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Multifunctional elements are a special class of elements, the reliability model of which differs from the classical two-pole "on-off" model. A multifunctional element can have partly false states in addition to nonfalse and false states. The multifunctionality of the elements leads to the formation of flexible, adaptable systems with reconfigurable structure, in which, in case of partial failure of the element, it is possible to continue the successful functioning of the system by redistributing the functions between the elements. In this paper, the properties of multifunctional elements (MFE) and systems, assembled on their basis, methods of structural analysis, logical-probabilistic reliability models and issues of optimal reconfiguration of systems based on MFE are discussed. [ABSTRACT FROM AUTHOR]

We investigate the reconfigurability and tunability of the tessellation of Tachi-Miura Polyhedron (TMP), an origami-based cellular structure composed of bellows-like unit cells. Lattice-based three-dimensional mechanical metamaterials have recently received significant scientific interest due to their superior and unique mechanical performance compared to conventional materials. However, it is often challenging to achieve tunability and reconfigurability from these metamaterials, since their geometry and functionality tend to be pre-determined in the design and fabrication stage. Here, we utilize TMP's highly versatile phase-transforming and tessellating capabilities to design reconfigurable metamaterial architecture with tunable mechanical properties. The theoretical analyses and experiments with heat processing discover the wide range of the in-situ tunability of the metamaterial – specifically orders of magnitude change in effective density, Young's modulus, and Poisson's ratio – after its fabrication within the elastic deformation regime. We also witness a rather unique behavior of the inverse correlation between effective density and stiffness. This mechanical platform paves the way to design the metamaterial that can actively adapt to various external environments.

Abstract Unmanned robotic systems are expected to liberate people from heavy, monotonous, and dangerous work. However, it is still difficult for robots to work in complicated environments and handle diverse tasks. To this end, a robotic system with four legs, four wheels, and a reconfigurable arm is designed. Special attention has been given to making the robot compact, agile, and versatile. Firstly, by using separate wheels and legs, it removes the coupling in the traditional wheeled–legged system and guarantees highly efficient locomotion in both the wheeled and legged modes. Secondly, a leg–arm reconfiguration design is adopted to extend the manipulation capability of the system, which not only reduces the total weight but also allows for dexterous manipulation and multi‐limb cooperation. Thirdly, a multi‐task control strategy based on variable configurations is proposed for the system, which greatly enhances the adaptability of the robot to complicated environments. Experimental results are given, which validate the effectiveness of the system in mobility and operation capability.

The article describes a method for documenting the principles of functioning and internal organization of computing platforms, including reconfigurable computing systems and non-standard processor architectures. The novelty is in using of unified tools to describe: the design process and the computing process, hardware, software and tools, computing components of different granularity. The proposed approach is to describe computing platform as an ideal model that represents abstract algorithms for fulfilling functional requirements without specifying of how to implement it. Then the iterative model refinement follows including selection of physical implementation options, specifying the technological stacks, and additional mechanisms that provide the specified system qualities. A feature of the method is a kernel used for structuring information, classifying and describing the computational mechanisms the system consists of. The kernel includes elements common for different systems and is based on the analysis of a large number of computing architectures. The method describes the principles of the organization of platforms which are usually not considered together. These are: generalized processors with classical architecture which is an evolution of the von Neumann principles; systems based on microcontrollers; operating systems; large- and small-granular reconfigurable systems; specialized processors and accelerators; artificial neural networks. The proposed method can be used to structure information in both traditional and rapidly developing areas: reconfigurable systems and specialized processors. Based on the method, it is possible to create a common database of computing mechanisms suitable for use in different functional units of the system and at different levels of granularity. The results of the work can be useful for system architects to describe complex computing mechanisms consisting of software, hardware and dynamically generated adaptive “intelligent” components which will simplify their reuse and can be used to generate new architectural solutions. Also, the proposed method can be used in the process of training specialists, for a visual demonstration of the basic principles of computer technology.

Modern discrete-event systems (DESs) are often characterized by their dynamic structures enabling highly flexible behaviors that can respond in real time to volatile environments. On the other hand, timed automata (TA) are powerful tools used to design various DESs. However, they lack the ability to naturally describe dynamic-structure reconfigurable systems. Indeed, TA are characterized by their rigid structures, which cannot handle the complexity of dynamic structures. To overcome this limitation, we propose an extension to TA, called dynamic timed automata (DTA), enabling the modeling and verification of reconfigurable systems. Additionally, we present a new algorithm that transforms DTA into semantic-equivalent TA while preserving their behavior. We demonstrate the usefulness and applicability of this new modeling and verification technique using an illustrative example. [ABSTRACT FROM AUTHOR]

Dataflow Models of Computation (MoCs) are widely used in embedded systems, including multimedia processing, digital signal processing, telecommunications, and automatic control. In a dataflow MoC, an application is specified as a graph of actors connected by FIFO channels. One of the first and most popular dataflow MoCs, Synchronous Dataflow (SDF), provides static analyses to guarantee boundedness and liveness, which are key properties for embedded systems. However, SDF and most of its variants lack the capability to express the dynamism needed by modern streaming applications. In particular, the applications mentioned above have a strong need for reconfigurability to accommodate changes in the input data, the control objectives, or the environment. We address this need by proposing a new MoC called Reconfigurable Dataflow (RDF). RDF extends SDF with transformation rules that specify how and when the topology and actors of the graph may be reconfigured. Starting from an initial RDF graph and a set of transformation rules, an arbitrary number of new RDF graphs can be generated at runtime. A key feature of RDF is that it can be statically analyzed to guarantee that all possible graphs generated at runtime will be consistent and live. We introduce the RDF MoC, describe its associated static analyses, and present its implementation and some experimental results. [ABSTRACT FROM AUTHOR]

The need for automated production plans has evolved over the years due to internal and external drivers like developed products, new enhanced processes and machinery. Reconfigurable manufacturing systems focus on such needs at both production and process planning level. The age of Industry 4.0 focused on mass customization requires computer aided planning techniques that are able to cope with custom changes in products and explores intelligent algorithms for efficient scheduling solutions to reduce lead time. This problem has been categorized as NP-Hard in literature and is addressed by providing intelligent heuristics that focus on reducing machining time of the products at hand. However, as 70% of the lead time is consumed in non-value added tasks, it is fundamental to provide modular solutions that can reduce this time and handle part variety. To address the subject, this paper focuses on the generation of automated process plans for a single machine problem while focusing on reducing time lead time. Two evolutionary algorithms (EAs) have been proposed and compared to answer complex problem of process planning. A modified genetic algorithm (GA) has been proposed in addition to cuckoo search (CS) heuristic for this discrete problem. On testing with selected benchmark part ANC101, significant improvement was seen in terms of convergence with proposed EAs. Moreover, a novel Precedence Group Algorithm (PGA) is proposed to generate quality input for heuristics. The algorithm produces a set of initial population which significantly effects the performance of proposed heuristics. For the discrete constrained process planning problem, GA outperforms CS providing 10% more feasible scheduling options and three times lesser run time as compared to CS. The proposed technique is flexible and responsive in order to accommodate part variety, a necessary requirement for reconfigurable systems.

With the end of both Dennard's scaling and Moore's law, computer users and researchers are aggressively exploring alternative forms of computing in order to continue the performance scaling that we have come to enjoy. Among the more salient and practical of the post-Moore alternatives are reconfigurable systems, with Coarse-Grained Reconfigurable Architectures (CGRAs) seemingly capable of striking a balance between performance and programmability. In this paper, we survey the landscape of CGRAs. We summarize nearly three decades of literature on the subject, with a particular focus on the premise behind the different CGRAs and how they have evolved. Next, we compile metrics of available CGRAs and analyze their performance properties in order to understand and discover knowledge gaps and opportunities for future CGRA research specialized towards High-Performance Computing (HPC). We find that there are ample opportunities for future research on CGRAs, in particular with respect to size, functionality, support for parallel programming models, and to evaluate more complex applications.

Origami-based mechanical metamaterials have recently received significant scientific interest due to their versatile and reconfigurable architectures. However, it is often challenging to account for all possible geometrical configurations of the origami assembly when each origami cell can take multiple phases. Here, we investigate the reconfigurability of a tessellation of origami-based cellular structures composed of bellows-like unit cells, specifically Tachi-Miura Polyhedron (TMP). One of the unique features of the TMP is that a single cell can take four different phases in a rigid foldable manner. Therefore, the TMP tessellation can achieve various shapes out of one original assembly. To assess the geometrical validity of the astronomical number of origami phase combinations, we build a graph-theoretic framework to describe the connectivity of unit cells and to analyze the reconfigurability of the tessellations. Our approach can pave the way to develop a systematic computational tool to design origami-based mechanical metamaterials with tailored properties.

Modern discrete-event systems (DESs) are often characterized by their dynamic structures enabling highly flexible behaviors that can respond in real time to volatile environments. On the other hand, timed automata (TA) are powerful tools used to design various DESs. However, they lack the ability to naturally describe dynamic-structure reconfigurable systems. Indeed, TA are characterized by their rigid structures, which cannot handle the complexity of dynamic structures. To overcome this limitation, we propose an extension to TA, called dynamic timed automata (DTA), enabling the modeling and verification of reconfigurable systems. Additionally, we present a new algorithm that transforms DTA into semantic-equivalent TA while preserving their behavior. We demonstrate the usefulness and applicability of this new modeling and verification technique using an illustrative example.

DR-BIP is an extension of the BIP component framework intended for programming reconfigurable systems encompassing various aspects of dynamism. It relies on architectural motifs to structure the architecture of a system and to coordinate its reconfiguration at runtime. An architectural motif defines a set of interacting components that evolve according to reconfiguration rules. With DR-BIP, the dynamism can be captured as the inter-play of dynamic changes in three independent directions: (1) the organization of interactions between instances of components in a given configuration; (2) the reconfiguration mechanisms allowing creation/deletion of components and management of their interaction according to a given architectural motif; and (3) the migration of components between predefined architectural motifs which characterizes dynamic execution environments. The paper lays down the formal foundation of DR-BIP, illustrates its expressiveness on few examples and discusses avenues for dynamic reconfigurable system design. [ABSTRACT FROM AUTHOR]

Inspired by the recent success of buckling‐induced reconfigurable structures, a new class of deployable systems that harness buckling of curved beams upon a rotational input is proposed. First, experimental and numerical methods are combined to investigate the influence of the beam's geometric parameters on its non‐linear response. Then, it is shown that a wide range of deployable architectures can be realized by combining curved beams. Finally, the proposed principles are used to build deployable furniture such as tables and lamp shades that are flat/compact for transportation and storage, require simple or no assembly, and can be expanded by applying a simple rotational input. [ABSTRACT FROM AUTHOR]

Motivated by navigation and control problems in robotics, Ghrist and Peterson introduced a class of non-positively curved (NPC) cubical complexes arising as configuration spaces of reconfigurable systems, best regarded as discretized state space representations of embodied agents such as a multi-jointed robotic arm. In current real world applications, agents are increasingly required to respond autonomously to sensory input in order for them to contend with a priori unknown obstacles to navigation. In particular, the configuration spaces in question may not be known in advance. This motivates the following problem formulation: Given a NPC cubical complex C and a point-separating collection Σ of Boolean queries on its 0-skeleton, C (0) , find an efficient algorithm for learning C from the outputs provided by Σ along an appropriately chosen path in C . In this note, we tackle the problem of identifying C when it is known that C is CAT(0). We show that the collection of canonical hyperplanes of C is the unique solution of a sub-modular minmax problem over the space of point-separating systems of Boolean queries on C (0) , which may also be formulated in terms of the quadratic form associated with the graph Laplacian of C (1) . [ABSTRACT FROM AUTHOR]

Although numerous studies have focused on the development and application of polyomino tiling theories, research of this nature is typically limited to the graphics and gaming fields. In this paper, we are presenting an innovative application of the polyomino tiling theory which is applied to Tetris-inspired reconfigurable robotic cleaning device as a means of solving the area coverage problem. The robotic floor cleaner (hTetro) that was developed as part of this research leverages the polyomino tiling theory to automatically generate the global tiling set required to ensure the full area of a given space is covered. In this paper, three Tetris tiling theorems were validated using our developed hTetro robot. The results of the research clearly indicated that the proposed approach offers a strong area coverage performance across all experimental cases. This paper includes an outline of the system architecture that underpins the hTetro robot and a comprehensive overview of the three tiling theorems that were applied in this research.

Hardware accelerators are increasingly employed in conjunction with general-purpose processors to meet stringent performance constraints. In these heterogeneous systems, security has become a prime concern. In this article, we present a design approach to generate platform-independent secure multiprocessor systems-on-chip (MPSoC) from a high-level abstraction. The aim of this article is to simplify the implementation of MPSoC, while ensuring security. The proposed design flow starts with a set of abstract and concrete specifications of a system, provided by the user, and ends up generating a generic description of the appropriate hardware design by setting up the communication structure of different components. The resulting abstract architecture is further processed using the vendor tool-chain to generate the target platform’s configuration. To enforce security, we proposed a distributed isolation framework for multilevel security, resource assess control including access to and from hardware accelerators. From a user specification, the security layer is transparently generated and security rules and requirements transparently enforced at run-time. Experimentation results show that our proposed tool can generate MPSoC designs capable of providing secure hardware execution with negligible execution overhead. [ABSTRACT FROM AUTHOR]

Mode-switchable ferroelectric thin-film bulk acoustic resonators (FBARs) are presented. Such resonators operate based on a dynamic nonuniform effective piezoelectricity in composite multilayer ferroelectrics with large electrostriction coefficients, like barium strontium titanate (BST). Harmonic resonance modes ($\textit {nf}_{o}$) of a multilayer ferroelectric bulk acoustic wave (BAW) resonator can be selectively excited with an electromechanical coupling coefficient (${K}_{\mathrm {eff}}^{{{2}}}$) equal to the fundament mode, which is contrary to the trend ${K}_{\mathrm {eff}}^{{{2}}}\propto {1}/{n}^{{{2}}}$ exhibited by conventional piezoelectric BAW resonators. Such a device can selectively be set to resonate at its different resonance harmonics by generating a pattern of nonuniform piezoelectric coefficient proportional to the stress field of each mode with an application of a proper set of dc control voltages applied across the ferroelectric layers. Such a resonator allows for the design of a new class of band-switching filters. As an experimental validation, a mode-switchable FBAR and a band-switching ladder-type filter based on a bilayer ferroelectric BST structure are designed and fabricated for the first time. The bilayer BST FBARs not only can be switched ON or OFF but also by choosing different bias configurations, two resonance modes at 2 and 3.6 GHz can be selectively excited having ${K}_{\mathrm {eff}}^{{{2}}}$ of 8% and 7%, respectively. [ABSTRACT FROM AUTHOR]

Modern systems evolve in unpredictable environments and have to continuously adapt their behaviour to changing conditions. The "DReAM" (Dynamic Reconfigurable Architecture Modelling) framework has been designed for modelling reconfigurable dynamic systems. It provides a rule-based language, inspired from Interaction Logic, which is expressive and easy to use encompassing all aspects of dynamicity including parametric multi-modal coordination with creation/deletion of components as well as mobility. Additionally, it allows the description of both endogenous/modular and exogenous/centralized coordination styles and sound transformations from one style to the other. The DReAM framework is implemented in the form of a Java API bundled with an execution engine. It allows us to develop runnable systems combining the expressiveness of the rule-based notation together with the flexibility of this widespread programming language. [ABSTRACT FROM AUTHOR]

Reconfigurable bulk acoustic wave filters provide a number of advantages for wireless communication systems, including compact size, cost effectiveness, and less complexity. This article presents the design methodology of an intrinsically switchable and bandwidth reconfigurable film bulk acoustic resonator (FBAR) filter, employing the electrostriction in ferroelectric barium strontium titanate (BST). Two examples of ferroelectric BST-based filters are designed and fabricated as a proof of concept. Under the application of a dc bias voltage, the fabricated switchable filters exhibit a bandpass response with a fractional BW of 3%. By changing the state of the ferroelectric BST FBARs through applied dc bias voltages, the bandwidth of the filters is adjusted. Without any bias, the filters switch OFF to provide isolation between the input and output ports. BST-based bandwidth reconfigurable filters can potentially reduce the number of required filters and switches in future multiband RF front ends. [ABSTRACT FROM AUTHOR]

The objective of this work is to describe a method of assessing the flexibility of a manufacturing system, in an uncertain market environment, under lifecycle considerations. The flexibility of a manufacturing system is determined by statistical analysis of the discounted cash flow (DCF) estimates of the manufacturing system's lifecycle cost, over a time horizon and for a large variety of market scenarios. The system's lifecycle cost is calculated at a minimum level with the help of a specially developed algorithm. The method is used in a test case for investing in a production system, using real-life data derived from the automotive industry. [ABSTRACT FROM AUTHOR]

Reconfigurable systems have evolved as a more comprehensive and better known area in the last years. Reconfigurability is strictly related to the ability to change: the more flexible a system is, the greater is its reconfigurability. Reconfiguration can provide the systems characteristics as self-adaptation, allowing their resources to be used according to the environment in which they are found and, consequently, extracting a better use of these resources. Unmanned Aerial Vehicles (UAVs), mine hoists, mobile robots, and balloon systems are some applications where self-adaptation and reconfiguration are important. Some reconfigurable systems are able to plan their reconfiguration at runtime, i.e., the system sets its new configuration while running. These systems are called Dynamically Reconfigurable Systems (DRSs). This paper aims to investigate DRSs seeking to answer four specific questions: (i) how the different kinds of DRSs are classified in the literature and what is their definitions; (ii) what are the hardware and software platforms, methodologies and techniques engaged in DRSs; (iii) what are the domains of application of DRSs; and, (iv) which countries lead the number of publications in DRSs. To do that, a systematic literature review was conducted, where, at the end, 85 articles between 1995 and 2017 were completely read. [ABSTRACT FROM AUTHOR]

Flexible, autonomous production systems form the basis for mastering increasing product diversity and customer-specific production. Industrial robots and modularization play a decisive role here, as they support the automation of complex processes and the reconfiguration of production systems. Yet, a change in the mechanical configuration of a production system always results in big efforts for robot programming. Standard teach-in solutions for robot programming are not suitable for highly varying configurations. An automated, adaptive path planning via simulation is necessary to fill this gap and even allow robot programming for non-expert persons. This paper presents a modular framework for automated robot path simulation and virtual robot programming in reconfigurable production systems, based on service oriented architectures and modularization. The framework is evaluated using a reconfigurable production system for flexible cultivation and differentiation of stem cells, the iCellFactory. Within the system, a gantry-mounted six-axis robot transports fluid filled vessels between multiple, freely positioned modules carrying laboratory devices. [ABSTRACT FROM AUTHOR]

Reconfigurable systems are the safe dynamical systems wherein the health of the control input and/or sensor output variables are continuously monitored and then they are reconfigured, if necessary, in an event of an unexpected fault detected online. This idea is applied, in particular, at the reconfigurable system where the number of control variables is more than the state variables considered to define its motion. In this paper, an adaptive pole placing controller is developed for use in such reconfigurable systems. Adaptive pole placing controller, in theory, is adaptive to take a fault size and retain the closed loop poles it assigns at fixed locations in the open left half plane of the complex plane. As a result, when the controller is not adaptive, it means that the pole perturbations could lead to catastrophes. However, to design adaptive pole placing controller for a reconfigurable system, fault size is required. Hence, the primary objective of the paper is to present a simple procedure that determines the fault size for tuning in the adaptive pole placing controller. Both direct and full-order Luenberger observer based state feedback adaptive pole placing controllers are presented. In situations where the adaptive pole placing controller is not possible, the fault size for which the reconfigurable system with a non-adaptive pole placing controller would transit from a stable to unstable system (referred as fault tolerant margin with respect to the non-adaptive pole placing controller) is also presented. Some of these features of this paper are illustrated by using the reconfigurable aircraft model available in the literature. [ABSTRACT FROM AUTHOR]

An intrinsically switchable and frequency reconfigurable bulk acoustic wave filter bank based on ferroelectric barium strontium titanate (BST) is presented. Ferroelectric BST possesses electric-field-induced piezoelectricity, enabling the design of voltage-controlled acoustic devices, including thin-film bulk acoustic resonators and solidly mounted resonators. In this paper, a triple-band switchable filter bank, consisting of three 2.5-stage filters based on BST FBARs, is designed, simulated, and fabricated for the first time. The bandpass filters have center frequencies at 1.85, 1.96, and 2.04 GHz and are selectively turned on based upon the external dc bias voltage applied to each filter. Turning off all the filters provide an isolation of more than 27 dB between the input and output ports. The presented intrinsically switchable ferroelectric filter bank potentially simplifies future radio frequency front ends by integrating both switching and filtering functionalities onto a single device and reduces the overall circuit area. [ABSTRACT FROM AUTHOR]

Abstract The improvements in connectivity and data availability enable to fully integrate all the components of a production system. Manufacturing processes are frequently reconfigured over time, due to changes in lot sizes, process parameters and product customization. Despite this, warehousing operations are often disregarded: usually, automation systems for warehouses are set-up during the installation and their management is hardly ever reviewed. As a consequence, the manufacturing process is adapted to the capabilities of the warehousing system, rather than the other way round. To overcome this issue, this paper aims to propose a method capable to support an easy reconfiguration of warehousing operations based on the current state of the manufacturing process. The method is applied to an Autonomous Vehicle Storage and Retrieval Systems (AVS/RS), one of the most recent and promising automation technologies for warehouses. The proposed approach is based on both discrete-event simulation and analytical techniques and is applied to a real case of an Italian company. [ABSTRACT FROM AUTHOR]

We investigate the reconfigurability and tunability of the tessellation of Tachi-Miura Polyhedron (TMP), an origami-based cellular structure composed of bellows-like unit cells. Lattice-based three-dimensional mechanical metamaterials have recently received significant scientific interest due to their superior and unique mechanical performance compared to conventional materials. However, it is often challenging to achieve tunability and reconfigurability from these metamaterials, since their geometry and functionality tend to be pre-determined in the design and fabrication stage. Here, we utilize TMP's highly versatile phase-transforming and tessellating capabilities to design reconfigurable metamaterial architecture with tunable mechanical properties. The theoretical analyses and experiments with heat processing discover the wide range of the in-situ tunability of the metamaterial – specifically orders of magnitude change in effective density, Young's modulus, and Poisson's ratio – after its fabrication within the elastic deformation regime. We also witness a rather unique behavior of the inverse correlation between effective density and stiffness. This mechanical platform paves the way to design the metamaterial that can actively adapt to various external environments. • A post-fabrication tuning method for origami-based mechanical metamaterials is demonstrated. • A tessellation of Tachi-Miura Polyhedron is manufactured with an efficient method inspired by honeycomb structures. • Heat-processing method is leveraged to achieve the post-fabrication tuning, accompanied by theoretical analyses. • The result shows the wide range of in-situ tunability in effective density, Young's modulus, and Poisson's ratio. [ABSTRACT FROM AUTHOR]