Attitude Measurement For Guided Projectile Under High Dynamic Enviroment

Guided projectile is one of the main development directions of the modern army's weapon equipment.With the significant improvement of its hit precision and overall operational effectiveness,barreled guns step into the era of low-cost and precision-strike.The accurate guidance and control of guided projectile is based on the accurate measurement of its attitude and angular velocity..With the increased demand of guided projectile's higher accuracy measurement,this paper studies the basic theory and key technologies of guided projectile attitude measurement under high dynamic environment.The main research contents are as follows:(1)A guided projectile attitude measurement scheme under high dynamic environment is designed.Firstly,the performance requirements of guided projectile attitude measurement system are analyzed,and then the attitude measurement devices are selected and the error calibration method for attitude measurement system is introduced.Meanwhile,the performance of angular rate gyroscope under the influence of high-g environment is analyzed,and then a vibration characteristic analysis method suitable for the bell-shaped vibratory angular rate gyro(BVG)is proposed,which realizes the precision detection of the natural frequency and natural mode of the BVG.(2)The attitude measurement algorithm of guided projectile based on gyro signal reconstruction is studied.On the basis of the high dynamic working environment of guided projectile,the guided projectile's actual motion environment is simplified to an environment where regular precession and the general linear angular velocity maneuvering coexist.After deriving the coning error of guided projectile in this compound environment,the algorithm of direct coning error compensation for vibration gyro signal reconstruction is proposed,and the precision criterion of coning error is established.The simulation and performance evaluations of direct coning error compensation algorithm based on vibration gyro signal reconstruction are carried out.Finally,the attitude measurement algorithm of guided projectile based on the reconstruction of the gyroscope signal is designed and the simulation experiment is carried out,which solves the attitude measurement problems of guided projectile in the high dynamic environment.(3)The attitude calculation algorithm based on the modified zero-crossing method with magnetoresistive sensors is proposed.After analyzing the traditional attitude calculation algorithms with magnetic sensors,an attitude calculation algorithm based on modified zero-crossing method with magnetoresistive sensors is proposed.The attitude calculation algorithm based on the combination of magnetoresistive sensors is studied.Firstly,an attitude calculation algorithm based on modified zero-crossing method with magnetoresistive sensors is proposed.Then,the advantages of the algorithm in terms of launch window range,anti-noise ability and measuring blind spot are compared and analyzed.Finally,the effectiveness of the new method was verified by carrying out attitude measurement simulation experiments.The result of performance comparison analysis shows that the proposed algorithm based on the modified zero-crossing method has certain advantages in measuring the projectile attitude,which can become an option for engineering application.(4)The decoupling algorithm of motion feature around the centroid of the guided projectile is studied.After analyzing decoupling principle of the guided projectile around the centroid,the decoupling algorithm is designed and the measurement methods of roll angular velocity,precession angular velocity and half cone angle are proposed,which lays a foundation for direct coning error compensation based on gyro signal reconstruction.Finally,a Kalman filter based on inertial/magnetoresistive sensors is designed to improve the accuracy and reliability of guided projectile attitude measurement.(5)Verification experiment of attitude measurement algorithm under high dynamic environment is carried out.A guided projectile attitude measurement system is designed and a flight experiment is carried out.The experimental results show that the attitude measurement algorithm proposed in this paper can calculate the projectile's attitude accurately under the environment of high-g and high rotation,where the launch overload along the longitudinal axis of the projectile is more than 15000 g and the maximum angular rate is 6.9r/s.The experimental results prove that the attitude measurement algorithm proposed in this paper can meet the application requirements for guided projectile under high-g and high rotation environment.