Research On Tool Trajectory Planning And Optical Performance Evaluation Method For Elliptical Vibration Cutting With Optical Free-form Surface

Freeform optics breaks the limitations of rotational symmetric optical surfaces and ha s a wide range of applications and strong versatility.Compared to traditional optical surfac es,freeform optics can achieve more compact and lightweight optical systems while effecti vely improving the optical performance of the system.However,due to its complex shape,manufacturing freeform optics is challenging.Currently,the three-dimensional elliptical vi bration cutting（3D-EVC）is an effective method for machining freeform optics,offering hi gh machining accuracy and efficiency.It has made breakthrough progress in research on to ol path generation algorithms and evaluation of the optical performance of machined surfac es.This paper analyzes and studies tool path generation algorithms,optical performance ev aluation,and optimization of cutting parameters based on these advancements.The main c ontents are as follows:（1）In order to address the inherent drawbacks of the constant-frequency and variable-frequency three-dimensional elliptical vibration cutting tool path generation algorithms for three-dimensional elliptical vibration cutting,this paper proposes a new tool path generatio n algorithm,namely the variable-frequency constant-frequency combination three-dimensi onal elliptical vibration cutting tool path generation algorithm.Through comparative analy sis of these three tool path generation algorithms,it is proven that this algorithm can effecti vely improve the surface quality and optical performance of the machined surface.（2）To overcome the limitations of existing optical performance evaluation methods fo r assessing the optical performance of machined surfaces,this paper establishes an optical r oughness model that includes optical reflection roughness and refraction roughness.The m odel enables the selection of appropriate optical evaluation criteria based on the operating mode of the optical element.The paper also investigates the effects of different cutting par ameters on the optical roughness valueR_a,r,R_a,t and surface roughness valueS_q of the mach ined surface.（3）By utilizing the response surface methodology,mathematical relationships betwee n cutting parameters and both surface roughness and optical reflection roughness of the ma chined surface are established.The reliability and accuracy of the model fitting are demons trated through variance analysis and the construction of normal probability plots for residu als.Perturbation diagrams are employed to evaluate the impact of cutting parameters on su rface roughness and optical roughness,providing a basis for improving the cutting paramet ers.Finally,based on the response surface methodology for multi-objective optimization,t he optimal combination of cutting parameters for three-dimensional elliptical vibration cutt ing is obtained.