A STABILIZATION METHOD FOR NONLINEAR TIME-DELAY SYSTEMS AND ITS DYNAMICS

This paper is concerned with a stabilization method for nonlinear time -delay systems. Generally, hunting will often occur due to the time de lay. Though the Smith method is known to be able to prevent it, there are many difficulties in its application. In this research, a new stab ilization method is proposed, which can prevent hunting and reduce the steady-state error to zero by parameter adjustment. First, the stabil ity analysis of nonlinear time-delay systems is clarified using the ci rcle theorem. Second, in order to analyze the robustness of the new co mpensator, its robust stability condition is derived for such control systems with a time delay and a saturated-type nonlinearity, and the s tability margins under the identified errors of time delay are evaluat ed. Third, the new compensator is directly represented by a form of z transform, and its stabilization and dynamical characteristics are ana lyzed using the root locus method. From these studies, it is verified that the new stabilization method is useful for general nonlinear time -delay control systems.