Abstract
This paper presents a new method, based on the Penalty-Augmented Lagrangian Formulation, that allows for the integration of the equations of motion of constrained multibody systems in descriptor form. The number of equations being solved is equal to the number of states, hence is independent of the number of constraint conditions, and therefore, it is particularly suitable for systems with redundant constraints, singular configurations or topology changes. The major advantage of the new method relies on the fact that for a low computational cost, the constraints in positions, velocities and accelerations are satisfied to machine precision during the integration process. This process is done efficiently through a mass orthogonal projection without the need for coordinate partitioning or reduction to a minimum set of coordinates. The improvement allows for a more accurate and robust integration since the constraint violations constitute one of the primary sources of numerical errors and instabilities during the integration process.
