Study On The Motion Posture Of Small Caliber Antiaircraft Projectile In Automatic Mechanism

Small caliber antiaircraft gun is still playing an important role in the field of air defense because of its good flexibility,high firing rate,fierce firepower,low cost and strong antijamming ability.However,in the use of small caliber antiaircraft gun,there are some accidents such as cartridge jamming and even bore explosion.By studying the attitude of small caliber antiaircraft projectile in the process of ammunition transportation and firing in the automata,we can not only detect or predict the failure of small caliber antiaircraft gun,but also provide the basis for the design and improvement of automata.In this paper,the basic algorithm of attitude detection is combined with storage test technology in weapon test.Aiming at the test difficulties of 57 mm small caliber antiaircraft gun in the process of ammunition delivery and firing,such as narrow test space,large overload and difficult signal transmission,a small missile borne Attitude Test System Based on inertial measurement unit composed of three-axis acceleration sensor and three-axis gyroscope is designed.The specific work is as follows:(1)This paper introduces the calculation principle of velocity,displacement and attitude of the measurement unit based on the combination of three-axis acceleration sensor and three-axis gyroscope.The advantages and disadvantages of Euler angle,direction cosine and quaternion are analyzed and compared.Quaternion is selected as the solution algorithm and combined with fourth-order Runge-Kutta method to solve the velocity,displacement and attitude of missile.(2)According to the characteristics of automatic test environment and measured parameters,the overall scheme of miniaturized missile attitude test system is designed.According to the design scheme,the mechanical structure and hardware circuit of the miniaturized attitude test system are designed.Aiming at the characteristics of overload and high speed of projectile,the error of measurement unit is analyzed and the calibration compensation model is established.(3)Finally,the test bomb is tested in the anti-aircraft gun.The obtained three-axis acceleration signal and three-axis angular velocity signal are analyzed in detail,and the velocity,displacement and attitude of the projectile in the process of projectile transportation are calculated.During the test,it is found that the measured data will diverge when using a large range sensor to solve the attitude in a high overload test environment.After using EMD detrended term algorithm,the accuracy of final point position is improved obviously,and the curves of attitude,velocity and position are more reasonable,which verifies the reliability of the test system.