Design And Experimental Study Of Magnetorheological Fluid Actuator Based On Ultrasonic Near-Field Action

As a research object of military development,guided projectiles not only have the advantages of low cost of traditional shells,but also modify the trajectory of shells to improve the accuracy of shells.The trajectory correction of the guided projectile is realized by the guidance component,and the core principle of the guidance component is the control of the attitude of the steering gear.Based on demand of the speed control of the rudder with fixed wing,a magnetorheological fluid actuator based on the effect of ultrasonic near field was proposed in this paper.When the steering gear is able to control,the output torque generated by the magnetorheological effect control of servo speed and attitude;when the actuator due to aerodynamic induced drag rotation does not need to control,using the inverse pressure ultrasonic traveling wave piezoelectric effect of piezoelectric ceramic disc stator excitation,which can adjust the steering gear to drive torque rotating in the work space magnetorheological fluid,additional damping torque of steering gear to reduce the fluid state of magnetorheological fluid,ensure the free rotation of the steering gear.The main contents of this paper are as follows:1.The research background of guided projectile and the development status at home and abroad are introduced.The working principle of the fixed wing actuators attitude control is pointed out,and the mechanism of ultrasonic near-field interaction and its typical application in non-contact actuator is introduced.2.Based on the working mode and typical structural form of magnetorheological fluid,combined with the working principle of non-contact disk actuators in ultrasonic near-field,a new type of magnetorheological fluid disc actuator based on near-field ultrasonic action was constructed,and its working principle was analyzed.3.For ultrasound near field cored part of stator disk structure dynamics design,analyzes the incentive principle of ultrasonic traveling wave generated by the finite element method based on circular stator modal analysis and harmonic response analysis and structural dynamics of the stator parameters were determined,the process of disc stator frequency swept and fixed frequency experiment,establish the foundation for further testing system.4.The disk type magnetorheological fluid actuator magnetic field,the magnetic actuator arrangement device,a magnetic reluctance by calculation,to determine the structure size of the coil,the actuator static magnetic field simulation analysis of the magnetic actuator to calculate the distribution of magnetic induction intensity and the working gap to verify the accuracy of the disc type magnetic circuit design.5.Processing of a magnetorheological fluid disc type actuator prototype is built for dynamic performance test system,experimental results show that the actuator can achieve step-less speed under different current,i.e.steering attitude control;the measured actuator output torque is small relative to the theoretical value.Besides,the near-field experiment of the optimized actuator shows that the zero field damping moment of actuators can be reduced when the excited disk stator and the motor speed is traveling in the same direction,and the output performance of the magnetorheological fluid of the actuator is better after the near-field ultrasonic action.Finally,the integration scheme of the steering gear attitude control system based on actuator is proposed.