With the growing range of applications in unmanned aerial vehicles and the push to make a vehicle cheaper and more reliable, it is crucial to develop more effective control algorithms. For the control of an autonomous aerial vehicle it is essential to know the exact position and orientation of the vehicle. This task is performed by navigation systems.
With inertial sensors we can measure the acceleration, angular velocity and the earth magnetic field of the Earth. In addition, we can measure the air pressure by absolute and differential pressure sensors, which enable us to estimate the attitude and velocity of the vehicle. Moreover, the GPS system is able to determine the absolute position of the vehicle.
As MEMS technology has developed, smaller sensors have appeared, which can measure three-dimensional acceleration, angular velocity and earth magnetic field in small packages, and they also include digital interfaces and other digital functions.
This thesis presents the design steps and implementation of a navigation unit, which consists of new digital sensors and a GPS module. The aim was to make a compact module, with small size and consumption, but accurate enough for the control of aerial vehicles. This thesis also describes the main error sources of sensors’ measurements, and provides a low-cost calibration method to reduce these effects.