Passive Model Reduction and Switching for Fast Soft Object Simulation with Intermittent Contacts

Abstract

We propose a novel fast simulation framework for soft objects/robots with intermittent contacts, whose contact areas/locations can be varying. We first perform a balanced model reduction of the full-order FEM (finite element method) model for each contact mode with the contact forcing as the input and the shape of the object/robot as the output. We then devise the strategy of passive model reduction and passive model switching of these reduced-order models (each with its contact mode) utilizing the techniques of our recently-proposed passive mid-point integration (for the passivity of each reduced-order model) and simultaneous diagonalization (for the passivity of model reduction and model switching). The efficacy of the theory is then demonstrated with simulation and experimental results.