Research on free-form surface optimization method based on surface shape transformation

2021 ◽  
Author(s):  
Junyang Li ◽  
Liang Zhou ◽  
You Long ◽  
ZHUO Li ◽  
Longfei Liu
Keyword(s):  
Optimization Method ◽  
Surface Shape ◽  
Free Form ◽  
Shape Transformation ◽  
Free Form Surface ◽  
Surface Optimization

Path Planning For Robotic Polishing of Sheet Metal Parts

2021 ◽  
Author(s):  
Yuezhi (Sean) Liu ◽  
Fengfeng (Jeff) Xi ◽  
Reza Faieghi
Keyword(s):  
Path Planning ◽  
Sheet Metal ◽  
Contact Force ◽  
Optimal Path ◽  
Surface Shape ◽  
Free Form ◽  
Metal Parts ◽  
Contact Areas ◽  
Sheet Metal Parts ◽  
Free Form Surface

Abstract Unlike solid parts, the deformation caused by a contact force during robotic polishing of sheet metal parts has become an issue. In this paper, a path planning method is purposed to resolve this issue. This method includes three steps. The first step is to apply the Hertz theory to compute the contact areas between the tool head and the free-form surface of a sheet metal part. The second step is to apply the finite element method to compute the deformation under a contact force. The third step is to reconstruct the deformed free-form surface and modify the contact areas accordingly. The underlying problem is dynamic because the deformed surface shape changes as the tool head moves along a tool path. Based on the proposed method, an optimal path can be determined to achieve full coverage of the entire surface without over or under polishing.

Multiple-Points Constraints Based Deformation for Free-Form Surfaces

1999 ◽  
Author(s):  
J. M. Zheng ◽  
K. W. Chan ◽  
I. Gibson
Keyword(s):  
Surface Deformation ◽  
Single Point ◽  
Displacement Function ◽  
Surface Shape ◽  
Free Form ◽  
Surface Model ◽  
Deformation Method ◽  
Multiple Points ◽  
Free Form Surface ◽  
Free Form Surfaces

Abstract There is an increasing demand in the conceptual design for more intuitive methods for creating and modifying free-form curves and surfaces in CAD modeling systems. The methods should be based not only on the change of the mathematical parameters but also on the user’s specified constraints and shapes. This paper presents a new surface representation model for free-form surface deformation representation. The model is a combination of two functions: a displacement function and a function for representing an existing NURBS surface called parent surface. Based on the surface model, the authors develop two deformation methods which are named SingleDef (Single-point constraint based deformation method), and MultiDef (Multiple-points constraints based deformation method). The techniques for free-form surface deformation allow conceptual designer to modify a parent surface by directly applying point constraints to the parent surface. The deformation methods are implemented and taken in an experimental CAD system. The results show that the designer can easily and intuitively control the surface shape.

Studies on the Algorithm for Five-Axis NC Machining with Triangular Facet Model

2013 ◽  
Vol 385-386 ◽  
pp. 726-730
Author(s):  
Ren Xian Geng ◽  
Hou Jun Qi ◽  
Xin Pan ◽  
Zhi Gang Liu
Keyword(s):  
Tool Path ◽  
Nc Machining ◽  
Surface Shape ◽  
Free Form ◽  
Cutting Efficiency ◽  
Triangular Facet ◽  
Constant Scallop Height ◽  
Free Form Surface ◽  
Five Axis ◽  
Facet Model

Using five-axis equipment for NC machining of free-form surface is an effective way to improve machining quality and machining efficiency, the surface shape and the five coordinate of the complexity of the machine tool movement led to its tool path planning technology is difficult. The paper aimed at the five coordinate NC machining of free-form surface and puts forward a five-axis NC machining method based on triangular facet model. The research based on triangular facet model, using constant scallop height method to calculate the step distance and improve the cutting efficiency to a great extent. In the process, tool path is generated, combining with the method of configuration space interference free.

A Golay3 sparse aperture optical system of primary mirror with free-form surface

2021 ◽  
Vol 28 (1) ◽  
pp. 113-118
Author(s):  
Bin Chen ◽  
Quanying Wu ◽  
Junliu Fan
Keyword(s):  
Optical System ◽  
Free Form ◽  
Primary Mirror ◽  
Sparse Aperture ◽  
Free Form Surface

Tool Path Generation for Five-Axis Controlled Machining of Free-Form Surface Using Barrel Tool: Control of Contact Point on Cutting Edge

2020 ◽  
Author(s):  
Tomonobu Suzuki ◽  
Koichi Morishige
Keyword(s):  
Tool Path ◽  
Contact Point ◽  
Cutting Edge ◽  
Free Form ◽  
End Mill ◽  
Ball End Mill ◽  
Surface Machining ◽  
Free Form Surface ◽  
The Cost ◽  
Five Axis

Abstract This study aimed to improve the efficiency of free-form surface machining by using a five-axis controlled machine tool and a barrel tool. The barrel tool has cutting edges, with curvature smaller than the radius, increasing the pick feed width compared with a conventional ball end mill of the same tool radius. As a result, the machining efficiency can be improved; however, the cost of the barrel tool is high and difficult to reground. In this study, a method to obtain the cutting points that make the cusp height below the target value is proposed. Moreover, a method to improve the tool life by continuously and uniformly changing the contact point on the cutting edge is proposed. The usefulness of the developed method is confirmed through machining simulations.

Application of Convex Hull for Tool Interference Avoidance in 5-Axis CNC Machining

1996 ◽  
Author(s):  
Yuan-Shin Lee ◽  
Tien-Chien Chang
Keyword(s):  
Convex Hull ◽  
Tool Path ◽  
Correction Method ◽  
Nc Machining ◽  
Cnc Machining ◽  
Free Form ◽  
Interference Avoidance ◽  
Tool Interference ◽  
Free Form Surface ◽  
Free Form Surfaces

Abstract In this paper, a methodology of applying convex hull property in solving the tool interference problem is presented for 5-axis NC machining of free-form surfaces. Instead of exhausted point-by-point checking for possible tool interference, a quick checking can be done by using the convex hull constructed from the control polygon of free-form surface modeling. Global tool interference in 5-axis NC machining is detected using the convex hull of the free-form surface. A correction method for removing tool interference has also been developed to generate correct tool path for 5-axis NC machining. The inter-surface tool interference can be avoided by using the developed technique.

Creation and Manipulation of Complex Displacement Features During the Conceptual Phase of Design

1996 ◽  
Author(s):  
P. A. van Elsas ◽  
J. S. M. Vergeest
Keyword(s):  
Boundary Conditions ◽  
Surface Feature ◽  
Free Form ◽  
Shape Design ◽  
Surface Model ◽  
Test Results ◽  
Base Surface ◽  
Feature Design ◽  
Data Explosion ◽  
Free Form Surface

Abstract Surface feature design is not well supported by contemporary free form surface modelers. For one type of surface feature, the displacement feature, it is shown that intuitive controls can be defined for its design. A method is described that, given a surface model, allows a designer to create and manipulate displacement features. The method uses numerically stable calculations, and feedback can be obtained within tenths of a second, allowing the designer to employ the different controls with unprecedented flexibility. The algorithm does not use refinement techniques, that generally lead to data explosion. The transition geometry, connecting a base surface to a displaced region, is found explicitly. Cross-boundary smoothness is dealt with automatically, leaving the designer to concentrate on the design, instead of having to deal with mathematical boundary conditions. Early test results indicate that interactive support is possible, thus making this a useful tool for conceptual shape design.

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