Discrete Pressure Controls in IC Engine Lubricating Pumps

2011 ◽  
Author(s):  
Massimo Rundo ◽  
Raffaele Squarcini
Keyword(s):  
Engine Speed ◽  
Closed Loop ◽  
Experimental Tests ◽  
Threshold Value ◽  
Operating Conditions ◽  
Absolute Pressure ◽  
Temperature Sensitive ◽  
Absorbed Energy ◽  
Ic Engine ◽  
Velocity Condition

The paper presents two displacement controls for IC Engine lubricating vane pumps. The main feature is the variable setting of the absolute pressure limiter that can switch from a high to a low level when a minimum threshold value of engine speed or oil temperature is exceeded. This is obtained by venting the displacement actuator of the pump by means of a two positions electrovalve or a temperature sensitive valve. Aim is the reduction of the circuit pressure in the less critical engine operating conditions in order to decrease the absorbed torque. These controls are contrasted with a traditional fixed setting device in terms of overall energy absorbed by the pump in the NEDC cycle. Comparisons are performed with a lumped parameters simulation model able to replicate the operating conditions encountered by the pump during the driving cycle, in terms of oil temperature and circuit permeability. Outcomes from simulation have been validated by experimental tests on pumps prototypes. Tests have been performed on a rig where the load on the pump is generated by a proportional throttle valve controlled in a closed loop in order to reproduce, for each temperature and velocity condition, the resistance of the lubricating circuit. The study brings to evidence that with both systems a significant reduction of the absorbed energy can be achieved in the NEDC without detrimental effects on engine lubrication.

Development of a Torsional Behavior Powertrain Model for Multiple Misfire Detection

2005 ◽  
Author(s):  
Fabrizio Ponti
Keyword(s):  
Torsional Vibration ◽  
Engine Speed ◽  
Experimental Tests ◽  
Detection Algorithm ◽  
Operating Conditions ◽  
False Alarms ◽  
Time Interval ◽  
Short Time Interval ◽  
Torsional Behavior ◽  
Misfire Detection

Many methodologies have been developed in the past for misfire detection purposes based on the analysis of the instantaneous engine speed. The missing combustion is usually detected thanks to the sudden engine speed decrease that takes place after a misfire event. Misfire detection and in particular cylinder isolation is anyhow still a challenging issue for engines with a high number of cylinders, for engine operating conditions at low load or high engine speed and for multiple misfire events. When a misfire event takes place in fact a torsional vibration is excited and shows up in the instantaneous engine speed waveform. If a multiple misfire occurs this torsional vibration is excited more than once in a very short time interval. The interaction among these successive vibrations can generate false alarms or misdetection, and an increased complexity when dealing with cylinder isolation. The paper presents the development of a powertrain torsional behavior model in order to identify the effects of a misfire event on the instantaneous engine speed signal. The identified waveform has then been used to filter out the torsional vibration effects in order to enlighten the missing combustions even in the case of multiple misfire events. The model response is also used to quicken the setup process for the detection algorithm employed, evaluating before running specific experimental tests on a test bench facility, the values for the threshold and the optimal setup of the procedure. The proposed algorithm is developed in this paper for an SI L4 engine; Its application to other engine configurations is possible, as it is also discussed in the paper.

Vehicle Simulation on the Test Bench

2004 ◽  
Author(s):  
Enrico Corti
Keyword(s):  
Engine Speed ◽  
Test Bench ◽  
Driving Cycle ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Absolute Pressure ◽  
Performance And Emission ◽  
Vehicle Simulation ◽  
Equivalence Condition ◽  
The Impact

International emission tests (EPA, SFTP, MVEG-B, J-10.15, etc.) are carried out with vehicles running on the rolls dynamometer. Results, in terms of total emissions, are influenced by vehicles parameters such as mass, gear ratios, front surface, drag coefficient, etc. It would be useful, in the automobiles design phase, to have information about the impact of these parameters on total emissions. The obvious solution would be to build up a complete vehicle model to simulate performance and emission levels. Engine pollutants production modeling is the weak point, since it is difficult to obtain reliable results. Anyway it is possible to avoid pollutants production simulation, testing the actual engine under the same operating condition it would face inside the car’s hood. This paper describes a methodology whose aim is to test the engine on a standard test bench, simulating on-board operating conditions. An equivalence condition has to be satisfied in order to guarantee the methodology effectiveness: engine speed and Manifold Absolute Pressure (MAP) must always match for the two types of test performed on the same driving cycle. Engine speed and torque can be controlled through the bench actuators, their values depending on the simulated vehicle motion: once the car dynamics are simulated by means of a model, engine speed and torque corresponding to the given driving cycle can in fact be evaluated. The model is solved in real time, its output being the brake load torque value satisfying the equivalence condition. The brake controller, used as a slave, regulates the engine operating conditions consequently. The global model incorporates tires, aerodynamic forces, clutch, gearbox and driveline behaviors simulation: its response has been first validated comparing its outputs with data measured on board, and then it has been used to control an eddy current brake, for vehicle test simulation on the test bench. Two different control philosophies can be used: either a human driver or an automatic controller can ride the simulated car. The influence of vehicle parameters and gearshift mode on fuel consumption and pollutant emissions can be investigated.

High Performance Continuously Variable Transmission Control Through Robust Control-Relevant Model Validation

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
Tom Oomen ◽  
Stan van der Meulen
Keyword(s):  
Robust Control ◽  
System Dynamics ◽  
High Performance ◽  
Closed Loop ◽  
Optimal Operation ◽  
Operating Conditions ◽  
Feedback Controller ◽  
Transmission Ratio ◽  
Absolute Pressure ◽  
Actuation System

Optimal operation of continuously variable transmissions (CVTs) is essential to meet tightening emission and fuel consumption requirements. This is achieved by accurately tracking a prescribed transmission ratio reference and simultaneously optimizing the internal efficiency of the CVT. To reduce the power losses in a CVT, the absolute pressure levels are lowered, which increases the sensitivity to torque disturbances and increases the importance of disturbance feedforwards. This requires a high performance feedback controller for the hydraulic actuation system in a CVT. The aim of this paper is to develop a multivariable feedback controller for the hydraulic actuation system that is robust with respect to the varying system dynamics that are induced by the varying operating conditions, including transmission ratio changes. Hereto, new connections between system identification and robust control are exploited to achieve high performance. As a result, the varying system dynamics are directly evaluated in terms of closed-loop performance objectives. Subsequent robust control design reveals an increase of the control performance of almost a factor two in terms of the criterion value. This leads to improved simulated and measured closed-loop step responses, including a decrease in settling time from 0.4 s to 0.2 s. Finally, the designed robust controller is successfully validated in a standardized driving cycle experiment.

Open-Loop Active Control of Combustion Dynamics on a Gas Turbine Engine

2004 ◽  
Author(s):  
Geo. A. Richards ◽  
Jimmy D. Thornton ◽  
Edward H. Robey ◽  
Leonell Arellano
Keyword(s):  
Gas Turbine ◽  
Active Control ◽  
Closed Loop ◽  
Experimental Tests ◽  
Gas Turbine Engine ◽  
Open Loop ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Combustion Dynamics ◽  
Turbine Engine

Combustion dynamics is a prominent problem in the design and operation of low-emission gas turbine engines. Even modest changes in fuel composition, or operating conditions can lead to damaging vibrations in a combustor that was otherwise stable. For this reason, active control has been sought to stabilize combustors that must accommodate fuel variability, new operating conditions, etc. Active control of combustion dynamics has been demonstrated in a number of laboratories, single-nozzle test combustors, and even on a fielded engine. In most of these tests, active control was implemented with closed-loop feedback between the observed pressure signal and the phase and gain of imposed fuel perturbations. In contrast, a number of recent papers have shown that open-loop fuel perturbations can disrupt the feedback between acoustics and heat release that drives the oscillation. Compared to the closed-loop case, this approach has some advantages because it may not require high-fidelity fuel actuators, and could be easier to implement. This paper reports experimental tests of open-loop fuel perturbations to control combustion dynamics in a complete gas turbine engine. Results demonstrate the technique was very successful on the test engine, and had minimal effect on pollutant emissions.

Open-Loop Active Control of Combustion Dynamics on a Gas Turbine Engine

2006 ◽  
Vol 129 (1) ◽  
pp. 38-48 ◽  
Author(s):  
Geo. A. Richards ◽  
Jimmy D. Thornton ◽  
Edward H. Robey ◽  
Leonell Arellano
Keyword(s):  
Gas Turbine ◽  
Active Control ◽  
Closed Loop ◽  
Experimental Tests ◽  
Gas Turbine Engine ◽  
Open Loop ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Combustion Dynamics ◽  
Turbine Engine

Combustion dynamics is a prominent problem in the design and operation of low-emission gas turbine engines. Even modest changes in fuel composition or operating conditions can lead to damaging vibrations in a combustor that was otherwise stable. For this reason, active control has been sought to stabilize combustors that must accommodate fuel variability, new operating conditions, etc. Active control of combustion dynamics has been demonstrated in a number of laboratories, single-nozzle test combustors, and even on a fielded engine. In most of these tests, active control was implemented with closed-loop feedback between the observed pressure signal and the phase and gain of imposed fuel perturbations. In contrast, a number of recent papers have shown that open-loop fuel perturbations can disrupt the feedback between acoustics and heat release that drives the oscillation. Compared to the closed-loop case, this approach has some advantages because it may not require high-fidelity fuel actuators, and could be easier to implement. This paper reports experimental tests of open-loop fuel perturbations to control combustion dynamics in a complete gas turbine engine. Results demonstrate the technique was very successful on the test engine and had minimal effect on pollutant emissions.

Multiple Misfire: Detection and Cylinder Isolation Based on Engine Speed Measurement

2003 ◽  
Author(s):  
Nicolo` Cavina
Keyword(s):  
Engine Speed ◽  
Diagnostic Algorithm ◽  
Experimental Tests ◽  
Spark Ignition ◽  
Specific Pattern ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
False Alarms ◽  
Misfire Detection ◽  
Engine Cycle

The diagnosis of misfire events (or missing combustions) is enforced by On-Board Diagnostics regulations (such as CARB OBD II or European OBD) over the whole engine operating range, for all vehicles equipped with spark ignition engines. Such regulations define both the minimum misfire frequency that is to be detected (related to catalyst damage and/or increased hydrocarbons emissions), and the various misfire patterns that the diagnostic algorithm should be able to detect. In particular, single (no more than one missing combustion per engine cycle) and multiple (more than one misfiring cylinder within the same engine cycle) misfire patterns are to be diagnosed, and the cylinder in which the misfire took place is to be isolated only when single misfires take place (cylinder identification is still not mandatory for multiple misfires). Various single misfire detection methodologies have been successfully developed in recent years (mostly based on the engine speed signal), and this type of misfire diagnosis is still challenging for engines with a high number of cylinders, especially during operating conditions characterized by high engine speed and low load. On the other hand, the detection of multiple misfires is still difficult even for the typical four cylinder engine, since their effects on the engine speed trend have not yet been clarified. In fact, a misfire occurrence is characterized by a sudden engine speed decrease and a subsequent damped torsional vibration. In case of multiple misfires, the engine speed oscillation induced by the first misfiring cylinder may still be present when the second missing combustion takes place, and the resulting engine speed waveform may be erroneously interpreted by the diagnostic algorithm, thus resulting in the improper cylinder being identified or missed detection of a misfiring cylinder. This paper deals with the identification of a specific pattern in the instantaneous engine speed trend, induced by a missing combustion and characteristic of the system under study, that allows performing the desired multiple misfire detection. The methodology has been designed in order to be run on-board, thus requiring low computational power and memory allocation. Its implementation has shown that false alarms can be avoided and correct cylinder isolation is possible, also in presence of multiple misfires. Experimental tests have been performed on a 1.2 liter spark ignition engine mounted in a test cell. Various multiple misfire patterns have been induced by controlling ignition and injection of the various cylinders. In-cylinder pressure signals have been acquired together with the instantaneous engine speed, in order to verify the capability of the methodology.

scholarly journals Comprehensive Parameters Identification and Dynamic Model Validation of Interior-Mount Line-Start Permanent Magnet Synchronous Motors

Machines ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 4 ◽  
Author(s):  
Luqman S. Maraaba ◽  
Zakariya M. Al-Hamouz ◽  
Abdulaziz S. Milhem ◽  
Ssennoga Twaha
Keyword(s):  
Mathematical Model ◽  
Permanent Magnet ◽  
High Efficiency ◽  
Experimental Tests ◽  
Induction Machines ◽  
Test Methods ◽  
Operating Conditions ◽  
Test Method ◽  
Permanent Magnet Synchronous Motors ◽  
Synchronous Motors

The application of line-start permanent magnet synchronous motors (LSPMSMs) is rapidly spreading due to their advantages of high efficiency, high operational power factor, being self-starting, rendering them as highly needed in many applications in recent years. Although there have been standard methods for the identification of parameters of synchronous and induction machines, most of them do not apply to LSPMSMs. This paper presents a study and analysis of different parameter identification methods for interior mount LSPMSM. Experimental tests have been performed in the laboratory on a 1-hp interior mount LSPMSM. The measurements have been validated by investigating the performance of the machine under different operating conditions using a developed qd0 mathematical model and an experimental setup. The dynamic and steady-state performance analyses have been performed using the determined parameters. It is found that the experimental results are close to the mathematical model results, confirming the accuracy of the studied test methods. Therefore, the output of this study will help in selecting the proper test method for LSPMSM.

scholarly journals Sensitivity Analysis of OTEC-CC-MX-1 kWe Plant Prototype

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2585
Author(s):  
Jessica Guadalupe Tobal-Cupul ◽  
Estela Cerezo-Acevedo ◽  
Yair Yosias Arriola-Gil ◽  
Hector Fernando Gomez-Garcia ◽  
Victor Manuel Romero-Medina
Keyword(s):  
Sensitivity Analysis ◽  
Experimental Tests ◽  
Caribbean Sea ◽  
Ocean Model ◽  
Operating Conditions ◽  
Working Fluid ◽  
Ocean Energy ◽  
Mexican Caribbean ◽  
Water Temperature Data ◽  
Mass Flows

The Mexican Caribbean Sea has potential zones for Ocean Thermal Energy Conversion (OTEC) implementation. Universidad del Caribe and Instituto de Ciencias del Mar y Limnologia, with the support of the Mexican Centre of Innovation in Ocean Energy, designed and constructed a prototype OTEC plant (OTEC-CC-MX-1 kWe), which is the first initiative in Mexico for exploitation of this type of renewable energy. This paper presents a sensitivity analysis whose objective was to know, before carrying out the experimental tests, the behavior of OTEC-CC-MX-1 kWe regarding temperature differences, as well as the non-possible operating conditions, which allows us to assess possible modifications in the prototype installation. An algorithm was developed to obtain the inlet and outlet temperatures of the water and working fluid in the heat exchangers using the monthly surface and deep-water temperature data from the Hybrid Coordinate Ocean Model and Geographically Weighted Regression Temperature Model for the Mexican Caribbean Sea. With these temperatures, the following were analyzed: fluctuation of thermal efficiency, mass flows of R-152a and water and power production. By analyzing the results, we verified maximum and minimum mass flows of water and R-152a to produce 1 kWe during a typical year in the Mexican Caribbean Sea and the conditions when the production of electricity is not possible for OTEC-CC-MX-1 kWe.

The analysis on the influence of mixed sliding-rolling motion mode to precision degradation of ball screw

2021 ◽  
pp. 095440622098201
Author(s):  
Qiang Cheng ◽  
Baobao Qi ◽  
Hongyan Chu ◽  
Ziling Zhang ◽  
Zhifeng Liu ◽  
...  
Keyword(s):  
Structural Parameters ◽  
Experimental Tests ◽  
Theoretical Models ◽  
Operating Conditions ◽  
Ball Screw ◽  
Rolling Motion ◽  
Degradation Model ◽  
Sliding Motion ◽  
Factors Analysis ◽  
Motion Mode

The combination of sliding/rolling motion can influence the degree of precision degradation of ball screw. Precision degradation modeling and factors analysis can reveal the evolution law of ball screw precision. This paper presents a precision degradation model for factors analysis influencing precision due to mixed sliding-rolling motion. The precision loss model was verified through the comparison of theoretical models and experimental tests. The precision degradation due to rolling motion between the ball and raceway accounted for 29.09% of the screw precision loss due to sliding motion. Additionally, the total precision degradation due to rolling motion accounted for 21.03% of the total sliding precision loss of the screw and nut, and 17.38% of the overall ball screw precision loss under mixed sliding-rolling motion. In addition, the effects of operating conditions and structural parameters on precision loss were analyzed. The sensitivity coefficients of factors influencing were used to quantitatively describe impact degree on precision degradation.

scholarly journals Methodology for Selecting the Operating Conditions of a Vibration Generator Used in the Hot-Dip Galvanizing Process

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2042
Author(s):  
Wojciech Kacalak ◽  
Igor Maciejewski ◽  
Dariusz Lipiński ◽  
Błażej Bałasz
Keyword(s):  
Simulation Model ◽  
Asynchronous Motor ◽  
Experimental Tests ◽  
Suspension System ◽  
Operating Conditions ◽  
Test Results ◽  
Forced Simulation

A simulation model and the results of experimental tests of a vibration generator in applications for the hot-dip galvanizing process are presented. The parameters of the work of the asynchronous motor forcing the system vibrations were determined, as well as the degree of unbalance enabling the vibrations of galvanized elements weighing up to 500 kg to be forced. Simulation and experimental tests of the designed and then constructed vibration generator were carried out at different intensities of the unbalanced rotating mass of the motor. Based on the obtained test results, the generator operating conditions were determined at which the highest values of the amplitude of vibrations transmitted through the suspension system to the galvanized elements were obtained.

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