Automated Air Drop System for Search and Rescue Applications Utilizing Unmanned Aircraft Systems

An Air-Drop payload was originally developed for inclusion into the Lockheed Martin Desert Hawk III unmanned aircraft system for delivering ½ pound of medical supplies to a known GPS location. A dropping algorithm was developed to account for aircraft speed, wind direction and speed, altitude, and other factors to facilitate a very accurate drop to a target. After successfully implementing this payload in a small form-factor with groundbased control, a larger payload was designed and implemented for the Unmanned Aircraft Systems Engineering Lab’s UAV, the Super Hauler. This aircraft was then used in the Australian UAV Outback Search and Rescue Challenge to locate a mannequin stranded in the outback and autonomously drop “life-saving” water to this mannequin. I. Introduction HE University of North Dakota’s Unmanned Aircraft Systems Engineering Lab’s Air-Drop Payload was originally developed for the Lockheed Martin Desert Hawk III unmanned aircraft system (UAS) platform. The objective of the Air-Drop Payload was to autonomously drop a “delivery box” with ½ pound of medical supplies from the hand-launched Desert Hawk III to within 100 feet of a known target GPS ground location. The project concept along with its requirements were suggested by Lockheed Martin as a senior design project for students in electrical and mechanical engineering. A team of four electrical engineering students and four mechanical engineering students chose the Air-Drop Payload as their senior design project. The students were advised by electrical engineering professor Dr. Richard R. Schultz and mechanical engineering professor Dr. William H. Semke with a point of contact at Lockheed Martin. Throughout the course of the project, the mentoring team aided in clarifying design requirements, evaluating design ideas, and addressing safety concerns. The Desert Hawk III (Figure 1) is a small hand-launched unmanned aircraft developed by Lockheed Martin. It is assembled in the field by “snapping together” its major parts. The payload cartridge essentially acts as the central portion of the aircraft, with the motor section connecting to its front, and the tail section connecting to its back. This design allows for quick and easy interchange of payloads. The highly ruggedized aircraft is designed to be retrieved by simply landing on its belly and separating into its individual parts if the landing is rough. Additional requirements were specified that the entire payload, including the delivery box, must weigh less than 1.5 pounds, must survive the hard belly landings performed by the aircraft, and must not cause interference with the aircraft’s GPS-waypoint based navigation or communication systems. A basic solution was proposed with a few key components; First, the airborne system would include software running on a microcomputer that would communicate with a GPS receiver and a ground control system so as to know where the delivery box was to land. Second, the airborne system would then calculate the predicted trajectory of the box and drop at the appropriate time. Third, the payload would not be able to control the flight of the Desert Hawk III; it would simply initiate the drop at the “best time” based upon the aircraft’s trajectory. This system was leveraged to develop a payload that was later used to compete in the Australian UAV Outback Search and Rescue challenge. In this system, a larger payload able to deliver a half-liter of water was needed. The Super Hauler UAS operated by the Unmanned Aircraft Systems Engineering (UASE) Lab was used to fly the larger payload. Drop trajectory calculations for this system were done using a ground-based system and then uploaded to the autopilot of the aircraft. This payload was integrated with the autopilot which allowed controlled flight directly over the drop target.