System identification of the two tanks system subjected to WirelessHART delays

Abstract

This paper proposes an integral-based method for parameter identification of the coupled tank model used in level control. The plant uses WirelessHART communication protocol to interact between devices in the system, which has a data update rate of 8 seconds, causing time delay impacting the stability of the control system. Two models are considered. The first model is the simple linear model where the delay from the WirelessHART is assumed to be negligible. The second model extends this first model, and introduces nonlinearity from the WirelessHART delay into the model. Results showed that although the both the linear and non linear models provides a good match to the WirelessHART-affected plant responses, the nonlinear model provides on average a 25% better match than the linear model. This model and method can be used to design a more effective controller to combat the WirelessHART induced delay systems.