Projects
Model Transformation: Hybrid Systems to Temporal Diagnosis Models
Overview
The aim of this project is to overcome the current approach of writing diagnostics code for control systems after the system is designed, which results in significant effort and potential discrepancies between design and diagnosis output. The implementation presented here is an approach for generating diagnostics code from global system models in order to reduce the need to construct multiple models. Using a model-transformation framework we can transform a hybrid-systems (HS) model into a propositional-logic diagnostics model with appropriate transformation rules.
The transformation is realized as a chain of three transformation steps:
- Hybrid2Discrete takes the HS model and a model that defines sets of intervals as input and generates a purely discrete systems model. This discrete abstraction is an “endogenous” model transformation since the target model conforms to the same metamodel as the source model.
- Discrete2DSSD executes an “exogenous” model transformation generating a model that conforms to the diagnosis metamodel. State machines are translated into temporal propositional logic with information regarding probability of failure and observability injected.
- DSSD2SSD unfolds cycles of a directed graph of component interconnectivity into a number of cloned systems with acyclic component interconnectivity. This unfolding is another “endogenous” model transformation.
Tools
In order to create HS models, we are using the CHARON toolkit for modelling and simulation of HS. The metamodel for the HS model, the source of the model transformation, has been developed with respect to the XML grammar of the visual CHARON editor. The toolkit is available on the CHARON homepage.
The generated diagnosis model can be analysed with the reasoning engine of the LYDIA framework for Model-based Diagnosis (MBD). The target metamodel has been developed in order to satisfy the Lydia modelling language. The framework is available from the LYDIA homepage.
Downloads
- A documentation containing figures of the metamodels, graphical illustrations of each transformation step, code examples and instructions for the usage of the provided project: HySys2Diag_201003.pdf
- The current version of the project contains the metamodels, the transformation rules and models for an example: HySys2Diag_201003.zip Please be aware that the sources provided here are still work-in-progress!
- The project has been developed on the openArchitectureWare framework version 4.3.1. Even though oAW has moved to the Eclipse Modelling Framework, the former version is still available from the oAW homepage