Design of nonlinear observers using Popov's criterion
Abstract
Recently there has been an intense activity in designing observers by means ofthe circle criterion. However, it is known that the use of Popov's criterionreduces the conservativeness of stability analysis based on the circlecriterion, if further restrictions are satisfied by the nonlinearity. It isshown in this paper that Popov's criterion can indeed be used with advantadgefor observer design, reducing the restrictions of previous designs. Althoughonly the scalar case will be considered here, it is possible to extend theresults to a multivariable setting.