Smart Munition Configuration And Drive Based On Multi Degree Of Freedom Ultrasonic Motor

The purpose of this paper is to design a smart munition, the caliber of which is between 20 mm to 120 mm, the inner space of which is not very big and the flying speed of which is between 0.8 and 1.5 Mach number, can satisfy certain aerodynamic control requirements and achieve the effective guidance effect.Based on this purpose, an aerodynamic configuration based on deflection of the warhead was proposed. And the aerodynamic force status and characteristics was also calculated in this paper. The smart munition actuator was designed by choosing a type of pyramid stator as the driving components. Finally, a sample smart munition model was made to finish the test verification. In n this paper, the research content is summarized as follows:Section 1 introduces the concept of smart munition as well as the current research situation both at home and abroad, and at the same time, this paper also introduces the single degree of freedom and the multi degree of freedom ultrasonic motor.Based on the research status of smart munition and ultrasonic motor, the thinking of applying multi degree of freedom ultrasonic motor to smart munition was introduced.In Section 2,ANSYS Fluent software was used for the Computational Fluid Dynamics(CFD) calculation and analysis of smart munition warhead partial. The relationship of lift coefficient and drag coefficient and pitching moment coefficient and the angle of warhead was obtained.In Section 3, a set of the smart ammunition warhead deflection control actuators were designed.Choosing a new pyramid stator as the driving source, concave spherical contact way was designed as contact way between stator and rotor. Using the joint bearing support as arbitrary Angle deflection method,a unique pressure regulating mechanism was designed.Multi-points driving was adopted, which not only reduced driving resistance force, but also multiplied the driving force.In Section 4, characteristics of actuators mechanics were analyzed. The contact between the stator and rotor was assumed as a linear contact spring. According to vibration characteristic, motion conditions and contact conditions of the pyramid stator, the driving moment, driving power, the power loss and drive efficiency of the stator was deduced.In Section 5, wind tunnel experiment was carried out to verify the the control mechanism of smart ammunition. It is concluded that when the projectile warheads deflection, deflection torque was produced and the aerodynamic state of the shell will be changed, therefore according to the mechanism the trajectories of artillery can be adjusted and the goal of guidance can be achieved.The modal experiment and fixed frequency test experiment of pyramid stator was carried out. The debugging experiment the assembled actuator was carried out. The results show that drive scheme is feasible.