Journal articles: 'Geometric accuracy of the machine'

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Morimoto, Yoshitaka, Keisuke Nakato, and Motoshi Gontani. "Accuracy Evaluation of 5-Axis Machining Center Based on Measurements of Machined Workpiece – Evaluation of Accuracy of 5-Axis Controlled Machining Center –." International Journal of Automation Technology 6, no. 5 (September 5, 2012): 675–81. http://dx.doi.org/10.20965/ijat.2012.p0675.

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A new method for evaluating the geometrical accuracy of a 5-axis Machining Center (MC) based on the measurement results of the machined workpiece has been developed. The strategy behind our method is to utilize, because of its accuracy, a Coordinates Measuring Machine (CMM) as a master gauge. Thus, the machine operator machines the workpiece and a technologist of precise measurement takes the measurements. In our study, non-rotational machining is utilized to copy and trace the machine trajectory on the workpiece, minimizing the machining error. The profiles of the machined workpiece are measured and evaluated by a CMM, and the geometric errors of the machining center are extracted. Themeasurement results are sufficiently accurate compared to those taken using the square master gauge calibrated by CMM previously. In this report, the machining setup, including workpiece design, tool design, and cutting conditions, is proposed, and the experimental procedures and results of the evaluation are given.

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Holub, Michal, and Jiri Rosenfeld. "Geometric Accuracy of Large Machine Tools." Acta Mechanica Slovaca 24, no. 3 (September 22, 2020): 56–62. http://dx.doi.org/10.21496/ams.2020.036.

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Hoang, Trung Kien, and Nguyen Minh Duc Ta. "Machining Based Geometric Error Estimation Method for 3-Axis CNC Machine." Applied Mechanics and Materials 889 (March 2019): 469–74. http://dx.doi.org/10.4028/www.scientific.net/amm.889.469.

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Computer numerical control (CNC) machine tool plays an extremely significant role in any manufacturing industry due to its automation and high accuracy. Keeping the CNC machine tool at its highest performance to meet the demand of high accuracy machining is always significant. To maintain the accuracy of a machine tool over the time, it is important to measure and compensate the geometric error, one of the main error source of machine tool, especially when the machine get old. There are totally 21 geometrical errors in a 3-axis machine tool including three translational errors and three rotational errors for each axis and three perpendicular error (Squareness) within three axes of the machine. This paper presents an economical and simple method for measuring the geometric error of a 3-axis CNC machine tool based on the machining of actual samples. Three samples for each axis will be machined following a design cutting path. The samples will then be measured using a coordinate measuring machine (CMM). The collect data will be used for estimating the geometric errors. The volumetric errors will be then computed and verified through machining of 3D geometries.

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Jian, Yi, Qian Qian Li, Hong Cheng, Bin Wu Lai, and Jian Fei Zhang. "Research on Geometric Error Compensating Technique of CNC P3G Grinding Machine." Advanced Materials Research 462 (February 2012): 287–94. http://dx.doi.org/10.4028/www.scientific.net/amr.462.287.

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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%.

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Czerech, Łukasz. "SELECTION OF OPTIMAL MACHINING STRATEGY IN THE MANUFACTURE OF ELEMENTS BOUNDED BY CURVILINEAR SURFACES." Acta Mechanica et Automatica 7, no. 1 (March 1, 2013): 5–10. http://dx.doi.org/10.2478/ama-2013-0001.

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Abstract Increasing machining accuracy realized on CNC machine tools causes that the more frequently surfaces machined with this technique are not subject to further finishing processing and directly affects on the final quality of the product. Achieving geometric accuracy established by the constructor is the problem that modern technologists and CAD/CAM programmers have to faced with. The paper presents the influence of toolpath tolerance and machining strategy available in CAD/CAM software on the constituting process of technological surface layer for elements limited with curvilinear surfaces. The impact of the above mentioned parameters on the location and direction of geometrical deviations were also analyzed. Following article is part of research of the impact of selected technological parameters on the freeform surfaces geometric structure manufactured on CNC machines

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IBARAKI, Soichi. "How Accurate is the Motion? : Geometric Accuracy Measurement for Machine Tools." Journal of the Society of Mechanical Engineers 118, no. 1164 (2015): 672–75. http://dx.doi.org/10.1299/jsmemag.118.1164_672.

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Yang, Lin, Jin Yuan Wang, Rui Nan Wu, and Wei Wu. "Machine Slideway Wear to the Precision of the Whole Machine Impact." Applied Mechanics and Materials 229-231 (November 2012): 2474–77. http://dx.doi.org/10.4028/www.scientific.net/amm.229-231.2474.

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This paper studies the influence of machine slideway precision on the overall accuracy of machine tools, and puts forward the root causes of the decline in accuracy of machine tool guide is rail wear, the decline of rail accuracy will impact on the adjacent unit cell, thus decline the accuracy of the machined parts; Finally takes floor-type milling & boring machine as research object, bases on geometric error models of the theory of multi-body system to describe the spindle box rail wear trends and establish relationship between the spindle box rail wear and the machine precision.

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Cheng, Qiang, Hongwei Zhao, Zhifeng Liu, Cui Zhang, and Peihua Gu. "Robust geometric accuracy allocation of machine tools to minimize manufacturing costs and quality loss." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 230, no. 15 (August 9, 2016): 2728–44. http://dx.doi.org/10.1177/0954406215600398.

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With increasing demands of machining accuracy, designing of machine tools for satisfactory performance using cost-effective geometric accuracy configurations is becoming a complex problem to the machine tool manufacturers. In this paper, a novel robust accuracy allocation method is proposed for multi-axis machine tools based on multi-objective quality and cost trade-offs. To model the volumetric accuracy of machine tool based on geometric errors, the multi-body system theory was introduced. A manufacturing cost model for the machine tool components with a significant effect on geometric errors was established based on the machining features. The quality loss of the machine tool was also integrated into a single optimization objective. After identifying the relationship between the accuracy grade parameters of the feeding components and the geometric errors, the maximum in the Euclidean norm of all the accuracy parameters was defined as another optimization objective. The robust accuracy allocation was performed using Isight software and the Non-Dominated Sorting Genetic Algorithm-II built in the MATLAB. The optimization results for a four-axis horizontal machining center showed that the proposed method can realize the optimization of geometric accuracy and can determine the optimal accuracy grade of the feeding components satisfying the machining accuracy requirements.

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KIKKAWA, Koichi, Masaki HIROSAWA, Hidekazu KIKUCHI, Yoshio MIZUGAKI, and Hisanobu TERAI. "3362 Dependency of Working Accuracy on Location of Truncated Conical Workpiece Machined by 5-axis Controlled Machine Tool with Geometric Error." Proceedings of International Conference on Leading Edge Manufacturing in 21st century : LEM21 2011.6 (2011): _3362–1_—_3362–4_. http://dx.doi.org/10.1299/jsmelem.2011.6._3362-1_.

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Li, Dianxin, Pingfa Feng, Jianfu Zhang, Dingwen Yu, and Zhijun Wu. "An identification method for key geometric errors of machine tool based on matrix differential and experimental test." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 228, no. 17 (March 11, 2014): 3141–55. http://dx.doi.org/10.1177/0954406214527272.

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This paper presents a key geometric errors identification method for machine tools based on matrix differential and experimental test. An error model for a machine tool was established by regarding the three-axis machining center as a multi-body system. The sensitivity coefficients of the machining error with respect to the geometric errors were determined using the matrix differential method, and the degree of influence of the geometric errors on the machining accuracy under ideal conditions was discussed. Using the 12-line method, 21 geometric errors of the machine tool were identified, allowing the three-dimensional volumetric error distributions of the machine tool to be mapped. Experimental results allow the degree of influence of the geometric errors on the machining accuracy under actual conditions to be confirmed. Finally, the key geometric errors affecting the machining accuracy were identified by a combination of matrix differential and experimental test. This paper provides guidance for the machine tool configuration design, machining technology determination, and geometric error compensation.

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Zou, Xicong, Xuesen Zhao, Zongwei Wang, Guo Li, Zhenjiang Hu, and Tao Sun. "Error Distribution of a 5-Axis Measuring Machine Based on Sensitivity Analysis of Geometric Errors." Mathematical Problems in Engineering 2020 (February 14, 2020): 1–15. http://dx.doi.org/10.1155/2020/8146975.

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Geometric errors are inevitably introduced into any multiaxis measuring system, and the geometric error is one of the main factors that seriously affects the measurement accuracy. The present work investigates the error distribution of the prototype of a 5-axis measuring machine based on sensitivity analysis of geometric errors. The measurement error modeling of the 5-axis measuring machine is first established via the homogeneous coordinate transformation, and the Sobol global sensitivity analysis method is then employed to quantify the influence of geometric errors on the measurement result with the sensitivity index. The result shows that most of the angular errors are the crucial geometric errors seriously affecting the measurement result. These errors are supposed to be fully considered in the accuracy design and manufacturing stages. The error levels of the crucial geometric errors were distributed and readjusted according to the sensitivity analysis result. Some practical approaches to distribute and improve the crucial geometric errors have been given in detail. The error distribution method is effective to equalize the influence of the crucial geometric errors on the measurement result as possible. The findings of this study provide significant meanings for the optimal design and accurate manufacturing of the 5-axis measuring machine, and the proposed method can be used to improve the measurement accuracy of the 5-axis measuring machine.

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Cheng, Qiang, Hong Wei Zhao, Li Gang Cai, and Pei Hua Gu. "Influence Analysis of Machine Tool’s Turntable Angle Errors to the Roundness of Machined Hole." Applied Mechanics and Materials 496-500 (January 2014): 816–22. http://dx.doi.org/10.4028/www.scientific.net/amm.496-500.816.

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Machining accuracy has always been a key problem to machine tool. Machine errors are caused by a variety of error factors among which the geometric error is a key element. An accuracy model of the 3-axis CNC machine tool is established in this paper with multi-body system (MBS).And based on the accuracy model, the mathematical model of roundness error also built up. At last, the influence of CNC machine tools turntable angle error to roundness error of machined hole is analyzed.

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Cheng, Qiang, Dong Sheng Xuan, Jie Sun, and Zhi Feng Liu. "Geometric Errors Sensitivity Analysis of Precision Vertical Machining Center Based on Multi-Body System Theory." Applied Mechanics and Materials 108 (October 2011): 61–66. http://dx.doi.org/10.4028/www.scientific.net/amm.108.61.

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Parts of geometric error coupled into space error is the main reason that affects machining accuracy of machine tools; therefore, how to determine the effect of geometric error to the machining accuracy and then assigning geometry precision of parts economically is a difficult problem in machine tool designing process. Therefore, based on multi-body system theory, a sensitivity analysis method of geometric error is put forward in this paper. Let’s take precision vertical machining center for an example. Firstly, an accuracy model of machining center is established based on multi-body system theory, and with 21 geometric errors obtained through experimental verification, key error sources affecting the machining accuracy are finally identified by sensitivity analysis. The example analysis shows that the proposed method can effectively identify the main geometric errors of parts that have great influence on volumetric error of machine tool, and thus provides important theoretical basis to improve the accuracy of machine tool economically.

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Wang, Wei Qing, and Huan Qin Wu. "Sensitivity Analysis of Geometric Errors for Five-Axis CNC Machine Tool Based on Multi-Body System Theory." Applied Mechanics and Materials 271-272 (December 2012): 493–97. http://dx.doi.org/10.4028/www.scientific.net/amm.271-272.493.

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Abstract: In order to determine that the effect of geometric error to the machining accuracy is an important premise for the error compensation, a sensitivity analysis method of geometric error is presented based on multi-body system theory in this paper. An accuracy model of five-axis machine tool is established based on multi-body system theory, and with 37 geometric errors obtained through experimental verification, key error sources affecting the machining accuracy are finally identified by sensitivity analysis. The analysis result shows that the presented method can identify the important geometric errors having large influence on volumetric error of machine tool and is of help to improve the accuracy of machine tool economically.

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Moravčíková, Jana, and Peter Pokorný. "Design of Complex Component for Determination of a CNC Milling Machines Accuracy." Key Engineering Materials 703 (August 2016): 22–26. http://dx.doi.org/10.4028/www.scientific.net/kem.703.22.

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The article is focused on the design of complex component to determine competence CNC milling machines designed to produce shapes with geometric tolerances by observing the shape, orientation and position of the standard EN ISO 1101. 3D model of a technological process for the production of complex components, it will contain the complete design of tools and cutting parameters for individual milling strategy, select clamping and workpiece material, a preview of the generated routing strategies and paths cut surface after each of their simulated. For milling machines with the so-called measurement system for machine OMM (On Machine Measurement), the proposal for a comprehensive parts serve as a reference in determining the accuracy of their measurements of geometric and dimensional tolerances. The main activity of systems OMM is the replace of the tool clamped in the spindle of milling machines with special touch probe which senses by the touch surface contours of produced parts.

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Derbaba, V., V. Nosachov, and Z. Rizo. "Research and improvement of methods of testing machines for geometric and kinematic accuracy." Collection of Research Papers of the National Mining University 64 (2021): 198–212. http://dx.doi.org/10.33271/crpnmu/64.198.

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Purpose. To analyze and check for adequacy the known calculation formulas in determining the geometric and kinematic accuracy, statistical and dynamic rigidity and testing the machine for technological reliability. To carry out comparative calculations to simplify the methodology of complex tests of metal-cutting machines of the universal group. To select and improve the measuring equipment during the complex tests of the milling machine. Methodology. The research is based on the use of analytical methods for calculating the static rigidity coefficient, additional calculation of the measuring instrument design due to the gear ratio, the angle of rotation of the lever and the theoretical error of the displacement mechanism based on the known probability distribution theorem. Findings. The formulas of researches of the coefficient of static rigidity, the mechanism of the measuring device, the angle of rotation of the lever, the theoretical error of the mechanism of movement and the density of probability of distribution of the angle of the lever mechanism of the indicator of tangent type has been obtained. Originality. The research has been carried out and the parametric relationship between the static rigidity coefficient in the design of the spindle assembly of the vertical milling machine with the error of the calculations of the design, the departure of the spindle cone and the location between the supports has been established. The values and functional dependences of the amplitude of oscillations on the maximum allowable spindle speeds and feed rates at which the surface roughness of the workpiece reaches the specified geometric limits has been obtained. It is experimentally confirmed that the parameters of the system of pre-planned repairs are directly related to the reliability of the machine. The resource on the accuracy of the machine determines the need for overhaul, and the repair period depends on the service life of parts and elements of the machine. The actual service life should be a multiple of the repair period, as the restoration of the part is planned during the current repair. Practical value. The practical achievement of the obtained results is to confirm the adequacy of the known calculation formulas in determining the geometric and kinematic accuracy, statistical and dynamic rigidity and testing the machine for technological reliability. On the basis of the received analytical and settlement data was made the simplified complex technique of test of the metal-cutting machine during the: testing the machine at idle; testing of the machine when working under load; testing of the machine for geometric and kinematic accuracy; determination of statistical and dynamic rigidity; research of vibration-resistant vertical milling machine; testing of the machine for technological reliability.

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Fu, Hong Ya, Han Wang, and Zhen Yu Han. "Modeling and Analysis of Key Geometric Error for Gravity Deformation of Heavy-Duty CNC Machine Tool." Applied Mechanics and Materials 552 (June 2014): 90–95. http://dx.doi.org/10.4028/www.scientific.net/amm.552.90.

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Gravity has huge impact on the accuracy of heavy-duty machine tools. To investigate errors caused by gravity, it is essential to figure out the most influential factor. This paper presents a geometric error modeling for heavy-duty CNC machine tools. Regarding a machine tool as a rigid multi-body system (MBS), the geometric error model has been established by utilizing kinematics chain and homogeneous transfer matrix (HTM). By analyzing the Jacobi matrix, the influence of all the geometric error parameters has been calculated to find out the key geometric error that affect the accuracy most. It is revealed that gravity of beam and tool affect the accuracy of the machine tool most through the ANSYS simulation. It supports a theoretical basis for the further research on error compensation of the key component of a machine tool.

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Hayashi, Akio, Hiroto Tanaka, Masato Ueki, Hidetaka Yamaoka, Nobuaki Fujiki, and Yoshitaka Morimoto. "Forward Kinematics Model for Evaluation of Machining Performance of Robot Type Machine Tool." International Journal of Automation Technology 15, no. 2 (March 5, 2021): 215–23. http://dx.doi.org/10.20965/ijat.2021.p0215.

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Robot-type machine tools are characterized by the ability to change the tool posture and machine itself with a wider motion range than conventional machine tools. The motion of the robot machine tool is realized by simultaneous multi-axis control of link mechanisms. However, when the robot machine tool performs a general milling process, some problems that affect the machining accuracy occur. Moreover, it is difficult to identify the motion errors of each axis, which influence machining accuracy. Thus, it is difficult to adjust the servo gain and alignment error. In addition, the machining performance is unidentified because of the rigidity differences when the posture changes. In this study, the focus was on robot-type machine tools consisting of a serial and a parallel link mechanism. A geometric model is described, and the forward kinematics model is derived based on the geometric model. Machining tests were then carried out to evaluate the machining accuracy by measuring the machined surfaces and the simulated motion of the tool posture based on the proposed forward kinematics model to identify the mechanism that affects the machined surface roughness and surface waviness. As a result, it was shown that the proposed model can separate and reproduce the behavior of each axis of the machine. Finally, it was clarified that the behavior of the second axis has a great influence on the tool posture and machined surface.

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Guo, Shijie, Shufeng Tang, and Dongsheng Zhang. "A Recognition Methodology for the Key Geometric Errors of a Multi-Axis Machine Tool Based on Accuracy Retentivity Analysis." Complexity 2019 (November 22, 2019): 1–21. http://dx.doi.org/10.1155/2019/8649496.

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This paper proposes a recognition methodology for key geometric errors using the feature extraction method and accuracy retentivity analysis and presents the approach of optimization compensation of the geometric error of a multiaxis machine tool. The universal kinematics relations of the multiaxis machine tool are first modelled mathematically based on screw theory. Then, the retentivity of geometric accuracy with respect to the geometric error is defined based on the mapping between the constitutive geometric errors and the time domain. The results show that the variation in the spatial error vector is nonlinear while considering the operation time of the machine tool and the position of the motion axes. Based on this aspect, key factors are extracted that simultaneously consider the correlation, similarity, and sensitivity of the geometric error terms, and the results reveal that the effect of the position-independent geometric errors (PIGEs) on the error vectors of the position and orientation is greater than that of the position-dependent geometric errors (PDGEs) of the linear and rotary axes. Then, the fruit fly optimization algorithm (FOA) is adopted to determine the compensation values through multiobjective tradeoffs between accuracy retentivity and fluctuation in the geometric errors. Finally, an experiment on a four-axis horizontal boring machine tool is used to validate the effectiveness of the proposed approach. The experimental results show that the variations in the precision of each test piece are lower than 25.0%, and the maximum variance in the detection indexes between the finished test pieces is 0.002 mm when the optimized parameters are used for error compensation. This method not only recognizes the key geometric errors but also compensates for the geometric error of the machine tool based on the accuracy retentivity analysis results. The results show that the proposed methodology can effectively enhance the machining accuracy.

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Liu, Xiaojian, Yang Wang, Lemiao Qiu, Chenrui Wu, Peng Zhang, and Shuyou Zhang. "An improved geometric error analysis method considering the variety of sensitivities over working space." Advances in Mechanical Engineering 10, no. 8 (August 2018): 168781401879238. http://dx.doi.org/10.1177/1687814018792389.

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Machine tool accuracy analysis has become increasingly important since accuracy as the major parameter of a machine is to a large extent determined by geometric accuracy design. In order to improve the comprehensiveness and veracity of geometric accuracy design, this article proposes an improved geometric error analysis method considering the variety of sensitivities over working space. A multi-rigid-body model which includes cutting tool’s wear-out error and workpiece’s clamping error is established to represent the position relationship of machine tool’s working components. The expression of geometric error is converted from matrix form to screw form through the screw mapping theory, so that rotational error can be expressed and calculated directly like the translational error. Considering motion errors along axes over the whole working space instead of at a fixed position, an improved sensitivity analysis algorithm is conducted to identify, among 38 components of errors increased the variety with tool wear and clamping errors, which of them have a significant impact on four different types of machine errors. Finally, the proposed method was implemented and validated on a horizontal boring machine, and the sensitivity analysis results over working space would offer vital evidence for the machine’s geometric accuracy design.

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Giniotis, Vytautas, and Darius Mariūnas. "ANALYSIS OF DISCRETISATION STRATEGY FOR AREA AND SPACE MEASUREMENT." Geodesy and cartography 31, no. 1 (August 3, 2012): 28–31. http://dx.doi.org/10.3846/13921541.2005.9636661.

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Measurement strategy is discussed in the article. It is important to optimise the data selection (sampling) from the object for the determination of its geometrical features within some limits of accuracy. The minimal and maximal intervals of measurement must be selected ensuring the maximal efficiency of operation and the accuracy as well. In machine engineering the typical case is in the calibration of coordinate measuring machines (CMMs) as it is a quite complicated task because of the variety of accuracy parameters to be checked and the high accuracy that must be assured. Some new techniques for the two- and three-dimensional measurements are discussed in this paper leading to a more efficient calibration process. This is relevant to machine engineering where geometric accuracy parameters are to be determined, to the geodetic measurements where slopes of terrain, area flatness and volumetric features are surveyed, in structural engineering, etc.

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Anikeeva, Olesya, Alexander Ivakhnenko, and Oleg Erenkov. "Approaches to nonlinear theory creation for machine tools geometric accuracy." MATEC Web of Conferences 224 (2018): 01037. http://dx.doi.org/10.1051/matecconf/201822401037.

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The justification of the nonlinear theory creation in machines geometrical accuracy field is given in the work. The problems accountings of which don’t allow providing the consecutive linearization method adequacy at geometrical accuracy calculating of metal-cutting machines are considered. The potential sources of not linearities at calculating of metal-cutting systems accuracy and the sources of the nonlinear members appearance are revealed. At the same time the nonlinear members are considering the machines geometrical errors at a shaping function variation. The full variation of shaping function is defined and the accuracy nonlinear model of the lathe is constructed on the function basis. The directions of further researches in the field of the machines geometrical accuracy nonlinear theory are presented.

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Jauhari, Khairul, and Mahfudz Al Huda. "The Geometric Accuracy of Complex Surface Using 5-Axis Turn-mill Machine." Jurnal Keteknikan Pertanian Tropis dan Biosistem 8, no. 3 (December 1, 2020): 253–62. http://dx.doi.org/10.21776/ub.jkptb.2020.008.03.07.

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This paper presents an analysis model for geometric accuracy measurement of marine propeller blades. Geometric accuracy of marine propeller models, which has been finished by machining processes are measured and analyzed using GOM 3D photo-scanning peripheral and software. The methods we used are firstly, marine propeller blades are scanned by GOM Scanner and then the effects of cutting parameters, that is step-over variation on the geometric accuracy are investigated. Inspection of geometric accuracy is performed by comparing the result of 3D scanning measurement of finished propeller with CAD design data using GOM Inspect 2016 software. The results showed that greater step-over value, the deviation value tends to be smaller. Finally, this method is proven effective in measuring by producing similar trends at two measurement position points.

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Lin, Zixin, Wenjie Tian, Dawei Zhang, Weiguo Gao, and Lina Wang. "A mapping model between the workpiece geometric tolerance and the end pose error of CNC machine tool considering structure distortion of cutting process system." Advances in Mechanical Engineering 13, no. 3 (March 2021): 168781402110047. http://dx.doi.org/10.1177/16878140211004771.

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Aiming at the problem that the geometric accuracy design index of machine tools is difficult to be determined reasonably in the geometric precision design process of CNC machine tools, this paper presents a mapping model between geometric tolerance of the workpiece and end pose error (positional and orientational error of the tool relative to the workpiece) of the machine tool considering structure distortion of cutting process system. Only considering the factors of the machine tool geometric errors, this paper first establishes the relationship between the geometric tolerance requirements of the workpiece and relative pose error at the end of machine tools, and completes the estimation of the machine tools end pose error. Then this paper analyzes the elastic deformations of the cutting process system caused by the cutting force. These elastic deformations produce machining errors. Based on the above analysis, the estimated variation range of the end pose error can be adjusted by the emulation of the geometric tolerance of the workpiece and used as the geometric accuracy design index of machine tools. This paper takes the international standard small size contour processing test piece as an example to explain the application process of the proposed model.

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Li, Pengzhong, Ruihan Zhao, and Liang Luo. "A Geometric Accuracy Error Analysis Method for Turn-Milling Combined NC Machine Tool." Symmetry 12, no. 10 (September 30, 2020): 1622. http://dx.doi.org/10.3390/sym12101622.

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Turn-Milling Combined NC machine tool is different from traditional machine tools in structure and process realization. As an important means in the design stage, the analysis method of geometric accuracy error is also different from the traditional method. The actual errors and the error compensation values are a pair of "symmetry" data sets which are connected by the movement of machine tools. The authors try to make them more consistent through this work. The geometric error terms were firstly determined by topological structure analysis, then based on homogeneous coordinate transformation and multibody system theory, the geometric error model was established. With the interval theory, the function rule of sensitivity of geometric error sources to spatial errors was analyzed in detail, and the global maximum interval sensitivity of nine geometric error sources was extracted, providing a theoretical basis for error compensation and precision distribution. The geometric error sensitivity analysis method proposed in this paper can accurately evaluate the influence weights of each error term on the machining accuracy, and identify the important sensitive error terms with great influence on the machining accuracy from many error terms.

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Cheng, Qiang, Lifang Dong, Zhifeng Liu, Jiaying Li, and Peihua Gu. "A new geometric error budget method of multi-axis machine tool based on improved value analysis." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 232, no. 22 (January 12, 2018): 4064–83. http://dx.doi.org/10.1177/0954406217749269.

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The improvement of the accuracy grade of main components in the production process through balancing between function and cost helps to improve the overall accuracy of machine tools. Therefore, this paper presents an improved value analysis method and uses the method of global sensitivity analysis and geometric error correlation analysis to analyze and optimize the error parameters of a 4-axis machining tool based on the proposed method. The geometric error modeling of the 4-axis machine tool was established by using the homogeneous transformation matrices (HTMs). By using global sensitivity analysis, the degree of influence of each error parameter on the accuracy of machine tool was obtained, and functional coefficient and cost coefficient of value analysis were gained by correlation analysis. An optimization model for geometric error budget of machine tool was established according to the improved value analysis theory, and the machining accuracy of machine tool was optimized according to the improved value analysis method.

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Li, Zihan, Wenlong Feng, Jianguo Yang, and Yiqiao Huang. "An investigation on modeling and compensation of synthetic geometric errors on large machine tools based on moving least squares method." Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture 232, no. 3 (May 17, 2016): 412–27. http://dx.doi.org/10.1177/0954405416645985.

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This article intends to provide an efficient modeling and compensation method for the synthetic geometric errors of large machine tools. Analytical and experimental examinations were carried out on a large gantry-type machine tool to study the spatial geometric error distribution within the machine workspace. The result shows that the position accuracy of the tool-tip is affected by all the translational axes synchronously, and the position error curve shape is non-linear and irregular. Moreover, the angular error combined with Abbe’s offset during the motion of a translational axis would cause Abbe’s error and generate significant influence on the spatial positioning accuracy. In order to identify the combined effect of the individual error component on the tool-tip position accuracy, a synthetic geometric error model is established for the gantry-type machine tool. Also, an automatic modeling algorithm is proposed to approximate the geometric error parameters based on moving least squares in combination with Chebyshev polynomials, and it could approximate the irregular geometric error curves with high-order continuity and consistency with a low-order basis function. Then, to implement real-time error compensation on large machine tools, an intelligent compensation system is developed based on the fast Ethernet data interaction technique and external machine origin shift, and experiment validations on the gantry-type machine tool showed that the position accuracy could be improved by 90% and the machining precision could be improved by 85% after error compensation.

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Ratajczyk, Eugeniusz. "New types of coordinate measuring machines and symbols used for their parameters. Part II: Examples of gantry machines." Mechanik 90, no. 5-6 (May 29, 2017): 462–67. http://dx.doi.org/10.17814/mechanik.2017.5-6.61.

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Gantry type coordinate measuring machines belong to a group of machines operating to the highest accuracy standards and they are most commonly used for geometric measurements of machine elements, especially in automotive industry. Description of characteristics and functions of the machines offered by different manufacturers is presented.

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Liu, Chun Lin. "The Analysis and Application of Machine Tool Spindle Self-Grinding Method." Advanced Materials Research 706-708 (June 2013): 1598–601. http://dx.doi.org/10.4028/www.scientific.net/amr.706-708.1598.

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The self-grinding method was adapted on the fine grinding machine spindle after the parts of machine tool were assembled, which was easy to guarantee the spindle datum plane geometric accuracy. The Self-grinding is a reliable and economical technology method. The turning accuracy of Machine Tool Spindle and grinding process system were analyzed to guarantee the grinding accuracy and cutting accuracy of the whole machine material.

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30

Han, Zhen Yu, Hong Yu Jin, Yu Long Liu, and Hong Ya Fu. "A Review of Geometric Error Modeling and Error Detection for CNC Machine Tool." Applied Mechanics and Materials 303-306 (February 2013): 627–31. http://dx.doi.org/10.4028/www.scientific.net/amm.303-306.627.

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Error compensation can improve the accuracy of machine tools effectively. Among the error sources affecting the accuracy of CNC machine tool, geometric error is always set as a key performance criterion. This paper summarizes several methods of geometric error modeling and reviews the characteristics of different methods. Furthermore, available methods for measuring geometric errors have been reviewed also based on the advanced instruments. This work aims at enhancing the efficiency of error detection and give a perspective for the application of error compensation in the future.

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31

Lee, Jae Ha, Yu Liu, and Seung-Han Yang. "Accuracy improvement of miniaturized machine tool: Geometric error modeling and compensation." International Journal of Machine Tools and Manufacture 46, no. 12-13 (October 2006): 1508–16. http://dx.doi.org/10.1016/j.ijmachtools.2005.09.004.

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32

Liu, H. L. "Effects of Rotation Angle on the Circular Test of Geometric Errors." Key Engineering Materials 295-296 (October 2005): 289–94. http://dx.doi.org/10.4028/www.scientific.net/kem.295-296.289.

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DBB was originally manufactured and proposed for checking the accuracy of NC machine tools. The device can also be used to study the relations between motion error of trace and the machine motion error for the purpose of error compensation. The nominal angle obtained through rotation feed rate and sampling time was adopted instead of actual angle which cannot be measured by the device. This project examined in details the effect of the angle deviation problem caused by non-perpendicularity between the movements in axis X and axis Y. The analysis and calculation verified that a squareness deviation would lead to more than 3 times error at some special points, decreasing the accuracy of NC machines for error compensation. For this reason, a device called as Two-Dimensional Ball Bar is proposed based on the DBB.

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Yang, Hongtao, Mei Shen, Li Li, Yu Zhang, Qun Ma, and Mengyao Zhang. "New identification method for computer numerical control geometric errors." Measurement and Control 54, no. 5-6 (May 2021): 1055–67. http://dx.doi.org/10.1177/00202940211010835.

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To address the problems of the low accuracy of geometric error identification and incomplete identification results of the linear axis detection of computer numerical control (CNC) machine tools, a new 21-item geometric error identification method based on double ball-bar measurement was proposed. The model between the double ball-bar reading and the geometric error term in each plane was obtained according to the three-plane arc trajectory measurement. The mathematical model of geometric error components of CNC machine tools is established, and the error fitting coefficients are solved through the beetle antennae search particle swarm optimization (BAS–PSO) algorithm, in which 21 geometric errors, including roll angle errors, were identified. Experiments were performed to compare the optimization effect of the BAS–PSO and PSO and BAS and genetic particle swarm optimization (GA–PSO) algorithms. Experimental results show that the PSO algorithm is trapped in the local optimum, and the BAS–PSO is superior to the other three algorithms in terms of convergence speed and stability, has higher identification accuracy, has better optimization performance, and is suitable for identifying the geometric error coefficient of CNC machine tools. The accuracy and validity of the identification results are verified by the comparison with the results of the individual geometric errors detected through laser interferometer experiments. The identification accuracy of the double ball-bar is below 2.7 µm. The proposed identification method is inexpensive, has a short processing time, is easy to operate, and possesses a reference value for the identification and compensation of the linear axes of machine tools.

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Figuet, Benoit, Raphael Monstein, and Michael Felux. "Combined Multilateration with Machine Learning for Enhanced Aircraft Localization." Proceedings 59, no. 1 (December 1, 2020): 2. http://dx.doi.org/10.3390/proceedings2020059002.

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In this paper, we present an aircraft localization solution developed in the context of the Aircraft Localization Competition and applied to the OpenSky Network real-world ADS-B data. The developed solution is based on a combination of machine learning and multilateration using data provided by time synchronized ground receivers. A gradient boosting regression technique is used to obtain an estimate of the geometric altitude of the aircraft, as well as a first guess of the 2D aircraft position. Then, a triplet-wise and an all-in-view multilateration technique are implemented to obtain an accurate estimate of the aircraft latitude and longitude. A sensitivity analysis of the accuracy as a function of the number of receivers is conducted and used to optimize the proposed solution. The obtained predictions have an accuracy below 25 m for the 2D root mean squared error and below 35 m for the geometric altitude.

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Cai, Li Gang, Cui Zhang, Qiang Cheng, Pei Hua Gu, and Hong Ying Wang. "An Optimization Method for Geometric Error of Machine Tool Based on NSGA-II." Applied Mechanics and Materials 418 (September 2013): 180–86. http://dx.doi.org/10.4028/www.scientific.net/amm.418.180.

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Balancing the cost and processing precision of machine tool by the method of error allocation without affecting the machining performances is a critical problem in the Machine tool industry. In this paper, a new accuracy allocation method for multi-axis machine tool based on Multi-body system theory, manufacturing and quality loss costs and relationship between tolerances and accuracy parameters of components is proposed. This optimization method is performed with Non-Dominated Sorting Genetic Algorithm II algorithm using Isight and Matlab software. A three-axis vertical machine tool is taken as an example to demonstrate the method, and the optimization results show that the accuracy allocation method proposed is feasible in the optimization of geometric errors on the premise of satisfying machining accuracy requirements.

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36

Mir, Y. A., J. R. R. Mayer, and C. Fortin. "Tool path error prediction of a five-axis machine tool with geometric errors." Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture 216, no. 5 (May 1, 2002): 697–712. http://dx.doi.org/10.1243/0954405021520391.

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Predicting the actual tool path of a machine tool prior to machining a part provides useful data in order to ensure or improve the dimensional accuracy of the part. The actual tool path can be estimated by accounting for the effect of the machine tool geometric error parameters. In computer aided design/computer aided manufacture (CAD/CAM) systems, the nominal tool path [or CL (cutter location) data] is directly generated from the curves and surfaces to be machined and the errors of the machine tool are not considered. In order to take these errors into consideration, they must first be identified and then used in the machine tool forward kinematic model. In this paper a method is presented to identify the geometric errors of machine tools and predict their effect on the tool-tip position. Both the link errors (position-independent geometric error parameters) and the motion errors (position-dependent geometric error parameters) are considered. The nominal and predicted tool paths are compared and an assessment is made of the resulting surfaces with respect to the desired part profile tolerance. A methodology is also suggested to integrate this tool within a CAD/CAPP (computer aided process planning)/CAM environment.

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Song, Zhanqun, Shuang Ding, Zhiwei Chen, Zhongwang Lu, and Zhouzhou Wang. "High-Efficient Calculation Method for Sensitive PDGEs of Five-Axis Reconfigurable Machine Tool." Machines 9, no. 5 (April 25, 2021): 84. http://dx.doi.org/10.3390/machines9050084.

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Sensitive geometric errors of a machine tool have significant influence on machining accuracy, and it is important to identify them. Complex modeling and analysis must be carried out to identify the sensitive geometric errors of a five-axis machine tool by using the traditional method. Once the configuration structure of the machine tools is reconstructed, repetitive error modeling and analysis are required, and the identification cycle of sensitive geometric errors is long. Therefore, this paper proposes a high-efficient calculation method for sensitive position-dependent geometric error (PDGEs) identification of a five-axis reconfigurable machine tool. According to the results of sensitive geometric errors of the RTTTR-type and TTTRR-type five-axis machine tools, the mapping expressions between sensitive PDGEs and the configuration structure of machine tools was established. In this method, sensitive PDGEs can be calculated directly according to the mapping expression, which eliminates the process of error modeling and analysis. Taking a RTTTR-type five-axis machine tool as an example, the sensitive PDGEs were calculated according to the presented mapping expressions without error modeling and analysis. A series of analysis points in the machining area were selected to compare the machining errors before and after sensitive PDGE compensation. The results show that this calculation method is accurate.

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38

Zhu, Xian Qiu, Dong Gao, and Gang Wei Cui. "Geometric Error Detection and Identification of a Heavy NC Boring and Milling Machine Tool by Using Laser Tracker." Applied Mechanics and Materials 37-38 (November 2010): 505–8. http://dx.doi.org/10.4028/www.scientific.net/amm.37-38.505.

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It is inefficient and complicate to detect geometric errors of a heavy machine tool with large scale dimensions by using traditional laser interferometer. With the development of the laser tracker convenient for measuring large scale dimension, the accuracy of the laser tracker can meet the accuracy requirements for geometric error measurement of heavy machine tools. In this paper a method of using laser tracker for detecting and identifying the error of a heavy NC boring and milling machine tool is introduced. The measuring experiment demonstrates that this new method can improve the measurement efficiency.

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Аникеева, Олеся, and Olesya Anikeeva. "METHODOLOGICAL FUNDMENTALS IN PARAMETERS STANDARDIZATION OF MACHINE-TOOLS GEOMETRICAL ACCURACY." Bulletin of Bryansk state technical university 2016, no. 3 (September 30, 2016): 202–9. http://dx.doi.org/10.12737/22098.

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Machinetools belong to the basic technological equipment in mechanical engineering ensuring the creation of other machines with high accuracy and productivity unattainable in coming decades on the basis of additive techniques. Machining accuracy on machinetools is an integral index of quality and despite the diversity of approaches to the identification of correla-tions, computations and estimates of machining accuracy, the value of a general error seems to be as a sum of partial errors. A significant part in the formation of a general error of machining cause machinetools them-selves. Besides, a significant role in assurance of guaranties for machinetools users (operators) the standards for their geometrical accuracy play. A significant problem having scientific and practical meaning is the absence of a single approach substantiated scientifically to the formation of a system of such standards both for machine-tools of new types, and for the revision of the system with actual standards on geometrical accuracy of machinetools. In the paper there are offered methodological fundamentals for the parameters standardization of machine-tools geometrical accuracy on the basis of revealed interrelations between accuracy of units and parts surfaces machined at the use of a variational method for the computation of machines accuracy. The practical use of the approach offered requires both the development of the variational method itself for the computation of machines accuracy in the field of obtaining corresponding estimates of accuracy of various surfaces machined, for example, deviations from parallelism of two faces and others, and thorough investigations of the structure of relationship equations themselves.

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Liang, Gui Qiang, Jun Xian Zhang, and Fei Fei Zhao. "Geometric Error Modeling of a Vertical Machining Center." Advanced Materials Research 694-697 (May 2013): 1842–45. http://dx.doi.org/10.4028/www.scientific.net/amr.694-697.1842.

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The effect of geometric error on machining accuracy was researched by multi-body system theory, as well as homogeneous coordinate transformation method. Taking a vertical machining center as example, topological structure of the machine tool was described by lower body array. Lower body array of the machining center, motion freedom between adjacent bodies and geometric errors of the vertical machining center were analyzed. Geometric errors of the bodies in the multi-body system were expressed by homogeneous coordinate transformation. Error model for machining accuracy was deduced and geometric errors having influence on the machining accuracy were identified. The research results provide guidance for analyze of geometric errors on machining accuracy.

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41

Deng, Yu Fen, Jun Jie Guo, Jin Dong Wang, and Jun Feng Lu. "The Detection of NC Machine Geometric Accuracy Based on the Principle of Multiple-Time GPS." Advanced Materials Research 308-310 (August 2011): 531–37. http://dx.doi.org/10.4028/www.scientific.net/amr.308-310.531.

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This paper presents a measurement method of NC machine geometric accuracy. The principle is that a laser tracker is used to collect a lot of target point coordinates on four different locations around the machine during the machine spindle moving. A redundant equations could be established through target point coordinates,then the exact location of each target point coordinates could be determined by the principles of GPS positioning.Through the target point coordinates,the geometric error of machine could be separated. The method has fast measuring speed and low cost.Moreover the measurement precision is higher than direct measurement only using one laser tracker because the GPS positioning principle is used to avoid the angle measurment of laser tracker.

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42

Wang, Wei, Yi Zhang, Jianguo Yang, Yusheng Zhang, and Feng Yuan. "Geometric and thermal error compensation for CNC milling machines based on Newton interpolation method." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 227, no. 4 (October 2, 2012): 771–78. http://dx.doi.org/10.1177/0954406212461595.

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The fast and accurate modeling for machine errors is an important step for the implementation of error compensation. In this article, a new approach for real-time compensation of geometric and thermal errors is presented, including an accurate error model and a real-time error compensation system. An experiment is carried out on a three-axis milling center to obtain machine positioning errors under different temperatures. A serial of error data collected under normal temperature is regarded as the basic error and modeled with the machine position coordinates based on Newton interpolation method which is also used for modeling the other error curves under different working temperatures in order to get their coefficients of fitting formulas. According to the relationship among these formulas, all the coefficients and the corresponding temperature variations are modeled using the Newton interpolation method again. The final compensation model can be obtained by substituting the coefficients of basic error formula. In addition, an external real-time error compensation system is developed based on the function of external machine zero point shift in Fanuc CNC systems. Experimental results show that the proposed geometric and thermal error compensation system can be utilized as an effective manner to improve the accuracy of CNC milling machines.

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Wang, Hong, Fang Yu Pan, and Cheng Qun Pan. "The Radome Detection Machine Tool Geometric Error Modeling and Measurement." Applied Mechanics and Materials 365-366 (August 2013): 697–701. http://dx.doi.org/10.4028/www.scientific.net/amm.365-366.697.

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Antenna is an important and valuable component in industry. In order to protect it, the radome is adopted. As the non-uniform thickness of radome affects the performance of the antenna, in order to maintain the performance of antenna, it is necessary to have a dedicated device to detect the radome, thus the detection machine tool is used. The accuracy is the key point of the detection machine tool, so in this paper, its error model and measurement are presented. By the pitch compensation, the accuracy is enhanced, which achieves the desired value.

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44

Murčinková, Zuzana, and Karol Vasilko. "Stiffness of Technological System and Final Accuracy of Turned and Milled Parts." Key Engineering Materials 686 (February 2016): 174–79. http://dx.doi.org/10.4028/www.scientific.net/kem.686.174.

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The paper analyzes static stiffness of technological system machine tool - cutting tool - workpiece as one of factors affecting machined part accuracy. It focuses on turning and milling and their tool and workpiece characteristics as size, geometry, stiffness, tool wear, clamping etc. The paper identifies inaccuracies as a result of deformation of elastic component joints during acting the cutting and clamping forces. The paper provides final shapes and its deviations from ideal shape. The analysed results are obtained either by numerical simulation or by experiment. Finding the deviations generating mechanisms, it is possible to link dimensional, geometric and surface accuracy of workpiece to specific elements of technological system that is the significant point of the machine and tool design.

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Chen, J. S., J. X. Yuan, J. Ni, and S. M. Wu. "Real-time Compensation for Time-variant Volumetric Errors on a Machining Center." Journal of Engineering for Industry 115, no. 4 (November 1, 1993): 472–79. http://dx.doi.org/10.1115/1.2901792.

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An error compensation system has been developed to enhance the time-variant volumetric accuracy of a 3-axis machining center by correcting the existing machine errors through sensing, metrology, and computer control techniques. A general methodology has been developed to synthesize both the geometric and thermal errors of machines into a time-variant volumetric error model. Instead of the well-known 21 geometric error components, 32 machine linkage errors are formulated as a 4D error field including the space domain and the time domain. Different types of models are proposed for different kinds of thermal error components. A compensation controller based on an IBM/PC has been linked with a CNC controller to compensate for machine errors in real time. This scheme has been implemented on a horizontal machining center and has been shown, using metrology instruments, to improve the machine accuracy by an order of magnitude. A cut workpiece inspected using a coordinate measuring machine (CMM) has also shown that dimension errors have been reduced from 92.4 μm to 18.9 μm in a dimension of 404 × 310 mm2 and the depth difference of milled surfaces has been reduced from 196 μm to 8 μm.

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Cheng, Qiang, Qiunan Feng, Zhifeng Liu, Peihua Gu, and Ligang Cai. "Fluctuation prediction of machining accuracy for multi-axis machine tool based on stochastic process theory." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 229, no. 14 (December 7, 2014): 2534–50. http://dx.doi.org/10.1177/0954406214562633.

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Geometric error has significant influence on the processing results and reduces machining accuracy. Machine tool geometric errors can be interpreted as a deterministic value with an uncertain fluctuation of probabilistic distribution. Although, the uncertain fluctuation can not be compensated, it has extremely profound significance on the precision and ultra-precision machining to reduce the fluctuation range of machining accuracy as far as possible. In this paper, a typical 3-axis machine tool with high precision is selected and the fluctuations in machining accuracy are studied. The volumetric error modeling of machine tool is established by multi-body system (MBS) theory, which describes the topological structure of MBS in a simple and convenient matrix form. Based on the volumetric error model, the equivalent components of the errors for the three axes are established by reducing error terms. Then, the fluctuations of equivalent errors and the machining accuracy in working planes are depicted and predicted using the theory of stochastic process, whose range should be controlled within a certain confidence interval. Furthermore, the critical geometric errors that have significant influence on the machining accuracy fluctuation are identified. Based on the analysis results, some improvement in the machine tool parts introduced and the results for the modified machine show that the prediction allow for reduction in errors for the precision and ultra-precision machining.

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47

Ni, Jun. "CNC Machine Accuracy Enhancement Through Real-Time Error Compensation." Journal of Manufacturing Science and Engineering 119, no. 4B (November 1, 1997): 717–25. http://dx.doi.org/10.1115/1.2836815.

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Improving CNC machine tool accuracy has received significant attention recently. This paper intends to provide an introduction of the real-time error compensation methods as applied to reduce both geometric and thermally induced quasistatic machine tool errors. An illustrative example is used to demonstrate the use of error compensation systems for a horizontal machining center. Although several industrial applications of these error compensation systems have achieved significant results, a few major barriers have prevented this promising technology from being applied widely in manufacturing. Several ongoing research activities aimed at overcoming the barriers are also presented.

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48

Cai, Li Gang, Qiu Nan Feng, Qiang Cheng, Pei Hua Gu, and Cui Zhang. "Influence Analysis of Geometric Errors to Volumetric Machining Accuracy of a 5-Axis CNC Machine Tool." Applied Mechanics and Materials 420 (September 2013): 85–91. http://dx.doi.org/10.4028/www.scientific.net/amm.420.85.

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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.

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Wang, Hongwei, Yan Ran, Shengyong Zhang, and Yulong Li. "Coupling and Decoupling Measurement Method of Complete Geometric Errors for Multi-Axis Machine Tools." Applied Sciences 10, no. 6 (March 22, 2020): 2164. http://dx.doi.org/10.3390/app10062164.

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Precision and ultra-precision machining technology rely mainly on the machine tools’ accuracy. To improve it, the measurement, calculation, prediction and control of geometric errors are critical. The traditional measurement methods have lower precision because of ignoring small angle errors. To obtain complete geometric errors of multi-axis machine tools, this paper proposes a new method of coupling and decoupling measurement. Specifically, we used a laser interferometer and dial indicators to measure 36 items of complete geometric errors of multi-axis machine tools. A homogeneous transformation matrix (HTM) was applied to model the error transfer route. The transfer law of complete errors for each machining point was explored and derived. Furthermore, we selected and calculated integrated errors of 36 machining points. Finally, we proved the correctness of the method by comparing the measurement result of a ball bar test and coupling and decoupling measurement of geometric errors. We found that items of small geometric angle errors have a greater impact on machining accuracy than those of geometric displacement errors. Complete geometric errors measured via the coupling and decoupling measurement method can evaluate integrated errors more precisely and comprehensively.

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50

Tian, Wenjie, Shaopeng Liu, and Xingxing Liu. "Accuracy design of high precision machine tools using error sensitivity analysis methodology." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 231, no. 18 (April 13, 2016): 3401–13. http://dx.doi.org/10.1177/0954406216645625.

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Geometric accuracy is a crucially important performance factor for machine tools. Theoretically, the effects of source errors on pose accuracy (positional and angular accuracy) of 3-, 4- or 5-axis machine tools cannot fully be compensated by software, and only those pose errors associated with the permission motions are compensatable by means of error compensation. Therefore, the uncompensatable pose errors should be strictly guaranteed in the processes of design and manufacture. In this paper, after the geometric error model is established, the source errors affecting the uncompensatable pose accuracy are identified out of all the source errors. In order to enhance the understanding of which source errors have more influences on the pose accuracy, a probabilistic sensitivity analysis method is proposed, and the global sensitivity index is defined to evaluate the influence in the overall workspace. According to the sensitivity analysis results, the uncompensatable pose accuracy index is allocated to each source error. And then, assembly accuracy acceptance criteria are proposed as a guideline for machine assemblers. As an application example, the presented approaches are applied to the accuracy design and manufacture of a 4-axis machine tool, and double ball bar measurement and machining test are carried out to check the accuracy of the designed machine tool.

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Journal articles on the topic 'Geometric accuracy of the machine'

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