Can I ask why you would want to do this?

You may not have enough information in your dynamic equation to be able to identify the effort and flow variables. Do you know the units and meaning of your input and output variables? Ditto the state variables? There may also be algebraic couplings that you would not be able to see in your dynamic model (eg transformers, gears etc).

If you have the units of your state variables you could identify the energy stores and work out a bond-graph that maps to your equations. 

thank you so much Alessandro Ruggiero

 Dear James Whidborne

thank you so much because of your attention

as matter of fact I wan to Implement Fault detection and Identification on the bond graph of the system to evaluate my result which is gained by implementing Fault detection and Identification on dynamic equation of system

"Do you know the units and meaning of your input and output variables?"

yes I know and variable too