Abstract:

A new algorithm of quaternion extended Kalman filter was adopted to estimate the attitude of small UAV. After the establishment of the models of quaternion attitude movement and magnetic, angular rate, and gravity sensor measurement, a new designed extended Kalman filter was given with the quaternion and random drifting of gyro being the static vectors and the accelerometer measurements and the heading solved by the magnetometer being the observational vectors. What’s more, an innovation amendment method based on an adaptive approach to construct the measurement noise covariance matrix was designed. Experimental results show that the algorithm not only solves the problems of micro electro mechanical systems inertial sensors used for attitude measurement to show low accuracy and to be easy to diverge and to disturb, but also significantly reduces the effect of random drifting of gyro scope on attitude estimation, and proves to be effective at improving the accuracy of attitude estimation.

Key words: quaternion, extended Kalman filter, attitude estimation, micro electro mechanical systems (MEMS), small UAV