Research On Multi Sensor Integrated Navigation Technology Based On Optical Flow

In recent years,quadrotor has been an important research field.Precise navigation is one of the key technologies of quadrotor.Typical navigation systems are GPS and INS.Although GPS positioning is accurate,it cannot be used indoors.Therefore,high precision navigation without GPS has a great impact on quadrotor.Since single INS cannot guarantee the accuracy of navigation when it works for a long time,a multi-sensor integrated navigation algorithm based on optical flow is designed in this paper,and its effectiveness has been verified by quadrotor.Firstly,LK pyramid optical flow method based on FAST feature point is proposed.Fast is a fast feature point detection algorithm.LK pyramid optical flow method is used to solve large displacement,and subpixel is used to improve the accuracy.The effectiveness of this algorithm is tested by an experiment of a moving ball.Secondly,the autonomous navigation algorithm of multi-sensor assisted optical flow is studied.Since optical flow is the velocity of pixels,the mathematical model between the image optical flow field and the carrier motion field is established by gyroscope and ultrasonic.The navigation information of the carrier is calculated through the transformation matrix.Compared with inertial navigation,the validity of this algorithm is verified by the hover and waypoint flight experiments of quadrotor.Thirdly,the attitude estimation algorithm based on MARG sensors and the multi-sensor integrated navigation algorithm based on optical flow are designed.The attitude is estimated by quaternion increment of acceleration and SFAD analysis method.Using the weighted values between optical flow autonomous navigation and inertial navigation,the position is estimated by kalman.The accuracy of MARG attitude estimation algorithm and integrated navigation algorithm are verified by simulation experiments respectively.Finally,the effectiveness of the multi-sensor integrated navigation algorithm based on optical flow is verified by quadrotor.The waypoint flight experiment shows that this algorithm has a certain reference value for navigation in the absence of GPS.