Tethered flight control of a small quadrotor robot for stippling

We investigate tethered flight of a small quadrotor robot in the context of creating stippled prints. At a low level, we use motion capture to measure the position of the robot and the canvas, and a robust control algorithm to command the robot to fly to different stipple positions to make contact with the canvas using an ink soaked sponge. With the objective of fully autonomous flight, we power our quadrotor using a wired tether. We compensate for the tether in our control of the robot by assuming a static catenary curve of fixed length between the robot and the power source, and model the forces and torques produced. We evaluate accuracy of hovering and flight on simple paths, and compare the results to untethered flight.