Geometric error modeling and compensation for five-axis CNC gear profile grinding machine tools

2017 ◽  
Vol 92 (5-8) ◽  
pp. 2639-2652 ◽  
Author(s):  
Baocang Zhou ◽  
Shilong Wang ◽  
Chenggang Fang ◽  
Shouli Sun ◽  
He Dai
Keyword(s):  
Machine Tools ◽  
Geometric Error ◽  
Error Modeling ◽  
Profile Grinding ◽  
Grinding Machine ◽  
Five Axis ◽  
Gear Profile

Product-of-exponential formulas for precision enhancement of five-axis machine tools via geometric error modeling and compensation

2015 ◽  
Vol 81 (1-4) ◽  
pp. 289-305 ◽  
Author(s):  
Guoqiang Fu ◽  
Jianzhong Fu ◽  
Hongyao Shen ◽  
Yuetong Xu ◽  
Yu’an Jin
Keyword(s):  
Machine Tools ◽  
Geometric Error ◽  
Error Modeling ◽  
Five Axis

Research on thermal deformation of large CNC gear profile grinding machine tools

2016 ◽  
Vol 91 (1-4) ◽  
pp. 577-587 ◽  
Author(s):  
Shilong Wang ◽  
Baocang Zhou ◽  
Chenggang Fang ◽  
Shouli Sun
Keyword(s):  
Machine Tools ◽  
Thermal Deformation ◽  
Profile Grinding ◽  
Grinding Machine ◽  
Gear Profile

Research on Geometric Error Compensating Technique of CNC P3G Grinding Machine

2012 ◽  
Vol 462 ◽  
pp. 287-294 ◽  
Author(s):  
Yi Jian ◽  
Qian Qian Li ◽  
Hong Cheng ◽  
Bin Wu Lai ◽  
Jian Fei Zhang
Keyword(s):  
Machine Tools ◽  
Geometric Error ◽  
Error Model ◽  
Error Modeling ◽  
Numerical Control ◽  
Geometric Errors ◽  
Real Time Control ◽  
Time Control ◽  
Applied Software ◽  
Grinding Machine

Kinematic accuracy is a key reason which influence workpiece's geometric error precision on traditional working process of precisely CNC（Computerized Numerical Control）P3G（polygon profile with 3 lobes） grinding machine. A systematic geometric error model has been presented for CNC P3G grinding machine， proposed multi-body system theory integrate with the structure of CNC P3G grinding machine tools, researched on the machine's space geometric errors. By means of separate geometric errors from the machine tools, build geometric mathematical error model. Then, identify 21 error parameters through method of 9 lines, analysis and calculate the total space geometric errors of the workpiece and wheel. Finally, formed a parameter-list and applied software error compensational technique ， achieved real-time control to the motions of workpiece and wheel. Experimental results shown that the geometrical error modeling technique is accurate and efficient, and the precision of CNC P3G grinding machine is highly raised 70%.

Free-Form Flank Correction in Helical Gear Grinding Using a Five-Axis Computer Numerical Control Gear Profile Grinding Machine

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
Yi-Pei Shih ◽  
Shi-Duang Chen
Keyword(s):  
Correction Method ◽  
Computer Numerical Control ◽  
Numerical Control ◽  
Free Form ◽  
Profile Grinding ◽  
Wheel Profile ◽  
Grinding Machine ◽  
Tooth Flank ◽  
Five Axis ◽  
Gear Profile

To reduce form grinding errors, this paper proposes a free-form flank topographic correction method based on a five-axis computer numerical control (CNC) gear profile grinding machine. This correction method is applied not only to the five-axis machine settings (during grinding) but also to the wheel profile (during wheel truing). To achieve free-form modification of the wheel profile, the wheel is formulated as B-spline curves using a curve fitting technique and then normal correction functions made up of four-degree polynomials are added into its working curves. Additionally, each axis of the grinding machine is formulated as a six-degree polynomial. Based on a sensitivity analysis of the polynomial coefficients (normal correction functions and CNC machine settings) on the ground tooth flank and the topographic flank errors, the corrections are solved using the least squares method. The ground tooth flank errors can then be efficiently reduced by slightly adjusting the wheel profile and five-axis movement according to the solved corrections. The validity of this flank correction method for helical gears is numerically demonstrated using the five-axis CNC gear profile grinding machine.

Geometric error compensation method based on Floyd algorithm and product of exponential screw theory

2016 ◽  
Vol 232 (7) ◽  
pp. 1156-1171 ◽  
Author(s):  
Qiang Cheng ◽  
Bingwei Sun ◽  
Zhifeng Liu ◽  
Qiunan Feng ◽  
Peihua Gu
Keyword(s):  
Error Compensation ◽  
Machine Tools ◽  
Screw Theory ◽  
Cost Effective ◽  
Geometric Error ◽  
Error Modeling ◽  
Compensation Method ◽  
Machining Accuracy ◽  
Distance Method ◽  
Five Axis

Error compensation technique is a recognized and cost-effective method to improve machining accuracy of machine tools. In this article, a new compensation method for geometric error is proposed based on Floyd algorithm and product of exponential screw theory. Based on topological structure and measured data, volumetric geometric error modeling is established by product of exponential screw theory. Then, the improved Floyd minimum-distance method was used to establish an error compensation model by adjusting weight unceasingly. In order to verify the effectiveness and generality of the method proposed in this article, two experiments were designed. A total of 5 five-axis machining centers of the same type with different use time were selected to carry out the simulation experiments. Results show that the Floyd method can provide higher compensation precision, that is, Floyd algorithm compensation method can keep positioning errors within the range [−8 µm, 9 µm]. In addition, roundness error, coaxial error, and surface roughness were reduced in the actual machining experiments of two machined conical tables. Therefore, it can be seen that the proposed compensation method is effective to improve machining accuracy of machine tools.

Volumetric error modeling and compensation considering thermal effect on five-axis machine tools

2012 ◽  
Vol 227 (5) ◽  
pp. 1102-1115 ◽  
Author(s):  
Yi Zhang ◽  
Jianguo Yang ◽  
Sitong Xiang ◽  
Huixiao Xiao
Keyword(s):  
Error Compensation ◽  
Machine Tools ◽  
Data Communication ◽  
Zero Point ◽  
Compensation System ◽  
Error Modeling ◽  
Volumetric Error ◽  
Position Errors ◽  
Homogeneous Transformation Matrix ◽  
Five Axis

This article intends to provide an error compensation system for five-axis machine tools. A volumetric error model is established with homogeneous transformation matrix method, from which compensation values of both orientation and position errors can be obtained. Thirty-seven errors on a five-axis machine tool are classified into three categories – functional, random, and negligible errors, among which the effect of the first one on volumetric accuracy is considered as great enough to be included in this model. Some typical modeling methods are discussed on positioning and straightness errors, considering both geometric and thermal effects. Then, we propose a compensation implementation technique based on the function of external machine zero point shift and Ethernet data communication protocol for machine tools. Finally, laser diagonal measurements have been conducted to validate the effectiveness of the proposed volumetric error compensation system.

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.

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