Semialgebraic Regularization of Kinematic Loop Constraints in Multibody System Models

摘要: Redundant constraints in multibody system (MBS) models, reflected by a singular constraint Jacobian, impair the efficient dynamics simulation. In particular, kinematic loop are often found to be permanently redundant. This problem is commonly attacked numerically decomposing Jacobian either at every simulation time step or beforehand an admissible assembly (assuming that redundancy permanent). paper presents method for elimination of redundant cloture constraints, which, instead relies on geometric characterization loops comprising lower pairs. invariant vector space velocities taken into account, which can determined as sum Lie (screw) algebras two sub-chains loop. The actual reduction achieved restricting this space. presented does not interfere with generation but considered preprocessing MBS models. It robust and only uses geometrically exact model. able completely eliminate "nonparadoxical" single-loop mechanisms applies conservatively multiloop MBS. requires information (vectors, matrices) readily available any package. numerical operations involved cross products value decomposition low dimensional matrix.