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.

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 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 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.

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.

Sheet Metal Laser Cutting Tool Path Generation: Dealing with Overlooked Problem Aspects

2015 ◽  
Vol 639 ◽  
pp. 517-524 ◽  
Author(s):  
Reginald Dewil ◽  
Pieter Vansteenwegen ◽  
Dirk Cattrysse
Keyword(s):  
Penalty Function ◽  
Laser Cutting ◽  
Tool Path ◽  
Cutting Tool ◽  
Tool Path Generation ◽  
Metal Sheet ◽  
Path Generation ◽  
Plate Edge ◽  
Tool Paths ◽  
Easy Problem

This paper deals with non-trivial problem aspects of laser cutting tool path generation that, to the best of our knowledge, received relatively little attention in the scientific literature. It is shown that some aspects such as plate edge nesting, skeleton and remnant cutting, and clamp positioning can be modeled and solved with little additional effort using existing tool path algorithms. However, concepts such as collision avoidance, pre-cut optimization, and bridge utilization prove to be more challenging and will require more profound algorithmic adjustments if these have to be taken into account fully. An even harder problem aspect is generating tool paths that are thermally feasible. Since laser cutting introduces net heat into the metal sheet, the metal sheet tends to heat up as the cutting progresses. Quality deterioration can occur if the laser spends too much time cutting in the same region. It is shown how to model the easy problem extensions in order to handle them using existing problem approaches and solution approaches are suggested to tackle the harder concepts. In addition, a proof of concept is presented that shows that thermal feasible tool paths can be generated through a multi-start heuristic utilizing a thermal penalty function. A finite difference method iteratively (or concurrently dependent on the used heuristic) evaluates the thermal feasibility and updates the penalty function.

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.

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