Repeatability Analysis of Overconstrained Kinematic Coupling Using a Parallel-Mechanism-Equivalent Model
A novel method for repeatability analysis of overconstrained kinematic coupling using a parallel-mechanism-equivalent-model is proposed. An overconstrained Kelvin-type coupling with one additional support is introduced and used for method illustration. Contact forces of the overconstrained coupling under preload are computed with Moore-Penrose inverse and the deformations are obtained using the Hertz theory. The couping is equivalently modeled as a 7-SPS parallel mechanism, spherical joints of which represent the centers of the supporting balls and the contact points, respectively, and prismatic joints are used to simulate the deformations. Therefore, pose error of the coupling arisen from preload is analyzed using the well-appraised incremental method for forward kinematics analysis of parallel mechanisms. The uncertainties of the preload are discussed and a boundary-sampling method is proposed for repeatability analysis. The main contribution of this study lies in that the proposed parallel-mechanism-equivalent-model and the boundary-sampling method greatly simplify the repeatability analysis of overconstrained kinematic couplings. Finally, the proposed methods are validated by case study.
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Due to technical limitations, full-text HTML conversion of this manuscript could not be completed. However, the manuscript can be downloaded and accessed as a PDF.
Posted 15 Dec, 2020
Invitations sent on 03 Jan, 2021
On 03 Jan, 2021
On 08 Dec, 2020
On 08 Dec, 2020
On 08 Dec, 2020
On 06 Dec, 2020
Repeatability Analysis of Overconstrained Kinematic Coupling Using a Parallel-Mechanism-Equivalent Model
Posted 15 Dec, 2020
Invitations sent on 03 Jan, 2021
On 03 Jan, 2021
On 08 Dec, 2020
On 08 Dec, 2020
On 08 Dec, 2020
On 06 Dec, 2020
A novel method for repeatability analysis of overconstrained kinematic coupling using a parallel-mechanism-equivalent-model is proposed. An overconstrained Kelvin-type coupling with one additional support is introduced and used for method illustration. Contact forces of the overconstrained coupling under preload are computed with Moore-Penrose inverse and the deformations are obtained using the Hertz theory. The couping is equivalently modeled as a 7-SPS parallel mechanism, spherical joints of which represent the centers of the supporting balls and the contact points, respectively, and prismatic joints are used to simulate the deformations. Therefore, pose error of the coupling arisen from preload is analyzed using the well-appraised incremental method for forward kinematics analysis of parallel mechanisms. The uncertainties of the preload are discussed and a boundary-sampling method is proposed for repeatability analysis. The main contribution of this study lies in that the proposed parallel-mechanism-equivalent-model and the boundary-sampling method greatly simplify the repeatability analysis of overconstrained kinematic couplings. Finally, the proposed methods are validated by case study.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Due to technical limitations, full-text HTML conversion of this manuscript could not be completed. However, the manuscript can be downloaded and accessed as a PDF.