Decision making in nonlinear dynamical system diagnosis by a nonparametric 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.