Research on indoor optical flow navigation algorithm for small quadrotor

This paper proposes a new method based on extended Kalman for the UAV indoor autonomous flight problem, by fusing inertial navigation and optical flow information. In this method, firstly the rotation matrix calculated by double-stage Kalman filter is used to convert the measured value of the inertial module from the body axis system to the north east ground coordinate system. Next, using a new method to compensate optical flow to get a more accurate velocity. Finally using rigid body kinematics principle to establish the state equation of the kinematics model, using the speed of the optical flow and the height of the ultrasonic to establish the observation equation of the kinematics model. The experimental results show the system reduces the speed drift caused by the error of the accelerometer, and also has the capability of short-time indoor navigation.