PD Controller Design with H∞ Performance for Linear Systems with Input Delay

This paper presents H∞ control problem for input-delayed systems. A neutral system approach is considered to the design of PD controller for input delay systems in presence of uncertain time-invariant delay. Using this approach, the resulting closed-loop system turns into a specific time-delay system of neutral type. The significant specification of this neutral system is that its delayed coefficient terms depend on the controller parameters. This condition provides challenging issues in theoretical research and provides new horizons in applications. In the present paper, new delay-dependent sufficient condition is derived for the existence of H∞ controller in terms of matrix inequalities. The resulting H∞ controller stabilizes the closed-loop neutral system and assures that the H∞ performance norm to be less than a prescribed level. An application example is presented to illustrate the effectiveness of the proposed method.