Collision handling with elastic response calculation and zero-crossing functions

The prototype Modia3D is used to test and evaluate ideas for modeling and simulating larger and more complex 3-dimensional systems than it is possible with a pure equation-based modeling system such as current Modelica. Collision handling in Modia3D is performed on convex geometries with elastic response calculation using an improved formulation of the contact forces and torques. The computed penetration depths and Euclidean distances are utilized in a novel way as zero-crossing functions. The resulting differential algebraic equations are solved with a variable-step solver.