Design of sliding-mode observers and filters for nonlinear dynamic systems

The problem of state estimation for a class of nonlinear systems with Lipschitz nonlinearities is addressed using sliding-mode estimators. Stability conditions have been found to guarantee convergence if no noise affects the system and the channel equations, and there is non-divergence in the presence of additive bounded disturbances. The design of such estimators is based on the solution of an algebraic Riccati equation that is difficult to solve. A method is presented in order to find a suitable solution that optimizes the performance. Successful simulations have been performed to illustrate the effectiveness of the proposed design method.