scholarly journals Study on Design and Diamond Turning of Optical Freeform Surface for Progressive Addition Lenses

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Yi Wei ◽  
Peng Zhai ◽  
Xiaoyi Chen ◽  
Lei He
Keyword(s):  
Tool Path ◽  
Single Point ◽  
Optical Design ◽  
Tool Path Generation ◽  
Diamond Turning ◽  
Freeform Surface ◽  
Path Generation ◽  
Nose Radius ◽  
Angle Method ◽  
Progressive Addition Lens

Optical freeform surface components have attracted much attention due to their high degree of design freedom and small size. However, the design and processing difficulty of such components limit its wide application in optics industry. In recent years, diamond turning has been considered an efficient method for processing optical freeform surfaces, but the research on tool path generation of this processing method is not systematic. Progressive addition lens (PAL) is a typical optical freeform surface and is widely used to correct people’s vision problems. Firstly, this paper introduces a method of designing PAL. Then, an optimized tool path generation method for diamond turning of the optical freeform surface is proposed, the equal angle method is used to select the discrete points, and a tool nose radius compensation method suitable for both slow slide servo (SSS) and fast tool servo (FTS) is adopted. Finally, the turning experiment is carried out with a single point diamond lathe, and a PAL surface with a roughness of 0.087 μm was obtained. The power and astigmatism distributions were measured using a Rotlex freeform verifier to verify the rationality of the optical design.

scholarly journals RBF Interpolation Algorithm for FTS Tool Path Generation

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Yahui Nie ◽  
Yinfei Du ◽  
Zhuo Xu ◽  
Zimiao Zhang ◽  
Yang Qi
Keyword(s):  
Manufacturing Industry ◽  
Tool Path ◽  
Single Point ◽  
Tool Path Generation ◽  
Diamond Turning ◽  
Path Generation ◽  
Interpolation Algorithm ◽  
Interpolation Accuracy ◽  
Freeform Optics ◽  
Simulation Results

Freeform optics are defined as nonrotational symmetric optical surfaces in the manufacturing industry. Freeform optics are extensively applied to many areas in order to improve system performance. Fast tool servo (FTS) assisting single-point diamond turning technology has high application prospects in freeform optics machining. This paper discusses the interpolation algorithm for tool path generation of FTS through the application of a radial basis function (RBF) algorithm. For this purpose, a positive definite RBF with compact support was employed as the interpolant. The existence is mathematically proven. Numerical simulations were performed to compare the performances of the RBF algorithm and commonly used algorithms for satisfying the requirements of existence, smoothness, and accuracy. Machining experiments were also conducted to validate the applicability of the algorithm. The simulation results showed that the RBF interpolation algorithm outperformed other algorithms in terms of smoothness. The RBF algorithm also provided the highest interpolation accuracy. Furthermore, the RBF interpolation algorithm exhibited the highest accuracy for error distribution, with large errors distributed mainly in transition areas. The machining results were also in general agreement with the simulation results although obvious practical errors were observed. Overall, RBF interpolation can provide higher accuracy and better smoothness in the tool path generation of FTS.

Theoretical Analysis about Off-Axis Parabolic Surface Machining under Two Different Accurate Spiral Tool Paths

2014 ◽  
Vol 625 ◽  
pp. 267-273
Author(s):  
Shi Jun Ji ◽  
Hui Juan Yu ◽  
Ji Zhao ◽  
Lei Zhang ◽  
Deng Peng Huang
Keyword(s):  
High Precision ◽  
Tool Path ◽  
Cutting Tool ◽  
Single Point ◽  
Tool Path Generation ◽  
Diamond Turning ◽  
Path Generation ◽  
High Precision Measurement ◽  
General Process ◽  
Parabolic Surface

Off-axis aspheric surface is an indispensable optical device for the high precision measurement and manufacturing equipment, and the tool path generation is a very important factor for the manufacturing to obtain the surface with high precision form and nanometric surface finish. In this paper, the systemic description of tool path generation method about the off-axis parabolic surface with ultra-precision single point diamond turning is processed. Two effective methods of generating the accurate spiral tool path are proposed and compared. The proposed methods are mainly based on mathematical calculation directly from analytic surfaces, including the general process of tool path generation, cutting-tool compensation and avoiding tool interference. This work can provide the theoretical basis of choosing the cutting tool path for off-axis parabolic surface and can improve the efficiency and precision of machine. Finally, some cutting simulations are implemented to prove the proposed methods.

Tool Path Generation for Single Point Incremental Forming Using Intelligent Sequencing and Multi-Step Mesh Morphing Techniques

2013 ◽  
Vol 554-557 ◽  
pp. 1408-1418 ◽  
Author(s):  
Amar Kumar Behera ◽  
Bert Lauwers ◽  
Joost R. Duflou
Keyword(s):  
Tool Path ◽  
Single Point ◽  
Tool Path Generation ◽  
Path Generation ◽  
Tool Paths ◽  
Mapping Strategy ◽  
Integrated Technique ◽  
Improved Accuracy ◽  
Sequencing Procedure

A new methodology of generating optimized tool paths for incremental sheet forming is proposed in this work. The objective is to make parts with improved accuracy. To enable this, a systematic technique of creating features using a morph mapping strategy is developed. This strategy is based on starting with a shape different from the final shape, available as a triangulated STL model, and using step-wise incremental deformation to the original mesh to arrive at the final part shape. Further, optimal tool path generation requires intelligent sequencing of partial tool paths that may be applied specifically to certain features on the part. The sequencing procedure is discussed next and a case study showing the application of the integrated technique is illustrated.

A generic uniform scallop tool path generation method for five-axis machining of freeform surface

2014 ◽  
Vol 56 ◽  
pp. 120-132 ◽  
Author(s):  
Zhiwei Lin ◽  
Jianzhong Fu ◽  
Hongyao Shen ◽  
Wenfeng Gan
Keyword(s):  
Tool Path ◽  
Tool Path Generation ◽  
Freeform Surface ◽  
Path Generation ◽  
Five Axis

scholarly journals Adaptive Spiral Tool Path Generation for Diamond Turning of Large Aperture Freeform Optics

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 810 ◽  
Author(s):  
Dongfang Wang ◽  
Yongxin Sui ◽  
Huaijiang Yang ◽  
Duo Li
Keyword(s):  
Tool Path ◽  
Tool Path Generation ◽  
Diamond Turning ◽  
Surface Generation ◽  
Machining Efficiency ◽  
Path Generation ◽  
Control Points ◽  
Large Aperture ◽  
Freeform Optics ◽  
Slow Tool Servo

Slow tool servo (STS) diamond turning is a well-developed technique for freeform optics machining. Due to low machining efficiency, fluctuations in side-feeding motion and redundant control points for large aperture optics, this paper reports a novel adaptive tool path generation (ATPG) for STS diamond turning. In ATPG, the sampling intervals both in feeding and cutting direction are independently controlled according to interpolation error and cutting residual tolerance. A smooth curve is approximated to the side-feeding motion for reducing the fluctuations in feeding direction. Comparison of surface generation of typical freeform surfaces with ATPG and commercial software DiffSys is conducted both theoretically and experimentally. The result demonstrates that the ATPG can effectively reduce the volume of control points, decrease the vibration of side-feeding motion and improve machining efficiency while surface quality is well maintained for large aperture freeform optics.

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