Firing speeds estimation for continuous Petri nets

Production frequencies provide useful information for analysis and faults diagnosis of manufacturing systems. However, such frequencies are not always measurable. In this case they can be estimated from the observation of other variables. This work deals with the production frequency estimation for systems that are modelled by continuous Petri nets. The buffers contents are measured online and the production frequency estimation results from the inversion of the Petri net model. The exact and approximated solutions of the estimation problem are described. Accuracy of the estimation is related to the measurement error and to the Petri net structure. When the estimation provides several solutions, results are proposed to complete the Petri net such that a unique solution is obtained