Designs, Volume 2, Issue 4 (December 2018) – 22 articles

Detecting bearing faults is very important in preventing non-scheduled shutdowns, catastrophic failures, and production losses. Localized faults on bearings are normally detected based on characteristic frequencies associated with faults in time and frequency spectra. However, missing such characteristic frequency harmonics in a spectrum does not guarantee that a bearing is healthy, or noise might produce harmonics at characteristic frequencies in the healthy case. Further, some defects on roller bearings could not produce characteristic frequencies. To avoid misclassification, bearing defects can be detected via machine learning algorithms, namely convolutional neural network (CNN), support vector machine (SVM), and sparse autoencoder-based SVM (SAE-SVM). Within this framework, three fault classifiers based on CNN, SVM, and SAE-SVM utilizing transfer learning are proposed. Transfer of knowledge is achieved by extracting features from a CNN pretrained on data from the imageNet database to classify faults in roller bearings. The effectiveness of the proposed method is investigated based on vibration and acoustic emission signal datasets from roller bearings with artificial damage. Finally, the accuracy and robustness of the fault classifiers are evaluated at different amounts of noise and training data. Full article

Electric Vehicles (EVs) impact on the grid could be very high. Unless we monitor and control the integration of EVs, the distribution network might experience unexpected high or low load that might exceed the system voltage limits, leading to severe stability issues. On the other hand, the available energy stored in the EVs can be utilized to free the distribution system from some of the congested load at certain times or to allow the grid to charge more EVs at any time of the day, including peak hours. This article presents dynamic simulations of the hour-to-hour operation of the distribution feeder to measure the grid’s reaction to the EV’s charging and discharging process. Four case scenarios were modeled here considering a 24-h distribution system load data on the IEEE 34 bus feeder. The results show the level of charging and discharging that were allowed on this test system, during each hour of the day, before violating the limits of the system. It also estimates the costs of charging throughout the day, utilizing time-of-use rates as well as the number of EVs to be charged on an hourly basis on each bus and provide hints on the best locations on the system to establish the charging infrastructure. Full article

Through billions of years of evolution, a latent record of successful and failed design practices has developed in nature. The endeavors to exploit this record have resulted in numerous successful products in various fields of engineering, including, but not limited to, networking, propulsion, surface engineering, and robotics. In this work, a study of existing biomimetic designs has been carried out by categorizing the designs according to the biological organizational level, the abstraction level, and a novelty measure. The criterion of novelty has been used as a partial measure of the quality of bio-inspired and biomimetic designs already introduced, or ready to be introduced to the market. Through this review and categorization, we recognize patterns in existing biomimetic and bio-inspired products by analyzing their cross-categorical distribution. Using the distribution, we identify the categories which yield novel bio-inspired designs. We also examine the distribution to identify less explored areas of bio-inspired design. Additionally, this study is a step forward in aiding the practitioners of biomimetics in identifying the categories which yield the highest novelty products in their area of interest. Full article

Function is a key central concept to the practice of biomimicry. Many published models of the biomimicry process include steps to identify, understand, and translate function of biological systems. Examples include functional modeling, decomposition, or abstraction with tools specifically designed to facilitate such steps. A functional approach to biomimicry yields a semantic bridge between biology and engineering, enabling practitioners from a variety of backgrounds to more easily communicate and collaborate in a biomimicry design process. Although analysis of function is likely a necessary part of biomimicry design, recent work suggests it is not sufficient without a more systematic understanding of the complex biological context in which a function exists (e.g., scale and trade-offs). Consequently, emerging tools such as ontologies are being developed that attempt to capture the intricacies of biological systems (including functions), such as their complex environmental and behavioral interactions. However, due to the complexity of such tools, they may be under-utilized. Here, we propose a solution through a computer-aided user interface tool which integrates a biomimetic ontology with a thesaurus-based functional approach to biomimicry. Through a proof of concept illustrative case study, we demonstrate how merging existing tools can facilitate the biomimicry process in a systematic and collaborative way, broadening solution discovery. This work offers an approach to making existing tools, specifically the BioMimetic Ontology, more accessible and encompassing of different perspectives via semantic translation and interface design. This provides the user with the opportunity to interface and extract information from both the Engineering-to-Biology Thesaurus and the BioMimetic Ontology in a way that was not possible before. The proposed E2BMO tool not only increases the accessibility of the BioMimetic Ontology, which ultimately aims to streamline engineers’ interaction with the bio-inspired design process, but also provides an option for practitioners to traverse biological knowledge along the way, encouraging greater interdisciplinary collaboration and consideration when conducting biomimicry research. Full article

Autonomous and Adaptative Cyber-Physical Systems (ACPS) represent a new knowledge frontier of converging “nano-bio-info-cogno” technologies and applications. ACPS have the ability to integrate new ‘mutagenic’ technologies, i.e., technologies able to cause mutations in the society. Emerging approaches, such as artificial intelligence techniques and deep learning, enable exponential speedups for supporting increasingly higher levels of autonomy and self-adaptation. In spite of this disruptive landscape, however, deployment and broader adoption of ACPS in safety-critical scenarios remains challenging. In this paper, we address some challenges that are stretching the limits of ACPS safety engineering, including tightly related aspects such as ethics and resilience. We argue that a paradigm change is needed that includes the entire socio-technical aspects, including trustworthiness, responsibility, liability, as well as the ACPS ability to learn from past events, anticipate long-term threads and recover from unexpected behaviors. Full article

Three case studies utilizing topology optimization and Additive Manufacturing for the development of space flight hardware are described. The Additive Manufacturing (AM) modality that was used in this work is powder bed laser based fusion. The case studies correspond to the redesign and manufacture of two heritage parts for a Surrey Satellite Technology LTD (SSTL) Technology Demonstrator Space Mission that are currently functioning in orbit (case studies 1 and 2), and a system of five components for the SpaceIL’s lunar launch vehicle planned for launch in the near future (case study 3). In each case, the nominal or heritage part has undergone topology optimization, incorporating the AM manufacturing constraints that include: minimization of support structures, ability to remove unsintered powder, and minimization of heat transfer jumps that will cause artifact warpage. To this end the topology optimization exercise must be coupled to the Additive Manufacturing build direction, and steps are incorporated to integrate the AM constraints. After design verification by successfully passing a Finite Element Analysis routine, the components have been fabricated and the AM artifacts and in-process testing coupons have undergone verification and qualification testing in order to deliver structural components that are suitable for their respective missions. Full article

Although condition monitoring is very important for a reliable operation of tram powertrain components, conventional wired sensor systems do not manage to find wide acceptance because of installation and security costs. To address those issues, we propose a novel condition monitoring system based on a wireless and energy self-sufficient sensor network, where the individual sensor nodes harvest energy from vibrations, occurring while the tram is in motion. First, we performed an experimental investigation to identify the most important boundary conditions for the system design. Second, we designed individual sensor nodes using parameters derived from the previous investigation. Finally, the sensor network was deployed and tested on the tram gearboxes. The obtained measurement data were recorded at a sufficient sampling rate of 4.56 kHz and were successfully transferred from the tram gearbox to the network base station within a radius of 10 m inside the tram despite factors such as reflections, fading and electromagnetic compatibility. A piezoelectric vibration harvester is the power supply for the sensor nodes and it delivers up to 21.22 mW for relevant vibration frequency range between 10 Hz and 30 Hz, thus enabling deployment of autonomous sensor nodes. Full article

Solid state lighting is nowadays widely diffused both in residential and office or industrial environment. Ambient light sensing to modulate lamp power is typical too, but sensors inside a lamp are a challenge, due to the high flux of these sources, which easily saturates nearby light detectors. Usually, separate sensing devices must be introduced in the system, thus increasing complexity and cost. In this work, a methodology will be presented, to allow integration of a light sensing device inside a lamp, using low cost circuitry to mitigate interactions between high power light-emitting diode (LED) sources and sensing photodiodes. Moreover, the same circuit allows visual light communication among sources. Full article

In this paper, we deal with a simple embedded electronic system for an industrial pneumatic–hydraulic system, based on a low-cost programmable logic controller (PLC) and industrial electronic parts with 24 V logic. The developed system is a hydraulic pulse system and generates a series of high-pressure hydraulic pulses with up to a max. 200 bar output pressure level and with up to a max. 2 Hz output hydraulic pulses frequency. In this paper we are describing requirements, the concept of the embedded control system in a diagram, security features and its industrial network connectivity (CAN bus, MODBUS). In description of the software solution we describe the implementation of the program threads approach in this low-cost PLC. The PLC programming with threads generate two layers of services—physical and application layer, and as a result, the threads create the main control state machine. In conclusion, we describe the calibration method of the system and the calibration curves. For further study we offer readers the full programming code written in sequential function charts to be used as PLC language. The cost of the described industrial networked control system with industry standard optoelectronic insulated interfaces and certified industrial safety relay does not exceed €1000 Euros. Full article

Biological systems have evolved over billions of years and cope with changing conditions through the adaptation of morphology, physiology, or behavior. Learning from these adaptations can inspire engineering innovation. Several bio-inspired design tools and methods prescribe the use of analogies, but lack details for the identification and application of promising analogies. Further, inexperienced designers tend to have a more difficult time recognizing or creating analogies from biological systems. This paper reviews biomimicry literature to establish analogy categories as a tool for knowledge transfer between biology and engineering to aid bio-inspired design that addresses the common issues. Two studies were performed with the analogy categories. A study of commercialized products verifies the set of categories, while a controlled design study demonstrates the utility of the categories. The results of both studies offer valuable information and insights into the complexity of analogical reasoning and transfer, as well as what leads to biological inspiration versus imitation. The influence on bio-inspired design pedagogy is also discussed. The breadth of the analogy categories is sufficient to capture the knowledge transferred from biology to engineering for bio-inspired design. The analogy categories are a design method independent tool and are applicable for professional product design, research, and teaching purposes. Full article

In our current building design philosophy, structural design is based on static predictions of the loads a building will need to withstand and the services it will need to provide. However, one study found that 60% of all buildings are demolished due to obsolescence. To combat our obsolescence-demolition culture, we turn to Nature for lessons about adaptable structural design. In this paper, we investigate the structural adaptability of the T. terebra spiraled turret shell through finite element modeling and parametric studies. The shell is able to change its structure over time to meet changing performance demands—a feat of adaptability that could transform our current infrastructure design. Modeling the shell’s growth process is an early and simple attempt at characterizing adaptability. As the mollusk deposits material overtime, its shell wall thickness changes, and its number of whorls increases. We designed parametric studies around these two modes of growth and investigated their effect on structural integrity and living convenience for the mollusk. By drawing parallels between the shell structure and human structures, we demonstrate connections between engineering challenges and Nature’s solutions. We encourage readers to consider biomimicry as a source of inspiration for their own quantitative studies for a more sustainable world. Full article

There are many types of agricultural water bowsers on the market, which vary in geometry and size. However, in all such bowsers there are “unused spaces” between the bottom of the tank and the axle. The objective of this research was to design an agricultural water bowser with improved capacity by exploiting the “unused spaces”. This would allow a sufficient amount of water to be supplied to wide areas in a short time. Each concept of agricultural water bowser was generated as an integrated chassis water tank to be hitched to a tractor, and the best concept was chosen using a multi-criteria decision-making methodology (house of quality matrix and Pugh selection matrix). The selected design consisted of an U-shaped angle bent bottom sheet welded to a top circular sheet. The Agreement Dangerous Road (ADR) European standard was used for the sizing of the bowser and the selected material was S275 steel. The resultant forces on the shell of the bowser were calculated using analytical methods. A 3-D model of the bowser was developed in SolidWorks 2015, and the static structural analysis tool was used to examine stresses on the body for various types of loading, roads, and driving maneuvers. The shape and size of the bottom part of the proposed bowser increased the capacity of the tank by 20.3%. Full article

The work presented here aims to demonstrate the technical, architectural, and energy viability of solar thermal collectors made with ceramic materials and their suitability for domestic hot water (DHW) and building heating systems in the Mediterranean climate. The proposal is for the design of a ceramic shell, formed by collector and non-collecting panels, which forms part of the building system itself, and is capable of responding to the basic requirements of a building envelope and harnessing solar energy. Ceramics considerably reduce the final cost of the collector system and offer the new system a variety of compositional and chromatic finishes, occupying the entire building surface and achieving a high degree of architectural integration, although less energy-efficient compared to a conventional metallic collector. Full article

Estimating the vehicle crashworthiness experimentally is expensive and time-consuming. For these reasons, different modelling approaches are utilised to predict the vehicle behaviour and reduce the need for full-scale crash testing. The earlier numerical methods used for vehicle crashworthiness analysis were based on the use of lumped parameters models (LPM), a combination of masses and nonlinear springs interconnected in various configurations. Nowadays, the explicit nonlinear finite element analysis (FEA) is probably the most widely recognised modelling technique. Although informative, finite element models (FEM) of vehicle crash are expensive both in terms of man-hours put into assembling the model and related computational costs. A simpler analytical tool for preliminary analysis of vehicle crashworthiness could greatly assist the modelling and save time. In this paper, the authors investigate whether a simple piecewise LPM can serve as such a tool. The model is first calibrated at an impact velocity of 56 km/h. After the calibration, the LPM is applied to a range of velocities (40, 48, 64 and 72 km/h) and the crashworthiness parameters such as the acceleration severity index (ASI) and the maximum dynamic crush are calculated. The predictions for crashworthiness parameters from the LPM are then compared with the same predictions from the FEA. Full article

Process reengineering (PR) in manufacturing organizations is a big challenge, as shown by the high rate of failure. This research investigated different approaches to process reengineering to identify limitations and propose a new strategy to increase the success rate. The proposed methodology integrates data as a procedure for process identification (PI) and mapping and incorporates process verification to analyze the changes made in a specific process. The study identifies interdependency within the manufacturing process (MP) and proposes a generic process reengineering approach that uses simulation and analysis of production line data as a method for understanding the changes required to optimize the process. The paper discusses the methodology implementation technique as well as process identification and the process mapping technique using simulation tools. It provides an improved data-driven process reengineering framework that incorporates process verification. Based on the proposed model, the study investigates a production line process using the WITNESS Horizon 21 simulation package and analyse the efficiency of data-driven process reengineering and process verification in terms of implementing changes. Full article

Cyber-Physical Systems (CPS) are the complex systems that control and coordinate physical infrastructures, which may be geographically apart, via the use of Information and Communication Technology (ICT). One such application of CPS is smart microgrids. Microgrids comprise both power consuming and power producing infrastructure and are capable of operating in grid connected and disconnected modes. Due to the presence of heterogeneous smart devices communicating over multiple communication protocols in a distributed environment, a system architecture is required. The objective of this paper is to approach the microgrid architecture from the software and systems’ design perspective. The architecture should be flexible to support various multiple communication protocols and is able to integrate various hardware technologies. It should also be modular and scalable to support various functionalities such as island mode operations, energy efficient operations, energy trading, predictive maintenance, etc. These requirements are the basis for designing the software architecture for the smart microgrids that should be able to manage not only electrical but all energy related systems. In this work, we propose a distributed, hybrid control architecture suited for microgrid environments, where entities are geographically distant and need to operate in a cohesive manner. The proposed system architecture supports various design philosophies such as component-based design, hierarchical composition of components, peer-to-peer design, distributed decision-making and controlling as well as plug-and-play during runtime. A unique capability of the proposed system architecture is the self-similarity of the components for the distributed microgrids. The benefit of the approach is that it supports these design philosophies at all the levels in the hierarchy in contrast to a typical centralized architectures where decisions are taken only at the global level. The proposed architecture is applied to a real system of 13 residential buildings in a low-voltage distribution network. The required implementation and deployment details for monitoring and controlling 13 residential buildings are also discussed in this work. Full article

Cyber-Physical Systems (CPS) integrate computation, networking and physical processes to produce products that are autonomous, intelligent, connected and collaborative. Resulting Cyber-Physical Systems of Systems (CPSoS) have unprecedented capabilities but also unprecedented corresponding technological complexity. This paper aims to improve understanding, awareness and methods to deal with the increasing complexity by calling for the establishment of new foundations, knowledge and methodologies. We describe causes and effects of complexity, both in general and specific to CPS, consider the evolution of complexity, and identify limitations of current methodologies and organizations for dealing with future CPS. The lack of a systematic treatment of uncertain complex environments and “composability”, i.e., to integrate components of a CPS without negative side effects, represent overarching limitations of existing methodologies. Dealing with future CPSoS requires: (i) increased awareness of complexity, its impact and best practices for how to deal with it, (ii) research to establish new knowledge, methods and tools for CPS engineering, and (iii) research into organizational approaches and processes to adopt new methodologies and permit efficient collaboration within and across large teams of humans supported by increasingly automated computer aided engineering systems. Full article

Growing software complexity is an increasing challenge for the software development of modern cyber-physical systems. A classical strategy for taming this complexity is to partition system behaviors into different operational modes specified at design time. Such a multi-mode system can change behavior by switching between modes at run-time. A complementary approach for reducing software complexity is provided by component-based software engineering (CBSE), which reduces complexity by building systems from composable, reusable and independently developed software components. CBSE and the multi-mode approach are fundamentally conflicting in that component-based development conceptually is a bottom-up approach, whereas partitioning systems into operational modes is a top-down approach with its starting point from a system-wide perspective. In this article, we show that it is possible to combine and integrate these two fundamentally conflicting approaches. The key to simultaneously benefiting from the advantages of both approaches lies in the introduction of a hierarchical mode concept that provides a conceptual linkage between the bottom-up component-based approach and system level modes. As a result, systems including modes can be developed from reusable mode-aware components. The conceptual drawback of the approach—the need for extensive message exchange between components to coordinate mode-switches—is eliminated by an algorithm that collapses the component hierarchy and thereby eliminates the need for inter-component coordination. As this algorithm is used from the design to implementation level (“compilation”), the CBSE design flexibility can be combined with efficiently implemented mode handling, thereby providing the complexity reduction of both approaches, without inducing any additional design or run-time costs. At the more specific level, this article presents (1) a mode mapping mechanism that formally specifies the mode relation between composable multi-mode components and (2) a mode transformation technique that transforms component modes to system-wide modes to achieve efficient implementation. Full article

Tire–pavement interaction noise (TPIN) is dominant for passenger vehicles above 40 km/h and 70 km/h for trucks. In order to reduce TPIN, numerous investigations have been conducted to reveal the influencing parameters. In this work, the influencing parameters on TPIN were reviewed and divided into five categories: driver influence parameters, tire related parameters, tread pattern parameters, pavement related parameters, and environmental parameters. The experimental setup on analyzing and insights into optimizing those parameters are given. At the end, summary tables are presented to compare all the parameters discussed, including the pertinent frequency, potential noise influence, physical mechanism, etc. As such, this review article can also serve as a reference tool for new researchers on this topic. This work covers references from 1950s till present, aiming to distribute key knowledge in both classic and recent studies. Full article

This work explores an additive-manufacturing-enabled combination-of-function approach for design of modular products. AM technologies allow the design and manufacturing of nearly free-form geometry, which can be used to create more complex, multi-function or multi-feature parts. The approach presented here replaces sub-assemblies within a modular product or system with more complex consolidated parts that are designed and manufactured using AM technologies. This approach can increase the reliability of systems and products by reducing the number of interfaces, as well as allowing the optimization of the more complex parts during the design. The smaller part count and the ability of users to replace or upgrade the system or product parts on-demand should reduce user risk, life-cycle costs, and prevent obsolescence for the user of many systems. This study presents a detailed review on the current state-of-the-art in modular product design in order to demonstrate the place, need and usefulness of this AM-enabled method for systems and products that could benefit from it. A detailed case study is developed and presented to illustrate the concepts. Full article

In this work, we investigate the computational design of a typical S-Duct that is found in the literature. We model the design problem as a shape optimization study. The design parameters describe the 3D geometrical changes to the shape of the S-Duct and we assess the improvements to the aerodynamic behavior by considering two objective functions: the pressure losses and the swirl. The geometry management is controlled with the Free-Form Deformation (FFD) technique, the analysis of the flow is performed using steady-state computational fluid dynamics (CFD), and the exploration of the design space is achieved using the heuristic optimization algorithm Tabu Search (MOTS). The results reveal potential improvements by 14% with respect to the pressure losses and by 71% with respect to the swirl of the flow. These findings exceed by a large margin the optimality level that was achieved by other approaches in the literature. Further investigation of a range of optimum geometries is performed and reported with a detailed discussion. Full article

There is international pressure for countries to reduce greenhouse gas emissions, which are blamed as the main cause of climate change. The countries in the Middle East and North Africa (MENA) region heavily rely on fossil fuel as the main energy source for buildings. The concept of nearly zero energy buildings (nZEB) has been defined and standardized for some developed countries. While most of the developing countries located in the MENA region with hot and tropical climate lack building energy efficiency standards. With pressure to improve energy and environmental performance of buildings, nZEB buildings are expected to grow over the coming years and employing these buildings in the MENA region can reduce building energy consumption and CO₂ emissions. Therefore, the paper focuses on: (a) reviewing the current established nZEB standards and definitions for countries in the hot and warm climate of Europe, (b) investigate the primary energy consumption for current existing buildings in the MENA region, and (c) establishing a standard for nZEB and positive energy buildings in kWh/m²/year for the MENA region using a building simulation platform represented using Autodesk Insight 360. The result of the simulation reveals high energy use intensity for existing buildings in the MENA region. By improving building fabric and applying solar photovoltaics (PV) in the base model, significant reductions in primary energy consumption was achieved. Further design improvements, such as increasing the airtightness and using high efficiency solar PV, also contributed to positive energy buildings that produce more energy than they consume. Full article