when the initial value of the tracking error satisfies a certain condition. Moreover, it is also shown in the case of zero initial tracking errors that the control input signal becomes close to the exact model matching input signal rapidly by setting only one design parameter, and then the input saturation does not occur.