Model-Based Test Signal Generation for Service Diagnosis of Automotive Systems

A main step in service diagnosis is the selection of dedicated tests for a faulty automotive system in order to decide in which component a fault has occurred. This paper develops a test selection approach that is based on structural models of the system. A structure graph represents the physical couplings of the input, state, and output signals. The test selection method aims at finding operating points in which faults distinguish with respect to their physical input-state-output paths through the components and, thus, can be isolated by steering the system into these operating points. The main ideas are illustrated by a spark ignition engine with the faults of a leakage in the intake manifold and damaged intake valves to be distinguished.