An approach to derivative causality in bond graph models of mechanical systems

✍ Scribed by Dean Karnopp

• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 546 KB
• Volume: 329
• Category: Article
• ISSN: 0016-0032
• DOI: 10.1016/0016-0032(92)90096-y

✦ Synopsis

Dynamic system models involving rigidly coupled inertia elements often result in derivative causality problems when represented in bond graph form. This means that explicit state equations can only be obtained after algebraic manipulation. The problem is particularly severe when geometric nonlinearities are invohed as represented by displacement moduIated transformers. A practical solution is to eliminate the derivative causality by defining an Iheld or an K-field using generalized momenta and (if necessary) generalized coordinates as is done when applying Lagrange's or Hamilton's equations. The inversion of a mass matrix is required. In the worst case, the inversion may have to be done repeatedly during a computer simulation.