Surface Generation and Machining With Rational B-Splines for Turbomachinery Components

2002 ◽  
Author(s):  
Der Min Tsay ◽  
Chien Wen Chen ◽  
Jiun Ren Chen
Keyword(s):  
Tool Path ◽  
Surface Generation ◽  
Approximation Procedure ◽  
Least Squares Approximation ◽  
Practical Application ◽  
B Splines ◽  
Tool Paths ◽  
Compressor Impeller ◽  
Geometric Deviations ◽  
Five Axis

To five-axis point mill turbomachinery components, a least squares approximation procedure for generating tool paths in terms of parametric rational B-splines is presented. The detailed processes of using the appropriate parameters of rational B-splines that will reduce the amount of geometric deviations between the designed and machined part surfaces are proposed. Compared to a traditional linear tool path, a rational B-spline tool path can substantially reduce the number of blocks on machine controllers without compromising the accuracy. As a result, the machining efficiency and machine dynamic behavior can be improved. Numerical and experimental results are given to show such improvements. A practical application example for machining a centrifugal compressor impeller with 12 blades is also illustrated to demonstrate the reliability and usefulness of the developed procedure.

Study of The Tool Path Generation Method of an Ultra-Precision Spherical Complex Surface Based on a Five-Axis Machine Tool

2021 ◽  
Author(s):  
Tianji Xing ◽  
Xuesen Zhao ◽  
Zhipeng Cui ◽  
Rongkai Tan ◽  
Tao Sun
Keyword(s):  
Surface Roughness ◽  
Tool Path ◽  
Spherical Surface ◽  
Tool Path Generation ◽  
Path Generation ◽  
Tool Paths ◽  
Spherical Surfaces ◽  
Spherical Complex ◽  
Ultra Precision ◽  
Five Axis

Abstract The improvement of ultra-precision machining technology has significantly boosted the demand for the surface quality and surface accuracy of the workpieces to be machined. However, the geometric shapes of workpiece surfaces cannot be adequately manufactured with simple plane, cylindrical, or spherical surfaces because of their different applications in various fields. In this research, a method was proposed to generate tool paths for the machining of complex spherical surfaces based on an ultra-precise five-axis turning and milling machine with a C-Y-Z-X-B structure. Through the proposed tool path generation method, ultra-precise complex spherical surface machining was achieved. First, the complex spherical surface model was modeled and calculated, and then it was combined with the designed model to generate the tool path. Then the tool paths were generated with a numerically controlled (NC) program. Based on an ultra-precision three-coordinate measuring instrument and a white light interferometer, the machining accuracy of a workpiece surface was characterized, and t[1]he effectiveness of the provided tool path generation method was verified. The surface roughness of the machined workpiece was less than 90 nm. Furthermore, the surface roughness within the spherical region appeared to be less than 30 nm. The presented tool path generation method in this research produced ultra-precision spherical complex surfaces. The method could be applied to complex spherical surfaces with other characteristics.

Path Planning for Motion Control of Hexapod Machines

2001 ◽  
Author(s):  
Zhiming Ji ◽  
Zhenqun Li
Keyword(s):  
Path Planning ◽  
Machine Tools ◽  
Tool Path ◽  
Local Planning ◽  
Tool Path Planning ◽  
Tool Paths ◽  
Condition Optimization ◽  
Planning Methods ◽  
Tool Motion ◽  
Five Axis

Abstract The dramatic departure in structure of the hexapod machine tools from the traditional five-axis machines leads to the question: can the planning and control methods for the traditional CNC machines be used for the hexapod machine tools? We studied several tool motion characteristics, such as Jocabian matrices, path tracking errors and the extra degree of freedom (e-DOF), and found that the traditional five-axis planning methods cannot take into consideration of the kinematics performance variation and the e-DOF in a hexapod. A kinematics-based tool path planning scheme for the hexapods is therefore proposed. It combines the traditional tool path planning with the kinematic condition optimization. The optimization is a two-step process. First a high accuracy zone of the workspace is identified globally for the placement of the part. Then a set of 5-DOF tool paths is generated and extended to a set of 6-DOF tool paths based on the local planning of e-DOF. Finally the relationship between the e-DOF and the stiffness of the Hexapods, another factor in the use of e-DOF, are discussed.

Generation of Optimal Tool-Paths for Five-Axis Finish Milling of Free-Form Surfaces

2012 ◽  
Vol 500 ◽  
pp. 440-446
Author(s):  
Lin Geng ◽  
Yun Feng Zhang
Keyword(s):  
Genetic Algorithm ◽  
Tool Path ◽  
Free Form ◽  
Machining Efficiency ◽  
Interference Avoidance ◽  
Tool Paths ◽  
Modified Genetic Algorithm ◽  
Novel Method ◽  
Five Axis ◽  
Free Form Surfaces

In this paper, a novel method is proposed to generate optimal 5-axis finish tool-paths regarding joint movements and machining efficiency. A modified genetic algorithm is used to search for the optimal posture sequence along a tool-path while interference avoidance and surface finish quality act as constraints. Case studies are then provided to prove the effectiveness of the algorithm.

A New Architecture of Tool Path Generation for Five-Axis Control Machining

2005 ◽  
Vol 291-292 ◽  
pp. 501-506 ◽  
Author(s):  
K. Nakamoto ◽  
K. Shirase ◽  
Akifumi Morishita ◽  
E. Arai ◽  
T. Moriwaki
Keyword(s):  
Machine Tool ◽  
Real Time ◽  
Manufacturing Systems ◽  
Tool Path ◽  
Cutting Parameters ◽  
Tool Paths ◽  
Nc Program ◽  
Digital Copy ◽  
Copy Milling ◽  
Five Axis

NC machine tools, which are widely employed in manufacturing systems, are basically driven by NC programs. However, it requires extensive amount of time and efforts to generate high quality tool paths before a machining operation. An NC program for five-axis control machining is more difficult to generate because the motion of machine tool is more complicated. In this paper, a new architecture is proposed to autonomously control the machine tool without an NC program for more rapid and flexible machining. A technique called digital copy milling is developed to generate the tool paths in real time based on the principle of copy milling. It means that the cutting parameters can be adaptively controlled in order to maintain stable cutting process and to avoid the cutting troubles. In the experimental verification, the improved digital copy milling system for five-axis control milling successfully detected and avoided tool collision in real-time.

Smooth Cutting Operation Strategy for High Finishing Machining

2014 ◽  
Vol 875-877 ◽  
pp. 896-900
Author(s):  
Xiao Fei Bu ◽  
Hu Lin ◽  
Long Chen
Keyword(s):  
Tool Path ◽  
Tool Path Generation ◽  
Machining Process ◽  
Path Generation ◽  
Tool Paths ◽  
Constant Scallop Height ◽  
Simulation And Experiment ◽  
Cutting Operation ◽  
Five Axis ◽  
Finishing Machining

High finishing machining tool path generation methods are usually adopted for five-axis computer numerically controlled machining of sculptured surface parts. The quality of the high finishing machining has an important effect on that of the surface. In this paper, a high finishing machining tool path generation method is introduced to generate an optimal tool path. The initial tool path is firstly created based on the constant scallop height, then the derived tool paths are generated as a kind of the diagonal curve by the initial tool path, and at last, the tool path smoothing algorithm is applied to the generated tool path. This path algorithm can ensure higher level of smooth of the surface been machined. Finally, the results of simulation and experiment of the machining process are given to verify the smooth and applicability of the proposed method.

scholarly journals Five-Axis Tool Path Generation of Injection Mold Represented by T-Spline Surface

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Ce Shang ◽  
Hongyao Shen ◽  
Jianzhong Fu ◽  
Yangfan Sun ◽  
Shuhua Yue ◽  
...  
Keyword(s):  
Injection Molding ◽  
Tool Path ◽  
Order Continuity ◽  
Freeform Surfaces ◽  
Tool Paths ◽  
Spline Surface ◽  
Surface Models ◽  
Processing Order ◽  
Patch Boundary ◽  
Five Axis

Injection molding is widely used in industries to produce polymeric products. At present, compound NURBS surfaces are commonly used to represent freeform surfaces in mold models. This work uses T-spline surface with extraordinary control points instead of NURBS to represent freeform surfaces in mold models. Compared with NURBS, T-splines’ higher-order continuity facilitates the mold quality control especially at the patch boundary. And, its patch layout information can be utilized for tool path planning. We propose an algorithm to determine the patch processing order and generate nonretraction tool path for T-spline surface models. The tool paths are generated patch by patch using isoparametric strategy. Actual machining and injection molding experiments have been conducted. The result shows the feasibility of the proposed method, and the final product is in good quality.

Optimized Tool Path Planning for Five-Axis Flank Milling of Ruled Surface Considering Tolerance

2012 ◽  
Vol 472-475 ◽  
pp. 114-118
Author(s):  
Jun Feng Tian ◽  
Hu Lin ◽  
Zhuang Yao ◽  
Jie Li
Keyword(s):  
Path Planning ◽  
Tool Path ◽  
Critical Issue ◽  
Flank Milling ◽  
Tool Path Planning ◽  
Machining Error ◽  
Tool Paths ◽  
Global And Local Optimization ◽  
Global And Local ◽  
Five Axis

Five-axis CNC flank milling has recently received much attention in industry. Tool path planning is a critical issue in five-axis CNC flank milling operation. Previous work based on dynamic-programming generated optimal tool path by global minimising the machining error. However, global minimal machining error may not guarantee a local machining error controllable. Therefore, this paper proposes a method based on combination of global and local optimization, which makes tool path of five-axis flank milling optimal and error controllable. Oversize error of tool paths can be partially adjusted so that a specified tolerance is met in global optimization processing. Finally, the experiments of the simulative are made by this algorithm. The result verifies the feasibility and validity of the proposed scheme.

Removing Tool Marks for Impellers in Five-Axis Machining With Improved Interference-Free Tool Paths

2008 ◽  
Author(s):  
Hsin-Pao Chen ◽  
Hsin-Hung Kuo ◽  
Der-Min Tsay
Keyword(s):  
Centrifugal Compressor ◽  
Tool Path ◽  
Reverse Motion ◽  
Tool Marks ◽  
Tool Paths ◽  
Cutting Processes ◽  
Five Axis

The paper deals with the procedure of removing a gouge phenomenon on impeller surfaces in 5-axis machining. That is, when an impeller of a centrifugal compressor is being cut, tool marks on its surfaces may exist in finish milling due to reverse movements of moving axes along a 5-axis interference-free tool path. For generating interference-free cutter location (CL) data needed in rough and semi-finish 5-axis cutting processes, first, a simple yet useful approach is proposed. To identify the potential gouge area and to solve the problem for a tool path having reverse motion directions with its moving axes in finish milling, the CL data are further smoothed to remove the reverse movements about its rotating and tilting axes. The effectiveness of this procedure has been experimentally confirmed by successful 5-axis finish milling of an impeller without leaving tool marks on its surfaces.

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