Analysis and Compensation Strategy of Non-Linear Error in Five-Axis CNC Machining

2014 ◽  
Vol 644-650 ◽  
pp. 4967-4970 ◽  
Author(s):  
Hong Jun Liu ◽  
Ai Guo Zhang ◽  
Ji Bin Zhao ◽  
Jin Shang ◽  
Jun Liu
Keyword(s):  
Complex Surface ◽  
Cnc Machining ◽  
Machining Accuracy ◽  
Machining Error ◽  
Tool Axis ◽  
Non Linear ◽  
New Strategy ◽  
Tool Position ◽  
Five Axis ◽  
Tool Axis Vector

This paper presents a new strategy of analysis and compensation of non-linear error. Non-linear error is an important source of machining error in multi-axis numerical controlled machining and it is unavoidable. In view of tool positions optimization in five-axis CNC machining of complex surface, this paper presents a strategy for non-linear error compensation in five-axis machining: Firstly, non-linear error caused by the change of tool axis vector is analyzed and the non-linear error model is established, in order to get the maximum non-linear error of interpolation segment; Then, the tool position that meets the machining accuracy is obtained; Finally, Simulation and analysis of the model show that the proposed method is effective and greatly improves the geometric accuracy.

Research of the Tool Orientation Optimization with Kinematical Constraints

2013 ◽  
Vol 712-715 ◽  
pp. 2143-2148
Author(s):  
Hong Jun Liu ◽  
Jing Yu Cao ◽  
Ji Bin Zhao
Keyword(s):  
Coordinate System ◽  
Correction Method ◽  
Cnc Machining ◽  
Contact Points ◽  
Axis Of Rotation ◽  
Tool Axis ◽  
Efficient Processing ◽  
Velocity Constraints ◽  
Five Axis ◽  
Tool Axis Vector

Drastic change of the tool axis vector for five-axis CNC machining due to avoid global interference, proposed gentle forward, over-backward correction method to optimize the tool axis vector. Established a machine tool axis of rotation angular velocity constraints, and feed coordinate system, through the feed coordinate system adjust the inclination angle and swing angle of the existing tool axis vector to make the tool axis vector change between each adjacent cutter contact points satisfy the machine axis of rotation kinematics constraints and to ensure the continuity of feed rate during processing. Algorithm simulation examples show that the proposed method is reasonably practicable, make the tool axis vector changes fairing to ensure the smooth and efficient processing.

Nonequivalent Milling of Roller Gear Cams Based on Approximation Method of Offset Surface

2010 ◽  
Vol 97-101 ◽  
pp. 1998-2001
Author(s):  
Rong Yu Ge ◽  
Xian Ying Feng ◽  
Pei Quan Guo
Keyword(s):  
Approximation Method ◽  
Least Square ◽  
Control Points ◽  
Machining Error ◽  
Theoretical Tool ◽  
Tool Axis ◽  
Milling Method ◽  
Tool Position ◽  
Tool Axis Vector ◽  
Offset Surface

The roller gear cam surface is manufactured with nonequivalent milling method in many cases, by which the machining error is unavoidable. In order to simplify the tool position, we can transform one problem approximating the designed surface with the tool envelope surface to another problem approaching the theoretical tool axis trajectory surface with the actual one. Furthermore, the theoretical tool axis trajectory surface, which is an offset surface of the designed cam surface, is reconstructed by the NURBS ruled surface. In order to find the best tool axis vector to minimize the machining error, a simple least square approximation method is established to figure out all the control points of the NURBS tool axis trajectory surface. A numerical calculation and simulation example is described to verify the effectiveness of the tool position method proposed in the paper.

Calculation and Optimization of Cutter Position for Flank Milling Spatial Cam Based on NURBS

2008 ◽  
Vol 375-376 ◽  
pp. 578-582
Author(s):  
Rong Yu Ge ◽  
Xian Ying Feng ◽  
Xian Chun Song
Keyword(s):  
Tool Path ◽  
Optimization Method ◽  
Least Square ◽  
Flank Milling ◽  
Normal Vector ◽  
Machining Error ◽  
Cam Mechanism ◽  
Tool Axis ◽  
Milling Method ◽  
Tool Axis Vector

In some cases the spatial cam is manufactured with a cutter whose diameter is smaller than that of the roller of cam mechanism, which is defined as nonequivalent manufacture method in the paper. By the analysis for manufacture of contact lines between the cam and the roller, it is indicated that errors caused by the different directions of normal vector are unavoidable for the nonequivalent manufacture method. In order to find the best tool axis vector to minimize the machining error, this paper realized the nonequivalent machining of spatial cam surfaces using the NC flank milling method and proposed a new generation algorithm of the tool path based on NURBS. The NURBS ruled surface of tool axis trajectory is confirmed based on the least square optimization method and the machining error model is given. At last, a numerical calculation and simulation example is described to verify the effectiveness of the algorithm proposed in the paper.

Sensitivity Analysis Between Error Motions and Machined Shape Errors in Five-Axis Machining Centers: In Case of S-Shaped Machining Test by a Square End Mill

2019 ◽  
Author(s):  
Zongze Li ◽  
Ryuta Sato ◽  
Keiichi Shirase ◽  
Yukitoshi Ihara
Keyword(s):  
Sensitivity Analysis ◽  
Coordinate System ◽  
Complex Surface ◽  
Machining Accuracy ◽  
Machined Surface ◽  
Machining Center ◽  
Shape Errors ◽  
Machining Test ◽  
Tool Motion ◽  
Five Axis

Abstract Five-axis machining center, combined three linear and two rotary axes, has been increasingly used in complex surface machining. However, as the two additional axes, the machined surface under table coordinate system is usually different from the tool motion under machine coordinate system, and as a result, it is very tough to predict the machined shape errors caused by each axes error motions. This research presents a new kind of sensitivity analysis method, to find the relationship between error motions of each axis and geometric errors of machined shape directly. In this research, the S-shaped machining test is taken as a sample to explain how the sensitivity analysis makes sense. The results show that the presented sensitivity analysis can investigate how the error motions affect the S-shaped machining accuracy and predicted the influence of error motions on certain positions, such as the reversal errors of the axes around motion reversal points. It can be proved that the presented method can help the five-axis machining center users to predict the machining errors on the designed surface of each axes error motions.

Optimizing of Integral Impeller NC Program Based on the Material Removal Rate

2014 ◽  
Vol 1030-1032 ◽  
pp. 1305-1308
Author(s):  
Shi Chao Li ◽  
Song Lin Wu ◽  
Yan Kun Liang
Keyword(s):  
Material Removal Rate ◽  
Machine Tools ◽  
Material Removal ◽  
Removal Rate ◽  
Cnc Machining ◽  
Machining Process ◽  
Machining Accuracy ◽  
Nc Machine ◽  
Nc Machine Tools ◽  
Five Axis

It is a general processing technology that multi-axis NC machine tools is used for machining impeller at present. In order to improve the machining accuracy of the five-axis NC machine tools, the paper analyzes the computing interpolation error of the Multi-axis CNC system in detail. Some of the measures of tools selection have been proposed in purpose of diminishing the accumulative error of the system. The paper also establishes the optimized objective function to optimize the process parameters of the CNC machining based on the material removal rate. All these measures will improve the machining efficiency significantly and increase the stationary of the machining process.

Influence Analysis of Geometric Errors to Volumetric Machining Accuracy of a 5-Axis CNC Machine Tool

2013 ◽  
Vol 420 ◽  
pp. 85-91 ◽  
Author(s):  
Li Gang Cai ◽  
Qiu Nan Feng ◽  
Qiang Cheng ◽  
Pei Hua Gu ◽  
Cui Zhang
Keyword(s):  
Machine Tool ◽  
Geometric Error ◽  
Cnc Machining ◽  
Machining Accuracy ◽  
Cnc Machine Tool ◽  
Cnc Machine ◽  
Spatial Error ◽  
Matrix Differential ◽  
Multi Body ◽  
Five Axis

The precision model of the 5-axis CNC machine tool can be built up based on the theory of kinematics for multi-body system (MBS). And then based on the precision model, the sensitivity analysis established with matrix differential is a method of identifying geometric error parameters for machine tool. And the geometric error factors of major parts that have relatively significant influence on comprehensive spatial error of the machine tool are identified. Finally, important theoretical basis for improving the titanium alloy Five-axis CNC machining center reasonably and for the error compensation can be provided.

The Stiffness Field Modeling and Analyzing of Tool Position and Orientation of Five-Axis NC Machining System

2013 ◽  
Vol 589-590 ◽  
pp. 692-695
Author(s):  
Shi Wu ◽  
Da Qu ◽  
Xian Li Liu ◽  
Hong Xu ◽  
Zheng Chun Wang
Keyword(s):  
Virtual Work ◽  
Analytical Calculation ◽  
Complex Surface ◽  
Field Modeling ◽  
Machining System ◽  
Nc Machine ◽  
Position And Orientation ◽  
Tool Position ◽  
Composite Stiffness ◽  
Five Axis

The transformation of tool position and orientation has impact on processing performance of the system when processing complex surface. Five-axis NC machine center was taken for example in this article. Semi-analytical calculation method was taken for stiffness field of system. Based on virtual-work principle, the composite stiffness field modeling of system was built by methods of Jacobian matrix, point transformation matrix and finite element, etc. For the key point of workpiece surface which is needed analyzed, 3D space force ellipsoid was introduced, composite stiffness field was modeled and composite stiffness performance of system was analyzed by force ellipsoid with different tool position and orientation. Guiding conclusion was obtained for following works by analyzing influence of tool position and orientation on stiffness performance.

Tool Path Planning for Five-Axis NC Machining of Implant Shaping Mold for Cranioplasty

2011 ◽  
Vol 697-698 ◽  
pp. 292-296
Author(s):  
Liang Zhang ◽  
J. Li ◽  
B.C. Lou
Keyword(s):  
Path Planning ◽  
Tool Path ◽  
Nc Machining ◽  
Normal Curvature ◽  
Tool Path Planning ◽  
Lead Angle ◽  
Tool Axis ◽  
Nc Machine ◽  
Five Axis ◽  
Tool Axis Vector

The necessity for skull patch surface for cranioplasty was introduced and it was divided according to maximum normal curvature in the discrete points after skull patch surface dispersed. Then the tool axis vector was determined by the lead angle of the tool, corresponding to generating the tool path in each area; At last, the implant shaping mold for cranioplasty was produced by five-axis NC machine.

A Method to Calculate Tool Accessible Domain Based on the Point Model for the Multi-Axis CNC Machining

2012 ◽  
Vol 591-593 ◽  
pp. 781-784
Author(s):  
Bing Chen ◽  
Kai Liu ◽  
Qiu Shi Gao
Keyword(s):  
Contact Point ◽  
Cnc Machining ◽  
Curved Surface ◽  
Point Model ◽  
The Third ◽  
Tool Axis ◽  
Accessible Domain ◽  
Tool Axis Vector

This paper puts forward a kind of method which can calculate tool accessible domain for tool axis optimization in the complex curved surface multi-axis machining. At first , the point model has been construced on the base of constrained surface.The second, based on any possible direction of tool axis vector of a given cutting contact point, the distance between a point and a line is used to decide whether occurs collision and interfence. The third, two angles related with cutter-axes vector is definied. The regulation of tool accessible domain can be implemented by getting the boundary of the discrete points in the coordinate planes. Finally, a tool has been developed to calculate tool accessible domain, and an example is given to verify the effectiveness of the method.

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