Modern industrial automation tasks require a high degree of flexibility, specifically when seeking for lot-size-one techniques.  
In order to achieve this goal, the interfaces between machines and the products, such as grippers or mountings need to be adaptable to a wide range of different products. Significant developments towards programmable structures, which could represent these adaptive interfaces, have been presented for the planar case recently. Programmable structures are formed by autonomous and adaptive triangular cells. However, they are composed of a large number of parts, specifically bearings, which make them laborious to manufacture and expensive.  
An essential part of these programmable structures are six-bar linkages, which allow to build cells that can  
preserve the underlying geometry of a triangular mesh. A major improvement, which is the main part of this paper, is to replace the joints of the six-bar-linkage by a compliant mechanism, which allows to manufacture them as one 3D printable part.  
The proposed compliant mechanism is based on solid-state flexure hinges, which are modeled regarding their kinematical behavior as well as their compliance. Furthermore, the displacement of the rotation axis of the six-bar-linkage is computed as a function of a single error in the compliant joints. As this error depends on the current configuration of the six-bar-linkage, the error is computed for the viable range of angles and it turns out that there is no significant error propagation, such that the error stays sufficiently small.  
A multibody system formulation is setup with the model of the compliant mechanisms, treating every joint either ideal or compliant with the given stiffness parameters. The multibody formulation furthermore allows to include friction as well as an actuator model in a straight-forward manner. The overall stiffness parameter of the real system is then identified from a comparison with an experimental setup of a real compliant triangular cell. Finally, the model is used to show the deviations of a medium-scaled programmable structure with respect to the idealized behavior.  
The present paper marks a relevant step towards the realization of larger programmable structures as well as the development of 3D programmable structures.


Six-Bar Linkages With Compliant Mechanisms for an Adaptive Robot

Division / Sponsors: 
Design Engineering Division and Computers & Information In Engineering Division


Paper Proceedings: https://asmedigitalcollection.asme.org/IDETC-CIE/IDETC-CIE2020/volume/83907

IDETC2020 - Virtual Conference

Supporting the need among researchers worldwide for additional online and multimedia content, ASME now offers the ASME Conference Video Collection. This platform will collect and provide long-term access to conference presentation videos, encompassing all technology areas within ASME's technical conference and events program. About 30,000-40,000 engineers across all mechanical engineering and related disciplines participate in ASME conferences each year. This includes authors of approximately 6,000 to 8,000 technical papers published by ASME, the majority of whom also submit video presentations for our virtual conferences. The video collection will be available as an add-on to existing product packages or as a separate subscription.