Computational modeling of N-body collisions

This paper presents an impulse-based model for n-body collisions with or without friction. In the frictionless case, impulses at all the contacts, initialized via solution of a non-linear system, accumulate over different phases (compression and restitution) tracked through numerical integration. Experiment over Newton´s cradle, using vision-based velocity estimation, achieves a close agreement with simulation. The presence of friction requires a contact mode analysis via solution of a linear system to check for contact mode consistencies with Coulomb´s friction law. Simulation of nine-ball break shots, drawing upon a recent trajectory study [6], yields realistic scenarios. The modeling approach is part of our efforts toward planning for robotic manipulation strategies using impulsive forces.