Voxel-Based Adaptive Toolpath Planning using GPU for Freeform Surface Machining

2021 ◽  
pp. 1-31
Author(s):  
Aman Kukreja ◽  
Mandeep Dhanda ◽  
Sanjay Pande
Keyword(s):  
Tool Path ◽  
Processing Technique ◽  
Image Processing Technique ◽  
Freeform Surface ◽  
Processing Unit ◽  
Cad Model ◽  
Cnc Machine ◽  
Toolpath Planning ◽  
Toolpath Generation ◽  
Freeform Surface Machining

Abstract Today freeform surfaces are widely used on products in automobile, aerospace, and die/molds industries, which are generally manufactured using multi-axis CNC machines. Frequent changes in the design of products necessitate creation of CNC part programs which need fast and accurate toolpath generation methods. Traditional toolpath generation methods involve complex computations and are unable to consider multiple surface patches together. The voxel-based CAD model provides the ability to represent the multi-patch surfaces in a discretized manner which can be processed using an advanced parallel computing framework for accurate tool path planning. This paper presents a new method to generate an adaptive Iso-planar toolpath for a 3-axis CNC machine using the voxel-based part model. The algorithm is designed to work on a Graphics Processing Unit (GPU) that allows parallel processing for faster toolpath generation. The proposed approach consists of two main steps, an algorithm to generate gouge free cutter location points from the voxel-based CAD model and an algorithm to find out sidestep and forward step from those cutter location points to create the final CNC tool path. A new image-processing technique has been proposed to identify gouge by detecting the shadow surface voxels and their intersection with the cutting tool. The developed system was extensively tested and compared with the various reported toolpath planning strategies for machining complex freeform surface parts. The results show that the developed method is computationally efficient, robust, and accurate in generating adaptive planar toolpath.

Recognition of Freeform Surface Machining Features

2010 ◽  
Vol 10 (4) ◽  
Author(s):  
Jun Wang ◽  
Zhigang Wang ◽  
Weidong Zhu ◽  
Yingfeng Ji
Keyword(s):  
Critical Points ◽  
Computer Aided Design ◽  
Tool Path ◽  
Machining Process ◽  
Freeform Surface ◽  
Critical Surface ◽  
Machining Features ◽  
Computer Aided ◽  
Freeform Surface Machining ◽  
Machining Process Planning

This paper describes a method of machining feature recognition from a freeform surface based on the relationship between unique machining patches and critical points on a component’s surface. The method uses Morse theory to extract critical surface points by defining a scalar function on the freeform surface. Features are defined by region growing between the critical points using a tool path generation algorithm. Several examples demonstrate the efficiency of this approach. The recognized machining features can be directly utilized in a variety of downstream computer aided design/computer aided manufacturing (CAM) applications, such as the automated machining process planning.

scholarly journals GPU Accelerated real-time Melanoma Detection

2018 ◽  
Vol 7 (3) ◽  
pp. 1208
Author(s):  
Ajai Sunny Joseph ◽  
Elizabeth Isaac
Keyword(s):  
Real Time ◽  
Video Processing ◽  
Processing Technique ◽  
Video Data ◽  
Image Processing Technique ◽  
Processing Unit ◽  
Central Processing ◽  
Melanoma Detection ◽  
Real Time Analysis ◽  
Graphical Processing

Melanoma is recognized as one of the most dangerous type of skin cancer. A novel method to detect melanoma in real time with the help of Graphical Processing Unit (GPU) is proposed. Existing systems can process medical images and perform a diagnosis based on Image Processing technique and Artificial Intelligence. They are also able to perform video processing with the help of large hardware resources at the backend. This incurs significantly higher costs and space and are complex by both software and hardware. Graphical Processing Units have high processing capabilities compared to a Central Processing Unit of a system. Various approaches were used for implementing real time detection of Melanoma. The results and analysis based on various approaches and the best approach based on our study is discussed in this work. A performance analysis for the approaches on the basis of CPU and GPU environment is also discussed. The proposed system will perform real-time analysis of live medical video data and performs diagnosis. The system when implemented yielded an accuracy of 90.133% which is comparable to existing systems.  

scholarly journals T-Spline Surface Toolpath Generation Using Watershed-Based Feature Recognition

2020 ◽  
Vol 10 (19) ◽  
pp. 6790
Author(s):  
Yazui Liu ◽  
Gang Zhao ◽  
Pengfei Han
Keyword(s):  
Feature Recognition ◽  
Machining Process ◽  
Freeform Surface ◽  
Local Refinement ◽  
Surface Machining ◽  
Spline Surface ◽  
Toolpath Generation ◽  
Comparison Results ◽  
Bounding Boxes ◽  
Freeform Surface Machining

The freeform surface is treated as a single machining region for most traditional toolpath generation algorithms. However, due to the complexity of a freeform surface, it is impossible to produce a high-quality surface using one unique machining process. Hence, region-based methods are widely investigated for freeform surface machining to achieve an optimized toolpath. The Non-Uniform Rational B-spline Surface (NURBS) represented freeform surface is not suitable for region-based toolpath generation because of the surface gaps caused by NURBS trimming and merging operations. To solve the limitation of the NURBS, T-spline is proposed with the advantages of being gap-free, having less control points, and local refinement, which is an ideal tool for region-based toolpath generation. Thus, T-spline is introduced to represent a freeform surface for its toolpath generation in the paper. A region-based toolpath generation method for the T-spline surface is proposed based on watershed technology. Firstly, watershed-based feature recognition is presented to divide the T-spline surface into a set of sub-regions. Secondly, the concept of a PolyBoundingBox that consists of a set of minimum bounding boxes is proposed to describe the sub-regions, and Manufacturing-Suitable Regions are constructed with the help of T-spline local refinement and the PolyBoundingBox. In the end, an optimized multi-rectangles toolpath generation algorithm is applied for sub-regions. The proposed method is tested using three synthetic T-spline surfaces, and the comparison results show the advantage in toolpath length and toolpath reversing number.

Deterministic polishing of freeform optical surface by iterative intersection tool path in an off-axial three-mirror anastigmat imaging system

2016 ◽  
Vol 232 (5) ◽  
pp. 816-826 ◽  
Author(s):  
Fusheng Liang ◽  
Ji Zhao ◽  
Shijun Ji ◽  
Lei Lu
Keyword(s):  
Tool Path ◽  
Imaging System ◽  
Freeform Surface ◽  
Optical Surface ◽  
Registration Method ◽  
Form Accuracy ◽  
Surface Machining ◽  
Point Set Registration ◽  
High Form ◽  
Freeform Surface Machining

Deterministic polishing as the final step of freeform surface machining can acquire preferable form accuracy. In this article, a deterministic polishing model based on iterative intersection tool path is presented to meet the requirement of high-form accuracy in freeform surface. In the polishing process, on-machine measurement and point set registration method are adopted for installation error extraction and form error calculation. The iterative polishing can be finished without discharging of workpiece by on-machine measurement strategy, which will reduce the processing time and improve the machining efficiency. In addition, a boundary extension method is employed to diminish the surface edge collapse generated by edge effect. Finally, the polishing experiment of freeform optical surface in an off-axial three-mirror anastigmat imaging system is conducted to verify the effectiveness of the proposed model.

High Efficiency Tool Path Generation for Freeform Surface Machining Based on NURBS Subdivision

2014 ◽  
Vol 625 ◽  
pp. 372-377 ◽  
Author(s):  
Jiang Zhu ◽  
Akimitsu Hozumi ◽  
Tomohisa Tanaka ◽  
Yoshio Saito
Keyword(s):  
Tool Path ◽  
High Efficiency ◽  
Rapid Development ◽  
Milling Process ◽  
Tool Path Generation ◽  
Freeform Surface ◽  
Path Generation ◽  
Nurbs Surface ◽  
Surface Machining ◽  
Freeform Surface Machining

Along with the rapid development of CAD/CAM system, the smooth surfaces are widely used in industry design. Especially NURBS surface attracts rising attentions because NURBS can describe flat surface, freeform surface and so on. Currently a lot of tool path generation patterns are proposed for milling process of freeform surface. Nevertheless there are still some problems on generating efficient tool path for freeform surface under the requested surface finish roughness. In this research, in order to resolve these problems, NURBS surface is divided into some patches and the tool path is generated on each patch. This paper proposes a surface divide method and makes a comparison between this method and undivided method. As a result, it is found that dividing the surface is helpful for the making shorter tool path and increase the machining efficiency.

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