The problem of fault diagnosis in technical systems with uncertainties described by linear discrete-time models is studied within the scope of analytical redundancy concept. Solution of the problem assumes the checking redundancy relations existing among system inputs and outputs measured over a finite time window. The non-parametric method is considered to construct redundancy relations involving transformation of initial system model into canonical form with the special properties. An attention is paid to the task of the redundancy relations checking. The obtained results are illustrated for the general electric servoactuator of manipulation robots.