project overview

Receiver Drone

Weight: 1068 grams

Tanker Drone

Weight: 3679 grams

Our project was based on a receiver-tanker drone model. The two different drones are shown above. The receiver is smaller and lighter than the tanker in order to enable it landing on the tanker drone. For a detailed explanation of the specific peripherals that we used in each of the drones, view the tutorial.

Receiver Low Battery Alert

The receiver and tanker drones begin their independent flight. The receiver reaches a critical low battery level and indicates to the tanker that it would like to begin the battery switching process. The receiver navigates to the tanker using waypoint navigation.

Waypoint Navigation

  • Tanker determines own GPS coordinates with centimeter-level accuracy using RTK
  • Tanker communicates GPS coordinates to Receiver over WiFi
  • Receiver navigates above Tanker using GPS

After navigating to the tanker and hovering above the landing platform, the receiver will begin the landing algorithm. The controls based algorithm helps land the receiver into the funnels on the tanker.

Landing Control System

  • AprilTag fiducial marker provides x, y, z (linear) and roll, pitch, yaw (rotational) coordinates
  • Receiver uses Pi Cam to collect AprilTag inputs and runs a controls algorithm to land stably on Tanker

Controls Algorithm

  • Hovers over AprilTag using PID controls algorithm
  • Velocity, Position, and the Integral of Position are independently scaled and input into the system
  • Algorithm works on XYZ directions independently
  • Controller inputs emulate an RC system

Once the receiver has landed in the tanker battery switching platform, the battery hot swap process begins.

Battery Hot Swap

7_current_functionality.mp4

Individual Battery Case

Receiver Battery Holder

Tanker Switching Base

The receiver finally takes off from the tanker and is free to resume its regular activity.