Error Recovery for a Boiler System with OTS PID Controller.

摘要

We have previously presented initial results of a case study which illustrated an approach to engineering protective wrappers as a means of detecting errors or unwanted behavior in systems employing an OTS (Off-the-Shelf) item. The case study used a Simulink model of a steam boiler system together with an OTS PID (Proportional, Integral and Derivative) controller. The protective wrappers are developed for the model of the system in such a way that they allow detection and tolerance of typical errors caused by unavailability of signals, violations of range limitations, and oscillations. In this paper we extend the case study to demonstrate how forward error recovery based on exception handling can be systematically incorporated at the level of the protective wrappers.