Decision Making in Nonlinear Dynamical System Diagnosis by aNonparametric Method

The problem of diagnosing dynamical systems described by models in the form of nonlinear differential equations with unknown coefficients (system parameters) is considered. To solve the problem, a nonparametric diagnostic method is used, which permits one to exclude the influence of unknown coefficients of the equations on the diagnosis results. The essence of the nonparametric method is presented. A new method for making decisions about the presence and type of a fault is proposed. The method takes into account model errors, uncontrolled disturbances, and measurement noise. A distinctive feature of the method is that it involves a complex combination of decision making by threshold logic with the comparison of the error (residual) signal against the fault signatures formed during the diagnosis process.