New-Type Numerical Control System Of Aspheric Ultra-Precision Machining

For its unparalleled optical properties, aspheric optical parts are obviously used in many fields such as military affairs, astronaviation, aviation, nuclear energy, chronometer and some important civil industry fields. Especially in the modern national defense industry, along with the development of model weapons, the use of aspheric optical parts will be more and more extensive, with even bigger size and higher surface quality and face accuracy. But the domestic ultra-precision machining of aspheric surface, especially the large-scale aspheric surface, is just the same as blank, which has no systemic research. Therefore, it has been the imperative development trends that, according to the domestic existing technology level, breaking through the existing craft, exploiting new aspheric optical parts processing method with high precision and developing the relevant ultra-precision machine.This subject aims to develop a relative self-contained Numerical Control system of large-scale aspheric optical parts ultra-precision machining device, in order to realize the low cost and high efficiency of aspheric surface machining and content the needs of accuracy and surface roughness. This paper first researched the general situation of domestic and abroad developments in the field of ultra-precision aspheric surface machining technology and its Numerical Control system, analyzed the aspheric surface machining principle of ultra-precision machine, and in these bases, founded the kinematics model of ultra-precision machine in ideal condition using the homogeneous coordinate conversion method in robotics. By analyzing the kinematics errors of the ultra-precision machine, an error compensation model was given in this paper. In order to realize the machining of optical aspheric surface, a long stroke ultra-precision moving control system was overall designed, in which the step-serve motor and piezoelectric ceramic micro positioner were used separately to first positioning (glancing positioning ) and error compensation second positioning (precise positioning) which realized the long stroke ultra-precision moving control system. Using the parallel string non-circular curve interpolation arithmetic that based on the optical universal equation, this paper firstly empoldered the Numerical...