scholarly journals A mimicking technique of back pressure in the hardware-in-the-loop simulation of a fuel control unit

SIMULATION ◽  
2019 ◽  
Vol 96 (4) ◽  
pp. 375-385 ◽  
Author(s):  
Yuan Yuan ◽  
Zhiwen Zhao ◽  
Tianhong Zhang
Keyword(s):  
Control Unit ◽  
Back Pressure ◽  
Hardware In The Loop ◽  
Fuel System ◽  
Working Process ◽  
Aero Engine ◽  
Aero Engines ◽  
Performance Results ◽  
The Impact ◽  
Hil Simulation

In the hardware-in-the-loop (HIL) simulation of the fuel control unit (FCU) for aero-engines, the back pressure has a great impact on the metered fuel, thus influencing the confidence of the simulation. During the practical working process of an aero-engine, the back pressure of the FCU is influenced by the combined effect of the pressure of the combustion chamber, the resistance of the spray nozzles, and the resistance of the distribution valve. There is a need to study the the mimicking technique of FCU back pressure. This paper models the fuel system of an aero-engine so as to reveal the impact of FCU back pressure on the metered fuel and come up with a scheme to calculate the equivalent FCU back pressure. After analyzing the requirements for mimicking the pressure, an automatic regulating facility is designed to adjust the FCU back pressure in real time. Finally, experiments are carried out to verify its performance. Results show that the mimicking technique of back pressure is well suited for application in HIL simulation. It is able to increase the confidence of the simulation and provide guidance to the implementation of mimicking the FCU back pressure.

Model-Based Design and Hardware-in-the-Loop Simulation of Engine Lean Operation

2014 ◽  
Author(s):  
Pushkar Agashe ◽  
Yang Li ◽  
Bo Chen
Keyword(s):  
Gasoline Engine ◽  
Control Strategies ◽  
Electronic Control Unit ◽  
Control Unit ◽  
Simulation Models ◽  
Operating Conditions ◽  
Hardware In The Loop ◽  
Vehicle Performance ◽  
Model Based ◽  
Hil Simulation

This paper presents model-based design and hardware-in-the-loop (HIL) simulation of engine lean operation. The functionalities of the homogeneous combustion subsystem in engine Electronic Control Unit (ECU) in dSPACE Automotive Simulation Models (ASM) are first analyzed. To control the gasoline engine in lean operation without the drop of output torque, the combustion subsystem in engine ECU is modified by introducing two control loops, torque modifier and fuel multiplier. The performance of these two controllers is evaluated by HIL simulation using a dSPACE HIL simulator. The HIL simulation models, including vehicle plant model and softECUs in HIL simulator and engine lean control model in hardware engine ECU are modeled using model-based design. With HIL simulation, the designed engine control strategies can be immediately tested to evaluate the overall vehicle performance. The HIL simulation results show that the designed lean combustion control strategy can reduce fuel consumption and is able to meet the torque requirement at lean engine operating conditions.

scholarly journals Power Hardware-in-the-Loop-Based Performance Analysis of Different Converter Controllers for Fast Active Power Regulation in Low-Inertia Power Systems

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3274
Author(s):  
Jose Rueda Torres ◽  
Zameer Ahmad ◽  
Nidarshan Veera Kumar ◽  
Elyas Rakhshani ◽  
Ebrahim Adabi ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Power Systems ◽  
Real Time ◽  
Control Strategies ◽  
Active Power ◽  
Power Electronic ◽  
Hardware In The Loop ◽  
Digital Controllers ◽  
Power Regulation ◽  
The Impact

Future electrical power systems will be dominated by power electronic converters, which are deployed for the integration of renewable power plants, responsive demand, and different types of storage systems. The stability of such systems will strongly depend on the control strategies attached to the converters. In this context, laboratory-scale setups are becoming the key tools for prototyping and evaluating the performance and robustness of different converter technologies and control strategies. The performance evaluation of control strategies for dynamic frequency support using fast active power regulation (FAPR) requires the urgent development of a suitable power hardware-in-the-loop (PHIL) setup. In this paper, the most prominent emerging types of FAPR are selected and studied: droop-based FAPR, droop derivative-based FAPR, and virtual synchronous power (VSP)-based FAPR. A novel setup for PHIL-based performance evaluation of these strategies is proposed. The setup combines the advanced modeling and simulation functions of a real-time digital simulation platform (RTDS), an external programmable unit to implement the studied FAPR control strategies as digital controllers, and actual hardware. The hardware setup consists of a grid emulator to recreate the dynamic response as seen from the interface bus of the grid side converter of a power electronic-interfaced device (e.g., type-IV wind turbines), and a mockup voltage source converter (VSC, i.e., a device under test (DUT)). The DUT is virtually interfaced to one high-voltage bus of the electromagnetic transient (EMT) representation of a variant of the IEEE 9 bus test system, which has been modified to consider an operating condition with 52% of the total supply provided by wind power generation. The selected and programmed FAPR strategies are applied to the DUT, with the ultimate goal of ascertaining its feasibility and effectiveness with respect to the pure software-based EMT representation performed in real time. Particularly, the time-varying response of the active power injection by each FAPR control strategy and the impact on the instantaneous frequency excursions occurring in the frequency containment periods are analyzed. The performed tests show the degree of improvements on both the rate-of-change-of-frequency (RoCoF) and the maximum frequency excursion (e.g., nadir).

Design and development of a backstepping controller autopilot for fixed-wing UAVs

2021 ◽  
pp. 1-27
Author(s):  
D. Sartori ◽  
F. Quagliotti ◽  
M.J. Rutherford ◽  
K.P. Valavanis
Keyword(s):  
Real Time ◽  
Control Law ◽  
Parametric Uncertainties ◽  
Hardware In The Loop ◽  
Aircraft Control ◽  
Backstepping Approach ◽  
Small Uav ◽  
Backstepping Controller ◽  
Definition Of ◽  
Performance Results

Abstract Backstepping represents a promising control law for fixed-wing Unmanned Aerial Vehicles (UAVs). Its non-linearity and its adaptation capabilities guarantee adequate control performance over the whole flight envelope, even when the aircraft model is affected by parametric uncertainties. In the literature, several works apply backstepping controllers to various aspects of fixed-wing UAV flight. Unfortunately, many of them have not been implemented in a real-time controller, and only few attempt simultaneous longitudinal and lateral–directional aircraft control. In this paper, an existing backstepping approach able to control longitudinal and lateral–directional motions is adapted for the definition of a control strategy suitable for small UAV autopilots. Rapidly changing inner-loop variables are controlled with non-adaptive backstepping, while slower outer loop navigation variables are Proportional–Integral–Derivative (PID) controlled. The controller is evaluated through numerical simulations for two very diverse fixed-wing aircraft performing complex manoeuvres. The controller behaviour with model parametric uncertainties or in presence of noise is also tested. The performance results of a real-time implementation on a microcontroller are evaluated through hardware-in-the-loop simulation.

scholarly journals When is a Match Sufficient? A Score-based Balance Metric for the Synthetic Control Method

2020 ◽  
Vol 8 (1) ◽  
pp. 209-228
Author(s):  
Layla Parast ◽  
Priscillia Hunt ◽  
Beth Ann Griffin ◽  
David Powell
Keyword(s):  
Los Angeles ◽  
Control Method ◽  
Control Unit ◽  
Treated Group ◽  
Control Group ◽  
Synthetic Control ◽  
Donor Pool ◽  
Synthetic Control Method ◽  
The Mean ◽  
The Impact

AbstractIn some applications, researchers using the synthetic control method (SCM) to evaluate the effect of a policy may struggle to determine whether they have identified a “good match” between the control group and treated group. In this paper, we demonstrate the utility of the mean and maximum Absolute Standardized Mean Difference (ASMD) as a test of balance between a synthetic control unit and treated unit, and provide guidance on what constitutes a poor fit when using a synthetic control. We explore and compare other potential metrics using a simulation study. We provide an application of our proposed balance metric to the 2013 Los Angeles (LA) Firearm Study [9]. Using Uniform Crime Report data, we apply the SCM to obtain a counterfactual for the LA firearm-related crime rate based on a weighted combination of control units in a donor pool of cities. We use this counterfactual to estimate the effect of the LA Firearm Study intervention and explore the impact of changing the donor pool and pre-intervention duration period on resulting matches and estimated effects. We demonstrate how decision-making about the quality of a synthetic control can be improved by using ASMD. The mean and max ASMD clearly differentiate between poor matches and good matches. Researchers need better guidance on what is a meaningful imbalance between synthetic control and treated groups. In addition to the use of gap plots, the proposed balance metric can provide an objective way of determining fit.

scholarly journals Two Sides of the Same Coin. University-Industry Collaboration and Open Innovation as Enhancers of Firm Performance

2021 ◽  
Vol 13 (7) ◽  
pp. 3866
Author(s):  
Joana Costa ◽  
Ana Rita Neves ◽  
João Reis
Keyword(s):  
Firm Performance ◽  
Open Innovation ◽  
Primary Data ◽  
Company Performance ◽  
Innovation Ecosystem ◽  
Industry Collaboration ◽  
And Performance ◽  
Performance Results ◽  
The Impact ◽  
University Industry

Open innovation is proved to be determinant in the rationalization of sustainable innovation ecosystems. Firms, universities, governments, user communities and the overall environment are called to contribute to this dynamic process. This study aims to contribute to a better understanding of the impact of open innovation on firms’ performance and to empirically assess whether university-industry collaborations are complementary or substitutes for this activity. Primary data were collected from a survey encompassing 908 firms, and then combined with performance indicators from SABI (Spanish and Portuguese business information). Econometric estimations were run to evaluate the role of open innovation and university-industry collaboration in the firm innovative propensity and performance. Results highlight the importance of diversity in collaborations with the academia and inbound open innovation strategy as enhancers of firm performance. The two activities reinforce each other. By testing the impact of open innovation practices on company performance, the need for heterogeneity in terms of contact type and university is also demonstrated. Findings cast light on the need to reformulate existing policy packages, reinforcing the ties with academia as well as the promotion of open innovation strategies. The connection to the innovation ecosystem needs to be further encouraged as well as the promotion of persistent connections with the knowledge sources in an open and multilateral framework.

Life Prediction of Power Turbine Components for High Exhaust Back Pressure Applications: Part I — Disks

2015 ◽  
Author(s):  
Dipankar Dua ◽  
Brahmaji Vasantharao
Keyword(s):  
Steady State ◽  
Secondary Flow ◽  
Gas Turbines ◽  
Life Prediction ◽  
Creep Damage ◽  
Back Pressure ◽  
System Level ◽  
Cyclic Life ◽  
Power Turbine ◽  
The Impact

Industrial and aeroderivative gas turbines when used in CHP and CCPP applications typically experience an increased exhaust back pressure due to pressure losses from the downstream balance-of-plant systems. This increased back pressure on the power turbine results not only in decreased thermodynamic performance but also changes power turbine secondary flow characteristics thus impacting lives of rotating and stationary components of the power turbine. This Paper discusses the Impact to Fatigue and Creep life of free power turbine disks subjected to high back pressure applications using Siemens Energy approach. Steady State and Transient stress fields have been calculated using finite element method. New Lifing Correlation [1] Criteria has been used to estimate Predicted Safe Cyclic Life (PSCL) of the disks. Walker Strain Initiation model [1] is utilized to predict cycles to crack initiation and a fracture mechanics based approach is used to estimate propagation life. Hyperbolic Tangent Model [2] has been used to estimate creep damage of the disks. Steady state and transient temperature fields in the disks are highly dependent on the secondary air flows and cavity dynamics thus directly impacting the Predicted Safe Cyclic Life and Overall Creep Damage. A System-level power turbine secondary flow analyses was carried out with and without high back pressure. In addition, numerical simulations were performed to understand the cavity flow dynamics. These results have been used to perform a sensitivity study on disk temperature distribution and understand the impact of various back pressure levels on turbine disk lives. The Steady Sate and Transient Thermal predictions were validated using full-scale engine test and have been found to correlate well with the test results. The Life Prediction Study shows that the impact on PSCL and Overall Creep damage for high back pressure applications meets the product design standards.

scholarly journals Aero-Engine Fault Diagnosis Using Improved Local Discriminant Bases and Support Vector Machine

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Jianwei Cui ◽  
Mengxiao Shan ◽  
Ruqiang Yan ◽  
Yahui Wu
Keyword(s):  
Support Vector Machine ◽  
Fault Diagnosis ◽  
Wavelet Packet ◽  
Energy Difference ◽  
Test System ◽  
Support Vector ◽  
Svm Classifier ◽  
Aero Engine ◽  
Aero Engines ◽  
Optimal Set

This paper presents an effective approach for aero-engine fault diagnosis with focus on rub-impact, through combination of improved local discriminant bases (LDB) with support vector machine (SVM). The improved LDB algorithm, using both the normalized energy difference and the relative entropy as quantification measures, is applied to choose the optimal set of orthogonal subspaces for wavelet packet transform- (WPT-) based signal decomposition. Then two optimal sets of orthogonal subspaces have been obtained and the energy features extracted from those subspaces appearing in both sets will be selected as input to a SVM classifier to diagnose aero-engine faults. Experiment studies conducted on an aero-engine rub-impact test system have verified the effectiveness of the proposed approach for classifying working conditions of aero-engines.

Impact of dental implant diameter on the efficiency of fatigue - a systematic review analysis

2021 ◽  
pp. 1-12
Author(s):  
Mohamed Tharwat Hamed ◽  
Hisham Abdullah Mously ◽  
Moayyad Motaz Ghulman ◽  
Ghada Hussein Naguib
Keyword(s):  
Systematic Review ◽  
Dental Implant ◽  
Extensive Literature ◽  
Wide Diameter ◽  
Review Analysis ◽  
Body Fracture ◽  
Extensive Literature Search ◽  
Technical Complication ◽  
Performance Results ◽  
The Impact

Abstract Objective: The present study explains the success and failure of dental implant diameter on the efficiency of fatigue by conducting a systematic review analysis. Methods: An extensive literature search was conducted to carry out systematic review using different scholarly platforms and libraries. A total of 12 studies published within the past 20-year time (1999-2019) were included following the inclusion and exclusion criteria based on the PRISMA guidelines. Additionally, the study outcomes were evaluated to determine their perceptions regarding the role of dental implant diameter in influencing the implant’s fatigue performance. Results: The implant diameter can be categorized into wide diameter (5-6 mm), regular diameter (3.75-4 mm), and small/narrow diameter (3-3.4 mm). The narrow diameter implants are indicated through thin alveolar ridges and mesiodistal spaces (less than 7 mm). The implants with narrow diameter would offer greater risk of fatigue failure for clinical situations with significant functional loading. No significant differences were found either in success or failure of dental implant diameter on fatigue efficiency after 1-year and 3-year follow-up. Conclusion: The technical complication of dental implant include abutment screw loosening or fracture, abutment and superstructure fracture, and implant body fracture. The study has study has mainly focused on the impact of dental implant diameter on the efficiency of fatigue and reviewed a significant impact of dental implant diameter on the fatigue efficiency. Keywords: Dental Implants, Efficiency, Perception. Continuous...

scholarly journals Methodological adequacy of articles published in two open-access Brazilian cardiology periodicals

2010 ◽  
Vol 128 (2) ◽  
pp. 85-89 ◽  
Author(s):  
Cristiane Rufino Macedo ◽  
Davi Leite da Silva ◽  
Maria Eduarda Puga
Keyword(s):  
Web Of Science ◽  
Scientific Information ◽  
Quality Standards ◽  
Scientific Activity ◽  
Electronic Library ◽  
Scientific Methods ◽  
Assessment Performance ◽  
Performance Results ◽  
Study Designs ◽  
The Impact

CONTEXT AND OBJECTIVE: The use of rigorous scientific methods has contributed towards developing scientific articles of excellent methodological quality. This has made it possible to promote their citation and increase the impact factor. Brazilian periodicals have had to adapt to certain quality standards demanded by these indexing organizations, such as the content and the number of original articles published in each issue. This study aimed to evaluate the methodological adequacy of two Brazilian periodicals within the field of cardiology that are indexed in several databases and freely accessible through the Scientific Electronic Library Online (SciELO), and which are now indexed by the Web of Science (Institute for Scientific Information, ISI). DESIGN AND SETTING: Descriptive study at Brazilian Cochrane Center. METHODS: All the published articles were evaluated according to merit assessment (content) and form assessment (performance). RESULTS: Ninety-six percent of the articles analyzed presented study designs that were adequate for answering the objectives. CONCLUSIONS: These two Brazilian periodicals within the field of cardiology published methodologically adequate articles, since they followed the quality standards. Thus, these periodicals can be considered both for consultation and as vehicles for publishing future articles. For further analyses, it is essential to apply other indicators of scientific activity such as bibliometrics, which evaluates quantitative aspects of the production, dissemination and use of information, and scientometrics, which is also concerned with the development of science policies, within which it is often superimposed on bibliometrics.

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