An Adjustable Model Reference Adaptive Control for a Time Delay System

Current developments in signal processing tools for hardware and software applications have led to employment of these approaches for vibration control in flexible structures. The main challenge of this method is the delay directly generated from the processing in the closed-loop of the vibration control system. This delay causes considerable degradation of the stability of the dynamic system. This study uses the Smith predictor (SP) of common time delay systems to propose an adjustable model reference, where the delay generated from the signal processing block is compensated for vibration control. The vibration control system based on signal processing is applied on a flexible launch vehicle in which the bending vibration modes are modeled as undesirable sinusoidal signals. The results of a numerical simulation of a linear model of the vehicle with the adjustable model reference adaptive system show that the delay in the closed-loop control system is adequately compensated. This approach allows the use of the signal processing tools for vibration analysis and control without substantial delay.