This paper deals with the fault diagnosis of a linear continuous variable dynamical system represented by a discrete state-space model. The proposed fault diagnoser was based on a special Petri net (PN) called continuous-time delay Petri net (CTDPN). According to the theorem presented in this paper, an exact correspondence between discrete state-space equations and fundamental equations of the CTDPN was established. Based on this theorem, a systematic method was proposed for the realization of classical parity equations by a CTDPN that played the role of the fault diagnoser. By integrating the concept of state-space models and PNs in this paper, new and effective methods can be proposed for the analysis and fault diagnosis of hybrid systems. Finally, the performance of the proposed method was investigated for the fault diagnosis of a DC motor. The results demonstrated that, with the help of the proposed PN, fault diagnosis can be performed well and the traditional diagnoser can be replaced with this novel network.
