Redundancy Relations for Fault Diagnosis in Nonlinear Uncertain Time Retarded Systems

The problem of fault diagnosis in nonlinear uncertain time retarded systems is studied within the scope of analytical redundancy concept. Solution of the problem assumes the checking redundancy relations existing among measured system inputs and outputs. A novel method is proposed for constructing redundancy relations on the base of system models described by differential equations whose right-hand side is polynomial. The method involves nonlinear transformation of the initial system model into time delay strict feedback form and, then, its conversion to input-output description. Existing conditions are formulated and designing algorithms are proposed for the model transformation.