Design For Flight Control Platform And Research On Navigation Algorithm

The micro unmanned aerial vehicle (UAV) has been widely applied in military and civilian due to its advantages of small size and low price. The recent applications of UAV require better ability of position and navigation from UAV, and further research on navigation technology should be made.Firstly, a low cost flight control platform, which integrated ZYNQ-7000 and MEMS sensors,is developed in this paper. The software core is based on a real time operating system on this platform, which can improve the execution efficiency and real-time performance of complex algorithm. Secondly, the algorithm of error compensation is carried out to calibrate the sensors used in this paper, so as to achieve navigation algorithm with higher accuracy. The three-axis gyroscope is calibrated by leaving the gyroscope standing; The three-axis acceleration is calibrated using the six plane calibration method; The three-axis magnetometer is calibrated using ellipsoid fitting and online learning method. Filters are used to reduce the noise of sensors used in this study: mean filter is used to reduce the noise of three-axis gyroscope and three-axis acceleration; sliding window filter is used to reduce the noise caused by the airspeed meter; first order low pass filter is used to the noise caused by the barometer. Finally, this paper focuses on the algorithm of navigation in micro UAV. The algorithm of attitude calculation based on the complementary filtering is applied on the platform. The velocity and the position received from GPS is used to show the performance of the navigation algorithm. The algorithm employs the extended Kalman filter which fuses measurements from the sensors including gyroscope,acceleration, magnetometer, airspeed meter and barometer. The algorithm bears the advantage of high robustness, and if the GPS information is lost, navigation can be still available in this algorithm.The flight experiment of the flight control platform is conducted, and the results show that the navigation algorithm based on extended Kalman filter can provide effective navigation in practice. The task of waypoint tracking is completed successfully under the navigation algorithm,which proves the availability and practicability of this algorithm, and the reliability of the flight control platform designed.