Analytical determination of shape singularities for three types of parallel manipulators

Wu, Xiaoyong; Bai, Shaoping

doi:10.1016/j.mechmachtheory.2020.103812

Cited by 12 publications

(5 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A redundant chain makes the mechanism design symmetrical and suitable for applications like those listed above. Using different kinematic chains is a trade-off: a 4-RRR mechanism is less rigid than a 4-RPR one, while the latter is prone to architecture singularities [72]. In addition, the redundant actuation affects the manipulator performance [73], and it can also be used in other hybrid manipulators we presented in Section 3.…”

Section: Discussionmentioning

confidence: 99%

Type Synthesis of 5-DOF Hybrid (Parallel-Serial) Manipulators Designed from Open Kinematic Chains

et al. 2023

View full text Add to dashboard Cite

The article proposes an approach for synthesizing hybrid (parallel-serial) manipulators with five degrees of freedom (5-DOF) using open kinematic chains. The method idea consists in taking an open kinematic chain, selecting a subchain within it, and replacing the subchain with a parallel mechanism. The article considers 5-DOF open chains and 3-DOF subchains, substituted for 3-DOF parallel mechanisms with the same motion pattern as the subchain. Thus, synthesized hybrid manipulators have a 3-DOF parallel part and a 2-DOF serial part. First, we grouped 26 structures of open chains with revolute and prismatic joints into five types and 78 subtypes. Next, for each type, we selected one subtype and presented several hybrid mechanisms that can correspond to it. We considered hybrid manipulators that included 3-DOF parallel mechanisms with planar, spherical, and other commonly used motion types. The suggested synthesis method is intuitive for a designer, and it does not need any mathematical formulations like screw theory or group theory approaches.

show abstract

Section: Discussionmentioning

confidence: 99%

Type Synthesis of 5-DOF Hybrid (Parallel-Serial) Manipulators Designed from Open Kinematic Chains

et al. 2023

View full text Add to dashboard Cite

show abstract

“…Nurahmi et al [21] detected the conditions for selfmotions of a 4-CRU PM (C stands for a cylindrical joint). Wu and Bai [22] proposed an analytic approach to the determination of architectural singularity, the presence of self-motions were validated in the 3-PPR planar PM and the 3-PPS spatial PM.…”

Section: Introductionmentioning

confidence: 99%

A Coordinate-Free Approach to the Design of Generalized Griffis-Duffy Platforms

Shen,

Pei,

Hang

et al. 2024

Chin. J. Mech. Eng.

View full text Add to dashboard Cite

Architectural singularity belongs to the Type II singularity, in which a parallel manipulator (PM) gains one or more degrees of freedom and becomes uncontrollable. PMs remaining permanently in a singularity are beneficial for linear-to-rotary motion conversion. Griffis-Duffy (GD) platform is a mobile structure admitting a Bricard motion. In this paper, we present a coordinate-free approach to the design of generalized GD platforms, which consists in determining the shape and attachment of both the moving platform and the fixed base. The generalized GD platform is treated as a combination of six coaxial single-loop mechanisms under the same constraints. Owing to the inversion, hidden in the geometric structure of these single-loop mechanisms, the mapping from a line to a circle establishes the geometric transformation between the fixed base and the moving platform based on the center of inversion, and describes the shape and attachment of the generalized GD platform. Moreover, the center of inversion not only identifies the location of rotation axis, but also affects the shape of the platform mechanism. A graphical construction of generalized GD platforms using inversion, proposed in the paper, provides geometrically feasible solutions of the manipulator design for the requirement of the location of rotation axis.

show abstract

“…Nurahmi et al [21] detected the con ditions for self-motions of a 4-CRU PM (C stands for a cy lindrical joint). Wu and Bai [22] proposed an analytic app roach to the determination of architectural singularity, the presence of self-motions were validated in the 3-PPR plan ar PM and the 3-PPS spatial PM.…”

Section: Introductionmentioning

confidence: 99%

A coordinate-free approach to the design of generalized Griffis-Duffy platforms

Shen

Hang

et al. 2022

Preprint

View full text Add to dashboard Cite

Parallel manipulators remaining permanently in a singularity are beneficial for linear-to-rotary motion conversion. The Griffis-Duffy (GD) platform is mobile structure which can admit a Bricard motion. In this paper, we present a coordinate-free approach to the design of generalized GD platforms, which consists in determining the shape and attachment of both the moving platform and the fixed base. The generalized GD platform is treated as a combination of six coaxial single-loop mechanisms under the same constraints. Owing to the inversion, which is hidden in the geometric structure of these single-loop mechanisms, the mapping from a line to a circle establishes the geometric transformation between the fixed base and the moving platform based on the center of inversion. Moreover, the center of inversion not only identifies the location of rotation axis, but also affects the shape of the generated platform. The graphical construction of generalized GD platforms using inversion, proposed in the paper, provides geometrically feasible solutions of the manipulator for the requirement of the location of rotation axis.

show abstract

Analytical determination of shape singularities for three types of parallel manipulators

Cited by 12 publications

References 24 publications

Type Synthesis of 5-DOF Hybrid (Parallel-Serial) Manipulators Designed from Open Kinematic Chains

Type Synthesis of 5-DOF Hybrid (Parallel-Serial) Manipulators Designed from Open Kinematic Chains

A Coordinate-Free Approach to the Design of Generalized Griffis-Duffy Platforms

A coordinate-free approach to the design of generalized Griffis-Duffy platforms

Contact Info

Product

Resources

About