Design And Implementation Of Micro AHRS Based On Adaptive Extended Calman Filter

Due to its advantages of low power consumption,low cost,high concealment and high mobility,micro UAV has been widely applied in military,industrial,commercial fields and agricultural fields in recent years.The attitude angle of unmanned carrier(i.e.,angle of pitch,path angle and roll angle)is the most popular information in the execution task,which has become a hot spot of research.The development of multi-sensor information fusion technology provides a scheme and idea for the fusion of low cost and medium precision MEMS inertial navigation devices and GPS information.This subject is based on the LPC3250 core processor to design the hardware module of the micro navigation attitude system,and on this platform,the navigation filtering algorithm is studied and verified,the main tasks are as follows:(1)In view of the low power consumption,low cost and small size of the unmanned spacecraft cabin,the central processor LPC3250 with the kernel of ARM9 is selected;MEMS inertial navigation is an inertial navigation chip GY953 integrated with three axis accelerometers,magnetometers and gyroscopes;the satellite receiver is BLOX 6M GPS.The underlying circuit and schematic diagram of all kinds of interfaces are designed.After wiring,the PCB bottom plate is obtained,and all kinds of components are installed on the bottom plate,then each functional module is tested and fault detection is done;(2)When the unmanned carrier is disturbed by the gross and abnormal values,a system with slow changing application conditions of robust Calman filter based on M value estimation is proposed.The application of indirect method in attitude calculation is introduced as a whole,the adaptive Calman output value of the theoretical error and the actual error is used to correct the attitude calculation of the gyroscope so as to obtain the optimal solution of the attitude of the unmanned carrier.Unmanned vehicle high maneuver flight,the harmful value exists for the accelerometer and magnetometer derived acceleration,the Doppler velocity solution algorithm for motion compensated acceleration of carrier GPS.(3)The system and measurement equation based on the angle error of navigation attitude are introduced,then,the extended Calman filter,strong tracking adaptive filter,robust Sage-Husa adaptive extended Calman filter,and improved robust Sage-Husa adaptive Calman filter are established.The simulation results show that the improved robust Sage-Husa adaptive Calman filter algorithm has high precision,strong real-time performance and good overall performance.(4)Based on the development environment of ADS1.2,the software of the navigation and attitude system is designed with the idea of modularization.Laboratory static test,outdoor hand hold attitude module dynamic experiment,turntable static and rotational test and turntable running car experiment are carried out to verify the performance of the designed micro attitude heading system,and the experimental results show that the practicality is feasible.