Hollow Ultrasonic Motor And Its Application In Actuator

Faced with the local,sudden and efficient characteristics of modern warfare,the Army has put forward an urgent need for precise attack on traditional artillery operations.Moreover,the traditional shell also needs to be developed in the direction of information and intelligence.Under such background,guided munitions play a crucial role in modern warfare.The guided munitions launched by barrel have its peculiarity including large interior ballistic overload,narrow system space and short trajectory control time,which draws a high demand for the guidance and control system,especially for executing mechanism.Ultrasonic motor has the unique advantages of compact structure,light weight and fast response(millisecond level).It has the potential of shock resistance based on its construction principle,and it also has great advantages in the field of guided projectiles with short control time.Based on this,this paper presents a hollow type of ultrasonic motor and carries out structural dynamics design.The motor can be integrated directly with the driving load mechanism,which can not only eliminates the intermediate transmission components,but also improves the driving efficiency and greatly reduces the quality of components.At the same time,different integration schemes are proposed for low-spin and high-spin guided munitions.A ground platform is built and a series of experiments are carried out.The main contents are as follows:1.The research background and significance are analyzed.The research status of various actuators and ultrasonic motors at home and abroad is elaborated in detail with enumerated relevant application examples.Afterwards,the main research content of this paper is introduced.2.The working principle of the ultrasonic motor is introduced,and the configuration of the hollow ultrasonic motor for guided ammunition is put forward.Besides,the structural dynamics model of the motor stator is established,and the working mode is designed.The integration of the motor rotor and the duck rudder is carried out according to the overall aerodynamic requirements.3.The stator parameters of the hollow ultrasonic motor are optimized to obtain better output performance.The sensitivity of the motor to the impact direction and its failure mode in the shock environment is analyzed with a view to the motor's construction features.And on this basis a better scheme of the hollow ultrasonic motor is proposed.Principle prototype is trial-produced,which makes it possible to carry out the modal experiment of motor stator and the test of mechanical output characteristics.4.In allusion to the specific pneumatic layout and correction principle of low-rotation guided ammunition,the system integration scheme of hollow ultrasonic motor actuator is proposed with the aim to realize the speed control function of duck rudder.A ground test platform is designed and built to simulate the rotation state of low-rotation guided ammunition.The working environment of low-rotation guided ammunition can be simulated and the control ability of hollow ultrasonic motor actuator to duck rudder attitude can be tested.5.In view of the problems of ultrasonic motor like low output speed and nearly unobtainable speed control of the duck rudder on the high-spinning projectile,a unique two-stage spin reduction scheme and two corresponding actuators are proposed.The overall spin reduction dynamics model of the high-spinning projectile rudder system is established.The speed control characteristics of the hollow ultrasonic motor are analyzed and the experimental verification platform of the above-mentioned scheme is built.The integration and preliminary validation of the steering gear speed control system for high rotation guided ammunition have been initially completed.