Performance Of Prototype Research Articles

Solar PV-Fed Reverse Saliency Spoke-Type PMSM With Hybrid ANF-Based Self-Sensing for Water Pump System

In this work, a reverse saliency (RS) spoke-type permanent magnet (PM) synchronous motor (PMSM) besides its hybrid adaptive notch filter (HANF)-based self-sensing for driving a solar photovoltaic water pump system (WPS) is presented. The conventional spoke-PMSM-driven WPS experiences two types of problems. First, the motor is operated with a flux-weakening current to produce positive reluctance torque, thereby increasing the PM demagnetization risk. Second, an encoder is used to sense the rotor angle, which, in turn, affects the cost and reliability. To solve the first problem, the RS-PMSM is presented, which operates with a flux-intensifying current to produce positive reluctance torque, while the second issue is resolved by using the HANF-based rotor angle estimation. Although conventional methods give an estimate of rotor angle, they do not eliminate both the dc offset and dominant harmonics. The superiority of both the RS-PMSM and HANF over existing solutions is shown, respectively, by using finite-element methods and MATLAB-/Simulink-based performances. Besides, a prototype motor is also manufactured. The performance of the RS-PMSM prototype along with its HANF-based self-sensing is obtained in the laboratory, and various test results are reported. Meanwhile, a comparison of the HANF with available self-sensing techniques is also performed.

Analysis and Experiments of a Pendulum Vibration Energy Harvester With a Magnetic Multi-Stable Mechanism

This work couples a magnetic multi-stable mechanism to a pendulum vibration energy harvester so as to widen its bandwidth, especially in low-frequency operation. Multiple stable points are formed by a movable permanent magnet installed on the pendulum and two fixed permanent magnets installed symmetrically on the base of the energy harvester. Thus, the pendulum can swing between the stable points at two sides, which causes large motion amplitude and power generation. In designing the prototype of the energy harvester, dynamical modeling and potential energy analysis are carried out to achieve a low threshold for snap through. An experimental setup is developed and a series of comparative experiments are implemented to investigate prototype performance. It is shown that the energy harvester with the fixed magnets can generate a noticeable normalized induced voltage at 0.7 Hz, while the energy harvester without the fixed magnets requires the excitation frequency of 1.0 Hz to reach a similar level. The electrical outputs varying with vibration acceleration and load resistance are also examined. In general, the experimental results verify the effectiveness of the proposed structure on enlarging frequency bandwidth. This work can provide a promising candidate of energy harvesting for low-frequency applications such as ocean wave.

Performance of TPC detector prototype integrated with UV laser tracks for the circular collider

Several new experimental concepts in high-energy particle physics have been proposed in recent years. The physical goals include precisely measuring the properties of particles such as Higgs, Z and W, and even looking for signs of new physics at future colliders. To meet the evolving requirements for particle track detector, Time Projection Chamber (TPC) detector prototype integrated with a UV laser track system was developed for the main track detector at Circular Electron Positron Collider (CEPC). This prototype consists of 6 horizontal laser tracks around TPC detector chamber, a fast electronics readout of 1280 channels, a GEM detector with 200×200mm2 active area, and the DAQ system. The hit resolution, dE/dx resolution and drift velocity were studied by measuring and analyzing using the TPC prototype and UV laser tracks. The dE/dx resolution of the prototype was measured to be (8.9±0.4)%. Extrapolating this to CEPC TPC with 220 layers and longer track, the resolution was estimated to be (3.36±0.26)%. All results indicated that the TPC detector prototype integrated with UV laser tracks can work well.

A hybrid five‐level inverter configuration with improved reliability and reduced number of components

SummaryThe provision of significant redundant states in multilevel inverters (MLIs) aids in fault‐tolerant operation. However, this deals with several components, leading to low reliability. This paper proposes a new fault‐tolerant five‐level MLI with reduced component count, which can withstand both single‐ and multiple‐switch faults. The reduced carrier‐based level shifted sinusoidal pulse width modulation (RCLSPWM) strategy is developed to generate control signals for the switches. The employed control scheme automatically balances the voltage across the capacitor. The logic gate expressions for generating gate pulses of the switches under normal and fault‐tolerant operating modes are described in detail. The comparative analysis is carried out to demonstrate the effectiveness of the proposed topology over other existing similar topologies. The performance of the laboratory prototype developed is found satisfactory as compared to other existing topologies under various operating conditions.

Comparison between Piezoelectric and Piezoresistive Wearable Gait Monitoring Techniques.

Insole plantar stress detection (PSD) techniques play an important role in gait monitoring. Among the various insole PSD methods, piezoelectric- and piezoresistive-based architectures are broadly used in medical scenes. Each year, a growing number of new research outcomes are reported. Hence, a deep understanding of these two kinds of insole PSD sensors and state-of-the-art work would strongly benefit the researchers in this highly interdisciplinary field. In this context, this review article is composed of the following aspects. First, the mechanisms of the two techniques and corresponding comparisons are explained and discussed. Second, advanced materials which could enhance the performance of current piezoelectric and piezoresistive insole prototypes are introduced. Third, suggestions for designing insole PSD prototypes/products for different diseases are offered. Last, the current challenge and potential future trends are provided.

Practical Considerations in the Development of 3 and 15 Ah Rechargeable Lithium Pouch Cells

Commercially available Li-ion batteries using graphite or graphite-silicon blended anodes are currently approaching a cell level specific energy of 350 Wh kg−1. EaglePicher previously demonstrated a 2 Ah rechargeable pouch with a lithium metal anode that delivered 375 Wh kg−1 (Crowther, Owen. "Solving Barriers to Commercialization of Cells with Lithium Metal Anodes." 236th ECS Meeting (October 13-17, 2019). ECS, 2019). Further improvements to chemistry and cell design resulted in a 3 Ah pouch with longer cycle life and specific energies above 400 Wh kg−1 (Crowther, Owen. "Rechargeable Lithium Metal Pouch Cell Development." ECS Meeting s. No. 1. IOP Publishing, 2021). This paper will discuss several new areas that resulted in improved cell performance such as increasing the tab size, optimizing the electrolyte type and amount, and introducing excess lithium metal into the anode. Figure 1 demonstrates the rate capability of the cell with larger tabs to minimize the ohmic resistance. The cell with delivers ~425 Wh kg−1 at low rate and >300 Wh kg−1 at a 6.6C rate. The maximum continuous rate for the cell with the original tabs was 1C. Finally, the initial prototype performance of a 15 Ah rechargeable lithium pouch cell with a specific energy >500 Wh kg−1 will be highlighted. Figure 1

Influence of Salt Anions on the Reactivity of Polymer Electrolytes in All-Solid-State Sodium Batteries

Solid-state batteries have received renewed attention in recent years. The present study compares all-solid-state sodium batteries containing sodium metal anodes, NaTi2(PO4)3 (NTP) cathodes and PEO polymer electrolyte (PE) with two salts—NaPF6 and NaClO4. Electrochemical properties were determined by means of both AC and DC measurements. For fresh symmetric cells, it seems like using NaClO4 as the salt leads to a lower interfacial resistance, but during contact with Na anodes, PEO:NaClO4 PE produces an unstable interface whereas PEO-NaPF6 forms a stable interface upon contact with sodium anodes. Battery prototypes with PEO:NaClO4 showed a better performance than those using PEO:NaPF6 in terms of specific capacity and energy content, as NaPF6 produces HF by-product which impairs the performance of full cells. However, the use of composite solid electrolyte containing PEO:NaPF6 and TiO2 nanotubes alleviates detrimental effects of HF and thus enables a better performance of SS Na battery prototypes. This is probably due to the titania particles acting as a scavenger of HF, an inevitable contaminant in electrolyte systems containing PF6 − anions. On adding TiO2 to polymer electrolytes, of both salts, the performance improves, what means that the TiO2 has several positive effects in these systems.

A simulation and analysis framework for CEE-eTOF

This work reports the development status of a software framework for the external Time-Of-Flight wall (eTOF) of the Cooler-storage-ring External-target Experiment (CEE). The framework is implemented on CeeRoot, a FairRoot-based simulation and analysis platform. The chains for eTOF simulation and analysis have been developed and described in this paper. The examination of such a structure is in parallel with the technical design and prototype developments. Simulation has given reasonable evaluations on the coverage, occupancy, rate condition, etc., which validated the system design. The analysis chain has been successfully applied to processing the cosmic test data and has contributed to the validation of the prototype performances. The CEE-eTOF software is a continuously refining framework for practice in real operations.

PytuTester: RaspberryPi open-source ventilator tester

PytuTester is an open-source ventilator tester developed to help bio-engineers in the design and verification of new ventilator prototypes. A ventilator tester allows measuring the flow, pressure, volume, and oxygen concentration provided to the patient. During the global pandemic COVID-19, several open-source ventilators prototypes were developed; however, due to high cost and demand testers, they were not available. In this context, a low-cost tester was developed using a Raspberry Pi and medical-grade sensors for the test ventilators prototypes. This paper presents the design files, software interface, and validations tests. Our results indicate that the tester has good accuracy to evaluate the efficacy and performance of new prototypes. When tested on two ventilator designs developed in Paraguay, PytuTester reported flow profiles that were concordant with the industry-standard VT650 Gas Flow Analyzer. PytuTester was then field deployed to test several DIY ventilator designs in low-resource areas.

Development of a Patient-Centered Preference Tool for Patients With Hematologic Malignancies: Protocol for a Mixed Methods Study.

BackgroundThe approval of novel therapies for patients diagnosed with hematologic malignancies have improved survival outcomes but increased the challenge of aligning chemotherapy choices with patient preferences. We previously developed paper versions of a discrete choice experiment (DCE) and a best-worst scaling (BWS) instrument to quantify the treatment outcome preferences of patients with hematologic malignancies to inform shared decision making.ObjectiveWe aim to develop an electronic health care tool (EHT) to guide clinical decision making that uses either a BWS or DCE instrument to capture patient preferences. The primary objective of this study is to use both qualitative and quantitative methods to evaluate the perceived usability, cognitive workload (CWL), and performance of electronic prototypes that include the DCE and BWS instrument.MethodsThis mixed methods study includes iterative co-design methods that will involve healthy volunteers, patient-caregiver pairs, and health care workers to evaluate the perceived usability, CWL, and performance of tasks within distinct prototypes. Think-aloud sessions and semistructured interviews will be conducted to collect qualitative data to develop an affinity diagram for thematic analysis. Validated assessments (Post-Study System Usability Questionnaire [PSSUQ] and the National Aeronautical and Space Administration’s Task Load Index [NASA-TLX]) will be used to evaluate the usability and CWL required to complete tasks within the prototypes. Performance assessments of the DCE and BWS will include the evaluation of tasks using the Single Easy Questionnaire (SEQ), time to complete using the prototype, and the number of errors. Additional qualitative assessments will be conducted to gather participants’ feedback on visualizations used in the Personalized Treatment Preferences Dashboard that provides a representation of user results after completing the choice tasks within the prototype.ResultsEthical approval was obtained in June 2021 from the Institutional Review Board of the University of North Carolina at Chapel Hill. The DCE and BWS instruments were developed and incorporated into the PRIME (Preference Reporting to Improve Management and Experience) prototype in early 2021 and prototypes were completed by June 2021. Heuristic evaluations were conducted in phase 1 and completed by July 2021. Recruitment of healthy volunteers began in August 2021 and concluded in September 2021. In December 2021, our findings from phase 2 were accepted for publication. Phase 3 recruitment began in January 2022 and is expected to conclude in September 2022. The data analysis from phase 3 is expected to be completed by November 2022.ConclusionsOur findings will help differentiate the usability, CWL, and performance of the DCE and BWS within the prototypes. These findings will contribute to the optimization of the prototypes, leading to the development of an EHT that helps facilitate shared decision making. This evaluation will inform the development of EHTs to be used clinically with patients and health care workers.International Registered Report Identifier (IRRID)DERR1-10.2196/39586

Review: A Survey on Configurations and Performance of Flow-Mode MR Valves

Magnetorheological (MR) actuators are semi-active devices controlled by magnetic stimuli. The technology has been commercialized in the automotive industry or high-quality optical finishing applications. It harnesses the rheology of smart fluids to result in the unique application of the material. By a wide margin, the most common example of an MR actuator is a flow-mode single-tube housing with a control valve (electromagnet with a fixed-size air gap filled with the MR fluid) operating in a semi-active vibration control environment. The analysis of the prior art shows that the developed configurations of MR valves vary in size, complexity, the ability to generate adequate levels of pressure, and the interactions with the MR fluid’s rheology resulting in various performance envelopes. Moreover, miscellaneous testing procedures make a direct valve-to-valve comparison difficult. Therefore, in this paper we present a detailed and systematic review of MR control valves, provide classification criteria, highlight the operating principle, and then attempt to categorize the valves into groups sharing similarities in the design and performance envelope(s). Moreover, a simple performance metric based on the shear stress calculation is proposed, too, for evaluating the performance of particular valving prototypes. In the review, we discuss the key configurations, highlight their strengths and weaknesses and explore various opportunities for tuning their performance range. The review provides complementary information for the engineers and researchers with a keen interest in MR applications, in general. It is an organized and and critical study targeted at improvements in the categorization and description of MR devices.

Research on combustion performance of a micro-mixing combustor for methane-fueled gas turbine

This research proposes an H-class micro-mixing gas turbine combustor prototype with a thermal power of 1.15 MW, which employs 40 exterior jet-in-crossflow micro-mixing nozzles with a tapered round outlet to reduce pollutant emissions and prevent the flashback. These nozzles are located by a distribution arrangement in order to improve the temperature distribution uniformity of field flow. To respond to off-design operation of gas turbine, the combustion performance of the micro-mixing combustor prototype is investigated numerically at the rated fuel temperature of 473 K and other ones of 373, 423, 523 and 573 K. The results indicate that NO emission has a relatively high augment as the fuel temperature decreases, which is due to the rising local equivalence ratio. The variation trends of the temperature distribution uniformity, combustion efficiency and total pressure loss are not obvious as the fuel temperature changes. Based on the rated and off-design combustion performance at different radial planes, this research finally proposes an optimal relationship between the axial liner length and micro-mixing nozzle outlet diameter.

Evaluation of the incidence of the geometry of the reflection area in the optical performance of a handmade prototype of a parabolic trough concentrator

Este artículo tiene como objeto evaluar la incidencia de la geometría del área de reflexión en el rendimiento óptico de un sistema a baja escala de concentrados cilindro-parabólico. El sistema fue desarrollado y probado para calentar agua o generar vapor de agua en las Unidades Tecnológicas de Santander, ubicadas en Bucaramanga, Colombia. Se tuvieron en cuenta factores ópticos del prototipo real para realizar un análisis de trazado de rayos de monte Carlo, aplicando la Herramienta SolTrace. El sistema de concentración real, fue sometido a una comparación con dos sistemas geométricamente diferentes, es decir, un concentrador con dimensiones inferiores al sistema real y uno con dimensiones mayores, con el fin de determinar los rendimientos ópticos y las relaciones de concentración, para determinar la relación existente entre estos dos parámetros y el rendimiento de la unidad. Los resultados obtenidos, mostraron que el área de reflexión afecta directamente el rendimiento óptico y la relación de concentración del dispositivo, evidenciando que, a mayor área de concentración, mayor rendimiento del equipo.

Manufacturing challenges and technological solutions for microwave ablation (MWA) probe prototyping

In this paper, the manufacturing challenges and related technological solutions concerning the prototyping of microwave ablation (MWA) probes are addressed. In particular, the intertwined aspects pertaining probe design, fabrication and target performance are tackled. The development of a 14G MWA probe prototype, working at a frequency of 2.45 GHz, is proposed as a case study, describing design efforts and the use of rapid prototyping technologies combined with other manufacturing processes. A specific focus is dedicated to the insulating part of the probe radiating section, featuring high aspect ratio and complex shape, which was fabricated by means of Digital Light Processing (DLP) and by using a biocompatible material, the EnvisionTEC E-Shell® 300. Furthermore, the probe handling, properly designed to arrange cables and tubes routing, was fabricated by means of Fused Deposition Modeling (FDM) technology. Finally, ex vivo experiments conducted on bovine liver showed satisfactory treatment performance and structural reliability of the 14G MWA probe prototype. Besides being characterized by a good impedance matching ( S11 = −25 dB), prototype performance were also in good agreement with design simulations and even satisfying if compared to other results available in literature as, with an input radiation power of 40 W, the ablated zone after a 10 min treatment exhibited a ratio of the radial and longitudinal axis of 0.66.

Modeling, design and control of normal-stressed electromagnetic actuated fast tool servos

The normal-stressed electromagnetic actuated fast tool servo (FTS) plays an important role in modern ultra-precision manufacturing due to its high actuation force density and fast dynamics response. In order to promote the design and control of the normal-stressed electromagnetic actuated FTS, this paper proposes a comprehensive dynamics model based on the principles of magnetic equivalent circuits, which can be described as a Hammerstein-like structure. The electromagnetic phenomena, including hysteresis, magnetic saturation, and eddy currents, as well as the coupling between electromagnetic and mechanical dynamics are explicitly represented in the model. Based on a simplified version of this model, an integrated optimal design method for simultaneously determining actuator and mechanism parameters of the FTS is developed with full consideration of various practical physical limitations, which is then systematically verified through the finite element analysis (FEA). Afterwards, the comprehensive model of the assembled FTS prototype is identified and experimentally verified with a two-step identification strategy. Finally, a dual-loop control scheme is employed to improve tracking accuracy while suppressing the hysteresis and lightly damped resonance. Both open-loop and closed-loop performance of the FTS prototype validate the feasibility and effectiveness of the proposed model and methods.

Triboelectric based high-precision self-powering cage skidding sensor and application on main bearing of jet engine

Monitoring the dynamic behavior of rolling bearings is important to ensure the reliability of rotating machinery. In this study, a novel, high-precision, self-powering triboelectric bearing skidding sensor (HP-TEBSS) is developed for the real-time monitoring of bearing skidding degree and cage stability characteristics. A floating sweeping, freestanding mode is adopted to ensure long-term reliability, and the HP-TEBSS does not affect the bearing structure and dynamic behavior. The proposed sensor consists of an interdigital electrode plate, a dielectric ring with a protruding surface, and a fixed ring. The dielectric ring, which is pasted to the side surface of the integral copper cage, rotates synchronously with the cage and sweeps to the electrode plate. The HP-TEBSS generates Ne (number of electrode finger pairs) times of instantaneous cage speed information than that of commercial sensor, and the deviation between these two sensors is less than 1%. This shows the advanced real-time performance and monitoring accuracy of the proposed sensor. Experiments are conducted under variable working conditions with different structural parameters to optimize the sensor output performance. The self-powering and 50 h durability capabilities of the HP-TEBSS are demonstrated. Bearing skidding and cage rotation stability under variable spindle rotation speeds and bearing axial loads are systematically evaluated. It was found that in the light-load range, the skidding degree showed an increasing trend as the speed increased, whereas it showed the opposite trend under the heavy-load range. The monitoring results of cage speed fluctuations, which indicate running stability, provide recommendations for preventing bearing operation in the vulnerable range. Furthermore, the proposed bearing dynamic model is validated using the HP-TEBSS test results to demonstrate the wide applicability, high portability, and high-speed performance of the HP-TEBSS prototype. The application of the HP-TEBSS on a high-speed jet engine test bench is analyzed. It is found that cage skidding shows a certain degree of hysteresis in the deceleration stage, as compared to the acceleration stage, owing to cage inertia. Finally, theoretical and experimental aspects of the presented self-powering multifunctional HP-TEBSS that can be applied in the smart rolling bearing field are presented.

High-throughput multi-resolution foveated laparoscope for minimally invasive surgery.

Feasibility and clinical utility of a multi-resolution foveated laparoscope (MRFL) was previously tested in a porcine surgical study. The study revealed several clinical limitations of the system including moisture proofing, working distance, image quality, low light performance, color accuracy, size, and weight. In this paper, we discuss the root causes of these limitations and strategies to correct them, present the design and prototyping of a new high throughput multi resolution foveated laparoscope (HT-MRFL), and demonstrate the HT-MRFL prototype performance in comparison to the MRFL and simulated performance metrics.

Understanding of Crucial Factors for Improving the Energy Density of Lithium-Sulfur Pouch Cells.

Rechargeable lithium−sulfur (Li−S) batteries are the most promising next-generation energy storage system owing to their high energy density and low cost. Despite the increasing number of publications on the Li-S technology, the number of studies on real prototype cells is rather low. Furthermore, novel concepts developed using small lab cells cannot simply be transferred to high-energy cell prototypes due to the fundamental differences. The electrolyte and lithium anode excess used in small lab cells is known to have a huge impact on the cycle life, capacity, and rate capability of the Li-S system. This work analyses the performance of pouch cell prototypes demonstrating the potential and hurdles of the technology. The impact of electrolyte variations and the sulfur cathode loading are studied. The energy density of Li-S pouch cell is improved up to 436 Wh kg−1 by a combination of different approaches related to cell manufacturing, sulfur cathode optimization, and electrolyte amount adjustment.

Simulation Analysis of Fault-tolerant Control for Dual Three- Phase Permanent Magnet Synchronous Motor

According to the demand of aerospace electromechanical servo system, a new type of fault-tolerant dual three-phase permanent magnet motor(PMSM) and its control system with simple structure, high reliability and high power density are proposed. The dual three-phase PMSM's structure and control model are introduced, the fault-tolerant control algorithm for dual three-phase PMSM is proposed, the simulation model is built and the fault-tolerant control simulation analysis is carried out, Based on the dSPACE control platform, the performance of the synchronous motor prototype is tested, the motor test results show the feasibility of the dual three-phase PMSM and its fault-tolerant control algorithm, which establishes the engineering foundation for the further study of high-reliability electromechanical servo systems.

A comprehensive review on fish-inspired robots

Recently, the increasing interest in underwater exploration motivates the development of aquatic unmanned vehicles. To execute hazardous tasks in an unknown or even hostile environment, researchers have directed on developing biomimetic robots inspired by the extraordinary maneuverability, cruising speed, and propulsion efficiency of fish. Nevertheless, the performance of current prototypes still has gaps compared with that of real fishes. In this review, recent approaches in structure designs, actuators, and sensors are presented. In addition, the theoretical methods for modeling the robotic fishes are consolidated, and the control strategies are offered. Finally, the current challenges are summarized, and possible future directions are deeply discussed. It is expected that the emergence of new engineering and biological technologies will enhance the field of robotic fish for further advancement.