Robotic Cutting: Mechanics and Control of Knife Motion

Effectiveness of cutting is measured by the ability to achieve a desired rate of material fracture. The work performed by a knife overcomes the material toughness to yield fracture, acts against friction between the material and the blade, and generates shape deformation. This paper studies how to control a robotic arm to achieve a desired time profile of material fracture along a prescribed cutting path. Based on fracture mechanics and inverse kinematics, this profile is transformed into a time trajectory of the arm, which is then realized using a PID control law that performs cutting while maintaining the knife’s orientation. Experiments, based on modeling and force sensing, respectively, were conducted.