Research And Design Of Small-scale UAV Attitude Measurement System

Fast and accurate attitude measurement is critical for flight control of small-scale UAVs.With the wide application of small-scale UAVs in military and civilian,the development of attitude measurement technology has received more and more attention.Research and design of attitude measurement system has become a research hotspot in the field of small-scale UAV.Aiming at the practical requirements of small-scale UAV attitude measurement,this paper designs and develops a high-performance attitude measurement system based on researching about key technologies such as MEMS sensor error compensation and attitude estimation algorithm,which provides strong support for the application of small-scale UAV in the future.In this paper,the measurement principle and error characteristics of each MEMS sensor are analyzed firstly.Considering the importance of gyroscope in the attitude measurement,the Allan variance analysis method of gyroscope is studied,and ARMA time series analysis technology is applied to the instrument drift error compensation of it,the experiment proves that the technology has good drift error compensation effect.On this basis,the paper analyzes the principles of attitude estimation algorithm,such as ARIAD,NCF,EKF.The analysis results are obtained: compared with the NCF algorithm,the EKF attitude estimation accuracy is high,but its calculation amount is large,and the real-time performance is poor,which adds burden to the airborne processor.According to the above analysis,this paper proposes the NCF-KF attitude estimation method.The simulation results show that NCF-KF improves the real-time performance of EKF solution by 38% at the cost of 25% accuracy.It realizes the balance between calculation accuracy and real-time.Its comprehensive performance is better than NCF algorithm and EKF algorithm.The attitude measurement system designed in this paper adopts dual CPU architecture,the main processor selects STM32F427-100 module,and the coprocessor uses RK3399 module.In this paper,the hardware selection and debugging of the whole attitude measurement system are introduced in detail.The software system in Keil environment is designed and implemented for STM32F427-100.Besides,the Linux-based software system is designed for RK3399.The attitude measurement system designed in this paper is a high-performance open measurement platform.It can be used in a variety of platforms in addition to small-scale UAVs.At the same time,it is compatible with flight control systems.Not only it can be used as an attitude measurement system alone,but also can assist flight controller performs other tasks.Finally,the verification of the measured data proves that the attitude measurement system is fully functional,and the proposed NCF-KF attitude estimation method can achieve the theoretical expected performance in practical applications.On this basis,the paper points out the shortcomings and improvement ideas in the current design,and makes planning arrangements for the next work.