Study On The Influence Of Servo Vibration In Ultra-precision Machining On Formation Of Microlens Array

Microlens array surface is a kind of micro-structured functional surface widely used in optical industrial.It is composed of sub-micron lens array structure.In addition to the basic functions of traditional lens,it also presents special functions that traditional lens does not have,especially with the advantages of light weight,miniaturization and integration.Therefore,microlens array has a wide range of applications in many new optical systems.At present,compared with other machining methods,ultra-precision machining is a deterministic forming method with high precision and high efficiency.However,the theoretical and experimental research on the influence of servo vibration on the formation of microlens array in ultra-precision machining is not enough at present.Therefore,this thesis mainly studied the internal mechanism of slow cutter servo vibration in ultra-precision machining microlens array,and analyzed its influence mechanism on the formation of microlens array.The main contents are as follows:(1)According to the composition of the slow cutter servo system,the moving part and the driving part were analyzed.The mechanical transmission and actuator were simplified into a second-order spring-damping system,and the characteristic equation was obtained through the Laplace transform.Consequently,the relationship between the theoretical displacement and the actual displacement was obtained.The mathematical model of PMLSM in each coordinate system was studied,and the model which could realize the decoupling of each axial component was selected,and the vector control principle was used to ensure the stable operation of the system.The vibration model of the servo system was established by simulation of each part in Simulink environment.(2)According to the forming principle of the microlens array in turning,the calculation method of the tool path of the array surface was presented.In the view of the problem that the traditional compensation method introduced the X-direction high-frequency components,the proposed compensation method could not only ensure the shape accuracy but also reduced the high-frequency components.According to the calculation of the surface residual height,considering the influences of spindle speed,feed speed and tool tip radius on the surface form,a microlens array generation model was obtained in turning.(3)Based on the above model,research on the theoretical path and surface by applying the servo vibration model has been made,and the influence of servo vibration on the formation of microlens was discussed.In the view of the fluctuation and deviation caused by vibration,the corresponding solutions were put forward and verified by using the established model.(4)At the different processing parameters and methods,the slow cutter servo was used to manufacture the microlens array,and the machined morphology was measured.The established servo vibration model was verified by comparing the simulation and the experimental results.By comparing the experimental results of each processing method,the proposed adjustment method was verified.The influence of machining parameters on servo vibration was discussed by comparing the experimental results of each machining parameter.