Ever seen a bit of graffiti in a strange location and wondered how the graffiti artist got up there? It might have been a drone rather than an athletic teen. Disney research has just published an interesting research paper that describes the PaintCopter: an autonomous drone fitted with a can of spray paint on a pan-tilt arm. It’s more than just sticking a paint can on a stick, though: they built a system that can scan a 3D surface then calculate how to paint a design on it, and then do it autonomously. The idea is that they want to use this to paint difficult-to-reach bits of theme parks, or to add seasonal decorations without sending someone up a ladder.
The PaintCopter is built from a DJI M100, with an Nvidia TX2 and Intel UP processor boards added to give it some more processing power. The paint can is fitted to a pan-tilt arm that can trigger the paint can with a servo. The surface is scanned using an Intel R200 RGBD (Red, Green Blue Depth) camera, which feeds data back to a base station, which then builds a 3D model of the target. The base station then calculates the path and orientation for the drone to paint the required design onto the surface, which is then passed to the drone for the actual painting. The examples that the team produced are simple but show that the technique can be quite effective at mapping the design onto a complex 3D surface. It only works with one color at the moment, but authors suggest that creating paint gradients and other more complex techniques are on the way.