The design of reduced-order observer for neutral delay system

For the neutral delay system with meromorphic transfer function, firstly the existence condition of reduced-order observer is analyzed. And the design method of reduced-order observer for neutral delay system is proposed by introducing an auxiliary state model. Secondly, the asymptotic stability of proposed reduced-order observer error equation is proved. And finally, the well-known separation property holds in the state feedback closed-loop system based on the proposed reduced-order observer design, and this proposed reduced-order observer is easy to engineering implement.