Developing a fault tolerant power-train control system by integrating design of control and diagnostics

Fault detection, isolation and fault tolerant control are investigated for an spark ignition engine. Fault tolerant control refers to a strategy in which the desired stability and robustness of the control system are guaranteed in the presence of faults. In an attempt to realize fault tolerant control, a methodology for integrated design of control and fault diagnostics is proposed. Specifically, the integrated design of control and diagnostics is achieved by combining the integral sliding mode control methodology and observers with hypothesis testing. Information obtained from integral sliding mode control and from observers with hypothesis testing is utilized so that a fault can be detected, isolated and compensated. As an application example, the air and fuel dynamics of an IC engine are considered. A mean value engine model is developed and implemented in Simulink (R). The air and fuel dynamics of the engine are identified using experimental data. The proposed algorithm for integration of control and diagnostics is then validated using the identified engine model. Copyright (C) 2001 John Wiley & Sons, Ltd.