Bond graph for the graphical representation of mechatronic systems.

Through the use of the bond graph language coupled with an inverse model approach for the design of mechatronic systems based on dynamic and energy criteria, the methodology developed proposes a design approach that fits into the V-cycle between the product's functional definition phase (concepts) and the geometric definition of the product components to be produced (prototypes). It should enable the designer to use the data in his specifications directly to determine the unknowns in his design problem (dimensions of components meeting the specified dynamic and energy criteria).

An example of the use of the bond graph in the context of direct and inverse modeling briefly reviews the language and shows how it can be used to reconstruct a model input from a given specification output.

The key concepts used by the proposed approach, in particular the notion of structural analysis, enable the designer to test whether his design problem is well posed. This analysis opens up various other levels of analysis, specifying at which level of the physical structure (architecture, phenomena, parameters) the (re)design can take place. To this end, the notions of power line, causal path and bicausality are introduced.

For each proposed design problem, a methodological solution is based on the bond graph language and inverse modelling following the steps :

• validity of the design model ;

• validity of specifications ;

• component specification and selection ;

• to validate the selected component ;

• open-loop control law determination.

This file is not intended to present the basic concepts of the bond graph language, and the reader is invited to refer to the following files:

• "Bond graphs and their application in mechatronics" [S 7 222] ;

• "Using link graphs in power electronics" [D 3 064] ;

• "Bond graph modeling – Basic elements for energetics"