The Trajectory Planning Of Ultrasonic Ultra-precision Polishing For Optical Complex Surfaces

As the core component of the photoelectric and communication industry,the optical complex curved surface component has become one of the marks to measure the modernization level of a national optical industry and even the whole manufacturing industry.However,with the wide application of optical curved surface elements,the requirements of machining accuracy and surface quality are becoming higher and higher.Besides,the special geometric characteristics of optical complex surfaces.make it difficult to process.Polishing process,as the last process in the process of optical surface machining,plays a vital role in ensuring the quality and service life of the curved surface.The manual polishing and automatic polishing are ways of polishing for the processing of optical surfaces.However,the manual polishing is time-consuming,laborious,and it depends on the polishing technology experience of workers,so the surface quality of the workpiece is hard to control,What’s more,the automatic polishing technology is still not mature and can’t fully meet the processing requirements.Therefore,the self-designed five-axis NC ultrasonic polishing machine for optical complex curved surface polishing can solve the problems of manual polishing and ensure safety of the operator in this paper.What’s more,it can finish multi-faceted machining in one clamping conditions,in order to avoid more the errors caused by repeated clamping.Moreover,the ultrasonic vibration can make the abrasive mixture more uniform and reduce the agglomeration phenomenon,so that a large number of ejected particles impact the workpiece in a high frequency reciprocating manner,which improve the machining accuracy and the processing efficiency of complex surface.In addition,the machine tool can adjust the posture of the polishing head conveniently,avoid the interference and collision between the machine tool,the fixture and the polishing head,and avoid the occurrence of over-cutting and residual phenomenon,which is more conducive to the high efficiency and high quality machining of the complex curved surface.In the NC Polishing of optical complex surfaces,the polishing trajectory planning is the key to realize the polishing automation.And the polishing trajectory directly affects the machining efficiency and final surface quality of the curved surface.Therefore,it is necessary to finish the polishing path planning of the optical complex surface.This paper did some research work in the polishing trajectory planning for optical complex curved surface,which mainly includes the following aspects:(1)The ultrasonic vibration assisted polishing of optical glass lens is the research object.And the material removal rate model of single and multiple abrasive particles was established through considering the particle size,polishing head rotation speed,feed speed and ultrasonic amplitude.The experiment proved the feasibility of the model.And this model provides the theoretical basis for the rational polishing trajectory planning of optical complex surface.(2)By selecting the polishing head,calculating the processing step and row spacing,and using the method of equal parameters,residual height and spiral,the Matlab software is used to accomplish the polishing trajectory planning of the complex curved surface.In the process of complex surface polishing,the trajectory of the contact point and the path of moving position of the polished head are generated.Through the trajectory length,continuity,consistency and other reference standards,the polishing trajectory is evaluated.(3)The UG software is used to model the optical complex surface and generate NC polishing trajectory.Based on the kinematics of the five-axis NC polishing machine,the postprocessor was built,and finally the NC machine tool can recognize the processed NC code.(4)By adding components of five-axis NC polishing machine to the Vericut software,the polishing machine was reconstructed.And the software created processing tool,imported the generated NC code and set the relevant system parameters for simulation of complex surfaces in full true and real form.Furthermore,it can check the collision,over-cutting and processing residues situation in the polishing process.