A Convex Formulation of Compliant Contact between Filaments and Rigid Bodies
Wei-Chen Li, Glen Chou
AI summary
Problem
Existing simulators struggle to accurately model frictional contact between slender deformable filaments and rigid bodies, often relying on simplified point contacts or computationally expensive methods that fail to prevent interpenetration or capture realistic compliance.
Approach
The method combines discrete elastic rod mechanics with a pressure field patch contact model and a convex solver to compute stable, globally optimal contact impulses at each time step.
Key results
- Extended convex contact solver to slender deformable filaments
- Adapted pressure field patch contact for distributed lateral compliance
- Accurately simulated knot tightening and shoelace tying with stable friction
- Validated against capstan effect benchmarks and soft robotics applications
Why it matters
Enables reliable simulation and control design for soft robotics and deformable object manipulation where accurate frictional contact is critical.
Abstract
We present a computational framework for simu- lating filaments interacting with rigid bodies through contact. Filaments are challenging to simulate due to their codimen- sionality, i.e., they are one-dimensional structures embedded in three-dimensional space. Existing methods often assume that filaments remain permanently attached to rigid bodies. Our framework unifies discrete elastic rod (DER) modeling, a pressure field patch contact model, and a convex contact formulation to accurately simulate frictional interactions be- tween slender filaments and rigid bodies – capabilities not previously achievable. Owing to the convex formulation of contact, each time step can be solved to global optimality, guaranteeing complementarity between contact velocity and impulse. We validate the framework by assessing the accuracy of frictional forces and comparing its physical fidelity against baseline methods. Finally, we demonstrate its applicability in both soft robotics, such as a stochastic filament-based gripper, and deformable object manipulation, such as shoelace tying, providing a versatile simulator for systems involving complex filament-filament and filament-rigid body interactions.