scholarly journals Corner Transition Toolpath Generation Based on Velocity-Blending Algorithm for Glass Edge Grinding

2019 ◽  
Vol 32 (1) ◽  
Author(s):  
Kun Ren ◽  
Yujia Pan ◽  
Danyan Jiang ◽  
Jun Pan ◽  
Wenhua Chen ◽  
...  
Keyword(s):  
Numerical Control ◽  
Sharp Corner ◽  
Shape Accuracy ◽  
Toolpath Generation ◽  
Three Phase ◽  
G1 Continuity ◽  
Increasing Demand ◽  
Sharp Corners ◽  
Glass Edge ◽  
Phase Motion

Abstract Sharp corners usually are used on glass contours to meet the highly increasing demand for personalized products, but they result in a broken wheel center toolpath in edge grinding. To ensure that the whole wheel center toolpath is of G1 continuity and that the grinding depth is controllable at the corners, a transition toolpath generation method based on a velocity-blending algorithm is proposed. Taking the grinding depth into consideration, the sharp-corner grinding process is planned, and a velocity-blending algorithm is introduced. With the constraints, such as traverse displacement and grinding depth, the sharp-corner transition toolpath is generated with a three-phase motion arrangement and with confirmations of the acceleration/deceleration positions. A piece of glass with three sharp corners is ground on a three-axis numerical-control glass grinding equipment. The experimental results demonstrate that the proposed algorithm can protect the sharp corners from breakage efficiently and achieve satisfactory shape accuracy. This research proposed a toolpath generation method based on a velocity-blending algorithm for the manufacturing of personalized glass products, which generates the transition toolpath as needed around a sharp corner in real time.

A Microchannel With Repeated Sharp Corners for Single Stream Particle Focusing

2014 ◽  
Author(s):  
Liangliang Fan ◽  
Xukun He ◽  
Liang Zhao ◽  
Yu Han ◽  
Jiang Zhe
Keyword(s):  
Centrifugal Force ◽  
High Throughput ◽  
Flow Rate ◽  
Lift Force ◽  
Channel Wall ◽  
Sharp Corner ◽  
Force Effect ◽  
Particle Focusing ◽  
Wide Range ◽  
Sharp Corners

A new microfluidic device for fast and high throughput microparticle focusing is reported. The particle focusing is based on the combination of inertial lift force effect and centrifugal force effect generated in a microchannel with a series of repeated sharp corners on one side of the channel wall. The inertial lift force effect induces two focused particles streams in the microchannel, and the centrifugal force generated at the sharp corner structures tends to drive the particles laterally away from the corner. With the use of a series of the repeated, sharp corner structures, a single and highly focused particle stream was achieved near the straight channel wall at a wide range of flow rates. In comparison to other hydrodynamic particle focusing methods, this method is less sensitive to the flow rate and can work at a higher flow rate (high throughput). With its simple structure and operation, and high throughput, this method can be potentially used in microparticle focusing processes in a variety of lab-on-a chip applications.

Sharp corner transitional trajectory planning based on arc splines in glass edge grinding

2017 ◽  
Vol 93 (9-12) ◽  
pp. 4089-4098 ◽  
Author(s):  
Kun Ren ◽  
Kai Xu ◽  
Wenhua Chen ◽  
Jun Pan ◽  
Bin Yao
Keyword(s):  
Trajectory Planning ◽  
Sharp Corner ◽  
Glass Edge

Single Point Incremental Forming of Friction Stir Processed AA6063-O Alloy

2015 ◽  
Author(s):  
Senthil Kumar Velukkudi Santhanam ◽  
Vigneshwaran Ganesan ◽  
Subramanian Pillappan Shanmuganatan
Keyword(s):  
Incremental Forming ◽  
Single Point ◽  
Three Dimensional ◽  
High Capacity ◽  
Numerical Control ◽  
Special Technique ◽  
Single Point Incremental Forming ◽  
Forming Process ◽  
Friction Stir ◽  
Increasing Demand

In the recent manufacturing trend and, in particular, in sheet metal forming, the requirement of customized production is still growing. Incremental forming is a special technique requiring no high capacity presses or set of dies, thus meeting the increasing demand for low volume production and rapid prototyping. The complex three dimensional parts of sheet metals are formed by the computer numerical control (CNC) movement of a simple generative hemispherical tool. In this paper, the single point incremental forming process is performed on friction stir processed AA 6063-O alloy. The process parameters for the experiment are taken based on L9 Orthogonal array. In this paper the maximum wall angle or the formability is investigated on a formed pyramid frusta. It is inferred that Friction stir process has improved the ductility of the aluminium alloy thus contributing to enhanced formability.

Isocontouring with sharp corner features

2019 ◽  
Vol 27 (1) ◽  
pp. 21-46
Author(s):  
Sui Gong ◽  
Timothy Newman
Keyword(s):  
Performance Analysis ◽  
Input Image ◽  
New Method ◽  
Sharp Corner ◽  
Sharp Corners

A method that achieves closed boundary finding in images (including slice images) with sub-pixel precision while enabling expression of sharp corners in that boundary is described. The method is a new extension to the well-known Marching Squares (MS) 2D isocontouring method that recovers sharp corner features that MS usually recovers as chamfered. The method has two major components: (1) detection of areas in the input image likely to contain sharp corner features, and (2) examination of image locations directly adjacent to the area with likely corners. Results of applying the new method, as well as its performance analysis, are also shown.

Minimum-Time Cornering for Manufacturing Machines Using Optimal Control

2014 ◽  
Author(s):  
Molong Duan ◽  
Chinedum E. Okwudire
Keyword(s):  
Optimal Control ◽  
Dynamic Programming ◽  
Preliminary Investigation ◽  
Free Form ◽  
Sharp Corner ◽  
Kinematic Constraints ◽  
Computationally Intensive ◽  
Future Work ◽  
Sharp Corners ◽  
Speed And Accuracy

When traversing sharp corners, manufacturing machines are forced to tradeoff speed and accuracy. The most common way of reducing this tradeoff is to smooth the sharp corner using a pre-specified curve (e.g., a circular arc or spline). However, pre-specified curves cannot guarantee optimal performance. This paper presents a preliminary investigation into the potential of using methods from optimal control to minimize this tradeoff. First, a useful simplification is made to the exact cornering problem to make it tractable. Dynamic programming is then used to determine the best free-form curve that minimizes corner traversal time while adhering to path tolerance and machine kinematic constraints. Significant improvements in cornering time are demonstrated compared to two methods that use pre-specified curves. However, dynamic programming is found to be too computationally costly, thus impractical. Less computationally intensive techniques in optimal control are considered for future work.

Stress Classification Lines Straight Through Singularities

2008 ◽  
Author(s):  
Arturs Kalnins
Keyword(s):  
Mesh Size ◽  
Theoretical Models ◽  
Pressure Vessels ◽  
The Other ◽  
Head Model ◽  
Sharp Corner ◽  
Element Analysis ◽  
Stress Classification ◽  
Bending Stresses ◽  
Sharp Corners

The paper considers geometries of pressure vessels and components for which the theoretical models contain sharp corners, representing singularities. The idea is proposed that a stress classification line passed straight through the singularity can yield linearized stresses that are applicable in pressure vessel design. Using elastic finite element analysis, details of the procedures by which this result can be achieved are given for two examples. One is a sharp corner at the toe of a fillet weld. Membrane and bending stresses are calculated directly in the toe plane, showing little or no dependence on mesh size. The other is an axisymmetric shell with a flat head and a sharp corner at the joint. The objective is to determine the primary-plus-secondary stress intensity on a Stress Classification Line (SCL) through the joint. Two methods are used. One is by determining the zone of valid SCLs and extrapolating the linearized stresses to the joint. The other is by calculating the linearized stresses directly on the SCL through the joint. Conditions for the use of the SCL through the joint for the shell/flat head model are established.

TOOL PATH GENERATION OF CONTOUR PARALLEL BASED ON ANT COLONY OPTIMISATION

2016 ◽  
Vol 78 (6-9) ◽  
Author(s):  
Haslina Abdullah ◽  
Rizauddin Ramli ◽  
Dzuraidah Abd Wahab ◽  
Jaber Abu Qudeiri
Keyword(s):  
Path Length ◽  
Manufacturing Industry ◽  
Tool Path ◽  
Previous Method ◽  
Ant Colony ◽  
Numerical Control ◽  
Ant Colony Optimisation ◽  
Sharp Corner ◽  
Machining Time ◽  
Simulation Results

In today’s competitive market of manufacturing industry, shorter machining time is one of important factor for reducing the manufacturer’s cost. This paper presents the minimisation of machining time of computer numerical control (CNC) by eliminating the uncut region of sharp corner based on contour parallel milling method.  Each uncut region at sharp corner is represented by uncut line which consists of two nodes in x and y directions.  An Ant Colony Optimisation (ACO) method is used to optimize the tool path length because of its capability to find the shortest tool path length. The optimisation of tool path length based on ACO algorithm ascertained that the cutting tool remove the uncut line once and able to eliminate the uncut region in the shortest tool path length. To observe the effectiveness of the ACO performance, the simulation results are compared with the results obtained by the previous method.  Finally the simulation results show the reduction of 5% machining time compared to previous method.

scholarly journals Toolpath Interpolation and Smoothing for Computer Numerical Control Machining of Freeform Surfaces: A Review

2019 ◽  
Vol 17 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Wen-Bin Zhong ◽  
Xi-Chun Luo ◽  
Wen-Long Chang ◽  
Yu-Kui Cai ◽  
Fei Ding ◽  
...  
Keyword(s):  
High Speed ◽  
Value Added ◽  
Computer Numerical Control ◽  
Numerical Control ◽  
Future Research ◽  
Numerical Control Machining ◽  
Advantages And Disadvantages ◽  
Product Surface ◽  
Function Integration ◽  
Increasing Demand

Abstract Driven by the ever increasing demand in function integration, more and more next generation high value-added products, such as head-up displays, solar concentrators and intra-ocular-lens, etc., are designed to possess freeform (i.e., non-rotational symmetric) surfaces. The toolpath, composed of high density of short linear and circular segments, is generally used in computer numerical control (CNC) systems to machine those products. However, the discontinuity between toolpath segments leads to high-frequency fluctuation of feedrate and acceleration, which will decrease the machining efficiency and product surface finish. Driven by the ever-increasing need for high-speed high-precision machining of those products, many novel toolpath interpolation and smoothing approaches have been proposed in both academia and industry, aiming to alleviate the issues caused by the conventional toolpath representation and interpolation methods. This paper provides a comprehensive review of the state-of-the-art toolpath interpolation and smoothing approaches with systematic classifications. The advantages and disadvantages of these approaches are discussed. Possible future research directions are also offered.

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