Research On The Theory And Method Of Attitude Measurement For Spinning Projectile Using Infrared And Geomagnetic Fusion

With the arrival of intelligent weapons era,precision strike capability has become a key factor in modern warfare.In order to achieve precise attack,it is important to measure the projectile flight attitude parameters accurately.Aiming at the intelligent transformation requirements of conventional ammunition,the application of diversification,new-type and low cost integrated navigation system is the inevitable trend of attitude measurement technology development.The attitude measurement method using infrared and geomagnetic fusion possesses several key advantages,it maintains low cost,small size,lacks moving parts,without drift and cumulative error,which is suitable for the attitude information acquisition of projectile.Therefore,the research of attitude measurement method using infrared and geomagnetic fusion has great significance to the precise development of conventional ammunition.It also has a wide range of applications in military,civil and other aspects.The mechanism of the earth infrared radiation field is studied and the attitude measurement model of infrared radiation is built.The error sources of infrared and geomagnetic are analyzed.The researches of compensation method are carried out.An attitude measurement method is designed based on thermopile sensors and magnetic sensors combination.Reasonable configuration and calculating method are discussed.The hardware-in-the-loop device is developed for the experiments,which are carried out to verify the effectiveness of the proposed method.Main research work can be summed up in the following aspects:(1)According to the mechanism of the earth infrared radiation field,the propagation law of infrared radiation in the atmosphere is studied.The 8?14 micron atmospheric window is selected as the research band of infrared radiation.On the basis of the temperature field distribution between the sky and the earth,the variation of infrared radiation on the zenith angle is studied using the atmospheric stratification theory.The measurement model of onboard thermopile sensors is established using Planck blackbody radiation law.A new attitude measurement theory is put forward based on the earth infrared radiation field.(2)The infrared radiation interference characteristics of clouds and mountains are analyzed,and the measurement error model is built using gray body approximation model.The error of attitude measurement caused by cloud and mountain disturbance is studied.Thesignal to noise ratio of the thermopile sensors is compared with different field of view.For the environmental background interference factors,a multi-sensor weighted fusion algorithm based on trust function is proposed,which improves the anti-interference ability of attitude measurement system using infrared radiation.(3)The error sources of geomagnetic field measurement are analyzed,and the measurement error model of magnetic sensor is established based on static interference.Static interference error is compensated using twelve-position calibrating method and recursive least squares algorithm.Aiming at the eddy current interference magnetic field existing in the process of high-speed motion of spinning projectile,a comprehensive error model of geomagnetic measurement is built considering dynamic interference.An artificial bee compensation algorithm based on dynamic search strategy and ellipsoid fit is proposed.The effectiveness and reliability of the proposed compensation methods are verified by the simulations and experiments.(4)Aiming at the attitude Calculation error using conventional infrared attitude measurement algorithm,an optimization algorithm for three-axis thermopile sensors is designed based on the error transfer theory.According to the output of the onboard three-axis magnetic sensor during the flight,a novel attitude measurement algorithm is put forward using the intersection ratio of the sensors.The applicability of the algorithm is further enhanced by heading correction and linear interpolation.The attitude solution mode based on infrared and geomagnetic fusion is built.An adaptive filter switching estimation algorithm is proposed,which enhances the adaptability of attitude detection system to complex environments.The validity and reliability of each algorithm are verified by numerical simulation.(5)Data acquisition system is designed for infrared and geomagnetic signal measurement according to the requirements of the attitude measurement system.The integrated design,the optimal choices of sensors and each sub-module are elaborated.The hardware-in-the-loop device is developed for the experiments,which are carried out using three-axis turntable.The experimental results show that the attitude measurement method using infrared and geomagnetic fusion is feasible and effective.