Aerial Observation Platform Jacob Cecil EKU - Dept. of Technology CEN
OUTLINE • Motivation – Previous interest in both aviation and unusual photography, and random searching on eBay. • Problem Statement – Short range battery operated aerial vehicle capable of transmitting live video onto the internet using off-the-shelf technology. • Solution – Build an electrically powered model airplane, a wireless camera and my miniDV camcorder as either storage for broadcast later, or as a real time analog to digital converter for live broadcast onto the internet. • Drawbacks – How is my project limited/how could it be improved. • Similar systems – The U.S. Marine Corps has built and are testing a device similar in concept to mine but much more advanced.
MOTIVATION • Have an interest in aviation/flight. • Within a short time span, I found both the small wireless camera and the plane kit on eBay. The airplane happened to be a model of the real plane I jump from on the weekends, a de Havilland DHC-2 Beaver.
MOTIVATION • I put a plan together to build this plane, originally having a different project in mind for EET499. I was going to build the flying camera just for the fun of it. • I have worked with streaming video before, and thought it would be an exciting prospect to stream live video from the air onto the internet, where it would be visible from anywhere with only a small delay. • I also thought it would add a very useful dimension to the airplane if it were able to lift, then drop small objects.
PROBLEM STATEMENT • The need for aerial surveillance over small areas with the ability to distribute live video from a small craft anywhere in the world, also being able to deliver small payloads to remote areas inaccessible by other means.
PROPOSED SOLUTION • This project was really more of a solution looking for a problem, as I was not seeking to solve a specific problem when I set out to build it. • I built it mainly to see if it could be done, a knowledge for the sake of knowledge type quest. • The fuselage, or body, of the plane was a kit, and only took an afternoon to put together. • The electronics that control the plane were basic elements of robotics called servos, tied to a radio receiver.
How it Works • The radio controller continually transmits an FM radio signal containing a 6 byte string, one byte for each channel of communication available between the controller and receiver. • The receiver interprets the signal and adjusts each servo tied to it according to how the transmitter is telling it to. • The servos are tied to the flight surfaces, and by adjusting them control of the airplane is possible. • To control the speed of the motor, there is a device called an Electronic speed controller that connects to the receiver. It takes the signal from the receiver and instead of adjusting a servo, it translates it into a throttle setting and uses pulse width modulation to spin the motor the desired speed.
How it Works (cont.) FM Receiver Electronic Speed Controller To motor Servos Battery Compartment
The Next Step • As I developed it and observed what it was capable of, I knew my initial goal was accomplished, and I knew it would be capable of more range, better quality video, etc. • This led to more advanced research in areas such as how RF (radio frequency) communication worked, antenna design, how video compression works, and the legality of using different radio frequencies.
RESULTS • The final result is a battery operated aerial observation platform capable of lifting and dropping small payloads that weigh less than 5 ounces that anyone could operate effectively with very little training.
CONCLUSIONS • While my exact plane would be of little practical use for any serious work due to its short flight time and very limited payload capacity, this proves that with parts mostly ordered off eBay this type of craft is possible. • As with anything else, the more money available for the project, the more capable the final result will be. For instance, the camera I used I bought used on eBay for $30. I have seen cameras the same size or smaller that produce much better picture quality and have much farther range, but can cost several hundred or even thousand dollars. • This has been a very educational venture for me. It has promoted me to look up how radio waves are generated and received, basic antenna theory and how to make the most effective antenna, basic and some advanced theory of photography, different forms of rechargeable batteries and the pros and cons of them (such as discharge rate, capacity, weight, etc), FCC regulations on radio communications and how to operate without violating them, video editing and compression techniques, and even some amateur radio theory and principles. • During my research I found information on how to become a licensed amateur radio operator, and realized with the electronics background in the CEN program the test was basically review. Also with an amateur license, it would open up more frequency ranges for future projects. I went ahead and learned International Morse code as well, and am now a licensed amateur radio operator.
Actual Systems • U.S. Marine Corp - Dragon Eye Unmanned Aerial Vehicle • The Dragon Eye UAV is battery-operated and capable of fully autonomous flight. Made of lightweight material, it is designed to disassemble into five separate pieces and is intended to be carried in an individual Marine's pack. Dragon Eye has a 45-inch wingspan once assembled and weighs about five pounds. Missions are programmed via a wireless modem that is integrated into a twelve-pound ground control station. After being hand- or bungee cord-launched, Dragon Eye flies to pre-assigned GPS waypoints and has the ability to be reprogrammed in flight. Its sensors include full motion color, low light and infrared cameras, each capable of transmitting video line-of-sight to a range of ten kilometers. Dragon Eye flies up to speeds of 35 knots and has a battery endurance of one hour. • http://www.jfcom.mil/about/experiments/mc02/concepts/drageye.htm
Demonstration This is a live video feed from the wireless camera. I am using Windows Media Encoder, a free download from Microsoft, to stream the video.