SSK: Robotic Pen-Art System for Large, Nonplanar Canvas

We present a semiautonomous robotic pen-drawing system, called SSK, that is capable of creating pen art on a large nonplanar surface. Our robotic system relies on a seven-degree-of-freedom impedance-controlled manipulator with a three-degree-of-freedom holonomic mobile platform. We use a vector-graphics engine to take an artist's pen drawing as input, and we generate Bézier spline curves to be drawn on the given target drawing canvas. Then, our system finds a set of minimal, discrete configurations for the mobile platform to cover the entire canvas surface while considering the reachability of the manipulator. The drawing is split into multiple subdrawings according to the found configurations. Our system replicates the spline drawing on the target surface using impedance control, which enables us to compensate for the uncertainty and incompleteness inherent to canvas-surface representations and various robotic and sensor noises. We demonstrate that our system can create visually pleasing and complicated pen art on large, nonplanar surfaces.