Model-based control of diesel engines with multiple fuel injections

In this study, a multiple-input multiple-output feedforward controller for use with multiple-point fuel injection systems is applied to a diesel engine using an original control-oriented model. The target-tracking performance of this multiple-input multiple-output feedforward controller was then tested in terms of how well the controller adjusts the fuel delivery ratios to the pilot injection, pre-injection, main fuel injection, and the main fuel injection timing, and controls the in-cylinder peak pressure and its timing. Control experiments are conducted at different engine outputs and speeds while changing the targets of the in-cylinder peak pressure and its timing. The controller is able to track the varying targets within an acceptable error included in the original model. The calculation time, which is almost double that of a single-input single-output controller, is sufficiently fast to derive the applicable inputs.

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“…This controller displayed adequate performance with the engine running at constant loads and speeds. 5…”

Section: Introductionmentioning

confidence: 99%

Multiple-input multiple-output control of diesel combustion using a control-oriented model

Yamasaki

Ikemura

Takahashi

et al. 2019

International Journal of Engine Research

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“…14 Here, the engine operating parameters such as number of injection pulses per cycle, injection timing and duration of each injection pulse could be adjusted in real time to obtain optimum combustion phasing. 15 This would enable the engine to perform optimally even in its off-calibration points, typically those encountered during real driving transients. 16,17 Any model-based control system would require an ignition delay model, which can be physics based, in order to capture changes in any of the increased number of operating parameters of a modern diesel engine, especially during transients, and predict the corresponding ignition delay precisely with minimum engine calibration efforts.…”

Section: Introductionmentioning

confidence: 99%

Transient prediction capabilities of a novel physics-based ignition delay model in multi-pulsed direct injection diesel engines

Samuel

Ramesh

2019

International Journal of Engine Research

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This work is an extension of a novel physics-based ignition delay modeling methodology previously developed by the authors to predict physical and chemical ignition delays of multiple injections during steady operations in diesel engines. The modeling methodology is refined in this work to consider the influence of additional operating parameters such as volumetric efficiency, exhaust temperature and pressure on the ignition delay of multiple injections. Computational fluid dynamics predictions on two different engines indicated that the main spray encounters local temperatures about 60 K above average temperatures for about 1 mg of pilot. Hence, the modeling methodology was further refined to include this effect by considering the air mass trapped in pilot spray, computed based on the spray penetration and cone angle and tuned using results of the computational fluid dynamics studies. Comparisons of the ignition delay predictions with the stock boost temperature sensor and a specially incorporated, transient-capable fine wire thermocouple indicated that the measurements with stock sensor could be satisfactorily used for transients. Cycle-by-cycle changes in ignition delay could be predicted accurately when transients were imposed in boost pressure, rail pressure and main injection quantity in a turbocharged intercooled diesel engine controlled with an open engine control unit. Further validations were done even under a transient cycle when the engine was controlled by its stock engine control unit. The same tuning constants could be used for the prediction of the ignition delay under transients on another naturally aspirated engine. This indicates the suitability of the model for application in different engines. Finally, the model was incorporated within an open engine controller, and cycle-by-cycle prediction of ignition delays of the pilot and main injections were done in real time. It was possible to compute the ignition delays in less than 2 ms within engine control unit using the already available sensor inputs within an error band of ±60 µs.

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“…According to European Union (EU) legislation, 14 the fleet average by all new cars will be limited to 95 g of C O 2 per kilometer in 2020, which means a fuel consumption of around 3.6 L/100 km for a diesel car and represents a reduction of 27% in comparison with the 2015 target. To comply with these requirements, combustion concepts such as homogeneous charge compression ignition (HCCI) 15 and premixed charge compression ignition (PCCI) 16 and approaches such as cylinder deactivation 17 and variable compression ratio engines 18 along with new control strategies 19 are being studied.…”

Section: Introductionmentioning

confidence: 99%

Application of a zero-dimensional model to assess the effect of swirl on indicated efficiency

Broatch

Martín

García

et al. 2018

International Journal of Engine Research

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Increasing internal combustion engine efficiency continues being one of the main goals of engine research. To achieve this objective, different engine strategies are being developed continuously. However, the assessment of these techniques is not straightforward due to their influence on various intermediate phenomena inherent to the combustion process, which finally result in indicated efficiency trade-offs. During this work, a new methodology to assess these intermediate imperfections on gross indicated efficiency using a zero-dimensional model is developed. This methodology is applied to a swirl parametric study, where it has been concluded that the heat transfer and the rate of heat release are the single relevant changing phenomena. Results show that heat transfer always increases with swirl affecting negatively gross indicated efficiency (around −0.5%), while the impact of combustion velocity is not monotonous. It is enhanced up to a certain swirl ratio (it changes with engine speed) at low engine speed (resulting in an increment of +1.7% in gross indicated efficiency), but it is slowed down at high engine speed with the consequent worsening of gross indicated efficiency (−0.8%).

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Model-based control of diesel engines with multiple fuel injections

Cited by 15 publications

References 21 publications

Multiple-input multiple-output control of diesel combustion using a control-oriented model

Multiple-input multiple-output control of diesel combustion using a control-oriented model

Transient prediction capabilities of a novel physics-based ignition delay model in multi-pulsed direct injection diesel engines

Application of a zero-dimensional model to assess the effect of swirl on indicated efficiency

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