Full System Prototype Research Articles

Coherently Radiating Periodic Structures for Feeding Concentric Rings Array with Reduced Number of Phase Shifters

This paper presents the application of CORPS (coherently radiating periodic structures) for feeding CRA (concentric rings array) with a reduced number of phase shifters. The proposed design technique for the structure of concentric rings provides a better scanning capability with respect to other existing configurations. This design technique utilizes 2 × 3 or 4 × 7 CORPS networks depending on the configuration or the number of antenna elements in the phased array system. These CORPS networks are set strategically in the feeding network to provide several advantages with respect to others in the scanning capability and the reduction of the number of phase shifters of the array system. The contribution of this paper is the full antenna system design of phased CRA for analyzing scanning and the reduction of phase shifters. The proposed phased array reduces the number of phase shifter devices in CRA for a scanning range of ±25° in the elevation plane. Differential evolution (DE) was applied to optimize the amplitudes of the proposed system. Several design cases were analyzed using full-wave simulation results to verify the phased array model and to take mutual coupling into account. Full-wave simulation results provide radiation patterns with low SLL in all scanning directions. The proposed phased array was validated by experimental measurements of the full antenna system prototype.

Systematic design and power management of a novel parallel hybrid electric powertrain for heavy-duty vehicles

A novel multi-degree-of-freedom parallel hybrid propulsion system with multi-gear for heavy-duty vehicles is proposed to optimize fuel economy, driving comfort, and dynamic performance. The system has a compact structure and high integration. The detailed design and the power flow of the parallel hybrid propulsion system are introduced. The full power system prototype is designed and assembled. The control methods for the driving torque compensation and energy management are investigated. The simulated results of the parallel hybrid propulsion system are presented. The propulsion system power is not interrupted during gear shifting with the torque compensation control. The jerk of the vehicle is also reduced during shifting. The internal combustion engine can work more efficiently in the hybrid propulsion mode with the equivalent consumption minimization strategy. The purpose of this paper is to provide a hybrid driving scheme for commercial vehicles.

An Innovative Way of Using Coherently Radiating Periodic Structures for Phased Arrays With Reduced Number of Phase Shifters

This article presents an innovative design technique for feeding phase antenna arrays using coherently radiating periodic structure (CORPS) technology for reducing the number of phase shifters (PSs) in limited-scan applications with low sidelobe level (SLL). The proposed configuration is implemented taking advantage of the phase interpolation property of a CORPS network of one layer. This configuration is built by interconnecting <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2\times 3$ </tex-math></inline-formula> CORPS networks in a strategic way in order to provide a reduction in the number of PSs while maintaining the scanning capability. Experimental results and full-wave simulations based on CST Microwave Studio reveal that the proposed design technique reduces the recombination losses and generates a better phase slope with respect to the basic CORPS network providing a reduction in the number of PSs. As a novel contribution, this article provides the full antenna system design in order to analyze and study the PSs reduction performance and scanning capabilities of the proposed technique to feed linear antenna arrays. The proposed design technique provides a reduction in the number of PSs for a scanning range of ±25° in linear arrays. The array design model includes the application of the raised cosine amplitude distribution to generate a radiation pattern with minimum SLL. The linear array system was validated by experimental measurements of the full system prototype and full-wave simulations results are provided to verify the accuracy of the array model and to take mutual coupling into account. The proposed case provides a good design compromise with respect to other cases in the state of the art.

Adiabatic compressed air energy storage technology

Adiabatic compressed air energy storage technology

(Plenary) Integrate to Extend the Reach of Solid Oxide Fuel Cells

Solid Oxide Fuel Cells (SOFCs) offer the potential for compelling thermo-economic value propositions in wide range of stationary and transportation applications through their potential for high conversion efficiency and their inherent fuel flexibility. Furthermore, many of the core SOFC materials, component, and system technologies have tremendous potential in electrolysis applications where fuels or chemicals could be produced using renewable electricity. However, to date, the wide-spread commercialization of SOFC/SOEC systems has been hampered by their high cost and durability challenges.Fortunately, high temperature solid oxide-based energy conversion systems are well suited for integration with thermal-mechanical energy conversion systems in configurations that offer the potential for significant cost and thermodynamic performance synergies. Specifically, their integration with gas turbines or internal combustion engines offers the potential for ultra-high (>70%) efficiency at an attractive manufacturing cost (<$1/W). In these hybrid systems, engines or turbines are used to convert stack waste exergy to additional useful work resulting in higher overall efficiency and lower power-specific cost (e.g., $/kW) compared to SOFC-only systems.Furthermore, in the case of SOFC and gas turbine hybrid systems, the SOFC stacks are typically located downstream of the gas turbine compressor and are at elevated pressure—enabling increased Nernst potential and decreased overpotentials and thereby higher power density at constant voltage. This benefit translates into a significant power-specific stack cost reduction. Additionally, the gas turbine compressor and recuperator may serve as the SOFC stack blower and recuperator—yielding further cost synergies via the elimination of duplicative balance of plant components.In 2017, ARPA-E launched the INTEGRATE program to develop hybrid system concepts and enabling component technologies that if realized would result in 100kW-scale distributed generation systems with >70% fuel to electricity conversion efficiencies and system manufacturing costs of <$1/W. In the initial two-year Phase I portion of the program, nine teams developed a suite of hybrid system concepts. Given these concepts, the teams then proceeded to develop 1) durable SOFC stacks that are capable of operating at high (~4 bar) pressure, 2) high temperature (>600 °C) and low-cost heat exchangers, and 3) innovative control system approaches. In 2019, three of the original nine teams were selected to design, build and demonstrate 100kW-scale systems by 2023.In the interest of focusing limited financial resources on foundational development risks, while avoiding the weight, volume, and fuel flexibility challenges associated with transportation applications and mitigating the financial risks associated with adopting new technologies at utility (e.g., >100MW) scale, natural gas fueled distributed generation (DG) systems were selected as the initial INTEGRATE application target. These DG systems would offer a fuel to electric power conversion efficiency that is roughly double that of the fossil fueled portion of the US electric grid. Furthermore, as renewable fuels such as hydrogen, ammonia, and bio- or electro- derived hydrocarbons (e.g., renewable natural gas or synthetic kerosene) become available, these systems would be capable of operating on them with relatively minor fuel processing system adjustments.Moving beyond stationary DG applications, SOFC hybrid systems can leverage their fuel flexibility in the pursuit of a decarbonized of long-distance transportation sector—if the systems can be made both light and small enough. To this end, ARPA-E recently launched three programs that have taken on the challenge of developing ultra-efficient, yet compact and light weight carbon-neutral electrified propulsion systems for commercial aviation.One of these programs is focused on carbon-neutral fuel to electric power conversion sub-systems—Range Extenders for Electric Aviation with Low Carbon and High Efficiency (REEACH). In the two-year Phase 1 of this program, six of nine selected teams will develop SOFC/gas turbine/battery hybrid systems that are fueled with renewable natural gas or synthetic kerosene. Phase 1 focuses on system conceptual design and fuel conversion component risk reduction, while full system design and prototype demonstration of a sub-scale fuel-to-electric power conversion device using a carbon-neutral liquid fuel is planned for Phase 2.If the REEACH-envisioned systems are successfully developed, they would enable economically attractive all-electric commercial aircraft up to a narrow body airframe with dramatically reduced (ideally zero) net carbon emissions. Furthermore, INTEGRATE/REEACH hybrid system technologies would also have attractive value propositions in maritime, rail, or heavy-duty vehicle applications.

Technical design report for the Barrel DIRC detector**The use of registered names, trademarks, etc in this publication does not imply, even in the absence of specific statement, that such names are exempt from the relevant laws and regulations and therefore free for general use.

The (anti-Proton ANnihiliation at DArmstadt) experiment will be one of the four flagship experiments at the new international accelerator complex FAIR (Facility for Antiproton and Ion Research) in Darmstadt, Germany. will address fundamental questions of hadron physics and quantum chromodynamics using high-intensity cooled antiproton beams with momenta between 1.5 and 15 GeV/c and a design luminosity of up to 2 × 1032 cm−2 s−1. Excellent particle identification (PID) is crucial to the success of the physics program. Hadronic PID in the barrel region of the target spectrometer will be performed by a fast and compact Cherenkov counter using the detection of internally reflected Cherenkov light (DIRC) technology. It is designed to cover the polar angle range from 22° to 140° and will provide at least 3 standard deviations (s.d.) π/K separation up to 3.5 GeV/c, matching the expected upper limit of the final state kaon momentum distribution from simulation. This documents describes the technical design and the expected performance of the Barrel DIRC detector. The design is based on the successful BaBar DIRC with several key improvements. The performance and system cost were optimized in detailed detector simulations and validated with full system prototypes using particle beams at GSI and CERN. The final design meets or exceeds the PID goal of clean π/K separation with at least 3 s.d. over the entire phase space of charged kaons in the Barrel DIRC.

Enhancing transient fault tolerance in embedded systems through an OS task level redundancy approach

In numerous safety critical applications, the use of high-reliability or radiation-tolerant equipment may not be a viable option due to the presence of several constraints (such as cost) and the need to utilize Commercial off-the Shelf (COTS) equipment. However, such equipment may not meet reliability requirements, and therefore certain appropriate measures need to be taken to enhance their reliability. In this paper, a fully software-based method is presented to increase the reliability of COTS equipment against transient faults. The reliability of COTS is increased by utilizing a task-level redundancy in operating system. The proposed method is evaluated using a software fault injection method and a full system prototype. The experimental results show that the proposed method increases the fault coverage up to 99.34%. Moreover, the proposed method can be used in embedded systems without any hardware, software, or information redundancy.

External-Rotor &lt;inline-formula&gt;&lt;tex-math notation="LaTeX"&gt;$6-10$&lt;/tex-math&gt;&lt;/inline-formula&gt; Switched Reluctance Motor for an Electric Bicycle

As a cost-effective, healthy, and environmental friendly personal mode of transportation, electric bicycles (E-bikes) are gaining an increasing market share from conventional bicycles and automobiles. Considering the legal rules in Ontario, Canada, a 500-W electric motor providing power assist makes the E-bike more attractive to urban commuters. The simple structure, high torque, and power density, as well as the potential for low cost make the switched reluctance machine (SRM) a strong candidate for E-bike traction. In this paper, a three-phase, external-rotor SRM with 6 stator poles and 10 rotor poles is designed for a representative E-bike. The design of an external rotor arrangement of the $6-10$ SRM topology has not previously been reported, this brings the challenge of sizing the geometry of this topology, but the solution offers a new contribution to published works. The external-rotor arrangement is chosen to facilitate ease of integration into the wheel hub structure of a typical pedal bicycle. The increased rotor poles yield improved torque ripple reduction than more conventional (i.e., $6-4$ and $12-8$ ) SRM design, which is an essential feature for low-speed rider comfort. The final machine design is experimentally validated via a full system prototype and dynamometer test facility. Results highlight some limitation of the 2-D finite element analysis (FEA) study in terms of the winding inductance calculation, more accurate 3-D FEA model is implemented.

Cooperative Computing Techniques for a Deeply Fused and Heterogeneous Many-Core Processor Architecture

Due to advances in semiconductor techniques, many-core processors have been widely used in high performance computing. However, many applications still cannot be carried out efficiently due to the memory wall, which has become a bottleneck in many-core processors. In this paper, we present a novel heterogeneous many-core processor architecture named deeply fused many-core (DFMC) for high performance computing systems. DFMC integrates management processing elements (MPEs) and computing processing elements (CPEs), which are heterogeneous processor cores for different application features with a unified ISA (instruction set architecture), a unified execution model, and share-memory that supports cache coherence. The DFMC processor can alleviate the memory wall problem by combining a series of cooperative computing techniques of CPEs, such as multi-pattern data stream transfer, efficient register-level communication mechanism, and fast hardware synchronization technique. These techniques are able to improve on-chip data reuse and optimize memory access performance. This paper illustrates an implementation of a full system prototype based on FPGA with four MPEs and 256 CPEs. Our experimental results show that the effect of the cooperative computing techniques of CPEs is significant, with DGEMM (double-precision matrix multiplication) achieving an efficiency of 94%, FFT (fast Fourier transform) obtaining a performance of 207 GFLOPS and FDTD (finite-difference time-domain) obtaining a performance of 27 GFLOPS.

Increasing Radiation Tolerance of Field-Programmable-Gate-Array-Based Computers Through Redundancy and Environmental Awareness

Radiation-tolerant computing is of great importance to the aerospace community because future missions demand more computational power. Of special interest to the aerospace community are flight computers implemented on static random-access-memory-based field-programmable gate arrays. Such computer systems allow the in-flight reconfiguration of hardware that enables the practical deployment of truly reconfigurable computers. However, commercial static random-access-memory-based field-programmable gate arrays are uniquely susceptible to ionizing radiation. This paper introduces a computer architecture for static random-access-memory-based field-programmable gate arrays that resists failures caused by ionizing radiation. The approach extends the widely accepted fault mitigation practice of triple modular redundancy and configuration memory scrubbing by adding spare circuitry and environmental awareness through an ionizing radiation sensor. This paper describes the design of the system in addition to a theoretical analysis of its reliability using a Markov model and empirical analysis using a fault injector. A full system prototype is presented that includes a custom radiation sensor and a computer system implemented on a Xilinx Virtex-6 field-programmable gate array. Both the theoretical analysis and laboratory testing show the approach to be significantly more reliable than field-programmable-gate-array-based computers using only triple modular redundancy and scrubbing.

Implementation and Control of an AC/DC/AC Converter for Double Wound Flywheel Application

An all-electric driveline based on a double wound flywheel, connected in series between main energy storage and a wheel motor, is presented. The flywheel works as a power buffer, allowing the battery to deliver optimized power. It also separates electrically the system in two sides, with the battery connected to the low voltage side and the wheel motor connected to the high voltage side. This paper presents the implementation and control of the AC/DC/AC converter, used to connect the flywheel high voltage windings to the wheel motor. The converter general operation and the adopted control strategy are discussed. The implementation of the AC/DC/AC converter has been described from a practical perspective. Results from experimental tests performed in the full-system prototype are presented. The prototype system is running with satisfactory stability during acceleration mode. Good efficiency and unity power factor could be achieved, based on vector control and space vector modulation.

CHALLENGES AND OPPORTUNITIES FOR SYSTEM THEORY IN EMBEDDED CONTROLLER DESIGN

CHALLENGES AND OPPORTUNITIES FOR SYSTEM THEORY IN EMBEDDED CONTROLLER DESIGN