PALAPA-707: An Autonomous VTOL Drone for the Indonesia Flying Robot Contest 2018

PALAPA-707 was the Universitas Indonesia entry to the Indonesia Flying Robot Contest 2018, competing in the Vertical Take-Off and Landing category. The contest required the vehicle to complete three objectives autonomously:

1. drop a pre-loaded payload at a designated location;
2. pick up an additional payload; and
3. drop the retrieved payload at a second location.

The final two objectives carried the largest share of the points, the first being comparatively straightforward. The rules also constrained the airframe dimensions, total weight, and battery capacity.

The control stack was deliberately simple: a PID controller for flight control, paired with colour and shape detection from the onboard camera for target acquisition.

The principal difficulty was not algorithmic but mechanical. Barometer and GPS readings proved unreliable, largely a consequence of low-cost hardware. As a team of undergraduates with limited hardware experience, we converged on a working design empirically, iterating through several payload actuation mechanisms — a plain magnet, an electromagnet, and a claw-style gripper — before settling on a flap mechanism, shown in the first clip below on its first successful run.

The flap mechanism remained imperfect. Numerous attempts prior to it ended in crashes, and failures persisted afterwards; the clip below records one such case.

The contest was held in Kota Baru, Lampung Province, where each team was given two attempts. Two conditions we had not anticipated proved decisive. First, the competition field was not level as specified, which degraded the shape-detection system's ability to localise the targets — in the trial below, the drone fails to detect the second payload.

Second, the flap mechanism left the airframe somewhat unstable, and all of our testing had been conducted on campus under calm conditions. Our first attempt fell in a window of considerably harsher wind, which the vehicle was never tuned for. We flew it regardless and damaged the airframe substantially — leaving a great deal of repair work between the two attempts.

Only two teams completed the final two missions, and PALAPA-707 was one of them; the other took first place overall. We finished with an Honorable Mention — a result the team remains proud of, given the constraints we worked under.