Research On Focusing Optimization Method Of Ultrasonic Phased Array Based On Uncertainty

With the rise of femtosecond laser focusing and forming technology for internal pitting of transparent materials,a closed processing method for the internal microstructure of materials has emerged.Ultrasonic phased array focusing can be used for internal processing to solve the problem that the micro-nano structure of non-transparent materials such as ferrous metals is not easy to process.Through the phase modulation technology,the object can be accurately controlled in three-dimensional space for suspension,and then high-intensity focused ultrasound energy is used Various microstructures are formed by pitting inside the object.Improving the focus point energy and levitation accuracy,and exploring a new phased array motion control device are the problems that this article overcomes.The focus accuracy of the ultrasonic phased array will directly affect the position of the suspended object in the sound field,and the array element parameters will also affect the size of the focal spot formed in the focus area and the energy density of the focus.Based on the above-mentioned research background and existing problems,this paper proposes a method for focusing optimization of ultrasonic phased array based on uncertainty.The full text of the research is as follows:The background and the significance of uncertainty research proposed by internal processing.First,analyze the application value of ultrasonic phased array in internal processing and manufacturing technology,then introduce the existing technology of phased array focusing and analyze its research status,and finally introduce the research status of uncertainty in the field of ultrasonic phased array focusing,And put forward the technical route researched in this article and the structure of the paper.The second chapter is the theoretical research on the influence of acoustic levitation and ultrasonic phased array parameters on focusing performance.This chapter first starts from the theory of traveling wave levitation and standing wave levitation,researches and analyzes the feasibility of suspending objects in two acoustic fields,and analyzes and researches the basic theory of ultrasonic radiation force;secondly,it introduces the theory of phased array ultrasonic focusing and analyzes the superimposed interference of sound waves.The phase relationship that needs to be satisfied when the sound pressure amplitude and sound energy density are maximized;the relationship between focusing parameters and the directivity of the sound field is studied,and the best simulation parameters are determined;the feasibility of focusing at any point in the sound field is explored,and the focusing parameters and focus are analyzed.The relationship between spot size and focusing energy density;Finally,the COMSOL Multiphysics module is used to simulate and analyze the relationship between ultrasonic phased array focusing parameters and focusing performance.The third chapter is the research and optimization simulation analysis of the relationship between the uncertainty of the ultrasonic phased array focusing parameters,the focal length and the total uncertainty of the focal spot.According to the one-dimensional phased array mathematical model,through the analysis of focusing parameter beam synthesis,the effect of the distance error and time delay error of the array element on the focusing accuracy of the phased array is studied;the uncertainty synthesis theory is used to study the influence of the uncertainty of each parameter on the system focal length And the total uncertainty of the focal spot,and establish the corresponding numerical relationship;based on the analysis of the uncertainty of the one-dimensional ultrasonic phased array,optimize the design of the phase control and array,and propose a new phase control theory and device model.Chapter four,experimental research on ultrasonic phased array motion control device.Build an optimized phased array motion control experiment platform to study the stability of the device's levitation,positioning accuracy,and levitation ability;use a high-speed camera(CCD)to shoot the movement of particles in suspension,and obtain the position timing diagram of the object.Analyze the accuracy of phase control;use different materials for levitation,and explore the ability of the device to suspend objects after arraying.