This paper proposes a relay-based performance-improving method for servo mechanism systems. The method first utilizes a relay-based feedback technique to identify the model parameters and the Coulomb friction value. Then, based on the identified results, a control algorithm, which consists of a feedforward controller, a time-delay compensator and a sliding mode controller, is designed. The feedforward control-ler and the time-delay compensator are used to compensate the syst...