机床动态性能约束下的确定性抛光低中频误差综合控制方法研究

The control of low-spatial and mid-spatial frequency errors (LMFE) for deterministic polishing technology is the frontier issue recently focused by optics manufacturing circle, and the challenging topic awaiting the solution for the application of laser nuclear fusion and astronomic observation. The existing deterministic polishing technology often adopted simplified model to compute the dwell time, insufficiently considering the influence of kinematic performance of machine tool on dwell time, lacking the simultaneous optimization of both low-spatial and mid-spatial frequency errors and the optimization mechanism of the machining parameters. These factors shows the existing methods are incompetent for satisfying the growing demand of high-precision optical manufacturing. For the existing problems, the project studies the relationship among dwell time, feedrate and acceleration of machine tool, and by introducing residual error and figure gradient as optimization goals, establishes the model of computing dwell time based on unitedly controlling LMFE under kinematic constraints of machine tool, including axial velocities and accelerations. And the project explores high-efficient and high-precision method of solving the optimization model. Furthermore, the project studies the optimization strategy of polish parameters based on LMFE control, including the arrangement of removal quantity and the optimization tactic of kinematic constraint boundary. Finally, a methodology of controlling LMFE under kinematic constraints of machine tool is developed, providing a new algorithmic theory and technological way for large-aperture and complicated-trajectory polishing.

确定性抛光工艺的低中频误差(LMFE)控制问题是当前国内外光学制造界聚焦的前沿课题，也是激光核聚变、天文观测等高新技术应用亟待解决的挑战性课题。当前的确定性抛光工艺方法往往采用简化的模型计算驻留时间，未充分考虑机床动态性能约束对驻留时间的影响，没有兼顾中频误差的控制，并缺乏抛光工艺参数的优化机制，难以满足光学制造日益增长的精度要求。本项目针对此问题，研究驻留时间与机床进给速度、加速度的关系，将面形残差和面形梯度作为优化目标，建立机床动态性能约束下（各运动轴速度、加速度）低中频误差综合控制的驻留时间求解模型，探索该模型的高效率、高精度的求解方法。进一步研究基于低中频误差控制的工艺参数优化策略（包括去除量分配、机床运动学约束边界值的优化策略），最终形成一套机床动态性能约束下的低中频误差综合控制工艺方法，为实现大口径、复杂轨迹抛光的低中频误差控制提供一种新的算法理论和工艺技术途径。

确定性抛光工艺的低中频误差(LMFE)控制问题是当前国内外光学制造界聚焦的前沿课题，也是激光核聚变、天文观测等高新技术应用亟待解决的挑战性课题。当前的确定性抛光工艺方法往往采用简化的模型计算驻留时间，未充分考虑机床动态性能约束对驻留时间的影响，没有兼顾中频误差的控制，并缺乏抛光工艺参数的优化机制，难以满足光学制造日益增长的精度要求。本项目针对此问题，研究驻留时间与机床进给速度、加速度的关系，将面形残差和面形梯度作为优化目标，建立机床动态性能约束下低中频误差综合控制的驻留时间求解模型，开发了高效率、高精度的求解方法。进一步研究基于低中频误差控制的工艺参数优化策略（包括去除量分配、机床运动学约束边界值的优化策略），最终形成一套机床动态性能约束下的低中频误差综合控制工艺方法，为实现大口径光学元件低中频误差控制提供一种新的算法理论和工艺技术途径。实验加工一块平面微晶镜，PV从0.135λ收敛为0.01λ，中频PSD1RMS从3.7750nm收敛为1.9268nm，结果显示抛后面形低中频误差同时实现了高效抑制。