Physical Reconfiguration Research Articles

Rural greenways for urban environmental demands: Environmentalised urbanisation in the Pearl River Delta

China’s environmental turn is diversifying the country’s urbanisation trajectories. Previously abstracted and exploited as a vast land reserve for urban expansion, the countryside of China now captures the imagination of a growing crowd of green-loving urbanites with its ecological and cultural resources, propelling a new, environmentalised form of urbanisation. In the Pearl River Delta, the development of rural greenways has driven this urbanisation, in which rural lives and landscapes have evolved in response to their encounters with urban users of the greenways. Based on the late John Friedmann’s multidimensional understanding of China’s urbanisation, this paper unpacks four aspects of changes brought about by greenway-driven urbanisation in the Pearl River Delta’s countryside since the 2010s, namely, economic diversification, institutional adaptation, physical reconfiguration, and sociocultural transformation. These changes underscore the need for research on China’s urban-rural relations to pay more attention to the growing centrality of the environment in the politics and practices of urbanisation.

USE OF DIGITAL DOUBLE FOR COMPONENT MANUFACTURING

One of the contemporary approaches to production planning involves the application of digital twins technology, which aims to combine information from a real physical object and its virtual counterpart. The integration and synchronization of this information enable the realization of the manufacturing process with real-time tracking of the current state of the product and production. Utilizing the capabilities of modern computer technologies and digital twins creation technology allows for the assessment of the manufacturing process and its shortcomings even at the creation stage. The digital twins of the physical production process enable timely evaluation of design efficiency, avoidance of costly physical reconfigurations, attainment of maximum efficiency, shortened timelines, and reduced implementation costs through optimization. The model of the assembly process constructed in this way reflects the essential components and sequences. The foundation for implementing the digital twins of production is the model of the product itself, which serves as an integral part and basis of the entire digital model. Assessing the assembly of such a product objectively, its constituent elements, and the sequence of their assembly, allowed for the formulation of a description of the digital model of product assembly. The language used to describe the model is based on sets of relation types between components, assembly units of the product, and the constraints imposed on them within the given assembly. Such analytical notation of product components reflects the assembly process and constitutes a model of the technological assembly sequence. The proposed linguistic description of the product and the digital twins of the design enable the formalization of the three-dimensional assembly process during the design of assembly units and products, allowing for the modeling of their assembly process at the stage of design engineering.

Performance Enhancements and Modeling of Photovoltaic Panel Configurations During Partial Shading Conditions

The growing focus on solar energy has led to an expansion of large solar energy projects in the world. Though the most widely adopted Total Cross Tie (TCT) interconnection patterns will reduce the loss of mismatch, the appearance of shades in large-scale photovoltaic arrays drastically decreases the output power as well as several peaks of power in the P-V characteristics. To overcome these problems, the PV panels are organised using either electrical or physical reconfiguration methods. In this respect, it has been established that physical relocation methods are both cost-effective and efficient to disperse the shadow. In this context fits this work, his goal is to study the magic square view (MSV) for the physical rearrangement of the PV module in a TCT scheme. The simulation results reveal the effectiveness of the MSV method efficiently scattering the shade over the whole photovoltaic array. For validation, four types of Partial Shading Conditions (PSCs) patterns are considered and are then compared with the TCT and the recently proved Competence Square (CS) techniques: Short and Wide (SW), Long and Wide (LW), Long and Narrow (LN), and Short and Narrow (SN) shading patterns. Overall, MSV method is important in achieving improved output power enhancement of PV array under shaded conditions. A very clear improvement is obtained in the Long and Wide partial shading pattern.

A reprogrammable mechanical metamaterial with origami functional-group transformation and ring reconfiguration

Recent advancements in reprogrammable metamaterials have enabled the development of intelligent matters with variable special properties in situ. These metamaterials employ intra-element physical reconfiguration and inter-element structural transformation. However, existing mono-characteristic homo-element mechanical metamaterials have limited reprogramming functions. Here, we introduce a reprogrammable mechanical metamaterial composed of origami elements with heterogeneous mechanical properties, which achieves various mechanical behavior patterns by functional group transformations and ring reconfigurations. Through the anisotropic assembly of two heterogeneous elements into a functional group, we enable mechanical behavior switching between positive and negative stiffness. The resulting polygonal ring exhibits rotational deformation, zero Poisson’s ratio stretching/compression deformation, and negative Poisson’s ratio auxetic deformation. Arranging these rings periodically yields homogeneous metamaterials. The reconfiguration of quadrilateral rings allows for continuous fine-tunability of the mechanical response and negative Poisson’s ratio. This mechanical metamaterial could provide a versatile material platform for reprogrammable mechanical computing, multi-purpose robots, transformable vehicles and architectures at different scales.

Augmenting Power Efficiency by Virtue of a Novel Physical Reconfiguration of Solar Photovoltaic Array in Tandem with Experimental Validation

The growing interest in solar energy has led to large photovoltaic (PV) energy parks in today's world. Though the commonly used total‐cross‐tied (TCT) interconnection scheme reduces mismatch losses (MLs), the occurrence of partial shading on massive PV arrays (PVAs) reduces the output power. It invokes numerous local maximum power points (LMPPs) on the power–voltage (P–V) profiles. To counteract the undesired LMPPs, reconfiguration of PVAs is done either through electrical or physical reconfiguration methods. In this respect, physical relocation scheme is more economical for better distribution of partial shade. A novel greater‐than‐SuDoKu (GTS) topology is presented in this paper for achieving physical rearrangement of PV modules amalgamated with TCT interconnection scheme. For analysis, five shading cases are considered and obtained results are compared with conventional TCT and 10 newly established methods. In general, the proposed GTS strategy has shown its eminence in receiving a smoother P–V characteristic, enhanced efficiency, better fill factor, and reduced MLs, which ranges up to 1343 W. Moving forward, herein, the efficacy of the proposed reconfiguration scheme is validated, under the influence of partial shading conditions, through an experimental lab prototype for a 3 × 3 PVA.

An Accordion-Folding Series-Fed Patch Array With Finite Thickness: A folding technique for CubeSat arrays

Combining antenna arrays with physical reconfigurability (i.e., origami) allows for additional degrees of freedom in operation and enables larger structures to be folded into smaller volumes. The packaging ability of origami antennas is of great interest for CubeSat applications in particular. However, traditional origami is based on the manipulation of thin sheets, making physical reconfigurability with thick substrates very difficult. In this article, we present a foldable series-fed patch array designed on a strictly rigid printed circuit board (PCB). Notably, the array does not require any external mechanical folding appendages (i.e., brackets, tapes, or offsets), and it can be manufactured using commercially available PCBs and equipment. The PCB itself is strategically cut to form lamina emergent torsion (LET) joints. When fully deployed, the array operates at 5.7 GHz. A significant shift is not seen in the operational frequency until the folding exceeds 60° (5.7–5.61 GHz). This shows that the array, even in a state of near extreme faulty deployment, will operate as intended. An 8 × 6 prototype array was fabricated using a Rogers DiClad 880. When fully deployed, the array is extended in a surface area of 280 × 198 × 1.524 mm and can be folded into a 35.5 × 198 × 12.5-mm compartment. The array held its integrity well after 100 cycles. (One cycle starts at a state of full deployment, moves to a state of being fully packaged, and goes back to a state of full deployment.) Measurements show that the active reflection coefficients are in good agreement with the finite array simulations. The measured realized gains at 5.7 GHz for 0° and 30° folds were 22.4 and 21.4 dBi, respectively. At the 60° fold, a realized gain of 20.6 dBi was achieved at the frequency of 5.61 GHz.

Digital twin enabled optimal reconfiguration of the semi-automatic electronic assembly line with frequent changeovers

• This paper proposes a digital twin enabled optimal reconfiguration approach of semi-automatic electronic assembly line with frequent changeovers. The contributions can be summarized as following: • A digital twin enabled reconfiguration assembly mode and its related reconfiguration & operation platform are developed for electronic products assembly. • An open architecture in equipment and line levels is developed to support the rapid physical reconfiguration. • A generalized knowledge encapsulation technique is constructed to speed up the procedure of virtual reconfiguration. • An optimal reconfiguration algorithm via analytical target cascading, named minimal reconfiguration (MR), is proposed to solve the coupled optimization of order scheduling, line balancing, and buffer allocation. The survival of original equipment manufacturers (OEMs) requires rapid responses to changing customer demands while keeping cost savings as their top priority. This paper proposes a Digital Twin (DT) enabled reconfiguration framework for the semi-automatic electronic assembly line with frequent changeovers. The DT platform develops an open architecture for the equipment and the assembly line to support its rapid physical reconfiguration, and a generalized knowledge encapsulation technique is applied to facilitate virtual reconfiguration. The dynamic performance is evaluated by max-plus semiring. Subsequently, an optimal reconfiguration algorithm via analytical target cascading, named minimal reconfiguration, is proposed to solve the coupled optimization of order scheduling, line balancing, and buffer allocation. A smart-phone assembly line is applied to verify the DT platform efficiency and minimal reconfiguration optimization approach.

Digital twins-based flexible operating of open architecture production line for individualized manufacturing

Individualized manufacturing implies high flexibility of both the hardware and software of the production lines based on a fast physical and logical system (de)commissioning. This paper proposes an open architecture production line (OAPL) design together with a digital twins-based flexible operating approach for individualized manufacturing. Firstly, an OAPL is designed and implemented with physical reconfigurability by orchestrating different open architectural platforms together with open architecture machine tools (OAMTs). Secondly, an open architectural style modeling and configuration method is presented to enable the software reconfigurability of the controls of the OAPL. Thirdly, a digital twin-based online process emulating and multi-physics simulation is integrated to aid the comprehensive characterizing of the operation status of the OAPL. Based on the system reconfigurability and digital twins system, a triple-layer Learning-Optimization-Reacting approach together with an ensemble algorithm for flexible operating of the OAPL is proposed. The digital twins are formed with the ability to flexibly operate the OAPL for catering to different individualized requirements. A demonstrative implementation of a stepping-motor assembly OAPL is presented finally.

Virtual indoor-GPS for measurement uncertainty determination in reconfigurable environments

In Line-less Mobile Assembly Systems, the mobilization of assembly resources and products enables rapid physical system reconfigurations to increase flexibility and adaptability. The clean floor approach discards fixed anchor points, so that assembly resources such as mobile robots and automated guided vehicles transporting products can adapt to new products and form new processes. Associated challenges are accurate spatial referencing between mobile resources to meet assembly tolerance requirements. There is a need for more accurate positioning data to locate and navigate mobile assembly resources. An indoor-GPS, as a distributed large-scale metrology system, is able to cover a wide shop floor area and to obtain positioning data with uncertainties in the submillimeter range. The measurement uncertainty of such a system depends on the spatial distribution of the transmitters and the receiver positions. To be able to validate positioning tolerance requirements of an assembly process, measurement uncertainties must be determined. Virtual measurements simulate measurement processes and model dependencies between the environment and the metrology system. This work presents a novel approach for a virtual indoor-GPS to determine measurement uncertainties during a process and to evaluate the measurement process capability. Experiments show the validity of the virtual indoor-GPS which can be used as a planning tool for metrology system setups within Line-less Mobile Assembly Systems.

A framework for planning a reconfigurable assembly system for press brake production

This article presents the design of a framework for the development of a reconfigurable assembly system (RAS) to facilitate the assembly of press brakes varieties. A consideration of press brake varieties is achieved by examining the parts taxonomy of press brakes from which a framework for assembly process plan is developed that considers all the types of press brakes identified from the classification. Also, a layout for the RAS is developed by considering a prototype of the major enabling equipment of the system which is a reconfigurable assembly fixture (RAF). The development of the assembly process plan and layout of the RAS enabled the design of a reconfiguration model for operation in the RAS. The designed assembly framework will provide: rapid and physical reconfiguration of the RAF in the RAS; generation of assembly sequence for press brake varieties; and allocation of assembly operations to assembly work cells in the system. [Submitted 27 May 2020; Accepted 3 December 2020]

Insta-Gaze: Aesthetic representation and contested transformation of Woljeong, South Korea

Woljeong was a secluded fishing village on Jeju island before being popularized on social media via aesthetic photographs of the local beach. Turned into a destination where tourists flood to achieve visually captivating photos, this small village has undergone tourism-induced gentrification, displacement, and overdevelopment. Unpacking the processes of Woljeong’s transformation offers insights to grasp the connection between new media and tourism, and between the representation of a place and its physical reconfiguration. Driving new tourism trends, Instagram has emerged as a dominant platform to create, circulate, and consolidate tourism imaginaries. The functional protocols of Instagram—its graphic-oriented nature, ability to promote inter-subjective communication of self-reflexivity, and role as an individual and collective archive of particular place images—construct the place myth centering on aesthetic representational qualities. Such representational practices reshape the material and spatial realities of the place involving property value hikes, construction boom, and land use change. Rapid changes to the area to fulfill tourists’ material and physical demands are contrasted with non-contested aesthetic representations of the beach, which should be visually and photographically preserved to serve tourists’ fantasies. Woljeong’s recent reconfiguration functions as a proxy to contemplate the historical process of Jeju in which tourism, both through the material and representational practices, perpetuates the marginalization of Jeju as an exclusively touristic island.

A Novel Magic Square Based Physical Reconfiguration for Power Enhancement in Larger Size Photovoltaic Array

Partial shading is the prevailing problem in Photovoltaic arrays. It results in severe consequences like multiple peaks in electrical characteristics, hot spots on Photovoltaic panels, disruptions in tracking maximum power and reduced output power. During most of the shading conditions, the shade concentrates in a particular area of the Photovoltaic (PV) array. This shading reduces PV array efficiency. Several physical reconfiguration schemes based on puzzle patterns are proposed to minimize this problem. The majority of these methods deduced to fixed PV array size for which the algorithm has proposed. Further, few of them are applicable only to lower size PV array. This paper presents a novel magic square puzzle for scattering the shade in the PV array to overcome the above constraints. In this method, the module physical position remains the same. However, the electrical wiring alters according to the puzzle pattern to change the row current in the Total-Cross-Tied topology PV array. The efficiency of the proposed system is examined under different shading conditions using characteristic curves. The relative analysis was carried between the conventional Total-Cross-Tied topology and the proposed Novel Magic Square-based Total-Cross-Tied topology. The MATLAB/SIMULATION results demonstrate that placing the modules according to the proposed reconfiguration method minimizes the peaks and enhances the output power (11.53%), with the global peak always on the right side of the PV curve under partial shading conditions.

Circularly‐polarised origami‐inspired folding patch antenna sub‐array

This work discusses the design of a microstrip patch antenna and its use as an orientation-agnostic radiator in an origami-inspired folding antenna array. The antenna is based on a perturbed circular patch design that is impedance matched to reside in a radial feed network for a 2 × 2 array. This 2 × 2 array can be switched to provide sum and difference pattern behaviour. Both the feed network and the ground plane are modified to enable folding of the structure according to the Miura-ori pattern. The performance of a circularly polarised array is evaluated for a comprehensive range of fold angles to evaluate the impact of physical reconfiguration. Results for a simulated and fabricated circularly polarised array are provided for a 3 GHz design.

Drone Reconfigurable Architecture (DRA): a Multipurpose Modular Architecture for Unmanned Aerial Vehicles (UAVs)

This work proposes the Drone Reconfigurable Architecture ( $\mathcal {DRA}$ ), which is a modular architecture for UAVs with electrical, mechanical, and computational specifications. The theoretical aspects of the architecture are introduced through a case study with practical implementations aiming to design a multi-rotor UAV, which also includes the manufacturing steps of a functional prototype. Our proposal can be used in a scenario where the capacity of physical reconfiguration of a UAV would confer an enormous advantage to these aircraft in terms of applicability. This happens in the case where each task typically requires a robot with a particular physical architecture (number and position of propellers, autonomy, thrust, sensors, and communication). Results of a set of tests with an aircraft assembly are presented to verify the versatility of the proposed architecture, demonstrating the better performance of these aircraft when compared with conventional UAVs. The proposed methodology allows applications in a variety of scenarios like cargo transportation, support, agriculture, publicity, pest control, surveillance, inspection, and entertainment, between others. In these scenarios, although a software with some generic components could easily control drones to perform all of them, it is unthinkable to consider that a single drone with a particular physical structure would be able to be adapted to all of the tasks necessary (as path following, localization, and mapping).

Performance Analysis of Partially Shaded Photovoltaic Array Using Magic Square View Configuration for Shade Dispersion

Abstract The power generated by the photovoltaic (PV) array is affected by the partial shading, caused by the neighboring object shadows, dirtiness, moving clouds, bird droppings, different orientation angles of PV modules, deposition of dust in modules, and the physical location of the PV module. Therefore, the PV systems exhibit multiple peaks of generated power and do not always track the maximum power point (MPP). Thus, to overcome these problems of multiple peaks, the PV panels are reconfigured using either electrical or physical reconfiguration methods. The main aim of this paper is to investigate the performance of magic square view (MSV) configuration of PV modules under partial shading conditions (PSCs). For validation, three kinds of PSCs patterns are considered and are then compared to the Total Cross Tied (TCT) and Sudoku (SDK) configurations: long and wide, short and narrow, and long and narrow. Overall, the obtained results show that the MSV configuration allows us to increase the power generated by the PV array by 34% and 7% under the three types of shadow studied as compared to the TCT and SDK configurations, respectively. The PV array configurations parameters are performed based on matlab/simulink software. The simulation and performance analysis of PV array configurations is performed with 81 PV modules of BP Solar Poly BP 380 modules.

The urban effects of the emerging middle class in the global south

AbstractThis article explores the implications of a growing middle‐income population on the cities of the global South. The emergence of this group, situated between the poor and the very rich, long the standard binary categorization of understanding the global urban South, has important implications for physical reconfigurations and changing social structures. We discuss the reasons behind the rise of this middle‐income category, note some of its characteristics and review its urban impacts. We focus on just three themes: new consumption patterns, housing markets and, urban politics. We contribute to broader theories of global urbanism by highlighting how an expanding middle‐income‐class are shaping and configuring a new urban realm in the global South.

Tailoring reflected and diffracted wave fields from tessellated acoustic arrays by origami folding

Recently the physical reconfigurations of origami-inspired acoustic arrays have been leveraged for adaptive guidance of acoustic wave energy. The spatial translations and rotations of transducer elements in tessellated arrays may tailor how reflected and diffracted waves contribute to the total acoustic pressure at the field point. To date such wave phenomena have not been illuminated, which inhibits understanding on how to best leverage the concept for highly reconfigurable arrays. Here, the reflection and diffraction phenomena induced from a Miura-ori based acoustic array are examined, wherein such wave fields superpose with directly radiated waves to yield the total acoustic response at receiving locations. As tessellated arrays take on highly folded configurations, reflected waves are shown to greatly contribute to the acoustic field at points normal to the plane of the unfolded array, whereas diffracted waves primarily govern the acoustic pressure for locations at nearly grazing angles of incidence to the unfolded array plane. Supported by experimental validation, the modeling methods established here can be extended to arbitrary wave-radiating architectures and may inspire investigations for other physical domains where reconfigurable array concepts are of great interest.

On a silver platter

on a silver platter

A novel Competence Square based PV array reconfiguration technique for solar PV maximum power extraction

The ever growing interest on solar energy has augmented large solar power parks in the contemporary time. Even though the most commonly used Total Cross Tie (TCT) interconnection scheme minimizes mismatch losses, shade occurrence in large PV arrays drastically reduces the power output and invokes multiple power peaks in the P-V characteristics. To counteract the multiple peak issue, PV arrays are reconfigured either via electrical or physical reconfiguration techniques. In this regard, physical relocation methods are proven to be efficient and economical in achieving better shade dispersion since, it neither demands complex switching arrangements or high end controllers for reconfiguration. Therefore, this paper introduces an innovative Competence Square (CS) technique for physical rearrangement of PV panels in a TCT interconnection scheme. The method devised is a onetime relocation technique that follows a unique number pattern for relocating the PV panels. Moreover, various test results elucidate the effectiveness of the CS technique in effectively dispersing the shade over the entire PV array. For validation, four typical shade cases are considered and the results are comprehensively compared with the recently proved TCT and Dominance Square (DS) techniques. In addition, the proposed method is computationally easy and is adaptable for PV arrays of any size. Overall, CS technique has showed its eminence in obtaining smoother output characteristics, better fill factor, power enhancement and increased energy savings.

Fast distribution network reconfiguration algorithm based on minus feasibility analysis unit

Because of the defects of the nonlinear optimization algorithm and the complexity of the physical constraints of the distribution network reconfiguration, the speed and the convergence of the algorithms are usually poor. A fast algorithm for distribution network reconfiguration based on feasibility analysis unit is presented. Firstly, the network simplification method is presented based on the radial construction of the distribution network, and then the conception of basic loop is proved by using the impedance-branch dissipation power theory. By analyzing the quantitative relationship between load and branch power loss and the characteristics of the nodal impedance matrix, the basic loop that is just the minus feasibility analysis unit of the physical reconfiguration optimization is verified. Based on this theory, the path dissipation factor is presented which formed a novel heuristic rules and an improved branch exchange method in order to solve the distribution network reconfiguration problem. In this proposed method, the processing sequence of all the basic loops is firstly defined by the load dissipation component, and then optimal reconfiguration scheme is simply obtained by repeating the above operation until there is no branch need to exchange. Test results of IEEE-69 buses system verified the efficiency and reliably of the proposed method.