A New Stiffness Performance Index: Volumetric Isotropy Index

Görgülü, İbrahimcan; Dede, Mehmet İsmet Can

doi:10.3390/machines7020044

Cited by 10 publications

(8 citation statements)

References 48 publications

(118 reference statements)

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“…3 The stiffness used in this concept reflects direct mapping between an applied wrench and Moving Platform (MP) deflection due to the deformation of the manipulators. As revealed in Refs., [4][5][6][7] stiffness analysis has been generally carried out by three approaches, namely, (i) Finite Element Analysis (FEA), (ii) Matrix Structural Analysis (MSA), and (iii) Virtual Joint Method (VJM).…”

Section: Introductionmentioning

confidence: 99%

“…4,6,[19][20][21] As the third method, the so-called VJM, which is also known as the lumped-parameter method, the links are assumed rigid and compliancy is taken into account by rotational and translational virtual joints. 5,[22][23][24] As investigated in Gonc xalves et al, 25 in which a comparison of stiffness methods has been performed, two modeling methods have been presented for VJM. In the latter study, the first method which was initiated by Salisbury 26 and Gosselin 27 is based on the Jacobian matrix and the second method uses the kinematic and forces distributions.…”

Section: Introductionmentioning

confidence: 99%

“…In the latter study, the first method which was initiated by Salisbury 26 and Gosselin 27 is based on the Jacobian matrix and the second method uses the kinematic and forces distributions. 28,29 In Go¨rgu¨lu¨and Dede, 5 Yang et al, 16 and Corves et al, 30 the FEA approaches are considered as purely numerical methods, VJM and MSA are classified as methods which could provide an analytical method, and the approaches in which FEA is combined with MSA or VJM methods 18,21 are categorized as semi-analytical approaches. The MSA in comparison to FEA still involves matrix operations of rather high-dimension matrix inversions, reported by Refs.…”

Section: Introductionmentioning

confidence: 99%

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An analytical approach to the stiffness calculation of statically indeterminate 3-DOF delta parallelogram-type parallel robot

Dastjerdi,

Sheikhi,

Tale Masouleh

2023

Proceedings of the Institution of Mechanical Engineers, Part C:

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This paper introduces an analytical approach entailing a clear physical meaning for calculating the stiffness of the 3-DOF Delta parallel robot. By defining suitable linear and torsion springs, the stiffness of the robot components in different postures and the stiffness coefficients of the indeterminate parallelogram under conceivable wrenches are comprehensively obtained. Moreover, the stiffness coefficients for each limb chain are assigned, and then by considering the assigned stiffness coefficients and static equilibriums the indeterminate problem of 3-RUU DPRs is solved. By reformulating the forward kinematics which takes into account the deflected components and based on the elastic properties, the deflection in each manipulator component is calculated and the amount of moving platform twist is obtained. The proposed approach is validated by the FEA method and results reveal that the maximum error of the proposed method is 0.1489° in the orientation and 0.1420 mm in translation compared to the FEA. Then to avoid the problem of different units of translation and orientation in indexing, the virtual work concept is used for assigning an index number.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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An analytical approach to the stiffness calculation of statically indeterminate 3-DOF delta parallelogram-type parallel robot

Dastjerdi,

Sheikhi,

Tale Masouleh

2023

Proceedings of the Institution of Mechanical Engineers, Part C:

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“…It can effectively evaluate the overall stiffness magnitude of the robot. Stiffness isotropy describes the stiffness difference of the robot in different directions [28]. In addition to overall stiffness magnitude, the stiffness isotropy also has a serious impact on the machining performance especially the consistency of accuracy.…”

Section: Introductionmentioning

confidence: 99%

Stiffness Evaluation of an Adsorption Robot for Large-Scale Structural Parts Processing

Chen

Xie

Liu

et al. 2021

Journal of Mechanisms and Robotics

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Efficient and economical processing of large-scale structural parts is in increasing need and is also a challenging issue. In this paper, an adsorption machining robot for processing of large-scale structural parts is presented. It has potential advantages in flexible, efficient and economical processing of large-scale structural parts because of the adsorption ability. Stiffness is one of the most important performance for machining robots. In order to investigate the stiffness of the robot in the workspace, the kinematics of the adsorption manipulator, the five-axis machining manipulator and the adsorption machining robot is derived step by step. Then with the help of Finite Element Analysis (FEA), a stiffness modeling method considering the compliance of the base is proposed. A stiffness isotropy index is put forward to evaluate the robot's overall stiffness performance by taking all possible working conditions into consideration. Based on the index, stiffness evaluation in the reachable workspace is carried out and an optimized workspace is identified considering the overall stiffness magnitude, stiffness isotropy and workspace volume, which will be used in the machining process. The stiffness modeling method and stiffness isotropy index proposed in the paper are universal and can be applied to other parallel robots.

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“…Paper [9] deals with non-linear effects in tilting pad journal bearings with test results of an experimental identification procedure. Paper [10] proposes a new index for a precise calculation of a manipulator's stiffness isotropy with a numerical validation through an evaluation of an R-CUBE manipulator design. Paper [11] presents an experimental characterization of a two-stage planetary gearbox as function of the attached load and the internal friction forces between gears.…”

mentioning

confidence: 99%