A tool path generation method for quasi-intermittent vibration assisted swing cutting

2020 ◽  
Vol 234 (6) ◽  
pp. 624-633
Author(s):  
Zhimin Zhu ◽  
Mingming Lu ◽  
Jieqiong Lin ◽  
Jiakang Zhou ◽  
Allen Yi ◽  
...  
Keyword(s):  
Tool Path ◽  
Spline Interpolation ◽  
Interpolation Theorem ◽  
Tool Path Generation ◽  
Diamond Turning ◽  
Tool Geometry ◽  
Machining Accuracy ◽  
Path Generation ◽  
Freeform Surfaces ◽  
Tool Trajectory

During the machining of freeform surfaces, the tool path will directly affect the machining accuracy of the surface, the execution of each axis of the machine tool, and the machining efficiency. Therefore, tool path planning is a very critical link in all types of diamond turning processes. In this paper, a new tool path generation strategy is proposed for machining freeform surfaces by quasi-intermittent vibration assisted swing cutting (QVASC) method. Due to the unique tool swing motion law of QVASC, the effective central angle of tool nose arc participating in the cutting is a parameter that is ignored by traditional cutting and is considered. This makes the generation of tool trajectories, tool geometry selection and freeform surfaces very different from traditional diamond cutting. According to the principle of QVASC, the tool parameters are analysed, and the tool position is designed in the cylindrical coordinate system. Interpolation was then performed by the Hermite spline interpolation theorem. The application of this strategy is discussed, and the sinusoidal surface, sinusoidal mesh surface and toric surface are taken as examples to simulate. The simulation succeeded in obtaining the tool path corresponding to the three curved surfaces processed by the QVASC method. The results prove that the tool trajectory generation strategy proposed in this paper is feasible. The proposed tool path generation strategy can provide a new reference for future freeform surfaces processing.

An Optimal Method of Tool Path Generation for Radial Sinusoidal Surface

2014 ◽  
Vol 1027 ◽  
pp. 20-23 ◽  
Author(s):  
Shi Jun Ji ◽  
Hui Juan Yu ◽  
Ji Zhao ◽  
Jin Chao Li ◽  
Lei Lei Liu
Keyword(s):  
Tool Path ◽  
Tool Path Generation ◽  
Diamond Turning ◽  
Machining Accuracy ◽  
Path Generation ◽  
Optimal Method ◽  
Spiral Tool Path ◽  
Ultra Precision ◽  
Sinusoidal Surface ◽  
Theoretical Analyses

Tool path generation is an important part of ultra-precision manufacturing, and spiral tool path is one typical driving path. For single point diamond turning (SPDT), two methods are commonly used to generate the driving points on the spiral tool path, which are equally spaced angles and equally spaced arcs for two adjacent cutting points. But these two methods both have the defects for machining radial sinusoidal surface with SPDT. In this paper, the theoretical analyses of the two different methods are conducted and compared respectively. Then, an optimal method of generating the spiral cutting tool path is proposed on the base of theoretical analyses, which can avoid disadvantages of two original methods. The proposed method can enhance the machining accuracy and fabricating efficiency for ultra-precision machining of the radial sinusoidal surface with SPDT.

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

2016 ◽  
Vol 231 (5) ◽  
pp. 825-837 ◽  
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.

Tool Path Generation Method for High-Quality Machining of Free-Form Surfaces

2020 ◽  
Author(s):  
Yuki Takanashi ◽  
Hideki Aoyama
Keyword(s):  
Tool Path ◽  
High Accuracy ◽  
Tool Path Generation ◽  
Free Form ◽  
Machining Accuracy ◽  
Path Generation ◽  
High Quality ◽  
Nc Program ◽  
Free Form Surface ◽  
Free Form Surfaces

Abstract Machining data (NC program) is generated by a CAM system, which generates the tool path from the target shape as a plane approximation surface instead of a free-form surface. Owing to this plane approximation, machining accuracy is reduced. In this paper, we propose a method to process the shape with high accuracy by defining the areas where accuracy is not required as a plane approximation surface and defining the part where accuracy is required as free-form surfaces.

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 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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