Study on Tool-Path Generation for Ultra-Precision Machining of Optical Lens Array

2012 ◽  
Vol 516 ◽  
pp. 595-599
Author(s):  
Kui Liu ◽  
Pei Ling Liu ◽  
Hu Wu ◽  
Kah Chuan Shaw
Keyword(s):  
Tool Path ◽  
Cutting Tool ◽  
Tool Path Generation ◽  
Numerical Control ◽  
Precision Machining ◽  
Path Generation ◽  
Software Platform ◽  
Optical Lens ◽  
Lens Array ◽  
Ultra Precision

In this study, a computer numerical control (CNC) programming software platform for ultra precision machining of optical surfaces was developed based on an MS Windows application framework and openGL. Using cylindrical coordinates, the tool path can be generated based on the polar angle, radius and a linear coordinate of the Z-axis, as well as cutting tool nose radius compensation. A 3D simulation based on tool path generation was developed for machining verification, which largely reduces the oscillation of the machine during the ultra precision machining process. Ultra precision machining of an optical lens array was carried out on a 5-axis ultra precision machining centre using a single crystalline diamond cutter. The experimental results indicated that the oscillation effect can be largely reduced using the cutting tool path using a super steady machining strategy. This software platform is designed as a framework, where the capability and functions can be expanded by adding in more freeform surface packages.

Tool Path Generation for 5-Axis Rough Cutting Using Haptic Device

2020 ◽  
Vol 14 (5) ◽  
pp. 808-815
Author(s):  
Koichi Morishige ◽  
Satoshi Mori ◽  
◽  
Keyword(s):  
Tool Path ◽  
Cutting Tool ◽  
Control Program ◽  
Target Object ◽  
Tool Path Generation ◽  
Haptic Device ◽  
Numerical Control ◽  
Path Generation ◽  
Haptic Devices ◽  
Tool Paths

CAM software is generally used to generate tool paths for 5-axis controlled machining. However, adjusting its several parameters and settings is difficult. We propose a system for tool path generation to be applied to 5-axis controlled machining. The system allows machining movements to be established by manipulating haptic devices in a virtual environment. Therefore, the cutter location for 5-axis machining can be easily controlled by operating a virtual cutting tool. The contact between the cutting tool and the target shape is reflected to the user through the haptic device. The generated path can be converted into a numerical control program for the actual machining of the target object. We detail the implementation of the proposed interface using two haptic devices and a method of tool path generation that improves rough cutting by smoothing the generated cutting points and simplifying the tool postures. The effectiveness of the developed system is confirmed through machining simulations.

Tool path generation for ultra-precision polishing of freeform optical surfaces in an off-axis three-mirror imaging system

2015 ◽  
Vol 231 (5) ◽  
pp. 814-824 ◽  
Author(s):  
Dengpeng Huang ◽  
Lei Zhang ◽  
Shijun Ji ◽  
Ji Zhao
Keyword(s):  
Tool Path ◽  
Imaging System ◽  
Concentric Circle ◽  
Tool Path Generation ◽  
Numerical Control ◽  
Path Generation ◽  
Freeform Surfaces ◽  
Primary Mirror ◽  
Tool Paths ◽  
Ultra Precision

The optical performance of the off-axis three-mirror imaging system can be greatly improved using freeform surfaces. This article focuses on the polishing of the primary mirror and tertiary mirror in an off-axis three-mirror imaging system. The primary mirror and tertiary mirror are fabricated on one monolithic substrate and described by non-uniform rational B-spline–based freeform surfaces. The separated and integrated polishing strategies are presented for polishing the two mirrors on the four-axis computer numerical control polishing platform. A tool path generation approach is proposed for polishing of the non-uniform rational B-spline–based freeform surface. Three kinds of the tool paths are given for ultra-precision polishing of the primary mirror and tertiary mirror with the freeform surfaces. The concentric circle path and the approximately concentric circle path are generated for polishing two mirrors separately, while the spiral path is calculated for integrated polishing of two mirrors simultaneously. The polishing tool posture along the planned tool paths is also analyzed. The ultra-precision polishing experiments of the primary mirror and tertiary mirror on the four-axis computer numerical control polishing platform are performed to verify the proposed approach for tool path generation.

scholarly journals Analysis of a novel tool path generation method for corrective machining in ultra-precision diamond turning based on point clouds

2021 ◽  
Author(s):  
Marco Buhmann ◽  
Erich Carelli ◽  
Christian Egger ◽  
Klaus Frick
Keyword(s):  
Point Cloud ◽  
Tool Path ◽  
Cutting Tool ◽  
Measurement Data ◽  
Tool Path Generation ◽  
Diamond Turning ◽  
Surface Measurement ◽  
Computation Method ◽  
Path Generation ◽  
Ultra Precision

Abstract The increasing demand for machining non-rotational optical surfaces requires capable and flexible cutting tool path generation methods for ultra-precision diamond turning. Furthermore, the recent interest in on-machine metrology and corrective machining require efficient as well as accurate algorithms capable to handle point cloud based surface data. In the present work, a new computation method for the tool path generation is proposed that focuses on three-axes corrective machining. Therefore, it is based on the principle of defining the surface to be machined by a point cloud of certain density, since surface measurement data is usually available as point cloud. Numeric approximation techniques are used to compute the surface normal vectors and calculate the resulting positions of the cutting tool path preserving a uniform radial axis motion for face turning. Investigations are performed in order to quantify the error between the calculated tool path and the exact analytical solution. The error dependencies are analyzed regarding the local surface slope and numerical parameters. Error values below 1nm are achieved. In addition, form deviation results prove the method’s capability for corrective diamond turn machining.

scholarly journals Theoretical and Experimental Investigation of Surface Topography Generation in Slow Tool Servo Ultra-Precision Machining of Freeform Surfaces

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2566 ◽  
Author(s):  
Duo Li ◽  
Zheng Qiao ◽  
Karl Walton ◽  
Yutao Liu ◽  
Jiadai Xue ◽  
...  
Keyword(s):  
Surface Topography ◽  
Tool Path ◽  
Tool Path Generation ◽  
Surface Generation ◽  
Precision Machining ◽  
Path Generation ◽  
Freeform Surfaces ◽  
Ultra Precision ◽  
Slow Tool Servo ◽  
Radius Compensation

Freeform surfaces are featured with superior optical and physical properties and are widely adopted in advanced optical systems. Slow tool servo (STS) ultra-precision machining is an enabling manufacturing technology for fabrication of non-rotationally symmetric surfaces. This work presents a theoretical and experimental study of surface topography generation in STS machining of freeform surfaces. To achieve the nanometric surface topography, a systematic approach for tool path generation was investigated, including tool path planning, tool geometry selection, and tool radius compensation. The tool radius compensation is performed only in one direction to ensure no high frequency motion is imposed on the non-dynamic axis. The development of the surface generation simulation allows the prediction of the surface topography under various tool and machining variables. Furthermore, it provides an important means for better understanding the surface generation mechanism without the need for costly trial and error tests. Machining and measurement experiments of a sinusoidal grid and microlens array sample validated the proposed tool path generation and demonstrated the effectiveness of the STS machining process to fabricate freeform surfaces with nanometric topography. The measurement results also show a uniform topography distribution over the entire surface and agree well with the simulated results.

Study of The Tool Path Generation Method of an Ultra-Precision Spherical Complex Surface Based on a Five-Axis Machine Tool

2021 ◽  
Author(s):  
Tianji Xing ◽  
Xuesen Zhao ◽  
Zhipeng Cui ◽  
Rongkai Tan ◽  
Tao Sun
Keyword(s):  
Surface Roughness ◽  
Tool Path ◽  
Spherical Surface ◽  
Tool Path Generation ◽  
Path Generation ◽  
Tool Paths ◽  
Spherical Surfaces ◽  
Spherical Complex ◽  
Ultra Precision ◽  
Five Axis

Abstract The improvement of ultra-precision machining technology has significantly boosted the demand for the surface quality and surface accuracy of the workpieces to be machined. However, the geometric shapes of workpiece surfaces cannot be adequately manufactured with simple plane, cylindrical, or spherical surfaces because of their different applications in various fields. In this research, a method was proposed to generate tool paths for the machining of complex spherical surfaces based on an ultra-precise five-axis turning and milling machine with a C-Y-Z-X-B structure. Through the proposed tool path generation method, ultra-precise complex spherical surface machining was achieved. First, the complex spherical surface model was modeled and calculated, and then it was combined with the designed model to generate the tool path. Then the tool paths were generated with a numerically controlled (NC) program. Based on an ultra-precision three-coordinate measuring instrument and a white light interferometer, the machining accuracy of a workpiece surface was characterized, and t[1]he effectiveness of the provided tool path generation method was verified. The surface roughness of the machined workpiece was less than 90 nm. Furthermore, the surface roughness within the spherical region appeared to be less than 30 nm. The presented tool path generation method in this research produced ultra-precision spherical complex surfaces. The method could be applied to complex spherical surfaces with other characteristics.

Tool Path Generation Method of Equal Approximation Error for Free-Form Surface in High Speed Machining

2010 ◽  
Vol 102-104 ◽  
pp. 544-549 ◽  
Author(s):  
Chun Jiang Zhou ◽  
Hong Chun Chen
Keyword(s):  
High Speed ◽  
Tool Path ◽  
Cutting Tool ◽  
End Milling ◽  
Approximation Error ◽  
Tool Path Generation ◽  
Free Form ◽  
Path Generation ◽  
High Speed Machining ◽  
Free Form Surface

The development of surface high-speed machining has put forward higher demands for uniform cutting load and smooth cutting tool path. Most current tool-path planning methods are based on constant scallop height, but they have the disadvantage of path point redundancy during the path discretization process. To overcome the problem, a tool path generation method of equal approximation error in each step for free-form surface is presented based on geodesic principle and curvature judgment. In this method, the NURBS curve is employed to realize smooth transition for adjacent two tool paths in high-speed machining. A certain angle of inclination of flat-end milling cutter during multi-axis machining improves the machining efficiency. Because of the advantage of this machining condition, the cutter location point generation algorithm during the machining condition is given by the method. The method is verified and simulated by C++. Experiment results proved that it can obtain uniform cutting load and continuous smooth cutting tool path during surface high-speed machining by the proposed method.

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