Measurement uncertainty of generalized stiffness of machine tools

Majda, P.; Jastrzębska, Joanna

doi:10.1016/j.measurement.2020.108692

“…The frame was designed based on the criterion that the deflection of the frame with the attached robot should be less than 0.5 mm. As a result, a generalized stiffness was obtained, determined from [ 15 ] in the X and Y directions at

and

in the Z direction. The weight of the frame was 828 kg.…”

Section: Methodsmentioning

confidence: 99%

Finite Element Modeling of Dynamic Properties of the Delta Robot with Base Frame

Grabiec

¹

,

Pajor

²

,

Dunaj

³

2022

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The paper presents the finite element modeling of the dynamic properties of a delta robot attached to a steel frame. A distinguishing feature of the proposed modeling method is the application of the Guyan reduction method in modeling of frame foundations. The frame in question was analyzed in two variants: (i) without attached robot and (ii) with attached robot. Based on the established model, the dynamic properties (i.e., natural frequencies, mode shapes, and frequency response functions) of the frame in the two variants were analyzed. The obtained results were then experimentally verified and validated. It was found that the developed model showed an average relative error for natural frequencies of 4.3% in the case of the frame and 5.6% in the case of the frame with the robot. The paper demonstrated the validity of the proposed model, allowing accurate and fast determination of robotic system dynamic properties.

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“…While, for 5-axis milling machines the stiffness was between 7 and 15 N/µm in X and Y axes and between 50 and 80 N/ µm in Z-axis. Also, in [4] the stiffness was measured for medium sized milling machine; obtained values in X and Y axis were about 13 N/µm, when in Z-axis it was about 30 N/µm. As it might be seen, in almost all mentioned cases the stiffness values in speci c axis differ.…”

Section: Introductionmentioning

confidence: 99%

“…Based on the mentioned research, it can be concluded that there is no common standardized approach of machine tool stiffness studies. What is more, in most studies the results of stiffness are reported without information about the uncertainty [4]. Unfortunately, in this respect, it can be inappropriate to compare static stiffness values obtained using various methods.…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, it results in spatial variation of static stiffness of the system. The importance of conducting studies of the static stiffness distribution in the workspace is being highlighted in recent years [2][3][4]. Both the knowledge of the stiffness distribution and cutting force parameters can be used to predict some machining errors in machine's workspace.…”

Section: Introductionmentioning

confidence: 99%

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Measurement and identification of generalised translational static stiffness in machining space of five-axis machine tool

Jastrzębska

¹

,

Parus²,

Jastrzębski³

et al. 2022

Preprint

Self Cite

0

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This work presents a measurement for the identification of translational quasi-static stiffness of machine tool using Stiffness Workspace System (SWS). The novelty of this work is a significant modification of the SWS. The changes in measurement procedure and data analysis as well as new technical solutions are described in detail. A methodology for generalised translational static stiffness determination is presented. The major purpose of this paper is to provide the information about quasi-static stiffness values that characterise a typical machine tool. The measurement procedure is implemented in a case study on a 5-axis machining centre. Measurement results were used to determine the generalised translational stiffness indicators of points in the workspace. Then, the static stiffness distribution on the XY plane over machining space was estimated. The obtained results confirm the importance of analyses of static stiffness distribution as they point out areas where some possible changes occur. In the conclusion of the paper the utility value of the information of translational static stiffness is emphasized.

show abstract

“…Therefore, it results in spatial variation of static stiffness of the system. The importance of conducting studies of the static stiffness distribution in the workspace is being highlighted in recent years [3][4][5]. Both the knowledge of the stiffness distribution and cutting force parameters can be used to predict some machining errors in machine's workspace.…”

Section: Introductionmentioning

confidence: 99%

Measurement and identification of translational static stiffness in workspace of a machine tool

Jastrzębska

¹

,

Parus

²

,

Jastrzębski

³

et al. 2023

Int J Adv Manuf Technol

Self Cite

0

View full text Add to dashboard Cite

This work presents a measurement for the identification of translational quasi-static stiffness of machine tool using Stiffness Workspace System (SWS). The novelty of this work is a significant modification of the SWS. The changes in measurement procedure and data analysis as well as new technical solutions are described in detail. A methodology for generalised translational static stiffness determination is presented. The major purpose of this paper is to provide the information about quasi-static stiffness values that characterise a typical machine tool. The measurement procedure is implemented in a case study on a 5-axis machining centre. Measurement results were used to determine the generalised translational stiffness indicators of points in the workspace. Then, the static stiffness distribution on the XY plane over machining space was estimated. The obtained results confirm the importance of analyses of static stiffness distribution as they point out areas where some possible changes occur. In the conclusion of the paper the utility value of the information of translational static stiffness is emphasised.

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Measurement uncertainty of generalized stiffness of machine tools

Cited by 15 publications

References 26 publications

Finite Element Modeling of Dynamic Properties of the Delta Robot with Base Frame

Finite Element Modeling of Dynamic Properties of the Delta Robot with Base Frame

Measurement and identification of generalised translational static stiffness in machining space of five-axis machine tool

Measurement and identification of translational static stiffness in workspace of a machine tool

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