scholarly journals Modeling the Influence of Engine Dynamics on Its Indicator Diagram

Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 7885
Author(s):  
Piotr Deuszkiewicz ◽  
Jacek Dziurdź ◽  
Paweł Fabiś
Keyword(s):  
Rotational Speed ◽  
Digital Signal ◽  
Position Angle ◽  
Acceleration Process ◽  
Integration Step ◽  
Angle Sensor ◽  
Indicator Diagram ◽  
Work Cycle ◽  
Variable Integration ◽  
Pressure Changes

This article presents a proposal to describe the pressure changes in the combustion chamber of an engine as a function of the angle of rotation of the crankshaft, taking into account changes in rotational speed resulting from acceleration. The aim of the proposed model is to determine variable piston forces in simulation studies of torsional vibrations of a crankshaft with a vibration damper during the acceleration process. Its essence is the use of a Fourier series as a continuous function to describe pressure changes in one cycle of work. Such a solution is required due to the variable integration step during the simulation. It was proposed to determine the series coefficients on the basis of a Fourier transform of the averaged waveform of a discreet open indicator diagram, calculated for the registration of successive cycles. Recording of the indicative pressure waveforms and shaft angle sensor signals was carried out during tests on the chassis dynamometer. An analysis of the influence of the adopted number of series coefficients on the representation of signal energy was carried out. The model can also take into account the phenomenon of work cycle uniqueness by introducing random changes in the coefficients with magnitudes set on the basis of determined standard deviations for each coefficient of the series. An indispensable supplement to the model is a description of changes in the engine rotational speed, used as a control signal for the PID controller in the simulation of the load performed by the dynamometer. The accuracy of determining the instantaneous rotational speed was analyzed on the basis of signals from the crankshaft position angle sensor and the piston top dead center (TDC) sensor. Limitations resulting from the parameters of digital signal recording were defined.

scholarly journals Quantification of the Feedback Regulation by Digital Signal Analysis Methods: Application to Blood Pressure Control Efficacy

2019 ◽  
Vol 10 (1) ◽  
pp. 209 ◽  
Author(s):  
Nikita S. Pyko ◽  
Svetlana A. Pyko ◽  
Oleg A. Markelov ◽  
Oleg V. Mamontov ◽  
Mikhail I. Bogachev
Keyword(s):  
Blood Pressure ◽  
Stress Test ◽  
Digital Signal ◽  
External Input ◽  
The Body ◽  
Differential Diagnostics ◽  
Pulse Interval ◽  
Control Mechanisms ◽  
Pressure Changes ◽  
Feedback Responses

Six different metrics of mutual coupling of simultaneously registered signals representing blood pressure and pulse interval dynamics have been considered. Stress test responses represented by the reaction of the recorded signals to the external input by tilting the body into the upright position have been studied. Additionally, to the conventional metrics like the joint signal coherence Coher and the sensitivity of the pulse intervals response to the blood pressure changes baroreflex sensitivity (BRS), also alternative indicators like the synchronization coefficient Sync and the time delay stability estimate TDS representing the temporal fractions of the analyzed signal records exhibiting rather synchronous dynamics have been determined. In contrast to BRS, that characterizes the intensity of the pulse intervals response to the blood pressure changes during observed feedback responses, both Sync and TDS likely indicate how often such responses are being activated in the first place. The results indicate that in most cases BRS is typically reciprocal to both Sync and TDS suggesting that low intensity of the feedback responses characterized by low BRS is rather compensated by their more frequent activation indicated by higher Sync and TDS. The proposed additional indicators could be complementary for the differential diagnostics of blood pressure regulation efficacy and also lead to a deeper insight into the involved concomitant factors this way also aiming at the improvement of the mathematical models representing the underlying feedback control mechanisms.

scholarly journals An Arduino Real-Time Jump Tagging System for Exploring Stereotyped Jumping Behavior in Mice

2021 ◽  
Author(s):  
Junye Ge ◽  
Guangyuan Li ◽  
Haibo Zhang ◽  
Haiying Liu ◽  
Chuchu Qi ◽  
...  
Keyword(s):  
Real Time ◽  
Primary Motor Cortex ◽  
Digital Signal ◽  
Stereotyped Behavior ◽  
Neural Mechanisms ◽  
Natural State ◽  
New Techniques ◽  
The Common ◽  
Pressure Changes ◽  
Tagging System

Abstract The jump is one of the common stereotyped behavior in rodents. It is the natural state in some types of mice and also can be found in certain types of disease models, such as addiction. It is straightforward and easy to identify by the human eye in offline analysis. However, jumping is a short-lived act that happens immediately. It is difficult to be tagged in real-time by manual operation, which limits the detailed exploration of its neural mechanisms with the new techniques, such as fiber photometry recording or optogenetics. Here we introduced an arduino real-time jump tagging system (Art-JT system) to record the jump based on online monitoring the pressure changes of the floor in which the mouse is free exploring. Meanwhile, the Art-JT system can send the digital signal of the jump timing to the external device for tagging the events in the fiber photometry system or triggering the optogenetics laser. We tested it with the mice induced by Naloxone precipitated withdrawal jumping. The results showed that it could accurately record the jump events and provide several detailed parameters of the jump. Furthermore, it was easy and fast to get the GCaMP6 signal correlated with the jump in the medial prefrontal cortex and primary motor cortex by combining the Art-JT system and multichannel fiber photometry system. Our results suggested that the Art-JT system may be a powerful tool for recording and analyzing jumping efficiently and helping us to understand stereotyped behavior.

scholarly journals The influence of auger wear on the parameters of the dehydration process of solid waste in the garbage truck

2021 ◽  
Vol 100 (2) ◽  
pp. 79-86
Author(s):  
O. Bereziuk ◽  
◽  
V. Savulyak ◽  
V. Kharzhevskyi ◽  
◽  
...  
Keyword(s):  
Mathematical Model ◽  
Energy Consumption ◽  
Angular Velocity ◽  
Solid Waste ◽  
Working Fluid ◽  
Integration Step ◽  
Dehydration Process ◽  
Hydraulic Motor ◽  
Variable Integration ◽  
The Cost

The article is dedicated to the study of the influence of auger wear on the parameters of the dehydration process of municipal solid waste in the garbage truck. An improved mathematical model of the drive operation of dehydration of solid waste in the garbage truck is proposed, which takes into account the wear of the auger and allowed to numerically determine the dynamics of the drive during start-up. It was also established that increasing wear of the auger, the pressure of the working fluid at the inlet of the hydraulic motor rises, and the angular velocity and speed of the auger is significantly reduced. The research of this mathematical model was carried out using the numerical Runge-Kutta-Felberg method of the 4th order with a variable integration step. By means of the method of regression analysis, the power dependencies of the change of nominal values ​​of pressures at the inlet of the hydraulic motor, angular velocity and speed of rotation of the auger from the value of its wear are determined. The last-mentioned dependence defines the detuning from the optimal speed of the auger during its wear and is used to determine the energy consumption of dehydration of solid waste, taking into account the wear of the auger. It is established that the wear of the auger by 1000 mm leads to an increase in the energy consumption of dehydration of solid waste by 11.6%, and, therefore, also leads to an increase of the cost of the process of their dehydration in the garbage truck. It was also established the expediency of further research to determine the appropriate material of the auger and the ways to increase its wear resistance.

scholarly journals AJUSTMENT OF THE POSITION SENSOR OF THE ROTOR OF THE SYNCHRONOUS RELUCTANCE MOTOR WITH ANISOTROPIC MAGNETIC CONDUCTIVITY OF THE ROTOR

2017 ◽  
pp. 80-86
Author(s):  
Veniamin Frantsevich Samoseyko ◽  
Sergey Vladimirovich Sharashkin
Keyword(s):  
Position Angle ◽  
Position Sensor ◽  
Propulsion Systems ◽  
Angle Sensor ◽  
Rotor Position ◽  
Advantages And Disadvantages ◽  
Reluctance Machine ◽  
Synchronous Reluctance Motor ◽  
Reluctance Motor ◽  
Magnetic Conductivity

The article is devoted to the development of the algorithm for adaptation the rotor position sensor of a synchronous reluctance electric machine with anisotropic magnetic conductivity of the rotor. The main advantages and disadvantages of synchronous electric machines are considered in the construction of ship propulsion systems. The advantages of reluctance motor with anisotropic magnetic conductivity of the rotor are given in the construction of propulsion systems. The essence of the method of adaptation of the rotor position sensor is given. The differential equation of adaptation of the rotor position angle sensor is obtained, its stability is investigated. A model of a reluctance machine with anisotropic magnetic conductivity of a rotor is given, which makes it possible to determine its parameters.

scholarly journals Stability Analysis and Optimization of Semi-Explicit Predictor–Corrector Methods

Mathematics ◽  
2021 ◽  
Vol 9 (19) ◽  
pp. 2463
Author(s):  
Aleksandra Tutueva ◽  
Denis Butusov
Keyword(s):  
Numerical Stability ◽  
Large Scale ◽  
Integration Step ◽  
Variable Integration ◽  
Predicted Values ◽  
Low Dimensional ◽  
Three Body ◽  
Systems Simulation ◽  
Predictor Corrector

The increasing complexity of advanced devices and systems increases the scale of mathematical models used in computer simulations. Multiparametric analysis and study on long-term time intervals of large-scale systems are computationally expensive. Therefore, efficient numerical methods are required to reduce time costs. Recently, semi-explicit and semi-implicit Adams–Bashforth–Moulton methods have been proposed, showing great computational efficiency in low-dimensional systems simulation. In this study, we examine the numerical stability of these methods by plotting stability regions. We explicitly show that semi-explicit methods possess higher numerical stability than the conventional predictor–corrector algorithms. The second contribution of the reported research is a novel algorithm to generate an optimized finite-difference scheme of semi-explicit and semi-implicit Adams–Bashforth–Moulton methods without redundant computation of predicted values that are not used for correction. The experimental part of the study includes the numerical simulation of the three-body problem and a network of coupled oscillators with a fixed and variable integration step and finely confirms the theoretical findings.

scholarly journals Methods of measuring crankshaft speed in mechatronics

2018 ◽  
Vol 19 (9) ◽  
pp. 105-107
Author(s):  
Monika Andrych-Zalewska ◽  
Radosław Włostowski ◽  
Radosław Wróbel
Keyword(s):  
Signal Processing ◽  
Digital Signal Processing ◽  
Rotational Speed ◽  
Can Bus ◽  
Digital Signal ◽  
Input Function ◽  
Diagnostic Information ◽  
New Method ◽  
Vibration Measurement

The article discusses methods of measuring rotational speed. Classical methods as well as a new method using vibration measurement as the input function in the process of obtaining the result of the crankshaft rotational speed were presented. A classic diagnostic path, as well as digital signal processing, is required to obtain the correct diagnostic INFORMATION. The work also includes information on the CAN bus as well as the EOBD system.

Numerical Investigations on the Aerodynamic Performance and Endwall Cooling Characteristics of Turbine During Acceleration Process With Lagging Effects

2021 ◽  
Author(s):  
Qingfeng Cong ◽  
Zhigang Li ◽  
Jun Li
Keyword(s):  
Flow Field ◽  
Rotational Speed ◽  
Aerodynamic Performance ◽  
Acceleration Process ◽  
Two Stage ◽  
Cooling Effectiveness ◽  
Mainstream Flow ◽  
Purge Flow ◽  
Secondary Air ◽  
Endwall Cooling

Abstract In the process of turbine acceleration, due to the influence of compressor and complex secondary air system, the change process of coolant purge flow is relatively lagging behind that of mainstream flow and rotational speed. The lagging egress of coolant flow influence the aerodynamic performance and endwall cooling effectiveness of turbine acceleration process. The flow field and aerothermal performance of two-stage axial turbines combined with rim seal structures and coolant purge flow lagging effects in the turbine acceleration process was numerically investigated using Unsteady Reynolds-Averaged Navier-Stokes (URANS) via SST turbulence model. The effects of lagging coolant purge flow across the rim seal on the turbine aerodynamics and endwall cooling effectiveness were analyzed. The obtained results show that the turbine aerodynamic efficiency obtains the maximum value when the coolant purge flow lagging time equals to half the acceleration time at the same rotational speed after the end of lagging times. The total-to-total efficiency for the second stage is more sensitive to lagging times. The turbine output power is almost un-changed due to combination of additional work capacity and aerodynamic loss with the introduction of coolant. The turbine endwalls have the maximum averaged cooling effectiveness in the turbine acceleration process without consideration of the coolant purge flow lagging time. And endwall cooling effectiveness decreases with the increase of coolant purge flow lagging time at the same rotational speed and mainstream flow conditions. The detailed flow field of two-stage turbine considering interaction between the coolant purge flow and mainstream was also discussed. The present work provides the reference for the match design between the turbine mainstream flow and secondary air flow system.

Research on transmission efficiency of high power hydro-viscous clutch

2019 ◽  
Vol 71 (7) ◽  
pp. 942-948
Author(s):  
Qi Sun ◽  
Fangwei Xie ◽  
Kuaidi Wan ◽  
Xinjian Guo ◽  
Jie Zhu ◽  
...  
Keyword(s):  
Rotational Speed ◽  
Power Transmission ◽  
Transmission Efficiency ◽  
Inlet Pressure ◽  
Lubricating Oil ◽  
Transmission Ratio ◽  
Content Type ◽  
Oil Film ◽  
Pressure Changes ◽  
The Relationship

Purpose The purpose of this paper is to study the influences of the oil film thickness between the friction pairs, the rotational speed of the active and passive friction disks and the inlet pressure of the lubricant on the transmission efficiency. Design/methodology/approach A mathematical model of transmission efficiency was established, and the efficiency of transmission was studied by means of numerical analysis. Findings The results demonstrate that the transmission efficiency decreases with the thickness of the oil film increases. When the thickness of oil film d = 0.1 mm, the relationship between transmission efficiency and transmission ratio is linear, that is, with the transmission ratio increases, the transmission efficiency also increases which does not change with the inlet pressure changes. However, when d = 0.1 mm, their relationship is non-linear; the efficiency increases first and then decreases as the transmission ratio increases, but decreases as the inlet pressure increases. Originality/value The authors obtained a rule is that increasing the rotational speed and reducing the inlet pressure of the lubricating oil can improve the transmission efficiency. This study can provide a theoretical basis for power transmission designing of hydro-viscous clutch.

The Optimum Technological Parameters and Properties of LDPE/LLDPE/Nano-Mg(OH)2 Systems

2011 ◽  
Vol 239-242 ◽  
pp. 437-440 ◽  
Author(s):  
Yu Hua Guo ◽  
Jian Jun Guo ◽  
Zhen Huang ◽  
Li Jun Teng
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Strength ◽  
Flame Retardant ◽  
Young’S Modulus ◽  
Magnesium Hydroxide ◽  
Rotational Speed ◽  
Technological Parameters ◽  
Technological Route ◽  
Pressure Changes

Nano-structured magnesium hydroxide (nano-MH) has been added into LDPE/LLDPE, the technological parameters, flame and mechanical properties, M.F.R. of LDPE/LLDPE/nano-MH samples have been examined. It is indicated two time extruder pelletization is a good technological route, which can make nano-MH disperse evenly in PE. The optimum rotational speed of screws changes from 37 to 42 rad/min, the die pressure changes from 35 to 61.5 bar. Nano-MH has good flame retardant and smoke suppressing properties. The samples added 60% nano-MH can reach UL94 FV-0 flame retardant rating. When nano-MH content is more than 40%, no smoke emits. With nano-MH content increases, the tensile strength, impact strength, elongation and M.F.R decreases, Young’s modulus increases.

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