Integral identification of continuous-time delay systems in the presence of unknown initial conditions and disturbances from step tests

In this paper, an integral identification method is proposed for continuous-time delay systems in presence of both unknown initial conditions and static disturbances from a step test. The integration limits are specifically chosen to make the resulting integral equation independent of the unknown initial conditions. This enables identification of the process model from a step test by one-stage least-squares algorithm without any iteration. The proposed identification method is demonstrated through numerical simulation and real time testing.