Microprocessor Development Research Articles

Optimal cut-off frequency and controller gain of an integrated skyhook active isolation

Vibration isolation is a crucial technology in precision manufacturing. With the rapid development of smart sensors, smart actuators, and microprocessors, active vibration isolation has emerged as a viable approach to improve the performance of manufacturing equipment. In integrated skyhook active vibration isolation, the cut-off frequency limits the controller gain. Base on the repeated poles technique, this paper reveals the simple analytical forms of the optimal cut-off frequency and controller gain of the integrated skyhook active isolation. The analytical formula is useful in the design of active isolation. Numerical calculations are performed to show the good performance of the optimal design. An experiment is carried out to show the existence of the optimal controller gain.

Enhanced performance of pinned metal foam heat sinks with dielectric coolant – A pore-scale numerical study

Recent advancements in the development of microprocessors have resulted in the design of smaller microchips with improved performance. The new designs require proper cooling systems to prevent performance degradation and permanent damage to the chips. Extended surfaces, including fin, pin, or metal foam, are one of the prominent approaches in cooling systems designs. So far, there has been limited research, especially considering pore-scale analysis on the combination of pin/fin with metal foam, which is expected to offer promising cooling performance. This study aims to evaluate the performance of pinned metal foam heat sinks with dielectric coolant as a potential cooling system for microchips. A three-dimensional pore-scale numerical model is developed to analyze the performance of the proposed heat sinks. The effect of different parameters such as Reynolds number, heat flux, pore density, and different pin shapes are investigated. The results reveal that at a Reynolds number of 100, almost all the metal foam heat sinks enhance the heat transfer performance, which can be as large as 22% in some cases. Furthermore, adding pins increases the heat energy dissipation with a slight penalty of pressure drop depending on its hydrodynamic adaptation. Too dense or loose metal foam either increases the pressure drop or decreases the heat transfer rate, deviating from the optimum range. Lastly, it is revealed that heat flux from the heater does not significantly change the performance of the pinned metal foam heat sinks.

Part I—Advancements in Power Converter Technologies: A Focus on SiC-MOSFET-Based Voltage Source Converters

Power converter technologies have become vital in various applications due to their efficient management of electrical energy. With the growing prominence of renewable energy sources such as solar and wind, the high penetration of power electronic converters has been justified. However, ensuring power quality has emerged as a significant challenge for grid-connected power converters. The divergence from the ideal sinusoidal waveform in terms of magnitude and frequency impacts both grid-side currents and voltages. Several studies have proposed solutions to address power quality issues at the load side. The advancement of power converters has been fueled by the development of high-performance microprocessors and the emergence of high-speed switching devices, such as SiC-MOSFETs. This paper focuses on the design of voltage source converters, particularly those based on SiC-MOSFET semiconductor devices. The article presents the design of H-Bridge cells, discusses two-level voltage source converters based on cascade H-Bridge cells in a parallel configuration with experimental fault analysis, addresses the seven-level voltage source converter topology, and explores the design and experimental results of the matrix converter. The findings underscore the importance of considering the entire converter design for improved performance at high switching frequencies. The article concludes by summarizing the main outcomes and implications of this research.

Evolution of cardiac pacemakers: a journey from Galvanic experiments to leadless pacemakers

The development of cardiac pacemakers has a rich history spanning over two centuries, beginning with Luigi Galvani's discovery of the heart's response to electrical currents in the late 18th century. Paul Zoll's pioneering work in the 1950s introduced external pacemakers and defibrillators, followed by the first successful implantation of a fully implantable pacemaker in Sweden in 1958. Since then, pacemakers have undergone major improvements, including advancements in lead design and battery technology, as well as the development of telephony and microprocessors. Recent innovations have led to leadless pacemakers with wireless communication capabilities, transforming patient care and monitoring. This evolution has made pacemakers highly sophisticated devices that synchronize with the heart's rhythm, offering hope and improved quality of life for millions of individuals with cardiac rhythm disorders.

Possible directions of increasing the efficiency of the health system through software development

In the modern world, software is practically inevitable and present everywhere. Today, software represents the key to the success of most computer systems and at the same time the differentiation factor of the organizations that own it. Software has become an essential component in healthcare decision-making and the basis of scientific research and healthcare problem solving. The development of microprocessors enabled the widespread infiltration of computers into biomedical instruments for measuring, monitoring and displaying a number of parameters in physiology, clinic, radiology, nuclear medicine, laboratories and others. Digital communication techniques have enabled the networking of computers and the exchange of large amounts of information needed by expert systems to improve the quality of decision-making.

Compact Foveated AR Displays with Polarization Selective Planar Lenses

The rapid development of powerful microprocessors, high-pixel density display panels, thin and small formfactor optics, and precise device fabrication capabilities enable wearable near-eye displays for augmented reality (AR) and virtual reality (VR) applications. However, in traditional near-eye displays, there is often a trade-off between field of view (FoV) and angular resolution when a single microdisplay light engine is employed. A high-resolution display panel helps overcome this conflict, but the device fabrication remains a challenge, not to mention the issues like huge data transfer, circuit overheating, and high computational load. Here, we propose a Maxwellian-type foveated AR display based on a single microdisplay light engine by using a temporal polarization multiplexing method, enabled by two polarization selective flat cholesteric liquid crystal lenses. One polarization lens provides a large FoV while the other realizes a high angular resolution imaging in a small fovea region. Moreover, the vergence-accommodation conflict issue is inherently nonexistent in the Maxwellian display, and the aberration can be eliminated for each view by matching the recording and reconstructing signals. In an experiment, we constructed a display breadboard and demonstrated that the angular resolution of the foveal view is enhanced by 3.12× while maintaining a compact formfactor. This work paves the way for implementing high-performance foveated AR displays while keeping a compact formfactor.

The Impact of Solid-State Physics on Modern Science: A Critical Review

Solid-state physics has played a crucial role in the development of modern science. This critical review explores the impact that solid-state physics has had on various fields, including materials science, condensed matter physics, and electronics. Solid-state physics has enabled the creation of new materials with novel properties, such as high-temperature superconductors and semiconductors. It has also revolutionized the field of electronics, leading to the development of microprocessors and computer technology. This review examines the historical context of solid-state physics and its significant contributions to the modern scientific landscape. Furthermore, this critical review evaluates the limitations and challenges that the field currently faces and discusses future directions for research. Ultimately, this review highlights the importance of solid-state physics in modern science and its potential for further breakthroughs in various scientific fields. The abstract introduces the topic of the impact of solid-state physics on modern science and briefly mentions the various fields that solid-state physics has contributed to. It also notes some of the key advances that solid-state physics has enabled, including the development of new materials with unique properties and the creation of electronic devices such as microprocessors. The abstract then goes on to provide more detail, exploring the historical context of solid-state physics and its significant contributions to the scientific landscape. This could include a discussion of some of the key discoveries and innovations that have arisen from solid-state physics research, as well as some of the prominent scientists who have worked in the field. The abstract also touches on some of the limitations and challenges that the field currently faces, such as the difficulty of working with complex materials and the need for new theoretical frameworks to better understand solid-state systems. Finally, it highlights the potential for further breakthroughs in various scientific fields, underscoring the ongoing importance of solid-state physics research. Overall, the abstract provides a comprehensive overview of the topic, laying out the key themes and arguments that the review will explore in more detail.

Exploring the Impact of Soft Errors on the Reliability of Real-Time Embedded Operating Systems

The continuous scaling of electronic components has led to the development of high-performance microprocessors that are suitable even for safety-critical applications where radiation-induced errors such as Single Event Effects (SEEs) can have a significant impact on the performance and reliability of the system. This work is dedicated to investigating the reliability of systems based on programmable hardware and Real-time operating Systems (RTOS) in the presence of architectural faults induced by soft errors in the configuration memory of the programmable hardware. We performed a proton radiation test campaigned at PSI radiation facility to identify the fault model affecting the configuration memory of Xilinx Zynq-7020 reconfigurable AP-Soc Device. The identified fault model in terms of SEU and MBU clusters has been used to evaluate the impact of proton-induced faults on applications running within FreeRTOS on a Microblaze soft processor. A Single Event Multiple Upset fault model resulting from a proton test is presented, focusing on characteristics such as shape, size, and frequency of observed cluster of errors. We conduct two fault injection campaigns and analyze the results to assess the effect of cluster size on system reliability. Moreover, we discuss software exceptions caused by faults that can affect the hardware structure of the soft processor.

Driving Control of GaN Devices for Transient Response Improvement of Voltage Regulator

With the continuous development of microprocessors, more stringent voltage regulation requirements have been put forward for the voltage regulators (VR) in the transient process. This letter proposes a driving control method for gallium nitride (GaN) devices to improve the transient response of the VR. When the GaN device conducts reverse, its source-drain voltage can be controlled by its gate voltage. During load step-down transient, the reverse conduction voltage of the GaN device is naturally applied across the inductor, which can be utilized to speed up the change rate of the inductor current. As a result, the overshoot of the output voltage can be reduced during load step-down transient. The proposed method does not need to modify the power circuit, and is easy to implement. Finally, the effectiveness of the proposed method is verified by experiments. The results show that the output voltage overshoot is reduced by 55%, and the transition time is shortened by 80% using the proposed method. The results also show that with the same overvoltage, using the proposed method can reduce the output capacitance by 57% and the transition time by 77%, thereby increasing the power density of the VR circuit and saving costs.

Design of an integral terminal-based sliding mode controller for PV and BESS-based DC microgrids

Conventional power generation is undergoing a dramatic upheaval, and renewable-based microgrids are playing an important part in this energy sector revolution. An integral terminal sliding mode controller based on a double-power reaching law control strategy for solar photovoltaic and battery-based DC microgrid systems has been proposed in this paper for the energy-environment nexus. First, a thorough mathematical model of the DC microgrid’s components is developed based on their electrical properties. The controller is therefore developed with the key goal of maintaining a consistent DC-bus voltage during the DC microgrid’s transient and steady-state situations. The asymptotic stability of the DC microgrid is then proven using the Lyapunov control theory. Finally, the proposed controller’s applicability is investigated using thorough analysis on both simulation and real-time platforms, as well as rigorous comparison studies with an existing sliding mode controller. For simulation studies, the MATLAB/Simulink platform is used, while the processor-in-loop validations of the proposed approach are performed on a Rasberry Pi 3B Quad-Core 64-bit Microprocessor Development Board.

Monitoring of an Electromechanical Prototype Material for Environmental Parameters Using IoT

The Internet of Things (IoT) is a phenomenon where everything is connected to everything, where the development of sensors and microprocessors helped in the rise of embedded technologies, such as Wi-Fi and Bluetooth, and the evolution of bandwidth available on the Internet. This phenomenon will continue unabated due to sensor technology, programmable chips, and embedded technologies. In recent years, the Internet of Things (IoT) has become one of the most prominent technology niches. IoT is the network of interconnected devices or “things” that exchange information or send data with each other over the Internet. The article describes a computer prototype for monitoring and controlling the environmental parameters of a communication equipment room. A technological tool, such as the one obtained, can be implemented in many applications, such as weather stations, food chains, smart home systems, measuring the heart rate of humans, and fruit dehydrators. The article’s research was focused on an IoT electronic device and a web platform. A major feature of this electronic device is that its Internet connectivity is achieved using the TCP/IP protocol, an integrated feature of the Shield Ethernet board stacked on top of the Arduino mega board.

Research and design of high-performance DSP control system based on frequency control

With the rapid development of power electronic devices and microprocessors, AC variable frequency and speed regulating system has also made a breakthrough. The thesis introduces the hardware circuit design based on TMS320F28335, and the result of the experiment proves the SVPWM algorithm is correct. It also does some research on VF control system of the inverter and the result of the experiments proves that the control system achieves the purpose, and has a quick dynamic response.

Wireless Communication-Based Design and Implementation of Digital Protection Platform on Folk Art

Numbers no longer only have a purely mathematical meaning but a code that can change the way of human existence, cognition, and thinking, and a basic element to convey information. With the advent of the “Internet+” era, the development of digital media technology, digitization, and informatization has been integrated into all walks of life and has a vital impact on the development of all walks of life, and also brought about the ideological change of fine arts. Nowadays, the digitization of fine arts is a new product of the computer age, and how to protect it is also an important topic. The continuous development of wireless mobile communications has promoted the rapid development of microprocessors. In this article, we will study the protective effect of microprocessors on the digitization of fine arts. This paper designs a microprocessor-based art digital protection website, with the purpose of preserving, inheriting, and disseminating folk art works through the website. The result of the experiment shows that the sampling rate of the microprocessor has reached the requirement of the signal. The largest number of users of the folk art digital website is young people aged 18–29, accounting for 32%; the highest average score for the website is those over 59 years old, with an average score of 90.

Experimental investigations on the thermal superposition effect of multiple hotspots for embedded microfluidic cooling

With the development of high-performance multi-core microprocessors, the increase in hotspots density poses a severe challenge to chip thermal management. Embedded cooling can improve the cooling performance at the chip level. However, the cooling efficiency will be deteriorated by the interaction of hotspots. This paper proposes the concept of thermal superposition effect based on the relationship between the cooling efficiency of two hotspots and their relative positions. The effective cooling area and superposition area describe the thermal characteristics and interaction of hotspots, and the superposition factor β evaluates the intensity of interaction. By optimizing the superposition factor, the average temperature reduces 22%. Moreover, the factor can predict the average temperature of hotspots within the error under14%. Therefore, the thermal superposition effect and factor β is an effective analysis tool in multi-hotspot cooling, simplifying the analysis process and making it possible to predict and optimize the interaction by experiment and finite element simulation.

Design and Test of a Spoke-like Piezoelectric Energy Harvester.

With the development of industry IoT, microprocessors and sensors are widely used for autonomously transferring information to cyber-physics systems. Massive quantities and huge power consumption of the devices result in a severe increment of the chemical batteries, which is highly associated with problems, including environmental pollution, waste of human/financial resources, difficulty in replacement, etc. Driven by this issue, mechanical energy harvesting technology has been widely studied in the last few years as a great potential solution for battery substitution. Therefore, the piezoelectric generator is characterized as an efficient transformer from ambient vibration into electricity. In this paper, a spoke-like piezoelectric energy harvester is designed and fabricated with detailed introductions on the structure, materials, and fabrication. Focusing on improving the output efficiency and broadening the pulse width, on the one hand, the energy harvesting circuit is optimized by adding voltage monitoring and regulator modules. On the other hand, magnetic mass is adopted to employ the magnetic field of repulsive and upper repulsion–lower attraction mode. The spoke-like piezoelectric energy harvester suggests broadening the frequency domain and increasing the output performance, which is prepared for wireless sensors and portable electronics in remote areas and harsh environments.

Wireless Transfer of Electric Power - a Disruptive Technology

Wireless (contactless) transfer of electric power is a disruptive technology because it abandons wired transmission technology, the only technology used in electrical and electronic engineering until recently, just like in the past animal traction and film photography were replaced by mechanical traction and digital photography. Although revealed at the end of the nineteenth century through Tesla’s inventions, it could be applied in practice only in the ‘80s of the twentieth century, with the development of power electronics and microprocessors. After an introduction and an overview of the operating principles, the paper presents the readiness level reached by this technology, the stage of standardization, Romanian achievements and future prospects for high power applications.

Analysis of Single Event Effects on Embedded Processor

The continuous scaling of electronic components has led to the development of high-performance microprocessors which are even suitable for safety-critical applications where radiation-induced errors, such as single event effects (SEEs), are one of the most important reliability issues. This work focuses on the development of a fault injection environment capable of analyzing the impact of errors on the functionality of an ARM Cortex-A9 microprocessor embedded within a Zynq-7000 AP-SoC, considering different fault models affecting both the system memory and register resources of the embedded processor. We developed a novel Python-based fault injection platform for the emulation of radiation-induced faults within the AP-SoC hardware resources during the execution of software applications. The fault injection approach is not intrusive, and it does not require modifying the software application under evaluation. The experimental analyses have been performed on a subset of the MiBench benchmark software suite. Fault injection results demonstrate the capability of the developed method and the possibility of evaluating various sets of fault models.

Performance Analysis of Direct Torque Controllers in Five-Phase Electrical Drives

The industrial application of electric machines has grown in the last decades, thanks to the development of microprocessors and power converters, which have permitted their use as variable-speed drives. Although three-phase machines are the common trend, the interest of the research community has recently focused on machines with more than three phases, known as multiphase machines. The principal reason lies in the exploitation of their advantages in terms of reliability, i.e., post-fault operating capability. Additionally, multiphase machines provide a better current distribution among phases, and lower current harmonic production in the power converter, than conventional three-phase machines. However, multiphase drive applications require the development of complex controllers to regulate the torque (or speed) and flux of the machine. In this regard, direct torque controllers have appeared as a viable alternative due to their easy formulation and high flexibility to incorporate control objectives. However, these controllers face some peculiarities and limitations in their use that require attention. This work aims to tackle direct torque control as a viable alternative for the regulation of multiphase drives. Special attention will be paid to the development of the control technique and the expected benefits and limitations in the obtained results. Case examples based on symmetrical five-phase induction machines with distributed windings in the motoring mode of operation will be used to this end.

Thermal Interface Materials with Both High Through-Plane Thermal Conductivity and Excellent Elastic Compliance

With the development of microprocessors toward higher power, larger chip, and higher frequency, heat dissipation is one of the central issues. Thermal interface materials (TIMs), which are used bet...

Virtuous Cycles

Reports on the development of microprocessors from an economic perspective. What shaped the economics of the microprocessor? In the beginning, replacement of components and redesign of equipment drove sales. Embedding logical instructions in the design of an integrated circuit changed calculators and scientific instruments. Those products found enthusiastic buyers in a generation of engineers and scientists raised on slide rules and vacuum tubes. The rise of personal computers changed the focus. Apple and IBM won a format war, which benefitted their respective suppliers, Motorola, Intel, and IBM’s semiconductor division. Third party software providers added applications. By 1985, IBM’s PC division achieved sales that would have made it the third largest computer company, had it been free-standing. Not long thereafter, IBM lost control over the design to clones such as Compaq.