Research On Key Technology Of Fault Diagnosis For Complex Mechatronic Equipment

The research on intelligent fault diagnosis for complex mechatronic equipment system is a very active and popular subject to which more and more attention has been paid by both academia and industry. The fault propagation and diagnosis processes are continuous and discrete, viz. they are very difficult to model and analyze. The dissertation focuses on the modeling and simulation of the fault propagation and diagnosis processes for complex mechatronic equipment.The main content and contribution of the dissertation are as follows:1. In order to model fault propagation and diagnosis processes, a new kind of extended Petri net, fuzzy probability Petri nets (FPPN) which integrates high-level Petri nets, fuzzy and probability theory and object-oriented concepts into one modeling frame, is put forward. And the definition, the evolutionary pattern and the conflict mode of FPPN are studied in detail in the dissertation.2. A method suited for solving fault diagnosis problem of complex system is presented, which integrates Lagrangian relaxation and subgradient optimization method to compute the fault set which has the maximal probability to be the fault source. The method avoids the combinatorial explosion, it is efficacious to solve fault diagnosis problem based on FPPN3. Fuzzy probability Petri nets system (FPPNS), which cooperates object-oriented design method into modeling process, is put forward. Embeding objects in Petri net and embeding Petri net in objects combine to structure the models formed by FPPNS, that makes the model are reusable, expandable and emendable.4. A method constructing simulation programme based on complex Petri nets, is put forward. The method constructs an object-oriented emluator, introduces a strategy based on control layer and operation layer, and carries out the structure conversion from Petri nets to simulation programme.5. In order to solve simulation problem of complex Petri nets, a new simulation...