Nowadays the Unmanned Aerial Vehicles became very important for the military. We can use them in many ways in the normal life as well. Thanks to the technical innovations of the last decade, UAV-s are smart enough for difficult missions too. To manage complex tasks the autopilot module has to know the accurate position of the plane.
In my thesis I'm working on an altimeter solution. This instrument is very important for safety landings. The landing process can be the most dangerous part in the UAV's life, so the altimeter has to be accurate and reliable. As a first step I did measurements and developments on a small and relative simple radar altimeter from BHE. This instrument is developed for UAV-s based on a DSPIC microcontroller. Later I developed a new altimeter which works with a LASER distance module, a GPS and a barometric pressure sensor. I did measurements with the sensors and calculated the altitude ranges where these can give accurate altitude data. I tested the barometer and the GPS during a 20km long bike trip. After that we released the LASER module from a 20m high building.
The LASER module can be used below 30 meters during low altitude maneuvers like the automatic landing. Above 20m height the BHE’s radar altimeter is accurate enough. The barometric measurement has the lowest power consumption. With a ground elevation database it can give accurate height data. The measurement ranges of the sensors are overlapped. Finally we can get a low power and accurate altimeter with an adaptive switching strategy between the three measurement methods.