Research On The Applications Of Information Fusion Technology In Unmanned Aerial Vehicle

Numerous sensors which belong to flight control system for unmanned aerial vehicle (UAV) make up a multi-sensor system. Information fusion technology provides forceful methods for comprehensive processing of the multi-sensor information. It is effective for improving the precision and reliability of flight control system to process multi-sensor information by means of information fusion. The aim of this paper is to study the application of information fusion technology on attitude and altitude measurement of UAV. Main research work is as follows.An approach of altitude measurement with high precision and reliability for UAV is presented by using barometric altitude sensor, GPS, accelerometer and attitude information based on the theory of federated filter. An effective method of calculating unbiased vertical acceleration is proposed by using accelerometer and attitude information. The problem of measuring information fusion of sensors with different output frequency is resolved by designing subsystems respectively. Calculation method for initial value is presented based on the theory of information fusion. The re-initialization time after fault isolation of the system is reduced greatly. The method ensures that the system has fast fault restoration characteristic.Attitude determination system uses accelerometer and gyro, when the UAV fly in maneuvering state, accelerometer can't modify the error of gyro drift effectively. Multi-sensor attitude determination system is designed aiming at this problem. Velocity data measured by GPS, strap-down acceleration data and angular rate data are used to build the attitude measurement system described by Euler's angles. The method can evidently estimate the drift error of gyro. The attitude measurement with high precision and reliability can be got and velocity can be modified meanwhile.Simulation study on the altitude and attitude determination system is done through establishing flight simulation model under given flight track passage. Simulation results show that the altitude determination system can give much more accurate estimation than other ones and has good ability of fault detection and restoration, the attitude determination system can alleviate the effect of model uncertainties effectively and output attitude accurately.