Continuous-time adaptive observer for linear system with unknown time delay

Although many objectives involving time-delay systems exist, the time-delay systems are often dealt with as finite dimensional systems by using Pade approximation, etc. The paper presents a design of a continuous-time adaptive observer for a linear system with unknown time delay without using such an approximation. To our best knowledge, no research result of an adaptive observer for an unknown time-delay system designed without the approximations has been previously proposed