Modeling of piezoelectrically actuated fuel injectors

Mehlfeldt, Dirk; Weckenmann, Hartmut; Stöhr, Günter

doi:10.1016/j.mechatronics.2008.03.001

Cited by 16 publications

(13 citation statements)

References 13 publications

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“…On account of the dumping effect of liquid fuels, which completely suppress any needle bounces, none of the abovementioned works [2] to [5], however, report any injector flow chart nonlinearities. The problem is a feature of gas injection systems.…”

Section: Literature Overviewmentioning

confidence: 99%

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Experimental Model-Based Linearization of a S.I. Engine Gas Injector Flow Chart

Pipitone

Beccari

Cammalleri

et al. 2014

SV-JME

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Experimental tests previously executed by the authors on the simultaneous combustion of gasoline and gaseous fuel in a spark ignition \ud engine revealed the presence of strong nonlinearities in the lower part of the gas injector flow chart. These nonlinearities arise via the injector \ud outflow area variation caused by the needle impacts and bounces during the transient phenomena that take place in the opening and closing \ud phases of the injector and may seriously compromise the air-fuel mixture quality control for the lower injection times, thus increasing both fuel \ud consumption and pollutant emissions.\ud Despite the extensive literature about the operation and modelling of fuel injectors, there are no known studies focused on the \ud nonlinearities of the gas injector flow chart and on the way they can be reduced or eliminated. The authors thus developed a mathematical \ud model for the prediction of mass injected by a spark ignition (S.I.) engine gas injector, validated through experimental data. The gas injector \ud has been studied with particular reference to the complex needle motion during the opening and closing phases, which may strongly affect \ud the amount of fuel injected.\ud In this work, the mathematical model previously developed has been employed to study and determine an appropriate injection strategy \ud in order to linearize the injector flow chart to the greatest degree possible. The injection strategy proposed by the authors is based on minimum \ud injection energy considerations and may be easily implemented in current engine control units (ECU) without any hardware modification or \ud additional costs. Once calibrated by means of simulation, this strategy has been validated by experimental data acquired on an appropriately \ud equipped injector test bench. As a result, the real injector flow chart has been substantially improved, reducing its deviation from linearity to \ud one third of the original flow chart, which is an excellent result, especially if the typical measurement dispersion of the injected mass is taken \ud into account. The injection strategy proposed by the authors could extend the linear behaviour of gas injectors and improve the fuel supply by \ud means of a simple software update of the ECU, thus obtaining higher engine efficiency and lower pollutant emissions

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Section: Literature Overviewmentioning

confidence: 99%

“…With regard to gasoline direct injection, the model developed in [5] refers to a piezoelectric injector and compares the capability of lumped parameters and distributed parameters to describe the needle motion and the behaviour of piezoelectric elements.…”

Section: Literature Overviewmentioning

confidence: 99%

Experimental Model-Based Linearization of a S.I. Engine Gas Injector Flow Chart

Pipitone

Beccari

Cammalleri

et al. 2014

SV-JME

View full text Add to dashboard Cite

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“…The hysteresis between charge and voltage is motivated by experiments. In other publications, for example, [10], the hysteresis is modelled between the voltage and the electric polarization with the electric polarization as an additional state in the model. Because only one hysteresis operator is used, the parametrization effort is much lower compared with other approaches.…”

Section: Existing Psa Modelsmentioning

confidence: 99%

“…This model is used by Raupach [9] to reconstruct an external force on the PSA to detect opening points in a fuel injection control valve. Mehlfeldt et al [10] presented a model of a fuel injection system and described different PSA models. They neither consider the change of the PSA behaviour with temperature, nor do they identify the idle stroke value.…”

Section: Introductionmentioning

confidence: 99%

Modelling and identification of a piezoelectrically driven fuel injection control valve

Müller

Kugi

Bachmaier

et al. 2010

Mathematical and Computer Modelling of Dynamical Systems

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In this article, the modelling and identification of a piezoelectrically driven control valve of a common-rail diesel fuel injector in an experimental setup is presented. The piezoelectric actuator of the control valve exhibits a strong temperature dependence. Furthermore, an unknown mechanical parameter in the control valve mechanics, the idle stroke value, has to be determined. An optimization-based method is used for temperature adaptation as well as for the identification of the unknown idle stroke value. Both the suppression of the temperature dependence and the exact knowledge of the idle stroke value are essential for the opening width and opening point of time of the control valve and thus for the accuracy of the fuel injection. The identification task becomes even more challenging because only the electrical signals of the actuator, namely voltage and current, are measurable. The method is successfully validated in an experimental setup.

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“…Piezoelectric actuators are utilized in a wide range of industrial, scientific and commercial applications including scanning probe microscope positioning systems [1,2], fuel injection valves [3], and laser beam manipulation [4]. Although piezoelectric actuators have a number of desirable characteristics, a major disadvantage is the hysteresis exhibited at high electric fields [5,6].…”

Section: Introductionmentioning

confidence: 99%

Precision charge drive with low frequency voltage feedback for linearization of piezoelectric hysteresis

Fleming

2013

2013 American Control Conference

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Abstract² A new charge drive circuit is proposed that utilizes a low frequency voltage feedback loop to linearize piezoelectric hysteresis down 0.1 Hz. This approach eliminates many of the present difficulties and allows extremely low transition frequencies without a long transient response. Experimental results demonstrate that the proposed charge amplifier can effectively reduce piezoelectric hysteresis and creep to less than 1.3% at scan-rates of 10 Hz, 1 Hz, and 0.1 Hz.

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Modeling of piezoelectrically actuated fuel injectors

Cited by 16 publications

References 13 publications

Experimental Model-Based Linearization of a S.I. Engine Gas Injector Flow Chart

Experimental Model-Based Linearization of a S.I. Engine Gas Injector Flow Chart

Modelling and identification of a piezoelectrically driven fuel injection control valve

Precision charge drive with low frequency voltage feedback for linearization of piezoelectric hysteresis

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