Nonlinear Error Compensation Based on the Optimization of Swing Cutter Trajectory for Five-Axis Machining

2021 ◽  
Author(s):  
Liangji Chen ◽  
Jinmeng Tang ◽  
Wenyi Wu ◽  
Zisen Wei
Keyword(s):  
Machine Tool ◽  
Error Compensation ◽  
Rotation Axis ◽  
Kinematic Model ◽  
Free Form ◽  
Nonlinear Error ◽  
Center Point ◽  
Parameterized Model ◽  
Five Axis ◽  
The Impact

Abstract In order to solve the problem of deviation between actual and theoretical machining paths due to the presence of rotation axis in five-axis machining, an interpolation algorithm based on the optimization of swing cutter trajectory and the method of corresponding nonlinear error compensation are proposed. Taking A-C dual rotary table five-axis machine tool as an example, the forward and reverse kinematic model of the machine tool is established according to the kinematic chain of the machine tool. Based on the linear interpolation of rotary axis, the generation mechanism of nonlinear error is analyzed, the modeling methods of cutter center point and cutter axis vector trajectory are proposed respectively, and the parameterized model of swing cutter trajectory is formed. The formula for the nonlinear error is obtained from the two-dimensional cutter center point trajectory. According to the established model of swing cutter trajectory, the synchronous optimization method of cutter center point trajectory and cutter axis vector trajectory is proposed, and the nonlinear error compensation mechanism is established. First, pre-interpolation is performed on the given cutter location data to obtain a model of the swing cutter trajectory for each interpolated segment. Then the magnitude of the nonlinear error is calculated based on the parameters of the actual interpolation points during formal interpolation, and the interpolation points with large errors are compensated for the nonlinear error. The simulation results show that the proposed method can effectively reduce the impact of nonlinear errors on machining, and is of high practical value for improving the accuracy of cutter position and the quality of complex free-form machining in five-axis machining.

The Research of Nonlinearity Error Control on Five-Axis Machining Post Processor

2011 ◽  
Vol 311-313 ◽  
pp. 2353-2357 ◽  
Author(s):  
Qing Chun Tang ◽  
Jun He ◽  
Lan Lan Gao ◽  
Yu Huo Lai ◽  
Xue Ming Fang
Keyword(s):  
Machine Tool ◽  
Error Compensation ◽  
Error Control ◽  
Estimation Method ◽  
Linear Interpolation ◽  
Nonlinearity Error ◽  
Motion Error ◽  
Nonlinear Error ◽  
Tool Motion ◽  
Five Axis

Abstract：This paper analyses the causes and effective estimation method of nonlinear error; By machine tool motion solution, established a five-axis machine tool BV100 motion transformation mathematical models, combined with linear interpolation principle established the error compensation and nonlinear motion error model of the machine tool .by VB language, developed nonlinear error compensation function of special post process; and through the impeller cutting experiment validate the processor is correct and practical.

Measuring Path without Tool Center Point Function for B-Type Five-Axis Machine Tool

2013 ◽  
Vol 284-287 ◽  
pp. 493-497
Author(s):  
Chen Hua She ◽  
Wen Yuh Jywe ◽  
Jheng Jie Huang
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
Simulation Software ◽  
Free Form ◽  
Motion Error ◽  
Center Point ◽  
Wide Range ◽  
Assembly Error ◽  
Five Axis ◽  
Free Form Surfaces

Five-axis machine tools with three linear axes and two rotary axes can produce complex products with free-form surfaces requiring a high degree of precision. However, motion errors of each axis and its assembly error are accumulated in the positioning error of the cutting tool relative to a workpiece. There are many devices reported in the literature on the identification of kinematic errors based on the measurement of the motion error. According to the measurement paths in the ISO draft, ISO/CD 10791-6, the kinematic tests can be applicable to different configurations of five-axis machine tools. However, the advanced controller with tool center point (TCP) function is required while performing kinematic tests. This paper proposed the methodology of generating measurement path without TCP function for B-type five-axis machine tool. The developed module can transform the measuring path into an NC program used for lower hand controller. Verification using VERICUT solid cutting simulation software demonstrated the veracity of the generated five-axis NC code. The proposed methodology is applicable in a wide range of five-axis machine tool configurations; however, further testing with actual measuring applications will be required for further verification.

scholarly journals Five-axis Tri-NURBS Spline Interpolation Method Considering Nonlinear Error Compensation and Correction of CC Paths

2021 ◽  
Author(s):  
Liangji Chen ◽  
Zisen Wei ◽  
Longfei Ma
Keyword(s):  
Error Compensation ◽  
Interpolation Method ◽  
Spline Interpolation ◽  
Nonlinear Error ◽  
Center Point ◽  
Spline Curves ◽  
Tool Axis ◽  
Five Axis ◽  
Tool Axis Vector ◽  
Interpolation Parameter

Abstract In order to improve the accuracy of tool axis vector position and direction in traditional five-axis NURBS interpolation methods and the controlling accuracy of cutter contacting(CC) paths between cutter and work-piece, a five-axis Tri-NURBS spline interpolation method is presented in this article. Firstly, the spline interpolation instruction format is proposed, which includes three spline curves, such as CC point spline, tool center point spline and tool axis point spline. The next interpolation parameter is calculated based on the tool center point spline combined with the conventional parametric interpolation idea. Different from the traditional spline interpolation using the same interpolation parameter for all spline curves, the idea of equal ratio configuration of parameters is proposed in this paper to obtain the next interpolation parameter of each spline curve. The next interpolation tool center point, tool axis point and CC point on the above three spline curves can be obtained by using different interpolation parameters, so as to improve the accuracy of tool axis vector position and direction. Secondly, the producing mechanism of CC paths’ nonlinear error of the traditional spline interpolation is analyzed and the mathematical calculation model of the nonlinear error is established. And then, the nonlinear error compensation and correction method is also put forward to improve the controlling accuracy of CC paths. In this method, the next CC point on the cutter can be firstly obtained according to the next interpolation tool center point, tool axis point and CC point on the three spline curves. And then, the error compensation vector is determined with the two next CC points. To correct the nonlinear error between the next CC point on the cutter and the CC point spline curve, the cutter is translated so that the two next CC points can be coincided. In the end, the new tool center point and tool axis point after translation can be calculated to obtain the motion control coordinates of each axis of machine tool. The MATLAB software is used as simulation of the real machining data. The results show that the proposed method can effectively reduce the CC paths’ nonlinear error. It has high practical value for five-axis machining in effectively controlling the accuracy of CC paths and im-proving the machining accuracy of complex surfaces.

Table-Based Volumetric Error Compensation of Large Five-Axis Machine Tools

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Jennifer Creamer ◽  
Patrick M. Sammons ◽  
Douglas A. Bristow ◽  
Robert G. Landers ◽  
Philip L. Freeman ◽  
...  
Keyword(s):  
Machine Tool ◽  
Error Compensation ◽  
Machine Tools ◽  
Data Gathering ◽  
Measurement Data ◽  
Geometric Error ◽  
Compensation Method ◽  
Geometric Errors ◽  
Simultaneous Generation ◽  
Five Axis

This paper presents a geometric error compensation method for large five-axis machine tools. Compared to smaller machine tools, the longer axis travels and bigger structures of a large machine tool make them more susceptible to complicated, position-dependent geometric errors. The compensation method presented in this paper uses tool tip measurements recorded throughout the axis space to construct an explicit model of a machine tool's geometric errors from which a corresponding set of compensation tables are constructed. The measurements are taken using a laser tracker, permitting rapid error data gathering at most locations in the axis space. Two position-dependent geometric error models are considered in this paper. The first model utilizes a six degree-of-freedom kinematic error description at each axis. The second model is motivated by the structure of table compensation solutions and describes geometric errors as small perturbations to the axis commands. The parameters of both models are identified from the measurement data using a maximum likelihood estimator. Compensation tables are generated by projecting the error model onto the compensation space created by the compensation tables available in the machine tool controller. The first model provides a more intuitive accounting of simple geometric errors than the second; however, it also increases the complexity of projecting the errors onto compensation tables. Experimental results on a commercial five-axis machine tool are presented and analyzed. Despite significant differences in the machine tool error descriptions, both methods produce similar results, within the repeatability of the machine tool. Reasons for this result are discussed. Analysis of the models and compensation tables reveals significant complicated, and unexpected kinematic behavior in the experimental machine tool. A particular strength of the proposed methodology is the simultaneous generation of a complete set of compensation tables that accurately captures complicated kinematic errors independent of whether they arise from expected and unexpected sources.

Tool Path Planning and NC Generation of Tilted Plane Machining Features for Five-Axis Machining

2011 ◽  
Vol 697-698 ◽  
pp. 309-313 ◽  
Author(s):  
Chen Hua She ◽  
Yueh Hsun Tsai
Keyword(s):  
Machine Tool ◽  
Degrees Of Freedom ◽  
Tool Path ◽  
Simulation Software ◽  
Free Form ◽  
Parent Child Relationship ◽  
Machining Feature ◽  
Machining Errors ◽  
Tilted Plane ◽  
Five Axis

Designs of free-form surface products are becoming increasingly complex. In traditional three-axis machine tool machining, errors that are caused by repetitive positioning and the costs of fixture jig design and manufacturing are critical. Since multi-axis machining provides two more rotational degrees of freedom than a three-axis machine tool, the former can solve these problems, and has therefore become the trend of precision cutting. As multi-axis machined parts often have holes and grooves on the tilted plane, this work proposes a method for machining tilted working plane features and for NC generation on a five-axis machine. The developed module can provide common geometric features, allowing the user to alter the machining feature and sequence on the tilted plane quickly using the parent-child relationship in a tree diagram, and plan the tool path. The postprocessor module developed in this paper can transform the tool path into an NC program required for machining. Finally, solid cutting simulation software is utilized to confirm the feasibility and correctness of the tool path and NC data of the tilted plane machining feature.

scholarly journals Tool-Path Planning Method For Kinematics Optimization of Blade Machining On Five-Axis Machine Tool

2022 ◽  
Author(s):  
Zhongyang Lu ◽  
Xu Yang ◽  
Ji Zhao
Keyword(s):  
Path Planning ◽  
Machine Tool ◽  
Tool Path ◽  
Machining Process ◽  
Free Form ◽  
Traditional Methods ◽  
Machining Quality ◽  
Blade Machining ◽  
Kinematic Performance ◽  
Five Axis

Abstract Planning tool-paths on free-form surfaces is a widely discussed issue. However, traditional methods of generating paths capable of meeting all the requirements of blade machining remain challenging. In this study, a new iso-parametric path-planning strategy based on a novel parameterization method combined with the conformal transformation theory was proposed. The proposed method could adapt to the curvature characteristics of the blade surface, improving the kinematic performance of the machining process, reducing multi-axis coordinated motion control complexity, and improving machining quality. The proposed method was then compared with three traditional methods. The influence of the tool-path on the kinematic performance of the machine tool was quantitatively examined based on the kinematics models of two different machine tools. A large cutting depth milling experiment was conducted to verify that kinematics optimization could improve machining quality. The proposed method provides a more reasonable path-planning approach for blade machining on a five-axis machine tool, which is of great significance in reducing the cost of blade machining and the risks of blade failure. Moreover, it is of great significance for the large-scale automated production of blades.

Calibration and Optimization for Spindle-Tilting Type Five-Axis Machine Tools with Inclinable Head AB Based on Compensation of Rotation Axis Direction Error

2013 ◽  
Vol 288 ◽  
pp. 19-24
Author(s):  
Feng Liu ◽  
Hu Lin ◽  
Liao Mo Zheng ◽  
Feng Wang ◽  
Lei Yang
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
Rotation Axis ◽  
Position Vector ◽  
Machining Accuracy ◽  
Direction Error ◽  
Rotation Center ◽  
Rtcp Function ◽  
On Line ◽  
Five Axis

To solve the five-axis machining accuracy problems that caused by assembly precision and direction error of rotary axes of inclinable head in high precision five axis machine tool. By selecting the five axis machine tool with inclinable head AB, GMC1230u, as the research object and analyzing the causes of the inclinable head error, the kinematics relationship of the rotation center position error and axis tilt error is established. By that, the direction vectors of each rotation axis and the position vector of rotation center are calculated based on the regression analysis of on-line measurement of the tool center point position and the calibration of five-axis RTCP function parameters is also accomplished. Finally, the compensation for inclinable head error in five-axis machine tools is fulfilled efficiently and remarkable improvement of RTCP machining accuracy is achieved.

A New Method for Identifying Geometric Errors Inherent to Revolving Axle of Multi-Axis Machine Tool

2011 ◽  
Vol 697-698 ◽  
pp. 262-267
Author(s):  
Guo Fu Ding ◽  
Lei Jiang ◽  
Shao Wei Zhu ◽  
Shu Wen Ma
Keyword(s):  
Machine Tool ◽  
Great Difficulty ◽  
New Method ◽  
Identification Algorithm ◽  
Structural Constraints ◽  
Geometric Errors ◽  
Point Function ◽  
Center Point ◽  
Ball Bar ◽  
Five Axis

Geometric errors identification of revolving axle of multi-axis machine tool has encountered a great difficulty in geometric errors compensation. This paper describes a new method to identify geometric errors inherent to revolving axle of multi-axis machine tool based on a ball-bar system. Under RTCP (Rotation Around Tool Center Point) or RPCP (Rotation Around Part Center Point) function, the displacement errors of revolving axle in X, Y and Z direction can be obtained by the ball-bar system respectively at every measurement angle. With the corresponding identification algorithm proposed in this paper, the whole six geometric errors of revolving axle can be identified. This new method is suitable for any type of multi-axis machine tool and without structural constraints. To confirm the validity of the proposed method, an experiment has been conducted on a five-axis machine tool, and the results show that this method is effective and applicable.

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