Implementation of a fault tolerant system for the internal combustion engine's MAF sensor

In this work, we present the design of a fault detection and isolation (FDI) system for the mass air flow (MAF) sensor of an internal combustion (IC) engine based on adaptive observers, which in turn are based on a couple of ordinary differential equations which express the dynamics of the intake temperature and the pressure. Specifically, the observers were designed to estimate the MAF value that enters into the system in order to generate analytical redundancy, i.e. to have two signals of the same variable, one provided by the observers and the other one provided by the sensor. The FDI system allows the uninterrupted operation of the IC engine, after a total failure of the MAF sensor, by switching the faulty signal to the healthy value given by the observers. This healthy value is injected to the engine control unit (ECU). Experimental results show the effectiveness of the proposed system.