Components Off The Shelf Research Articles

3D soft material printer as a mesoscale additive biomanufacturing platform for in-space manufacturing

With the burgeoning in-space manufacturing (ISM) industry, developing an on-demand additive manufacturing (AM) platform will be crucial for long-term space habitation. However, acute space boundary conditions, such as limited physical space, microgravity, vacuum, and others pose unique challenges for designing the printing process, the platform’s structure, and the materials’ printability. An AM platform operable in a space environment would enable production at the point of need (PoN), for example, on-demand food, nutrition, and pharmaceutical products. This research is focused on the design, fabrication, and testing of a 3D printer confined within CubeSat boundaries to study the feasibility of soft material printing aimed toward potential ISM applications. The printer unit was built using components off the shelf (COTS) while adhering to the severe spatial boundary conditions posed by the CubeSat dimensions and was tested using an edible material ink to demonstrate multi-layer prints of soft materials. Printing in ambient Earth conditions as well as under vacuum displayed consistent layer cohesion and comparison to 3D model data although vacuum prints showed visibly dehydrated prints owing to outgassing of air bubbles. The printer equipment’s structural integrity was validated under simulated launch and operation conditions using a vibration testing setup according to the NASA-recommended microsatellites standards. The results indicated that the printer assembly maintained its structural and operational integrity during and after testing. Using soft materials as the basis of testing allows scalability when expanding to more complex and structural materials to produce spare parts using a frugally engineered modular manufacturing platform.

Modeling swarm mission with COTS characterization: a series of return on experience

AbstractSystem design in defense systems is a competitive field, in which economical viability relies on a sequence of architectural decisions, aiming at quality, resource and time (Q,R,T) compromises. We observe that low‐cost unmanned ground vehicles (UGV) and drones appear as new threats on current battlefield. To face these new threats, Direction Générale de l'Armement (DGA) have organized challenges around robotization of battlefield, to design future employment doctrines and help technologies to reach maturity in a reasonable time. This article exposes a NATO Architecture Framework (NAF) 3.1‐based workflow that includes return of experience form the field over yearly iterations of such challenges. The capabilities depicted are requirements to match, constituent systems are based on Components‐Off‐The‐Shelf (COTS) answering to both edition of the challenge. This article details how manually re‐injecting feedback from field back to the system model failed to ensure the next iterations of the challenge. Our works propose conclusions on formulation of the “engineering leakage problem” and how resolution of this problem is NP‐Hard and should be addressed using optimization.

Spacecraft attitude testbed

Spacecraft attitude determination and control systems (ADCS) stand as a pivotal factor for ensuring the success of missions. As satellite sizes continue to decrease, the need for more intelligent and efficient control algorithms becomes increasingly pronounced. In response to this imperative, we propose the development of a scaled-down testbed specifically designed for evaluating satellites (ACDS). This testbed will demonstrate effective control of a CubeSat through the use of Helmholtz coils, magnetic torquer solenoids, reaction wheels and inexpensive student-made components and available components off the shelf (COTS) in the San Diego State University SPACE Lab. Referred to as the Spacecraft Attitude Testbed (SAT), this custom-designed 3-DoF experimental attitude platform replicates the conditions experienced by a weightless satellite in space. The objective of this research paper is to improve the understanding of how to manufacture a testbed and components like those within this paper, expose some of the issues encountered and improve the outcomes for future academic testbeds. Within this study, the testbed employs torque application to magnetic torquers and reaction wheels to regulate attitude. In summary, this research endeavors to establish a comprehensive and cost-effective testbed platform dedicated to the assessment of spacecraft attitude control and determination systems. It not only seeks to enhance our understanding of advanced control algorithms but also aims to contribute valuable insights into fault detection and adaptive control strategies, ultimately bolstering the efficiency and robustness of satellite operations.

Wearable High Voltage Compliant Current Stimulator for Restoring Sensory Feedback

Transcutaneous Electrical Nerve Stimulation (TENS) is a promising technique for eliciting referred tactile sensations in patients with limb amputation. Although several studies show the validity of this technique, its application in daily life and away from laboratories is limited by the need for more portable instrumentation that guarantees the necessary voltage and current requirements for proper sensory stimulation. This study proposes a low-cost, wearable high-voltage compliant current stimulator with four independent channels based on Components-Off-The-Shelf (COTS). This microcontroller-based system implements a voltage-current converter controllable through a digital-to-analog converter that delivers up to 25 mA to load up to 3.6 kΩ. The high-voltage compliance enables the system to adapt to variations in electrode-skin impedance, allowing it to stimulate loads over 10 kΩ with currents of 5 mA. The system was realized on a four-layer PCB (115.9 mm × 61 mm, 52 g). The functionality of the device was tested on resistive loads and on an equivalent skin-like RC circuit. Moreover, the possibility of implementing an amplitude modulation was demonstrated.

Inconsistent and Incomplete Datasheet: The Case for Systematic Use of Requirement Engineering

ABSTRACTThe lifecycle of a system is extended from its early conception to its retirement of service. The lifespan of unmanned ground vehicles (UGVs) can be expected to last over 50 years in the defense market. In this context, the rising complexity of UGV systems imposes engineering steps that would ensure both capabilities of the system and resilience to its future inclusion in a system‐of system context. During its operational usage, the UGV is supposed to be maneuvered for specifically designed purposes following user manual datasheet of the components off‐the‐shelf (COTS) that were integrated. This paper exposes the public user datasheet relevance compared to the system engineering requirements that are the artifacts of system design architecture. The use of connecting COTS user manual to system requirements is discussed, all the more if the systems are to be re‐used in a system production line. This article is intended to explore system of system conception methods for future robotized battlefield.

A SQUID controller unit for space-based TES sensor readout

We have developed a Superconducting Quantum Interference Device (SQUID) controller unit for Transition Edge Sensors (TES) readout, designed to be used in a space mission. The unit is made of 8 boards and each board can condition four SQUID array amplifiers. The board design is inspired by a similar one developed for ground based experiments, but specific changes have been made to adopt Components Off The Shelf (COTS) with space grade equivalents, to implement redundancy and cross-strapping capabilities. The design also includes the thermal path to lift the heat off the boards towards an in-house designed monolithic aluminum rack.

Inconsistent and Incomplete Datasheet: The case for systematic use of requirement engineering

AbstractThe lifecycle of a system is extended from its early conception to its retirement of service. The lifespan of Unmanned Ground Vehicles (UGVs) can be expected to last over 50 years in the defense market. In this context, the rising complexity of UGV systems imposes engineering steps that would ensure both capabilities of the system and resilience to its future inclusion in a system‐of‐system context. During its operational usage, the UGV is supposed to be maneuvered for specifically designed purposes following user manual datasheet of the components off‐the‐shelf (COTS) that were integrated. This paper exposes the public user datasheet relevance compared to the system engineering requirements that are the artifacts of system design architecture. The use of connecting COTS user manual to system requirements is discussed, all the more if the systems are to be re‐used in a system production line. This article is intended to explore system of system conception methods for future robotized battlefield.

Datasheet: where is requirements engineering gone? A case in Benchmarking Mobile Robotics

AbstractThe lifecycle of a system is extended from its early conception to its retirement of service. The lifespan of Unmanned Ground Vehicles (UGVs) can be expected to last over 50 years in the defence market. In this context, the rising complexity of UGV systems imposes engineering steps that would ensure both capabilities of the system and resilience to its future inclusion in a system‐of‐system context. During its operational usage, the UGV is supposed to be manoeuvred for specifically designed purposes following user manual datasheet of the components off‐the‐shelf (COTS) that were integrated. This paper exposes the public user datasheet relevance compared to the system engineering requirements that are the artefacts of system design architecture. The use of connecting COTS user manual to system requirements is discussed, all the more if the systems are to be re‐used in a system production line.

An Autonomous Wireless Sensor Node Based on Hybrid RF Solar Energy Harvesting

The widespread deployment of the Internet of Things (IoT) requires the development of new embedded systems, which will provide a diverse array of different intelligent functionalities. However, these devices must also meet environmental, maintenance, and longevity constraints, while maintaining extremely low-power consumption. In this work, a batteryless, low-power consumption, compact embedded system for IoT applications is presented. This system is capable of using a combination of hybrid solar and radiofrequency power sources and operates in the 900 MHz ISM band. It is capable of receiving OOK or ASK modulated data and measuring environmental data and can transmit information back to the requester using GFSK modulated data. The total consumption of the system during its sleep state is 920 nW. Minimum power required to operate is −15.1 dBm or 70 lux, when using only radiofrequency or solar powering, respectively. The system is fully designed with components off the shelf (COTS).

K/Ka-Band Very High Data-Rate Receivers: A Viable Solution for Future Moon Exploration Missions

This paper presents a feasibility study for a very high data rate receiver operating in the K/Ka-band suitable to future Moon exploration missions. The receiver specifications are outlined starting from the mission scenario and from a careful system analysis. The designed architecture uses a low noise front-end to down-convert the incoming K/Ka-band signal into a 3.7 GHz intermediate frequency (IF). For maximum flexibility, a software defined radio (SDR) is adopted for the I/Q demodulation and for the analog to digital conversion (ADC). The decoding operations and the data interface are carried out by a processor based on field programmable gate array (FPGA) circuits. To experimentally verify the above concepts, a preliminary front-end breadboard is implemented, operating between 27.5 and 30 GHz. The breadboard, which uses components off the shelf (COTS) and evaluation boards (EVBs), is characterized by a 46 dB gain, a 3.4 dB noise figure and a − 37 dBm input-referred 1 dB compression point. Finally, a 40 Msym / s quadrature phase shift keying (QPSK) signal is demodulated by means of a commercially available SDR, demonstrating the above concept. The importance of these results is that they have been obtained exploiting a class of miniaturized and low cost microwave integrated circuits currently available on the market, opening the way to a dense communication infrastructure on cislunar space.

An admission control method to provide higher sampling rates over space launchers networks

Nowadays, embedded network systems, like in space launcher application, trends to move from a bus communication to components off-the-shelf (COTS) such as Ethernet switched network in order to reduce the cost and the mass. In order to guaranty the real time and reliability constraints on an Ethernet switched network which is not deterministic, the network is oversized and redundant. In this way, lot of resources are not used. This paper focus on using these available resources to support higher sampling rates for better controllability, safety and freshness. A framework for rate admission control is defined and an algorithm is proposed to maximise the sampling rate (i.e. the throughput) of each flow while satisfying maximum end-to-end delays requirements. The purpose of using this algorithm has been brought to light through an experiment based on the next generation of space launcher network.

Effect of HTRB lifetest on AlGaN/GaN HEMTs under different voltages and temperatures stresses

Space and transport industries are facing a strong global competition which is setting economic constraints on the entire supply chain. In order to address decreasing development costs and to propose new features, components-off-the-shelf (COTS) have become a very attractive solution. This paper investigates the degradation of AlGaN/GaN HEMTs COTS submitted to HTRB lifetest. Temperature and voltage step stresses were applied to untangle the effect of each stressor. The main aim is to establish a lifetime model, taking into account several degradation mechanisms, over a large range of temperatures and voltages. The experimental outcomes highlight the activation of different failure mechanisms occurring during the stress tests, and which depend from the different temperature and voltage working ranges. In this work, experimental analysis has been performed in order to characterize the root cause behind the activation of these multiple failure mechanisms and estimate the operative range where they may superimpose.

Neurophysiological Evaluation of a Customizable μECoG-based Wireless Brain Implant.

The number of implantable bidirectional neural interfaces available for neuroscientific research applications is still limited, despite the rapidly increasing number of customized components. We previously reported on how to translate available components into "ready-to-use" wireless implantable systems utilizing components off-the-shelf (COTS). The aim of the present study was to verify the viability of a micro-electrocorticographic ($\mu $ECoG) device built by this approach. Functionality for both neural recording and stimulation was evaluated in an ovine animal model using acoustic stimuli and cortical electrical stimulation, respectively. We show that auditory evoked responses were reliably recorded in both time and frequency domain and present data that demonstrates the cortical electrical stimulation functionality. The successful recording of neuronal activity suggests that the device can compete with existing implantable systems as a neurotechnological research tool.

High Voltage Smart Power Module For Fault-Tolerant Launcher Applications

Generalization of electromechanical actuators use in thrust vector control launchers applications has increased electronics power level needs by a factor of ten, in a global context which puts costs under pressure.The need for a modular and affordable power solution being versatile to fulfil different launcher mission profiles has become thereby stronger.In order to target different power and functional needs, an attractive design should be modular and multipurpose, will work at higher voltages and will be able to deliver powers up to a dozen of kilowatts.Moreover, an efficient design to cost approach will consider alternative technologies, widely used by other high-reliability industries, including Components Off-The-Shelf (COTS) integration.This paper presents the design of a low cost and highly integrated smart power module (SPM) intended to be used into launchers applications, embedding technologies and components from automotive world and being mainly producible by large-scale industry.

Freshness analysis of functional sequences in launchers

Abstract: Nowadays, many embedded systems use specific data buses to guarantee the exchange of data. The next generation of space applications is moving to components off-the-shelf (COTS) technology as switched Ethernet network in order to reduce the financial cost, being attentive to the mass. However, performance should be gained without sacrificing the reliability and the properties that enabled a tele-monitoring. This paper focuses on how to obtain a single traffic capture file that will be sent over ground-board communications and how to test later the freshness requirement satisfaction. A freshness formalization is proposed as well as a freshness verification algorithm based on the analysis of single trace captured using multicast communications. An experimental evaluation has been leaded in nominal and link failure cases.

Industrial system knowledge formalization to aid decision making in maintenance strategies assessment

High competitiveness and the emergence of new Information and Communication Technologies in industrial enterprises require a higher understanding and mastering of their operation systems to improve expected performances. In that sense, managers should take decisions about the strategies to be implemented as well as the resources to be used to achieve the target performances. Decisions result either from subjective considerations either from models allowing performances assessment. To help managers in the decision making process, it is necessary to represent industrial systems by means of models to better control them. However, this task underlines two major issues. The first one deals with the development of these models which is time and money consuming for the enterprises. This issue leads the consideration of formalizing generic knowledge by means, for example, of generic patterns, as a relevant solution to support models capitalization. The second issue deals with the degree of confidence of the models regarding to the reality of the industrial systems in order to avoid unrealistic assumptions, decreasing complexity etc. To face these challenges, this paper presents a methodology to represent, in a generic way, the key concepts of an industrial system and the relationships between the concepts materialized by semantic rules. More precisely, this methodology is investigated in the domain of dependability in order to assess performances, from the concepts formalization of both the production system and the maintenance one, based on the maintenance strategies applied. Thus generic patterns are cogent to support knowledge capitalization and reuse for leading to Components Off The Shelf (COTS). Patterns are built on a Probabilistic Relational Model (PRM) and can be instantiated then assembled to form a global model of a specific industrial system. The global model allows simulation step for maintenance strategies assessment helping the decision making process. The feasibility and added-value of this methodology, mainly in terms of patterns capitalization and reuse, are shown on two case studies: a pumping system and a real harvest production system. Moreover, lessons-learned issued from these applications are discussed.

The e-st@r CubeSat: Antennas system

In this paper the design of a deployable antenna system for CubeSats is proposed. Its manufacturing and test for the use on e-st@r CubeSat (developed at Politecnico di Torino by students' team of the Aerospace Engineering Courses) is then reported. The design procedure is based on analyzing the CubeSat standard and defining the physical and geometrical constraints, both for a general Cubesat and the particular case of e-st@r, multiple possible configurations are analyzed and compared to define the most suitable one. The use of Components Off-The-Shelf (COTS) materials is considered for the manufacturing of all parts of the system and utilized if acceptable. The lock system can be seen as one of the critical points of the system because it has to ensure that the antenna will not open during launch, but also that it opens when in orbit, so an optimization of already existing lock systems is pursued. We considered a two fault tolerant system to have an acceptable level of confidence. Briefly the manufacturing of all parts and the tests campaign of the assembled system is then proposed with some conclusive considerations on the environmental impact of the system.

Real-time fault injection using enhanced on-chip debug infrastructures

The rapid increase in the use of microprocessor-based systems in critical areas, where failures imply risks to human lives, to the environment or to expensive equipment, significantly increased the need for dependable systems, able to detect, tolerate and eventually correct faults. The verification and validation of such systems is frequently performed via fault injection, using various forms and techniques. However, as electronic devices get smaller and more complex, controllability and observability issues, and sometimes real time constraints, make it harder to apply most conventional fault injection techniques. This paper proposes a fault injection environment and a scalable methodology to assist the execution of real-time fault injection campaigns, providing enhanced performance and capabilities. Our proposed solutions are based on the use of common and customized on-chip debug (OCD) mechanisms, present in many modern electronic devices, with the main objective of enabling the insertion of faults in microprocessor memory elements with minimum delay and intrusiveness. Different configurations were implemented starting from basic Components Off-The-Shelf (COTS) microprocessors, equipped with real-time OCD infrastructures, to improved solutions based on modified interfaces, and dedicated OCD circuitry that enhance fault injection capabilities and performance. All methodologies and configurations were evaluated and compared concerning performance gain and silicon overhead.

Wide dynamic range acquisition system for innovative radiation detectors

There is particular interest to develop low-noise and wide dynamic range data acquisition systems for silicon detectors in view of using the same acquisition readout electronics for a wide range of application fields like monitoring and characterization of radiation sources or particle beams. In the framework of a research project for the qualification of Components Off The Shelf (COTS) for their use in space, research groups from INFN-Perugia, INFN-LNS and from MAPRAD have developed a fully automated, remote controllable, wide dynamic range acquisition system for silicon strip or pixelated detectors. Its design and a basic description of the performance are given here.

COTS‐based software product line development

PurposeThe purpose of this paper is to provide an overview of a pragmatic approach to components off‐the‐shelf (COTS)‐based development. Software product line (SPL) is at the forefront among the techniques for reducing costs, decreasing schedule time, and ensuring commonality of features across a family of products – as COTS are reused in multiple products.Design/methodology/approachA disciplined process for SPL development is still needed. This paper proposes the Y‐model for COTS‐based SPL development. The model put forward identifies and elaborates the essential phases and activities of SPL development from COTS‐based repository.FindingsThe Y‐model provides an efficient way of integrating the approaches of SPL and COTS‐based development as a cohesive software development model.Practical implicationsThe model has the potential to tremendously increase software engineers' productivity. Thus, software architects, domain engineers and component designers should become aware of how to use these ideas to structure their models and designs.Originality/valueThis paper describes a systematic approach for COTS‐based development that takes into account the cataloguing and retrieval of software assets permeating a process that encompasses all stages of software development, from system product requirements engineering to system deployment.