Hardware Subsystems Research Articles

Effects of working fluid on performance of 4.5 K JT cooler

NASA is considering a “probe” class mission with a far-infrared imaging and spectroscopy space telescope. A critical technology need for this mission is an efficient, high capacity, low-temperature cryocooler with low exported vibrations to enable its cryogenic instruments to achieve exquisite sensitivity and low internal noise to observe far distant faint cosmic sources. This paper discusses the design of a 4.5 K hybrid cooler consisting of a pulse tube precooler and a JT stage. The JT stage uses 3He as its working fluid to achieve a low cooling temperature of 4.5 K. The cooler will build on the JWST MIRI spare flight cooler, using existing TRL 9 component and subsystem hardware technologies. The paper will discuss the cooler configuration, thermodynamic design, predicted performance, and sensitivity to operating conditions. The impact of pressure drops and thermal ineffectiveness in the JT stage recuperators are discussed and compared to those in the MIRI cooler. Finally, test results for MIRI Development Model (DM) compressor with 4He are presented. Test data include compressor volumetric flow rates and power inputs at different pressure ratios and piston stroke lengths. The DM compressor test results and flight compressor test data collected during MIRI spare flight cooler acceptance testing both indicate that the 4.5 K cooler will be able to meet the cooling requirement of 48 mW at 4.5 K and 230 mW at 18 K with a significant margin.

From integrated bridge system to marine bridge domain: A computational perspective

With the progressive advancement of ship intelligence, there has been a corresponding augmentation in the sensory, control, and other equipment within ship bridge systems. The accelerated expansion of both hardware and software components in ships poses formidable challenges to the existing bridge systems. The prevalent deployment format of ship bridge systems adheres to a traditional decentralized structure, limiting the system's computational prowess, equipment compatibility, and data fusion capabilities. Addressing these constraints and augmenting the ship bridge system's information processing, equipment compatibility, and functional integration represent pivotal objectives. Thus, this paper embarks on an analysis of the developmental trajectory, challenges, and predominant trends characterizing the current Integrated Bridge System (IBS) in ships. Subsequently, harnessing the inherent advantages of software and hardware decoupling, centralized computational capabilities, and seamless integration of data and functions, we propose a comprehensive maritime bridge domain architecture. This proposed architecture is meticulously delineated, encompassing aspects such as overall scheme design, hardware and software subsystems, and the mechanism of data service. In conclusion, the paper advocates a systematic approach to system development, encompassing implementation, testing, and evaluation of the proposed architecture. Rigorous testing and evaluation of the architecture, focusing on data collection, network transmission performance, functional availability, data distribution efficiency, and task processing capabilities, affirm its marked enhancements in computational proficiency, data service efficiency, and functional integration within the IBS. These results lay a robust foundation for the intelligent design of ship systems, paving the way for the evolution of intelligent ships.

Real-time signal processing and data acquisition for the Electric Field Detector (EFD-02) on the CSES-02 satellite

The Electric Field Detector (EFD-02) on board the second China Seismo-Electromagnetic Satellite (CSES-02) will measure the electric field components at a Low Earth Orbit (LEO) over a wide frequency band (DC – 3.5 MHz) and with 1 μV/m sensitivity in the Low Frequency band. EFD-02 will measure the voltage differences between pairs of probes installed at the tips of four booms deployed from the satellite. In this article, we describe the Zynq System on Chip (SoC)-based digital hardware subsystem dedicated to signal processing, and the selected implementation strategy, which successfully complied to the specific requirements of the space mission. Furthermore, we present a comprehensive overview of the assessed instrument performance.

Accelerated and Highly Correlated ASIC Synthesis of AI Hardware Subsystems Using CGP

Accelerated and Highly Correlated ASIC Synthesis of AI Hardware Subsystems Using CGP

Scalable and Multi-Channel Real-Time Low Cost Monitoring System for PEM Electrolyzers Based on IoT Applications

This paper discusses and evaluates a novel multi-channel real-time architecture aimed at monitoring a Proton Exchange Membrane (PEM) electrolyzer, both at the individual cell and stack levels. The proposed solution includes two primary subsystems: a hardware subsystem dedicated to data acquisition (DAQ) and a software subsystem focused on monitoring purposes. The DAQ subsystem utilizes an Arduino platform, being an affordable and open-source solution. The real-time monitoring data can be encoded in JSON format, widely used as a light-weight inter-exchange data format between a variety of IoT applications. They are also available to be transferred to Excel. Indeed, and to enhance convenience, the proposed system integrates graphs displaying a template based on Excel spreadsheets, which are commonly used in industrial environments. The current, voltage, temperature, and pressure data of both individual cells and stacks were monitored and collected, being configurable under a variety of ranges. As a case study, the validation of the system involved static and dynamic operational modes using a 1.2 kW PEM electrolyzer prototype (100 A, 1 A/cm2). The results successfully provided the monitored variables across individual cells and within the stack. The proposed approach exhibits relevant key characteristics such as scalability, flexibility, user-friendliness, versatility, and affordability and are suitable to monitor PEM electrolyzers in real-time at both the cell and stack levels.

An Exosuit System With Bidirectional Hand Support for Bilateral Assistance Based on Dynamic Gesture Recognition.

Hand motor impairment has seriously affected the daily life of the elderly. We developed an electromyography (EMG) exosuit system with bidirectional hand support for bilateral coordination assistance based on a dynamic gesture recognition model using graph convolutional network (GCN) and long short-term memory network (LSTM). The system included a hardware subsystem and a software subsystem. The hardware subsystem included an exosuit jacket, a backpack module, an EMG recognition module, and a bidirectional support glove. The software subsystem based on the dynamic gesture recognition model was designed to identify dynamic and static gestures by extracting the spatio-temporal features of the patient's EMG signals and to control glove movement. The offline training experiment built the gesture recognition models for each subject and evaluated the feasibility of the recognition model; the online control experiments verified the effectiveness of the exosuit system. The experimental results showed that the proposed model achieve a gesture recognition rate of 96.42% ± 3.26 %, which is higher than the other three traditional recognition models. All subjects successfully completed two daily tasks within a short time and the success rate of bilateral coordination assistance are 88.75% and 86.88%. The exosuit system can effectively help patients by bidirectional hand support strategy for bilateral coordination assistance in daily tasks, and the proposed method can be applied to various limb assistance scenarios.

Software-hardware embedded system reliability modeling with failure dependency and masked data

Traditional system reliability models often ignore failure dependency between subsystems and the existence of system failure masked data, thereby they can’t accurately reflect the reliability modeling analysis of the whole system. This paper investigates an embedded system that comprises software subsystems and hardware subsystems. In order to more accurately assess the embedded system’s reliability, we proposed a reliability superposition model of the software-hardware system with masked data and failure dependency. In the model, the influence of masked failure data and failure dependency between the hardware subsystem and software subsystem is considered in system reliability evaluation, and the influence of fault dependence is solved by Copula function. Estimating the parameters of this model is a challenging task due to the complexity of the parameters. With regards to this, we proposed an immune particle swarm optimization algorithm with enhanced learning ability (IPSO-ELA), which is used to calculate the parameter’s estimation. Additionally, we investigated the impact of varying degrees of failure dependence on system reliability. Finally, the numerical experiment shown that the proposed model, which considers failure dependency among subsystems, outperforms other reliability models that do not. It can be seen from the experimental fitting results and the reliability trend charts that the system reliability when failure dependence is considered is higher than isn’t considered, which is more realistic.

EU ENSEMBLE Project: Reference Design and Implementation of the Platooning Support Function

Platooning is a cooperative driving technology for driving in a longitudinal formation. Vehicle-to-vehicle (V2V) communication is the key enabling technology. Platooning is considered to be a closed application between well-known participants that use V2V data for their operation. For the deployment of platooning, multi-brand, i.e. interoperable, solutions are paramount. To achieve this, the European ENSEMBLE (ENabling SafE Multi-Brand pLatooning for Europe) project has been conducted. In this project, multi-brand specifications have been harmonized to a set of common specifications and requirements for a generic Platooning Support Function (PSF). Part of the specifications is a common interaction protocol, which also encompasses security features. A reference design has been developed to initially check the specifications. It consists of a detailed design of the common functionality and includes software and communication sub-system hardware prototypes. This reference design has also been used as benchmark for brand-specific implementations, e.g. in communication plug tests. Daimler Truck included the reference design directly in their PSF implementation, which gave the opportunity to continuously develop the reference design during the project. In this paper, the ‘final’ reference design is described as implemented in the Daimler truck, which took part in the verification, validation and demonstration of multi-brand platooning together with six other truck manufacturers.

A New Method for Controlling Fractional Linear Systems

The study of fractional linear time-invariant (LTI) systems has been an area of active research over the past thirty years. Results indicate that such systems are becoming important in the representation of certain types of dynamical behavior in biology and engineering. Several methods have been developed for the representation, identification, and control of fractional LTI systems. The primary purpose of this paper is to introduce a new approach to their control. Its principal contribution is the transformation of a fractional LTI system into one without fractional terms (standard LTI system) using feedback and feedforward compensation. While the former may be quite difficult to control, tools widely available in linear systems theory may be used to control the latter. Transformation of a fractional system into a standard one requires compensators with fractional transfer functions. It is shown, using research results from the past two decades, that such functions can be realized using hardware and software subsystems. The authors demonstrate, using an example, that better control performance is possible with the new method when compared to current ones that are most common in the research literature. Robustness in the presence of noise and model uncertainties is also studied for the new method and currently available ones. Simulation results presented illustrate improvements achievable in control robustness with the new method.

Construction of Very Low-Cost Loop Polymerase Chain Reaction System Based on Proportional-Integral-Derivative Temperature Control Optimization Algorithm and Its Application in Gene Detection.

Real-time polymerase chain reaction (PCR) technology is essential in nucleic acid detection and point-of-care testing (POCT). However, nowadays, the classical qPCR instrument has the deficiency of its bulky volume, high cost, and inconvenience to use; hence, a low-cost and easy-to-use PCR equipment was thus developed consisting of a hardware subsystem as well as a software subsystem based on an improved proportional-integral-derivative (PID) system. The proposed system not only could hold self-setting reaction cycles of temperature rising and falling automatically but also the temperature during the constant temperature stage was regulated steady based on improved temperature control algorithm, which proved its great effect compared with the reaction temperature derived from an infrared thermal imaging camera. The experimental results in gene detection research also could indicate its applicability and stability of our developed PCR system by using the amplification curve analysis, the melting curve analysis, and agarose gel electrophoresis analysis compared with the commercial PCR instrument, which illustrates the great potential application value of the proposed PCR system.

Wireless CCTV, a workable tool for overcoming security challenges during elections in Nigeria

There have been upheavals in areas where elections have been conducted lately in Nigeria. The latest being in Ekiti and Osun States where there were cases of ballot box snatching, electoral result fraud, sporadic shootings and killings which call for electoral security carefulness and concern. The government of the day has done well in trying to computerize the electoral process by introducing BVAS in all polling units, but has failed to implement a non-human monitoring mechanism which could watch over electoral conducts and support result collation in all voting points without loopholes, intricacies and injuries to members of the voting communities. Wireless Close Circuit Television (CCTV) is an electronic monitoring system that combines network Software and hardware subsystems which are installed with Wireless channels and other monitoring mechanisms to cover and record activities in a particular domain. Data recorded in this device are immediately transmitted from the remote database in real-time, to a cloud-based central server where all happenings and events are stored for future retrieval and decision making. This paper looked at various reports on security challenges and happenings in Nigerian elections for eight (8) years and recommended that all polling units in Nigeria should have a Wireless CCTV system installed before the 2023 presidential election, irrespective of the cost, instead of the always compromised human monitors. Data were gathered using the author’s lens as a Supervisory Presiding Officer (SPO) from 2011 to 2019, and from related literatures.

Empowering SDN-Docker Based Architecture for Internet of Things Heterogeneity

Internet of Things (IoT), an emerging technology, connects billions of smart devices to the Internet through heterogeneous communication technologies enabling novel services and applications. This complex and variable environment encounters several challenges such as managing and controlling the network and IoT applications, programming IoT devices, responding to some specific Quality of Service requirements of certain applications. The current IoT network based on the complex, static, and closed traditional architecture represents a serious concern, especially with the amounts of data generated from the huge and heterogeneous IoT devices. In this paper, we present a new model for IoT architecture that brings together the benefits of Software Defined Networking (SDN) architecture and containerization (i.e., Docker) to address most IoT challenges and abstract the underlying communication and hardware subsystem. The SDN concept decoupled the control plane from data plane which implies a centralized global network view and provides flexibility in network configuration and resource management. Moreover, containerization technique through the docker in the device brings the portability and scalability of the applications. First, we propose, an SDN-based architecture for IoT. Then, with lightweight virtualization of IoT device supplied by Docker, we empower the functionalities and effectiveness of the SDN based architecture solution to challenge the IoT heterogeneity. Furthermore, we use the smart supermarket as a use case to validate our SDN-Docker based architecture in a real IoT scenario. The experimental results validate the architecture implementation.

Distance Assessment by Object Detection—For Visually Impaired Assistive Mechatronic System

Techniques for the detection and recognition of objects have experienced continuous development over recent years, as their application and benefits are so very obvious. Whether they are involved in driving a car, environment surveillance and security, or assistive living for people with different disabilities, not to mention advanced robotic surgery, these techniques are almost indispensable. This article presents the research results of a distance assessment using object detection and recognition techniques. The first is a new technique based on low-cost photo cameras and special sign detection. The second is a classic approach based on a LIDAR sensor and an HQ photo camera. Its novelty, in this case, consists of the concept and prototype of the hardware subsystem for high-precision distance measurement, as well as fast and accurate object recognition. The experimentally obtained results are used for the motion control strategy (directional inverse kinematics) of the robotic arm (virtual prototype) component in special assistive devices designed for visually impaired persons. The advantages of the original technical solution, experimentally validated by a prototype system with modern equipment, are the precision and the short time required for the identification and recognition of objects at relatively short distances. The research results obtained, in both the real and virtual experiments, stand as a basis for the further development of the visually impaired mechatronic system prototype using additional ultrasonic sensors, stereoscopic or multiple cameras, and the implementation of machine-learning models for safety-critical tasks.

Risk mitigation by design of autonomous maritime automation systems

Abstract Autonomous marine surface vehicles rely on computer systems with computer intelligence making decisions to assist or replace the navigating officer. A fundamental requirement for the design and implementation of such a cyber-physical system is seamless, predictable, and secure interoperability between vendor-specific hardware and software subsystems. The article describes a system design that includes mechanisms to mitigate the risks and consequences of software defects, individual component malfunction, and harmful cyber interference. It addresses international regulations in the field and demonstrates a system design that can meet the requirements for safe behaviour in foreseeable events while also having the ability to call for human assistance if the autonomous system is unable to handle a situation. The paper presents a design for highly automated vessels with several inherent risk-reducing features, including the ability to isolate and encapsulate abnormal behaviours, built-in features to support resilience to unexpected events, and mechanisms for internal defence against cyber-attacks. The article shows how this is provided by a novel middleware that supports risk mitigation, dependability, and resilience.

An Intelligent Shadow Play System With Multi-dimensional Interactive Perception

We developed an intelligent shadow play system (ShadowTouch) based on multi-dimensional interactive perception technologies to let user interact with the shadow play figure naturally. ShadowTouch included a shadow play hardware subsystem and a multi-dimensional interactive software subsystem. In shadow play hardware subsystem, each joint of the shadow play figure was actuated by the connecting rod which was rotated through one steering gear. In multi-dimensional interactive software subsystem, a somatosensory interaction module synchronized motions between shadow play figure and human body based on skeleton point detection, and an automatic choreography module generated the motions automatically for the shadow play figure based on musical emotion recognition. The proposed system improved the immersive interaction experience and let users feel involved during the performance of shadow play, and the motions of shadow play figure (steering gear motion angles) could be saved digitally to further be applied for the reactivation and inheritance of traditional culture.

ПОРІВНЯЛЬНИЙ АНАЛІЗ ТА СТВОРЕННЯ БЕЗПІЛОТНИХ ЛІТАЛЬНИХ АПАРАТІВ ДЛЯ ФОРМУВАННЯ МАКЕТА РОЙОВОЇ ВЗАЄМОДІЇ

The subject of study is the process of creating an unmanned aerial vehicle of the helicopter type, which is able to perform autonomous flight and be used in the premises to test the algorithms of swarm interaction. The aim is to reduce the cost of forming and operating the UAV swarm intelligence model, ensuring compatibility with existing hardware positioning systems and simulation software platforms. Tasks: to analyze the existing prototypes of unmanned aerial vehicles of the helicopter type, used for modeling and testing of autonomous flight modes indoors; to review the systems of positioning and exchange of information between the participants of the swarm formation and to analyze the hardware systems necessary for the implementation of these systems; to develop the architecture of hardware subsystems for unmanned aerial vehicles capable of performing tasks at the level of the considered prototypes; design a case for a sound hardware platform, check its operational parameters, implement its collection and testing; install software that allows you to check the operability of the considered platform of the unmanned aerial vehicle. The methods used are: systems analysis used to compare models of unmanned aerial vehicles within the tasks, methods of analysis and synthesis of schemes for the implementation of the hardware platform, the method of graphic modeling for the design of the unmanned aerial vehicle, methods of system programming for flight program. The following results were obtained. The choice of the hardware platform of the unmanned aerial vehicle is substantiated; the hull for the helicopter was developed and implemented, two platforms of unmanned aerial vehicles were collected and tested during autonomous flight indoors. Conclusions. The study found that there are existing and widely used platforms for compatible indoor flight. These platforms are open and closed. The analysis of open hardware platforms and synthesis of architecture of own unmanned aerial vehicle is made. The designed and implemented unmanned aerial vehicle is capable of autonomous flight, has all the necessary components to perform a compatible flight program. As part of the layout of swarm interaction, it is necessary to further adjust the positioning system.

Wearable Supernumerary Robotic Limb System Using a Hybrid Control Approach Based on Motor Imagery and Object Detection

Motor disorder of upper limbs has seriously affected the daily life of the patients with hemiplegia after stroke. We developed a wearable supernumerary robotic limb (SRL) system using a hybrid control approach based on motor imagery (MI) and object detection for upper-limb motion assistance. SRL system included an SRL hardware subsystem and a hybrid control software subsystem. The system obtained the patient's motion intention through MI electroencephalogram (EEG) recognition method based on graph convolutional network (GCN) and gated recurrent unit network (GRU) to control the left and right movements of SRL, and the object detection technology was used together for a quick grasp of target objects to compensate for the disadvantages when using MI EEG alone like fewer control instructions and lower control efficiency. Offline training experiment was designed to obtain subjects' MI recognition models and evaluate the feasibility of the MI EEG recognition method; online control experiment was designed to verify the effectiveness of our wearable SRL system. The results showed that the proposed MI EEG recognition method (GCN+GRU) could effectively improve the MI classification accuracy (90.04% ± 2.36 %) compared with traditional methods; all subjects were able to complete the target object grasping tasks within 23 seconds by controlling the SRL, and the highest average grasping success rate achieved 90.67% in bag grasping task. The SRL system can effectively assist people with upper-limb motor disorder to perform upper-limb tasks in daily life by natural human-robot interaction, and improve their ability of self-help and enhance their confidence of life.

The Aperture Array Verification System 1: System overview and early commissioning results

The design and development process for the Square Kilometre Array (SKA) radio telescope’s Low Frequency Aperture Array component was progressed during the SKA pre-construction phase by an international consortium, with the goal of meeting requirements for a critical design review. As part of the development process a full-sized prototype SKA Low ‘station’ was deployed – the Aperture Array Verification System 1 (AAVS1). We provide a system overview and describe the commissioning results of AAVS1, which is a low frequency radio telescope with 256 dual-polarisation log-periodic dipole antennas working as a phased array. A detailed system description is provided, including an in-depth overview of relevant sub-systems, ranging from hardware, firmware, software, calibration, and control sub-systems. Early commissioning results cover initial bootstrapping, array calibration, stability testing, beam-forming, and on-sky sensitivity validation. Lessons learned are presented, along with future developments.

A Hybrid Model to Ensure Biosecurity during Pandemic Situations Using OpenCV

This paper presents a hybrid model consisting of hardware, software subsystems and publicly available trained feature sets. The developed hybrid model is useful in automated contactless collection and analysis of employees’ and visitors’ data in an organization especially during pandemic situations to ensure biosecurity. Such data include temperature and face mask status. If the set norms are not satisfied, the entry into the premises will be restricted or denied. The status is also updated in the corresponding record in the organization database. The hardware subsystem includes an arduino nano, sensors and audio visual alarms. The software subsystem was developed using OpenCV in Python and VSCode editor. Both offline and real time implementations were carried out. The model was validated using real time images and online data sources. The system was tested and found to work satisfactorily under practical input conditions.

A new framework of complex system reliability with imperfect maintenance policy

The interactions and dependencies between software and hardware are often neglected in modeling system reliability in the past few decades due to the mathematical complexity. However, many system failures occurred from the interactions or simultaneous occurrences of software and hardware. This paper first proposes a new diagram of categorizing system-level failures and further incorporates such a diagram into the development of complex system reliability framework. System-level failures result from software subsystem, hardware subsystem, and the interactions of software and hardware subsystems. The focus of this study is on the investigation of the interactions failures generated from the interactions of software and hardware subsystems. In addition to the considerations of total hardware failures, software-induced hardware failures, and hardware-induced software failures introduced by Zhu and Pham (Mathematics 7(11):1049, 2019), we further introduce the partial hardware failures that can be respectively induced by hardware and software to explicitly demonstrate the dependencies and interactions between software and hardware. Hence, a new complex system reliability framework is developed based on such system-level failure categorization with the Markov process. Furthermore, the numerical examples are studied to illustrate the impacts on system reliability with the changes of state transition parameters that modeling the interactions of software and hardware subsystems. Finally, we have studied two maintenance policies of the proposed complex system reliability model.