Design And Driving Control Method Of Standing Wave Suspension System With Concave Spherical Ultrasonic Array

In the field of container-free processing,ultrasonic standing wave suspension is widely used because of its good stability and strong anti-interference ability because of the acoustic radiation force generated by high standing wave field.Because the traditional stationary suspension device is composed of transmitter and reflector,the suspension target is limited to static state,which greatly limits the mobility of standing wave suspension,and due to the irregularity of the reflector material,Viscosity and heat conduction can cause the scattering and attenuation of ultrasonic wave and restrain the stability of standing wave sound field.At the same time,the introduction of temperature field in the container-free treatment will lead to the instability of the suspension target,which seriously affects the feasibility of the experiment.therefore,The research on a new type of ultrasonic standing wave levitation device and the stability control method of the suspended target under the temperature change is the focus of the research in the field of container-free processing to realize the moving of the suspended target and the levitation stability of the acoustic field of the standing wave.In this paper,the design and driving control method of standing wave suspension system with concave spherical ultrasonic array are studied.The concrete work is as follows:1.According to the characteristics of standing wave acoustic field,the acoustic pressure,radiation force and time average potential of acoustic field are analyzed.On the basis of this theory,the influence factors of temperature on suspension stability are discussed.The influence of temperature on the medium and the influence of temperature on the velocity of sound propagation are described.The variation of temperature and acoustic radiation force is analyzed.2.The working frequency,number,spacing and size of ultrasonic phased array are analyzed.The dynamic focusing of ultrasonic phased array is studied,the delay calculation method of phased array is derived,and the time delay and focusing position of plane and concave spherical array are simulated and verified respectively.3.The ultrasonic array suspension system is designed.The structure design and optimization of the planar ultrasonic array and the concave spherical ultrasonic array areanalyzed from the array structure.By analyzing the suspension ability and the ultrasonic coacervation performance of the two arrays,the performance of the concave spherical area array is obviously superior to that of the plane,so the concave spherical surface is selected as the structure of the ultrasonic array in this paper.And then the hardware part and the software part of the electric control part are designed.The suspension ability and dynamic manipulation of the suspension system were simulated and the experimental verification was carried out.4.The stability of suspended objects in the sound field is studied.The main research includes the changes of the sound field and the vibration amplitude of the suspended objects.First,the relation between the vibration frequency and the temperature change of the suspended object is analyzed,and the relation curve is drawn.Secondly,the simulation model of sound field and temperature field is established by comsol,and the curves of sound pressure and temperature change under different temperatures are simulated.The stability of suspended object under normal temperature was studied,and the stability of suspended object under normal temperature was studied.5.The control strategy based on fuzzy PID is put forward for the problem that the temperature in the sound field influences the stability of the suspended objects.In order to control the influence of temperature on the stability of the suspended objects,a nonlinear transfer function of temperature is established,the fuzzy PID is designed as a controller,the membership function and the fuzzy rule are established,and a stable control system of the suspended object based on the fuzzy PID algorithm is set up,The control effect under the temperature change is simulated.It can be seen from the simulation results that the fuzzy algorithm can realize the stability control of the suspension target well and has good robustness.