Graph representations of the multibody systems dynamics models

Using an example of the snakeboard, a vehicle with four wheels and nonholonomic constraints, the process of construction and verification for the spatial dynamical models of the multibody systems is analyzed. Two approaches for the formal representation of the models: object-oriented, and bond graph based are considered. Energy based similarities between these approaches are analyzed.
A description of the bond graph representation for the most general type of constraint is presented. It turned out the resulting total bond graph model of the multibody system dynamics always has exactly a canonical junction structure. This representation has a tight correspondence with our recent object-oriented implementation of the mechanical constraint architecture. As an example Modelica implementation of the joint classes family is investigated. Finally these classes are applied to construct the snakeboard dynamic model.