Optimization of Tool Path Generation for Freeform Surface by Slow Tool Servo Diamond Turning

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

Mathematical Problems in Engineering ◽

10.1155/2020/2850606 ◽

2020 ◽

Vol 2020 ◽

pp. 1-9 ◽

Cited By ~ 1

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.

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A tool path generation method for freeform surface machining by introducing the tensor property of machining strip width

Computer-Aided Design ◽

10.1016/j.cad.2015.03.003 ◽

2015 ◽

Vol 66 ◽

pp. 1-13 ◽

Cited By ~ 45

Author(s):

Xu Liu ◽

Yingguang Li ◽

Sibo Ma ◽

Chen-han Lee

Keyword(s):

Tool Path ◽

Tool Path Generation ◽

Strip Width ◽

Freeform Surface ◽

Path Generation ◽

Surface Machining ◽

Machining Strip Width ◽

Freeform Surface Machining ◽

Tensor Property

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Spiral tool path generation method in a NURBS parameter space for the ultra-precision diamond turning of freeform surfaces

Journal of Manufacturing Processes ◽

10.1016/j.jmapro.2020.10.073 ◽

2020 ◽

Vol 60 ◽

pp. 340-355

Author(s):

Shuai He ◽

Jianping Xuan ◽

Wenhao Du ◽

Qi Xia ◽

Shoucong Xiong ◽

...

Keyword(s):

Parameter Space ◽

Tool Path ◽

Tool Path Generation ◽

Diamond Turning ◽

Path Generation ◽

Freeform Surfaces ◽

Spiral Tool Path ◽

Ultra Precision

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Tool path optimal design for slow tool servo turning of complex optical surface

Proceedings of the Institution of Mechanical Engineers Part B Journal of Engineering Manufacture ◽

10.1177/0954405416654192 ◽

2016 ◽

Vol 231 (5) ◽

pp. 825-837 ◽

Cited By ~ 5

Author(s):

Xu Chen ◽

Min Kang ◽

Xingsheng Wang ◽

Muhammad Hassan ◽

Jun Yang

Keyword(s):

Optimal Design ◽

Tool Path ◽

Tool Path Generation ◽

Interpolation Error ◽

Machining Accuracy ◽

Calculation Error ◽

Path Generation ◽

Optical Surface ◽

Toric Surface ◽

Slow Tool Servo

In order to increase the machining accuracy of slow tool servo turning of complex optical surface, the optimal design for tool path was studied. A comprehensive tool path generation strategy was proposed to optimize the tool path for machining complex surfaces. A new algorithm was designed for tool nose radius compensation which had less calculation error. Hermite segment interpolation was analyzed based on integrated multi-axes controller, and a new interpolation method referred to as triangle rotary method was put forward and was compared with the area method and three-point method. The machining simulation indicated that the triangle rotary method was significant in error reduction. The interpolation error of toric surface was reduced to 0.0015 µm from 0.06 µm and sinusoidal array surface’s interpolation error decreases to 0.37 µm from 1.5 µm. Finally, a toric surface was machined using optimum tool path generation method to evaluate the proposed tool path generation method.

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