Dealing with the Constraints in Multibody Systems Dynamics

In this paper, an iterative method is presented for handling the constraints in multibody systems. Using this method, a constrained multibody system is treated as a group of free bodies moving under the constraint forces as well as external driving forces. Therefore the representation of system dynamics is very simple. A convergent iteration process is proposed for computing the constraint forces. This process can be deduced from Gauss Principle of Least Constraint. It not only minimizes the constraint forces in the sense of LSQ, but also vanishes system constraint error. Hence the motion obtained must be the actual one, and the stabilization of constraints is achieved in a fairly natural way.