Piezoelectric Bimorph Actuator And Its Applicationin In Attitude Control Of High Speed Spinning Projectile

With the development of military science and technology,Traditional non-guided munitions also need to be upgraded with information and intelligence.Therefore,the intelligentization of conventional ammunition has become a trend.Especially for small-caliber submunitions with high rotation characteristics based on the body-launching platform,due to its short external ballistic time and small available space,its guidance,control design and system integration face technical difficulties different from conventional guided projectiles.The challenge is therefore of great significance in studying a control device that has a higher response,control bandwidth and that maintains a good aerodynamic shape of the high-elastic body.The current general guidance method uses aerodynamic layout of the airfoil adjustment,and encounters insurmountable technical challenges when used for high-rotation ammunition that relies on the gyro stabilization mechanism.In this context,an attitude control system based on variable centroid control and piezoelectric bimorph actuator is proposed,taking advantage of piezoelectric bimorph such as the small size,light weight,high control bandwidth and fast response,for flight attitude adjustment of caliber high-rotation ammunition.Taking the piezoelectric bimorph actuator as the research object,the high-rotation bullet is the application platform,the structure and static and dynamic characteristics of the piezoelectric bimorph and piezoelectric bimorph actuator in the rotating environment,and the integrated attitude model design under the high-rotation platform and the output characteristic verification has carried out detailed analysis and research.The main research contents of this thesis are as follows:(1)Using the analytical mechanics and finite element method to establish the piezoelectric bimorph structure dynamic model of cantilever different conditions in high-rotation environment,combined with numerical analysis and finite element simulation to analyze the output characteristics of piezoelectric bimorph in high-spinning environment.Laid the theoretical foundation for the design of actuators in special environments.(2)According to the application characteristics of high-rotation aircraft(platform),the configuration scheme of the piezoelectric bimorph-based actuator is designed.A piezoelectric bimorph-mass model based on the variable centroid mechanism and a cantilever piezoelectric bimorph rudder based on the post-buckling pre-compression(PBP)principle are proposed.And the theoretical analysis of the output characteristics of the two schemes are carried out,which theoretically verified the influence of the high-rotation environment on the output characteristics of the piezoelectric bimorph actuator,and provides a theoretical basis for the choice of actuators for high-rotation platforms.(3)Establishing the attitude adjustment model of the micro-small high spinning aircraft(such as bullets)and analyzed the aerodynamic mechanism.The attitude adjustment and ballistic control method based on the gyro stability mechanism was proposed.The method didn't change the microsubmunition shapes of pneumatics,its superriority and combining the single-piezoelectric bimorph-mass acutor and the integrated design of attitude system was proposed.The aerodynamic simulation analysis of the high-rotation ammunition in flight was carried out and the high-elastic six-degree-offreedom rigid body dynamics model under variable centroid control was established.And the feasibility of the scheme is preliminarily verified.(4)The experimental platform of the piezoelectric bimorph high-rotation experimental platform and the piezoelectric mechanism based on principle of post-buckling pre-compression was built to verify the correctness of the above model,and the experimental prototype of the high-rotation aircraft principle was prototyped.Basing on the rigid body attitude adjustment and its ballistic correction mechanism,the high-rotation bullets simulated by the three-axis gyroscope platform were tested.The displacement output of the proposed attitude control actuator induced the attitude change effect of the platform,which confirmed the correctness of the theoretical analysis and the feasibility of the scheme.