Stability of time delay control systems with discontinuous bounded nonlinearities

Most systems using mechanical actuators are subject to discontinuous nonlinearities due to e.g. dry friction; also these nonlinearities are bounded since they account for position and/or rate limitations. All these aspects occur in flight control but not only and are usually accompanied by sliding modes. Time delay is another specific feature in such systems. The paper deals with theoretical aspects of these systems such as the mathematical sense of the solution and asymptotic behavior (boundedness, asymptotic stability). A stability frequency domain inequality of Popov type is given for a special structure of time delay systems which is significant both for theory and applications.