Compliance model of Exechon manipulators with an offset wrist

TY - JOUR

T1 - Compliance model of Exechon manipulators with an offset wrist

AU - López-Custodio, P. C.

AU - Fu, R.

AU - Dai, J. S.

AU - Jin, Y.

N1 - Funding Information: This work was supported by the Engineering and Physical Sciences Research Council (EPSRC), UK projects with reference numbers EP/P025447/1 and EP/P026087/1 . The support from Northern Ireland Technology Centre for the experimental work is also acknowledged. Publisher Copyright: © 2021 The Authors Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

PY - 2022/1

Y1 - 2022/1

N2 - The stiffness of the Exechon hybrid manipulator is a crucial performance indicator as the manipulator is used as a 5-axis machine tool. Normally, the serial module of the Exechon is not included in the kinematic and stiffness analysis. In terms of kinematics, the parallel and serial modules are said to be decoupled, i.e. parallel module can be solved for position and the serial module can be used to compensate the parasitic orientation of the parallel platform. This is only possible when the serial module is a perfect spherical wrist. However, several models of Exechon technology have an offset wrist rather than a spherical one. Such an offset makes it impossible to obtain a kinematic decoupling. In all publications available in the literature, the Exechon is considered to have a perfect spherical wrist. Therefore, this paper presents the inverse kinematics and compliance model of Exechon manipulators with offset wrists. The unknown coefficients in the compliance model are determined by optimizing the model against experimental data. The resulting predictions are then compared against more experimental results to validate the model.

AB - The stiffness of the Exechon hybrid manipulator is a crucial performance indicator as the manipulator is used as a 5-axis machine tool. Normally, the serial module of the Exechon is not included in the kinematic and stiffness analysis. In terms of kinematics, the parallel and serial modules are said to be decoupled, i.e. parallel module can be solved for position and the serial module can be used to compensate the parasitic orientation of the parallel platform. This is only possible when the serial module is a perfect spherical wrist. However, several models of Exechon technology have an offset wrist rather than a spherical one. Such an offset makes it impossible to obtain a kinematic decoupling. In all publications available in the literature, the Exechon is considered to have a perfect spherical wrist. Therefore, this paper presents the inverse kinematics and compliance model of Exechon manipulators with offset wrists. The unknown coefficients in the compliance model are determined by optimizing the model against experimental data. The resulting predictions are then compared against more experimental results to validate the model.

KW - Compliance

KW - Coupled kinematics

KW - Kinematics

KW - Parallel robots

KW - Stiffness

UR - http://www.scopus.com/inward/record.url?scp=85116358738&partnerID=8YFLogxK

U2 - 10.1016/j.mechmachtheory.2021.104558

DO - 10.1016/j.mechmachtheory.2021.104558

M3 - Article

AN - SCOPUS:85116358738

SN - 0094-114X

VL - 167

JO - Mechanism and Machine Theory

JF - Mechanism and Machine Theory

M1 - 104558

ER -