Design, motion planning and control of a reconfigurable hybrid structure

Phocas, Marios C.; Christoforou, Eftychios G.; Matheou, Maria

doi:10.1016/j.engstruct.2015.07.036

Cited by 21 publications

(6 citation statements)

References 28 publications

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“…Nevertheless, this means that multiple actuators would need to be attached to the main structure and increase respectively the structure's self-weight and the energy consumption during reconfigurations. In order to avoid this and at the same time, achieve flexibility and controllability in the structure's kinematics, a multistep procedure has been proposed [24,25]. Each step involves the selective locking of (n-4) joints of the primary members to define a corresponding 'effective 4-bar' mechanism (E4B), which is a 1-DOF system.…”

Section: Reconfiguration Approachmentioning

confidence: 99%

Reconfigurable Modular Bar Structure

Phocas¹,

Matheou²,

Müller³

et al. 2019

Journal of the International Association for Shell and Spatial

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Structural modularity and reconfiguration allow for enhanced flexibility and adaptability to changing functional, environmental or loading conditions, contributing thus to a sustainable built up environment. The current paper refers to a temporary spatial structure of planar modular bar linkages positioned in parallel and interconnected. The linkages consist of hinge-connected beams and a secondary system of struts and continuous cables with adjustable length. Identical and synchronous reconfigurations of the planar systems provide respective shapes of the spatial structure. In achieving the transformations, the effective 4-bar approach is implemented via cabledriven actuation, necessitating only two linear actuators on the planar systems supports. Following a brief description of the reconfiguration approach and related motion planning principles, a presentation of the fabrication and assembly of a small-scale prototype model and its experimental testing leads to a discussion on related mechanical design and reconfiguration approach issues. By extent, a Finite-Element Analysis of the spatial structure conducted for a specific transformation sequence followed from an initial to a target configuration provides further insight in the system's nonlinear load-bearing behavior.

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Section: Reconfiguration Approachmentioning

confidence: 99%

Reconfigurable Modular Bar Structure

Phocas¹,

Matheou²,

Müller³

et al. 2019

Journal of the International Association for Shell and Spatial

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“…Nonetheless, deployable structures are limited to specific target configurations, while transformable structures with enhanced flexibility and controllability may obtain different configurations in response to various contexts. Proposed systems enabling deployability refer to tensegrity [6,7], scissor-like [8][9][10], origami inspired [11,12], rigid-bar linkage [13,14] and adaptive compliant structures [15,16]. Transformability is possible in tensegrity systems through direct implementation of linear motion actuators in place of compression members, or tension members of variable length [17][18][19][20].…”

Section: Introductionmentioning

confidence: 99%

Transformable building structures in architectural engineering education

Phocas

Matheou

Haase

2022

Archit. Struct. Constr.

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In the last decade, various types of transformable building structures have been developed, such as deployable tensegrity, scissor-like and origami-inspired systems, as well as reconfigurable rigid-bar linkage and adaptive compliant structures. The development of the systems owns to advances in material design and kinetics, while aiming at an improved sustainability of the built environment. Their conceptualization and investigation have been enabled through associative parametric design and numerical analysis facilities that meanwhile provide robust digital visualizations and numerical analysis models. In principle, responsive building structures are capable to adapt to changing functional, loading, or environmental conditions. At university level, the integrated architectural design that involves an integrative development of the building form, functions and technical system parameters is increasingly enriched by performance-based design approaches through interdisciplinary experimentation and design-driven research, i.e., 'integrated interdisciplinary design', for the achievement of efficiency, sustainability and technological innovation in architecture. The paper discusses related influencing modes and preliminary design results of an integrated interdisciplinary approach driven by aspects of modularity, flexibility, transportability, deployability, adaptivity and interactivity, as well as their implications towards a framework of related research. The design projects presented have been supervised by the authors in recent years at the University of Cyprus and the University of Stuttgart. In all cases, the design methodology followed enables students to consider related morphological, functional and structural requirements, while being exposed to transformable building structures as related to aspects of materiality, functionality, sustainability and aesthetics.

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“…The "effective 4-bar" mechanism has been proposed for the reconfigurations of the 9-bar linkage in achieving flexibility and controllability, as well as minimum structural selfweight and energy consumption for the locomotion. Several different configurations, without being exclusively symmetrical, can be produced by the multi-DOF system based on the motion planning and control methodology as presented in Phocas et al (2015). Two different actuation methods, i.e., a direct and a cable-driven actuation one, have been proposed by Phocas et al (2015), Matheou et al (2017Matheou et al ( , 2018.…”

Section: Introductionmentioning

confidence: 99%

“…Several different configurations, without being exclusively symmetrical, can be produced by the multi-DOF system based on the motion planning and control methodology as presented in Phocas et al (2015). Two different actuation methods, i.e., a direct and a cable-driven actuation one, have been proposed by Phocas et al (2015), Matheou et al (2017Matheou et al ( , 2018. In addition, an experimental small-scale model was developed to address the integrated design process of reconfigurable structures through design, modeling, and assembly (Christoforou et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

Automated Optimal Motion Sequence of a 9-Bar Linkage

Matheou

Kallioras

Lagaros

et al. 2020

Front. Built Environ.

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Automated optimization-driven analyses may lead to an emersion of innovative design approaches, while investigating the potentials in design, analysis and control of highperformance engineering structures, and adaptive architecture. In the present study, an optimum motion sequence for the reconfiguration of a 9-bar linkage is succeeded through a robust automated optimization-driven approach of the metaheuristic algorithm, Pity Beetle Algorithm (PBA). The project explores the load-bearing behavior of the planar structure in different states of the "effective 4-bar" reconfiguration sequences considering its self-weight and a uniform distributed vertical load. Each motion step of the 9-bar linkage uses only one degree-of-freedom (DOF), in which four joints of the primary members are unlocked and the remaining joints are controlled by the brakes. The system is actuated by only one geared electrical motor detached from the structure and positioned on the ground. Different intermediate configurations of the 9-bar linkage are selected through the automated optimization-driven analysis, in such a way that all the joints are adjusted to the desired values and therefore to the target position. Hence, the objective of the optimization process focused at minimizing the brake torques in the locked joints of the structure through all the motion steps. The work-minimization problem has been solved by the metaheuristic algorithm, PBA, while the algorithm has the ability to search into large spaces for possible solutions regardless of the scale. Based on the aggregation behavior of the beetle Pityogenes chalcographus, the metaheuristic algorithm is able to find the global optimum solution among the plethora of possible solutions. The numerical studies of different possible motion sequences have been conducted with the software MATLAB and Simulink for a Model Based-Design. The obtained results demonstrate that the design of reconfigurable engineering structures and adaptive architecture can benefit from an automated optimization-driven analysis of the reconfiguration determination, in view of achieving improved performance and energy efficiency.

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Design, motion planning and control of a reconfigurable hybrid structure

Cited by 21 publications

References 28 publications

Reconfigurable Modular Bar Structure

Reconfigurable Modular Bar Structure

Transformable building structures in architectural engineering education

Automated Optimal Motion Sequence of a 9-Bar Linkage

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