Determination of coordinate transformations in UAVS

Estimation of vehicle attitude during autonomous flying of Unmanned Aerial Vehicles (UAVs) can be performed with Global Positioning System (GPS). But when vehicle is flying this method results in error, hence another approach i.e., Direction Cosine Matrix (DCM) is used. But while extracting attitude (Euler Angles) of UAVs with DCM creates a drawback known as Gimbal lock which is also known as singularity problem in mathematics. This problem is due to deviation in one of the angles of attitude and leads to loss of degree of freedom. To avoid this problem the proposed technique is quaternion which represents orientation of a body. Quaternion, which is produced from rotation sequence of Euler angles and it implements Euler angles with any one of rotation sequences. This paper deals with the mathematical modelling and implementation of the quaternion in Matlab. Finally results are represented for each orientation in terms of Euler angles due to quaternion. This method is more accurate even body is under motion.