Stability analysis of nonlinear parametric and coulomb control systems

Stability analysis of nonlinear control systems using Lypunov's direct method is reported in this paper. A general nonlinear controlled system and two different types of controllers are examined for stability analysis. The first category is the parametric controller. Importance of parametric controllers is illustrated through examples of various engineering systems. A general control algorithm is derived, and stability of the closed-loop system is examined. Stability under small external disturbances is also examined. The second category of controllers examined in this paper is the Coulomb-type controllers. Stability analysis is performed using Lypunov's direct method. Stability under a general forcing excitation is examined for linear systems with Coulomb controllers.