Voronoi-diagram-based linking of contour-parallel tool paths for two-and-a-half-dimensional closed-pocket machining

2010 ◽  
Vol 224 (9) ◽  
pp. 1329-1350 ◽  
Author(s):  
S Hinduja ◽  
M S A Mansor ◽  
O O Owodunni
Keyword(s):  
Voronoi Diagram ◽  
Pocket Machining ◽  
Tool Paths

Use of a virtual milling system to generate power-aware tool paths for 2.5-dimensional pocket machining

2019 ◽  
Vol 233 (13) ◽  
pp. 2419-2435 ◽  
Author(s):  
David Manuel Ochoa González ◽  
Joao Carlos Espindola Ferreira
Keyword(s):  
Power Consumption ◽  
Tool Path ◽  
Tool Path Generation ◽  
Path Generation ◽  
Machining Time ◽  
Power Requirement ◽  
Pocket Machining ◽  
Direction Parallel ◽  
Generation Algorithm ◽  
Tool Paths

Traditional (direction-parallel and contour-parallel) and non-traditional (trochoidal) tool paths are generated by specialized geometric algorithms based on the pocket shape and various parameters. However, the tool paths generated with those methods do not usually consider the required machining power. In this work, a method for generating power-aware tool paths is presented, which uses the power consumption estimation for the calculation of the tool path. A virtual milling system was developed to integrate with the tool path generation algorithm in order to obtain tool paths with precise power requirement control. The virtual milling system and the tests used to calibrate it are described within this article, as well as the proposed tool path generation algorithm. Results from machining a test pocket are presented, including the real and the estimated power requirements. Those results were compared with a contour-parallel tool path strategy, which has a shorter machining time but has higher in-process power consumption.

A Hybrid Approach to Polygon Offsetting Using Winding Numbers and Partial Computation of the Voronoi Diagram

2014 ◽  
Author(s):  
Greg Burton
Keyword(s):  
Voronoi Diagram ◽  
Recursive Algorithm ◽  
Hybrid Approach ◽  
Radius Of Curvature ◽  
Convex Polygons ◽  
Pocket Machining ◽  
Worst Case ◽  
Offset Curves ◽  
Complete Computation ◽  
Offset Curve

In this paper we present a new, efficient algorithm for computing the “raw offset” curves of 2D polygons with holes. Prior approaches focus on (a) complete computation of the Voronoi Diagram, or (b) pair-wise techniques for generating a raw offset followed by removal of “invalid loops” using a sweepline algorithm. Both have drawbacks in practice. Robust implementation of Voronoi Diagram algorithms has proven complex. Sweeplines take O((n + k)log n) time and O(n + k) memory, where n is the number of vertices and k is the number of self-intersections of the raw offset curve. It has been shown that k can be O(n2) when the offset distance is greater than or equal to the local radius of curvature of the polygon, a regular occurrence in the creation of contour-parallel offset curves for NC pocket machining. Our O(n log n) recursive algorithm, derived from Voronoi diagram algorithms, computes the velocities of polygon vertices as a function of overall offset rate. By construction, our algorithm prunes a large proportion of locally invalid loops from the raw offset curve, eliminating all self-intersections in raw offsets of convex polygons and the “near-circular”, k proportional to O(n2) worst-case scenarios in non-convex polygons.

Voronoi diagram-based tool path compensations for removing uncut material in 2½D pocket machining

2006 ◽  
Vol 38 (3) ◽  
pp. 194-209 ◽  
Author(s):  
M. Salman A. Mansor ◽  
S. Hinduja ◽  
O.O. Owodunni
Keyword(s):  
Voronoi Diagram ◽  
Tool Path ◽  
Pocket Machining

scholarly journals Development of Direction-Parallel Strategy for Shorting A Tool Path in The Triangular Pocket Machining

2019 ◽  
Vol 18 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Mochammad Chaeron ◽  
Budi Saputro Wahyuaji ◽  
Apriani Soepardi
Keyword(s):  
Path Length ◽  
Tool Path ◽  
Machining Efficiency ◽  
Machining Time ◽  
Pocket Machining ◽  
Direction Parallel ◽  
Numerical Examples ◽  
Tool Paths ◽  
Machining Strategy ◽  
Parallel Strategy

The machining strategy is one of the parameters which practically influences the time of the different manufacturing geometric forms. The machining time directly relates to the machining efficiency of the tool paths. In area milling machining, there are two main types of tool path strategies: a direction-parallel milling and contour-parallel milling. Then direction-parallel milling is simple compared with a contour-parallel strategy. This paper proposes a new model of the direction-parallel machining strategy for triangular pockets to reduce the tool path length. The authors develop an analytical model by appending additional the tool path segments to the basis tool path for cutting un-machined area or scallops, which remained along the boundary. To validate its results, the researchers have compared them to the existing model found in the literature. For illustrating the computation of this model, the study includes two numerical examples. The results show that the proposed analytic direction-parallel model can reduce the total length of machining. Thus, it can take a shorter time for milling machining.

scholarly journals Spiral tool paths for high-speed machining of 2D pockets with or without islands

2018 ◽  
Vol 6 (1) ◽  
pp. 105-117 ◽  
Author(s):  
Mikkel Abrahamsen
Keyword(s):  
High Speed ◽  
Outer Boundary ◽  
Central Point ◽  
High Speed Machining ◽  
Pocket Machining ◽  
Tool Paths ◽  
New Methods ◽  
Circular Arcs ◽  
Industrial Strength

Abstract We describe new methods for the construction of spiral tool paths for high-speed machining. In the simplest case, our method takes a polygon as input and a number δ>0 and returns a spiral starting at a central point in the polygon, going around towards the boundary while morphing to the shape of the polygon. The spiral consists of linear segments and circular arcs, it is G1 continuous, it has no self-intersections, and the distance from each point on the spiral to each of the neighboring revolutions is at most δ. Our method has the advantage over previously described methods that it is easily adjustable to the case where there is an island in the polygon to be avoided by the spiral. In that case, the spiral starts at the island and morphs the island to the outer boundary of the polygon. It is shown how to apply that method to make significantly shorter spirals in some polygons with no islands than what is obtained by conventional spiral tool paths. Finally, we show how to make a spiral in a polygon with multiple islands by connecting the islands into one island. Highlights It is described how to construct a spiral to be used for pocket machining. The spiral respects a user-defined maximum stepover distance between neighbouring revolutions. The algorithm can create a spiral that morphs an island to the boundary of the pocket. The obtained spirals are in some cases much shorter than previously described spiral toolpaths. The algorithm is fast and a popular industrial strength implementation has been created.

Optimization of the 2 1/2 D Pocket Machining Using Multiple Tools

2011 ◽  
Vol 223 ◽  
pp. 918-927
Author(s):  
Leandro Costa de Oliveira ◽  
Tsuzuki Marcos de Sales Guerra
Keyword(s):  
Dynamic Programming ◽  
Voronoi Diagram ◽  
Pocket Machining ◽  
Machining Strategy ◽  
Corner Machining

This work presents some contributions for optimization of the 2 ½ D pocket machining. The machining strategy considered is divided in internal machining and corners machining. The internal machining is carried through equidistant paths to the contour (offset) made by using Voronoi’s Diagram and the corner machining follows the same principle. As the Voronoi Diagram is parametric, the spaces between the paths can change. Thus, the best situation of spacing between paths can be determined to optimize the process. By using Dynamic Programming, the best combination of dimensions of the available tools can also be identified to remove the material of the pocket in smaller time.

Model and algorithm for searching for victims in emergency situations and fires using the Voronoi diagram

2019 ◽  
Vol 86 ◽  
pp. 53-61
Author(s):  
N. G. Topolskiy ◽  
◽  
A. V. Mokshantsev ◽  
To Hoang Thanh ◽  
◽  
...  
Keyword(s):  
Voronoi Diagram ◽  
Emergency Situations
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