Robotics

SandSketch

A robo-zen garden: a quadrotor with a pencil attachment, drawing geometric patterns into a sand table from the air.

CourseCSCI 1952Z, Brown University

TeamChristian Labrador, Kiara Vong, Michael Donoso

Figures3

Robotics

Context

A robo-zen garden: a quadrotor carrying a pencil attachment, drawing geometric patterns into a table of sand from the air. The piece is impermanent by design, since the next pass erases the last one.

My part of the team was the pattern code: working out trajectories that go beyond parametric curves while still being something a drone can actually fly and the medium can actually hold.

Robotics

Method

A sand table lit from beneath through tempered glass, a CAD nib attachment, and a guard around it to stop rotor downwash erasing the line as fast as it is drawn. Downwash shaped everything: it sets how long the nib has to be, which sets the payload, which sets the flight time.

The other constraint is that intricate patterns need slow movement, and slow movement costs battery. How complex a pattern can get is therefore a flight-time question rather than a code question, which is not the trade-off any of us expected going in.

Robotics

Selected results

Drawing — The quad over the table mid-pattern, with the target shape inset. The guard around the nib is there to keep rotor downwash from erasing the line as fast as it is drawn.

Setup — Sand table, lit from below through tempered glass.

Pattern — Trajectories beyond parametric curves: the interesting shapes are the ones a plotter would not choose.

Robotics

The full run

The full run — 6:58 · One uninterrupted pass, from an empty table to a finished pattern. The nib guard and the flight time are both easier to see here than in any still: the line has to be laid faster than the downwash can sweep it away, and the battery decides how intricate the pattern is allowed to get.