Accompanying video for the SIGGRAPH 2020 technical paper
"RoboCut: Hot-wire Cutting with Robot-controlled Flexible Rods"
by Simon Duenser, Roi Poranne, Bernhard Thomaszewski, and Stelian Coros.
ACM Transactions on Graphics 39, 4, Article 98 (July 2020).
Link to paper: https://n.ethz.ch/~sduenser/content/papers/robocut/paper.pdf
Computational Robotics Lab: http://crl.ethz.ch/
Hot-wire cutting is a subtractive fabrication technique used to carve foam and similar materials. Conventional machines rely on straight wires and are thus limited to creating piecewise ruled surfaces. In this work, we propose a method that exploits a dual-arm robot setup to actively control the shape of a flexible, heated rod as it cuts through the material. While this setting offers great freedom of shape, using it effectively requires concurrent reasoning about three tightly coupled sub-problems: 1) modeling the way in which the shape of the rod and the surface it sweeps are governed by the robot’s motions; 2) approximating a target shape through a sequence of surfaces swept by the equilibrium shape of an elastic rod; and 3) generating collisionfree motion trajectories that lead the robot to create desired sweeps with the deformable tool. We present a computational framework for robotic hot wire cutting that addresses all three sub-problems in a unified manner. We evaluate our approach on a set of simulated results and physical artefacts generated with our robotic fabrication system.