Synthesis of eight-bar linkages by constraining a 6R loop

Sonawale, Kaustubh H.; McCarthy, J. Michael

doi:10.1016/j.mechmachtheory.2016.07.001

Cited by 11 publications

(6 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To validate the proposed design framework, we compare it with the traditional linkage synthesis method [44]. In traditional linkage synthesis method, this is the motion generation for three task positions.…”

Section: Resultsmentioning

confidence: 99%

“…In actual engineering application, the wear extent of clearance joint directly determines the service life of four-bar linkage. In view of this, we select the solution with the minimum w A from the Pareto optimal set as the final optimal solution.To validate the proposed design framework, we compare it with the traditional linkage synthesis method[44]. In traditional linkage synthesis method, this is the motion generation for three task positions.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Design Framework for Motion Generation of Planar Four-Bar Linkage Considering Clearance Joints and Dynamics Performance

2022

View full text Add to dashboard Cite

In this paper, we present a novel design framework to connect linkage synthesis with dynamics performance of the linkage. The aim of the design framework is to improve the dynamics performance of the mechanism through linkage design, instead of improving manufacturing accuracy or changing driving strategy. Specifically, the design framework is to complete motion generation of four-bar linkage, considering clearance joints and dynamics performance. The constraint model of motion generation and the dynamics model of four-bar linkage are established, respectively. The coordinates of four joints of four-bar linkage are divided into two parts, one of parts is the parameters to improve the dynamics performance of the linkage and is selected as the optimization variables. The other parts of joint coordinates is to satisfy the kinematics requirements and is obtained by solving constraint equations of motion generation. Through optimization calculation, we can obtain the optimal configuration of the four-bar linkage that achieves specified task positions with high motion accuracy and low wear extent of clearance joint. Finally, a numerical example is proposed to demonstrate the novel design framework.

show abstract

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

Design Framework for Motion Generation of Planar Four-Bar Linkage Considering Clearance Joints and Dynamics Performance

2022

View full text Add to dashboard Cite

show abstract

“…The optimal inverse models are equivalent to Baranov trusses with 9 links, which have a single passive modular group with 8 elements. Such modular groups are found in literature exclusively in the case of structural models dedicated to the selection of the base and effector of bi-mobile mechanisms [1][2][3][4][12][13][14][15][16][17][18][19][20][21][22][23]. The number of passive modular groups with 8 elements obtained from a Baranov truss with nine elements is , from which non-distinct solutions due to symmetric elements are retained.…”

Section: Introductionmentioning

confidence: 99%

Passive modular groups with eight elements from inverse structural modeling of planar linkages

COMANESCU,

BOBLEA,

ONACA

2024

RJTS-AM

View full text Add to dashboard Cite

Bi-mobile mechanisms commonly used in robotics are obtained as structural solutions from plane linkages with five degrees of freedom, in which the basis and effector are nominated and two active kinematic pairs of the system are positioned. The basis and the effector are determined by inverse structural modeling, the inverse model consisting exclusively of passive modular groups. It is obtained by connecting the effector with plane motion dependent on two independent parameters through a virtual kinematic pair at the basis canceling the degree of mobility. The placement of active pairs is achieved by direct structural modeling, the direct model consisting of active and, eventually, passive modular groups. A mechanism performing with precision and accuracy of motion must have the inverse model and the direct model consisting of a minimum number of modular groups, as appropriate passive or active ones.The optimal inverse model is always a Baranov truss, from which the elimination of the basis results a single passive modular group. Bi-mobile mechanisms with three independent contours are obtained from the 40 kinematic chains with five degrees of freedom and three independent contours mentioned in the literature [Appendix 1]. They have a number of 8 mobile elements and 11 lower kinematic pairs, and the optimal inverse models, characterized by 9 elements and 12 kinematic pairs being Baranov trusses. The number of passive modular groups with 8 elements obtained from a Baranov truss with nine elements is , from which indistinct solutions due to symmetrical elements are eliminated. Thus, there are 188 structures, of which 95 ones are found in the solutions of the inverse models mentioned and are specially marked.

show abstract

“…11,12 They solved the six-bar linkage five-position problem by adding two revolute joint (RR) link to a 3R open chain, 11 extending the five-position synthesis method to eight-bar linkage. 12 They presented a design system for eight-bar linkage that used five-position synthesis to compute two RR links that constrain a planar 6R loop, and synthesized the eight-bar straight line linkage and multi-bar slider linkages. The contribution of the present work is more focused on N-position ( N ≥ 5) synthesis problem, whereas the precision four-position synthesis of multi-bar is still a problem.…”

Section: Introductionmentioning

confidence: 99%

Solution region synthesis methodology of planar eight-bar linkage for four specified positions of a 4R chain

Cui

Han

Xiao

et al. 2020

Proceedings of the Institution of Mechanical Engineers, Part C:

View full text Add to dashboard Cite

The solution region methodology for solving the problem of four-bar linkage synthesis with four specified positions was extended to solve the problem of eight-bar linkage synthesis. The processes to build solution regions for synthesizing different types of eight-bar linkages are described, and the methods of building solution regions are divided into five types. First, the synthesis equation is derived, and the curve expressed by the synthesis equation is called the solution curve. Second, the process to build the spatial solution regions from the solution curves is detailed, and a new defect identification method is developed for building the spatial feasible solution region, which is a set of linkage solutions meeting four positions and excluding defects. Finally, linkage solutions that do not meet practical engineering requirements are eliminated from the spatial feasible solution region to obtain the useful spatial solution region. The examples demonstrate the feasibility of the proposed method. The proposed synthesis methodology is simple and easy to program, and provides reference for four specified position synthesis of other multi-bar linkages.

show abstract

Synthesis of eight-bar linkages by constraining a 6R loop

Cited by 11 publications

References 10 publications

Design Framework for Motion Generation of Planar Four-Bar Linkage Considering Clearance Joints and Dynamics Performance

Design Framework for Motion Generation of Planar Four-Bar Linkage Considering Clearance Joints and Dynamics Performance

Passive modular groups with eight elements from inverse structural modeling of planar linkages

Solution region synthesis methodology of planar eight-bar linkage for four specified positions of a 4R chain

Contact Info

Product

Resources

About