Closed-loop identification with a quantizer

This paper proposes a new closed-loop identification scheme for a single-input single-output (SISO) control loop based upon a quantizer inserted into the feedback path. The quantizer can be used to generate an equivalent persistently exciting signal to which the well known two-stage method of closed-loop identification can be applied. The paper examines the performance and behaviour of the quantizer-based closed-loop identification and gives suggestions for the choice of quantizer interval. Simulation and experimental examples are used to illustrate the proposed new CLID scheme.