Optimized NURBS Based G-Code Part Program for High-Speed CNC Machining

2014 ◽  
Author(s):  
Sai Ashish Kanna ◽  
Andres Tovar ◽  
Jason Soungjin Wou ◽  
Hazim El-Mounayri
Keyword(s):  
Code Generation ◽  
High Speed ◽  
Tool Path ◽  
Optimization Method ◽  
Cnc Machining ◽  
Part Program ◽  
Tool Trajectory ◽  
Minimum Number ◽  
G Code ◽  
Gear Profile

This work presents the automation of high-accuracy CNC tool trajectory planning from CAD to G-code generation through optimal NURBs surface approximation. The proposed optimization method finds the minimum number of NURBS control points for a given admissible theoretical cord error between the desired and manufactured surfaces. The result is a compact part program that is less sensitive to data starvation than circular and spline interpolations with potential better surface finish. The proposed approach is demonstrated with the tool path generation of an involute gear profile.

A Novel Automatic Feedrate Adjustment Method for Die-Cavity Roughing

2005 ◽  
Vol 291-292 ◽  
pp. 625-630
Author(s):  
Min Jie Wang ◽  
Y.J. Cai ◽  
W.G. Yan
Keyword(s):  
High Speed ◽  
Tool Path ◽  
Orthogonal Cutting ◽  
Cnc Machining ◽  
Surface Model ◽  
Machining Time ◽  
Surface Machining ◽  
Cutter Deflection ◽  
Sculptured Surface Machining ◽  
Volumetric Models

Sculptured surface machining is a critical process commonly used in die and mold industries. Since there is a lack of scientific tools in practical process planning stages, feedrates of CNC machining are selected based on previous experiences. In the selection of feedrate, the feedrate is set an individual conservative constant value all along the die cavity roughing processes in order to avoid undesirable results such as chipping, cutter breakage or over-cut due to excessive cutter deflection. Usually, volumetric models or vector force models used for optimizaton of feedrates must be created to get the variable feedrates along the tool path. Considering the die cavity roughing being a 2.5D cutting, a novel cutting force surface model is created based on orthogonal cutting tests to adjust the feedrates. The model is tested by a typical die-cavity roughing, thinning down machining time and balanced cutting-load can be attained. The presented feedrate scheduling characterized by balancing the cutting-loads in die-cavity roughing will be more significative in high speed machining.

Research on Subdivision Interpolation for High Speed CNC Applications

2011 ◽  
Vol 141 ◽  
pp. 449-454
Author(s):  
Jing Chuan Dong ◽  
Qing Jian Liu ◽  
Tai Yong Wang
Keyword(s):  
High Speed ◽  
Tool Path ◽  
Tracking Error ◽  
Linear Interpolation ◽  
Cnc Machining ◽  
Contour Error ◽  
Interpolation Scheme ◽  
Simulation Results ◽  
Cnc Controller ◽  
Better Than

High speed CNC machining relies on the smooth interpolation of tool path in order to prevent impact and vibration. We present a new interpolation scheme for CNC controller based on 6-point subdivision. The subdivision interpolation improves the smoothness of the original trajectory, while maintaining the accuracy. The algorithm is simple and effective, and therefore it is suitable for real-time execution in CNC controllers. Simulation results show that the proposed method performs better than linear interpolation, since the tracking error and contour error is reduced.

Development of the PC-based Integrated Interface System of STEP file for CNC Machining Application: Circular Features

2020 ◽  
Vol 12 (7) ◽  
Author(s):  
Muhammad Abdulrahim Rabbani Md Sharizam ◽  
◽  
Saiful Bahri Mohamed ◽  
Tengku Mohd Shahrir Tengku Sulaiman ◽  
Zammeri Abd Rahman ◽  
...  
Keyword(s):  
Tool Path ◽  
Boundary Representation ◽  
Cnc Machining ◽  
Numerical Control ◽  
Setup Cost ◽  
Machining Features ◽  
Interface System ◽  
Computer Aided ◽  
G Code ◽  
Cam Software

STEP is a general data format that observes the international standard ISO 10303-21. STEP means Standard for the Exchange of Product model data. It consists of the 3D geometry of a computer-aided design (CAD) model in the configuration of boundary representation (B-rep). By extracting, refining and decoding the geometric data correctly, the data can be utilized for writing G-code for Computer Numerical Control (CNC) machining application. Usually G-codes can either be manually generated by skilled machinists or automatically generated by computer-aided manufacturing (CAM) software. However, manually generated G-code is inefficient and susceptible to error. Meanwhile automated generation G-code requires significant setup cost. This paper describes the design and development of an integrated interface system, an instrument aimed to be used to analyze STEP files and generate machining tool path based on ISO 6983 format. This developed interface reduces the need for high setup cost as well as eliminates human limitations. The interface at present is able of detecting circular machining features on the workpiece. Circular machining features are created by 3D modelling software and retained as STEP file. The STEP file which contains geometrical data is then uploaded to the interface system as an input file which is structurally analyzed and processed. Finally, the ideal machining tool path in the G Code format is proposed and generated. By bypassing the CAM software and its proprietary post processor, the outcome of this research is important to enhance compatibility between different CNC machine systems

Adaptive Error Control Algorithm for High Speed Two-Axis CNC Contouring

2013 ◽  
Vol 584 ◽  
pp. 149-153
Author(s):  
Jing Chuan Dong ◽  
Tai Yong Wang ◽  
Yan Yu Ding ◽  
Yu Long Cui
Keyword(s):  
High Speed ◽  
Control Algorithm ◽  
Error Control ◽  
Tool Path ◽  
Cnc Machining ◽  
Numerical Control ◽  
Contour Error ◽  
Curvature Radius ◽  
Contour Error Control ◽  
Cnc Controller

The computerized numerical control (CNC) machining program usually contains a large number of small line segments. The CNC controller must generate a smooth and optimized motion profile to achieve high speed and high precision machining. This paper proposed an adaptive contour error control algorithm. The curvature radius of the tool path is obtained by analyzing the geometry relationship. The algorithm uses the curvature information and a simplified servo error model to realize contour error estimation and adaptive control. The target feet rate filter (TFF) and planning unit merging (PUM) are introduced to obtain a smooth profile. Experiments result demonstrated the efficiency of the proposed algorithm.

A Speed Smoothing Algorithm in Micro Segment High-Speed Machining

2012 ◽  
Vol 190-191 ◽  
pp. 647-650
Author(s):  
Lei Luo ◽  
Jun Hu ◽  
Fan Deng
Keyword(s):  
High Speed ◽  
Tool Path ◽  
Simulation Analysis ◽  
Cnc Machining ◽  
Iteration Algorithm ◽  
Smoothing Algorithm ◽  
High Speed Machining ◽  
Continuous Feed ◽  
The Impact ◽  
Dynamic Restriction

A forecasting speed smoothing algorithm based on inflexion velocity has been presented in this paper. According to the geometry characters of the machining trajectory, the inflexions in CNC machining tool path can be confirmed by using the designed algorithm. The line segment between each inflexion can be treated as a continuous path that can be tracked under the continuous feed rate. Moreover the maximal permitted link-up speed can be calculated through dynamic restriction equations and the real-time modification of sinusoidal acceleration can be realized by using the speed iteration algorithm. By simulation analysis, it can be revealed that both the flexibility and efficiency of the CNC machining has been improved and the impact to the machine tool has been greatly reduced.

A Line and Arc Transition Tool Radius Compensation Algorithm for Convex Contour

2012 ◽  
Vol 542-543 ◽  
pp. 1167-1171
Author(s):  
Chun Wang ◽  
Sheng Lin ◽  
Quan Hai Peng
Keyword(s):  
High Speed ◽  
Tool Path ◽  
Cnc Machining ◽  
Work Piece ◽  
Sharp Corner ◽  
Machining Time ◽  
Tool Paths ◽  
Long Time ◽  
Tangent Direction ◽  
Radius Compensation

Tool radius compensation is necessary to CNC machining. However, B tool radius compensation leads to work piece burning at the sharp corner of convex contour because of the long time contacts between the work piece and tool, and C tool radius compensation frequently changes machining feed rate for its broken line tool path. This paper presents a novel tool radius compensation method suitable for high speed machining of convex contour, which have the advantages of both B and C tool radius compensation. It uses compound transition with line and arc between the adjacent blocks of CNC program. The offset tool paths of the adjacent blocks extend a small line segment respectively along their tangent direction, then insert an arc between the end points of the two extended line segments. The results of simulation and experiments show that the machining quality of the sharp corner of convex contour is improved and the machining time is shorter than C tool radius compensation.

CNC Routine for Manufacturing Spur Gear

2014 ◽  
Vol 598 ◽  
pp. 539-545
Author(s):  
Omar Monir Koura
Keyword(s):  
Spur Gear ◽  
Cnc Machining ◽  
Spur Gears ◽  
Part Program ◽  
Wire Cutting ◽  
Gear Profile ◽  
Special Cycle

Manufacturing of spur gears on CNC machining centers and CNC wire cutting is randomly used due to the difficulty in producing the perfect gear profile. The present paper faces this problem by developing a special cycle that can be used on both types of machines. A code for this cycles is designed to read the part program of any product and if detects the code nominated for this cycle (G77) which indicates that a gear needs to be cut, it develops the geometrical statements of the gear profile and the motion statements. It follows by writing the full code of the cycle. The validity of the designed model was verified on a CNC simulator.

Study on Numerical Control Machining Technology of Toy Car Cover

2012 ◽  
Vol 150 ◽  
pp. 235-239
Author(s):  
Jin Gui Wan ◽  
Xi Ping Wang ◽  
Wei Ding ◽  
Wei Li
Keyword(s):  
Code Generation ◽  
Tool Path ◽  
Integrated Design ◽  
Cnc Machining ◽  
Numerical Control ◽  
Machining Process ◽  
Three Dimension ◽  
Cnc Milling ◽  
Design And Manufacturing ◽  
Cad Cam

Based on UG II CAD/CAM system, the CNC machining process and technology of a toy car cover is studied in this paper. It includes three-dimension (3D) modeling, machining programming, fixture design and manufacturing, process parameter setting, tool path planning and editing, NC code generation (post processing), simulation processing, and practical machining. The part is manufactured successfully in a 3-axis CNC milling machine. It has a desirable shape and high accuracy. The result shows that, with the powerful CAD/CAM capabilities of UG, the integrated design and manufacturing of complex curved surface shell part is easy to implement, the process is reasonable and efficient, and the NC program is reliable. This exmple fully reflects the advantages of UG CAD/CAM integration technology. The method and technology introduced in this paper can provide valuable reference for processing of similar parts.

Effect of Tool Path Strategies in Pocket Milling of Aluminium Epoxy

2014 ◽  
Vol 903 ◽  
pp. 15-20 ◽  
Author(s):  
Rusdi Mat Song ◽  
Safian Sharif ◽  
Ahmad Yasir Md Said ◽  
Mohd Tanwyn Mohd Khushairi
Keyword(s):  
Computer Aided Design ◽  
High Speed ◽  
Tool Path ◽  
High Speed Steel ◽  
Cutting Parameters ◽  
Cnc Machining ◽  
Numerical Control ◽  
Machining Time ◽  
Pocket Milling ◽  
Cad Cam

Selection of the most suitable tool path strategy is very essential during machining especially in computer aided design and manufacture (CAD/CAM) as well as computer numerical control (CNC) machining. Existence of various tool path strategies to be applied on advanced composite materials such as aluminium epoxy required extensive researches in determining the best combination of tool path and cutting parameters for better machinability performance. Pocket milling of aluminium epoxy specimen via CAD/CAM was conducted in this study to investigate the effect of three types of tool path strategies namely Inward Helical, Outward Helical and Back and Forth. Uncoated high speed steel (HSS-Co8) ball end mill was used throughout the experiments. The machining responses that were evaluated include machining time, tool wear rate, tool life and surface finish of the machined pockets. In general, the effect of tool path strategy was highly significant on the machining responses and results showed that Back and Forth strategy offered the best machinability results when compared to the other strategies.

High Speed Information Network Planning using Stochastic Optimization Method

2013 ◽  
Author(s):  
Ki-Sang Song ◽  
Arun K. Somani
Keyword(s):  
Stochastic Optimization ◽  
Network Design ◽  
Multimedia Information ◽  
High Speed ◽  
Minimum Cost ◽  
Optimization Method ◽  
Multimedia Communication ◽  
Network Design Problem ◽  
Information Network ◽  
Traffic Characteristics

From the 1994 CAIS Conference: The Information Industry in Transition McGill University, Montreal, Quebec. May 25 - 27, 1994.Broadband integrated services digital network (B-ISDN) based on the asynchronous transmission mode (ATM) is becoming reality to provide high speed, multi bit rate multimedia communications. Multimedia communication network has to support voice, video and data traffics that have different traffic characteristics, delay sensitive or loss sensitive features have to be accounted for designing high speed multimedia information networks. In this paper, we formulate the network design problem by considering the multimedia communication requirements. A high speed multimedia information network design alogrithm is developed using a stochastic optimization method to find good solutions which meet the Quality of Service (QoS) requirement of each traffic class with minimum cost.

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