Journal ArticleDOI
Robust linear equation dwell time model compatible with large scale discrete surface error matrix.
Reads0
Chats0
TLDR
This study solves this ill-posed equation by Tikhonov regularization and the least square QR decomposition (LSQR) method, and automatically determines an optional interval and a typical value for the damped factor of regularization, which are dependent on the peak removal rate of tool influence functions.Abstract:
The linear equation dwell time model can translate the 2D convolution process of material removal during subaperture polishing into a more intuitional expression, and may provide relatively fast and reliable results. However, the accurate solution of this ill-posed equation is not so easy, and its practicability for a large scale surface error matrix is still limited. This study first solves this ill-posed equation by Tikhonov regularization and the least square QR decomposition (LSQR) method, and automatically determines an optional interval and a typical value for the damped factor of regularization, which are dependent on the peak removal rate of tool influence functions. Then, a constrained LSQR method is presented to increase the robustness of the damped factor, which can provide more consistent dwell time maps than traditional LSQR. Finally, a matrix segmentation and stitching method is used to cope with large scale surface error matrices. Using these proposed methods, the linear equation model becomes more reliable and efficient in practical engineering.read more
Citations
More filters
Journal ArticleDOI
Region adaptive scheduling for time-dependent processes with optimal use of machine dynamics
TL;DR: Gaussian mixture model (GMM) is proposed to model experimental tool influence functions (TIF) and this leads to a general analytical convolution model integrating processing depth, volumetric removal rate of TIF, path spacing and feedrate, suitable for any kind of smooth time-dependent processing beam.
Journal ArticleDOI
Theoretical Study of Path Adaptability Based on Surface Form Error Distribution in Fluid Jet Polishing
TL;DR: In this paper, a variable pitch path self-planning strategy based on the distribution of surface form error is proposed to optimize the residual error distribution, where the influence of different bulk material removal depths on residual error is compensated by fine adjustment of the path spacing according to the obtained path spacing optimization models.
Journal ArticleDOI
Zernike mapping of optimum dwell time in deterministic fabrication of freeform optics.
Wu-Le Zhu,Anthony Beaucamp +1 more
TL;DR: A new method based on Zernike decomposition and improved differential evolution optimization of the dwell time map is proposed, which can be applied to time-dependent optics fabrication processes such as fluid jet machining.
Journal ArticleDOI
Universal dwell time optimization for deterministic optics fabrication.
Tianyi Wang,Lei Huang,Matthew Vescovi,Dennis Kuhne,Yi Zhu,Vipender Singh Negi,Zili Zhang,Chunjin Wang,Xiaolong Ke,Heejoo Choi,Weslin C. Pullen,Daewook Kim,Qian Kemao,Kashmira Nakhoda,Nathalie Bouet,Mourad Idir +15 more
TL;DR: In this paper, the authors proposed a novel Universal Dwell time Optimization (UDO) model that universally satisfies the criteria of non-negative, non-overlapping, flexible parameter tuning, and reasonable computational cost.
Journal ArticleDOI
Dwell Time Algorithm Based on Bounded Constrained Least Squares Under Dynamic Performance Constraints of Machine Tool in Deterministic Optical Finishing
TL;DR: A dwell time algorithm, based on bounded constrained least-squares (BCLS) under dynamic performance constraints of the machine tool, has been developed and will give a very high convergence accuracy for optical finishing with machine tools with different dynamic performances.
References
More filters
Journal ArticleDOI
LSQR: An Algorithm for Sparse Linear Equations and Sparse Least Squares
TL;DR: Numerical tests are described comparing I~QR with several other conjugate-gradient algorithms, indicating that I ~QR is the most reliable algorithm when A is ill-conditioned.
Journal ArticleDOI
The ‘Precessions’ tooling for polishing and figuring flat, spherical and aspheric surfaces
David Walker,David J. Brooks,Andrew J. King,Richard R. Freeman,R. Morton,Gerry McCavana,Sug Whan Kim +6 more
TL;DR: The need for aspherics is summarized, some aspheric technologies are reviewed, and a 'wish-list' of attributes for an asPheric process is distill.
Journal ArticleDOI
Optimization of computer controlled polishing.
TL;DR: In this article, a computer controlled polisher is used for fast figuring of aspheric surfaces for lightweighted workpieces using a small, rotating tool which travels over the workpiece surface.
Journal ArticleDOI
Progress Update in Magnetorheological Finishing
William Kordonski,Don Golini +1 more
TL;DR: In magnetorheological finishing (MRF), magnetically stiffened magnetoreheological abrasive fluid flows through a preset converging gap that is formed by a workpiece surface and a moving rigid wall, to create precise material removal and polishing.
Related Papers (5)
Modified precise time step integration method of structural dynamic analysis
Mengfu Wang,Xiyuan Zhou +1 more