ON THE ROLE OF POWER LINES AND CAUSAL PATHS IN BOND GRAPH-BASED MODEL INVERSION

摘要

The bond graph model inversion is based on acausal and causal concepts such as power lines and causal paths. Although the procedure previously proposed by the authors enables most of the problems to be solved, recent works show that new elements are required to clarify the procedure particularly in the case of MIMO systems. First, the modified procedure focuses mainly on the use of the acausal notion of input-output (I/O) power lines since these are easier to determine at a first stage of the inversion procedure than causal paths. The new notion of independent power lines is introduced simplifying the study of the structural invertibility of a system as only sets of independent power lines are now required. Secondly, the association of a set of disjoint causal paths with a set of disjoint power lines is clarified giving the key-elements to determine the right choice of power lines leading to the minimal order inverse model. Finally, the problem of non-solvability of junction structures is investigated in the case of MIMO systems, and new steps are introduced in the inversion procedure in order to determine an explicit inverse model.