Modeling positive intake value overlap air charge response in camless engines

Gibson, Alex O.; Kolmanovsky, Ilya

doi:10.1109/acc.2003.1239112

Cited by 7 publications

(4 citation statements)

References 5 publications

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“…Since the cylinder flow is not measured and can only be inferred in a vehicle, a multi-cylinder engine model, such as the one developed in Reference [22], can be used for a more in-depth comparison of the algorithms developed here with the conventional 'speed-density' approach. Such a comparison is left to future publications.…”

Section: Discussionmentioning

confidence: 99%

Composite adaptive and input observer‐based approaches to the cylinder flow estimation in spark ignition automotive engines

Stotsky

Kolmanovsky

Eriksson

2004

Adaptive Control & Signal

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The performance of air charge estimation algorithms in spark ignition automotive engines can be enhanced using advanced estimation techniques available in the controls literature. This paper illustrates two approaches of this kind that can improve the cylinder flow estimation for gasoline engines without external exhaust gas recirculation (EGR). The first approach is based on an input observer, while the second approach relies on an adaptive estimator. Assuming that the cylinder flow is nominally estimated via a speed-density calculation, and that the uncertainty is additive to the volumetric efficiency, the straightforward application of an input observer provides an easy to implement algorithm that corrects the nominal air flow estimate. The experimental results that we report in the paper point to a sufficiently good transient behaviour of the estimator. The signal quality may deteriorate, however, for extremely fast transients. This motivates the development of an adaptive estimator that relies mostly on the feedforward speed-density calculation during transients, while during engine operation close to steady-state conditions, it relies mostly on the adaptation. In our derivation of the adaptive estimator, the uncertainty is modelled as an unknown parameter multiplying the intake manifold temperature. We use the tracking error between the measured and modelled intake manifold pressure together with an appropriately defined prediction error estimate to develop an adaptation algorithm with improved identifiability and convergence rate. A robustness enhancement, via a s-modification with the s-factor depending on the prediction error estimate, ensures that in transients the parameter estimate converges to a pre-determined a priori value. In close to steady-state conditions, the s-modification is rendered inactive and the evolution of the parameter estimate is determined by both tracking error and prediction error estimate. Further enhancements are made by incorporating a functional dependence of the a priori value on the engine operating conditions such as the intake manifold pressure. The coefficients of this function can be learned during engine operation from the values to which the parameter estimate converges in close to steady-state conditions. This feedforward learning functionality improves transient estimation accuracy and reduces the convergence time of the parameter estimate.

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Section: Discussionmentioning

confidence: 99%

Composite adaptive and input observer‐based approaches to the cylinder flow estimation in spark ignition automotive engines

Stotsky

Kolmanovsky

Eriksson

2004

Adaptive Control & Signal

Self Cite

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“…Finally, they quantified the required forces to open these valves when varying their opening time [55], [56]. Gibson and Kolmanowski [57] controlled the valves independently to improve the efficiency of the camless engine by increasing torque and minimizing fuel consumption. They delayed the IV closure at a specified time, which increased its recovery time.…”

Section: Introductionmentioning

confidence: 99%

“…They delayed the IV closure at a specified time, which increased its recovery time. However, this achievement can change the air-fuel combustion fraction [57], [58].…”

Section: Introductionmentioning

confidence: 99%

Numerical model of variable valve timing distribution for a supercharged diesel engine

Benallal,

Hayyani,

Mhadhbi

et al. 2024

IJAPE

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Recently, there's been a strong drive to improve performance of diesel engines while reducing their greenhouse gases emissions. Techniques like exhaust gas recirculation, turbocharging, and variable valve timing have become widespread. The last technique fine-tunes valve operation based on engine speed, which optimize efficiency and power output while saving fuel. This study zeroes in on a specific 4-cylinder, 4-stroke diesel engine of 1.56-liter, GT-Power software is employed to examine a supercharged version and implementing diverse valve lift techniques. The findings are revealing a substantial 30% increase in power output. At 1000 rpm, power rises from 15.1 kW for the standard engine to 19.72 kW for the modified version. For higher engine speeds, the improvements become even more pronounced, reaching a 66% boost compared to the standard configuration. Furthermore, the newly configured engine showcases an impressive 13% decrease in fuel-specific consumption at elevated engine speeds, contributing to enhanced technical performance and fuel efficiency. The numerical model developed in this study holds the potential to aid in the design of novel diesel engines equipped with variable valve timing systems. To lend further support to these findings, experimental validation is recommended.

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“…Typically, the period before the piston reaches the TDC in exhaust stroke and after the piston moves beyond the TDC in intake stroke. The advantage for valve overlapping is continuous variable valve timing (VVT) which provides adaptive adjustment to improve engine torque delivery across different revolution range [11,13]. When the engine speed is high, more air is needed for higher energy combustion; therefore, duration of intake valve opening needs to be longer.…”

Section: Valve Overlappingmentioning

confidence: 99%

Comparison of Engine Simulation Software for Development of Control System

Chan

Ordys

Волков

et al. 2013

Modelling and Simulation in Engineering

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Most commonly used commercial engine simulation packages generate detailed estimation of the combustion and gas flow parameters. These parameters are required for advanced research on fluid flow and heat transfer and development of geometries of engine components. However, engine control involves different operating parameters. Various sensors are installed into the engine, the combustion performance is recorded, and data is sent to engine control unit (ECU). ECU computes the new set of parameters to make fine adjustments to actuators providing better engine performance. Such techniques include variable valve timing, variable ignition timing, variable air to fuel ratio, and variable compression ratio. In the present study, two of the commercial packages, Ricardo Wave and Lotus Engine Simulation, have been tested on the capabilities for engine control purposes. These packages are compared with an in-house developed package and with reference results available from the literature. Different numerical experiments have been carried out from which it can be concluded that all packages predict similar profiles of pressure and temperature in the engine cylinder. Moreover, those are in reasonable agreement with the reference results while in-house developed package is possible to run simulations with changing speed for engine control purpose.

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Modeling positive intake value overlap air charge response in camless engines

Cited by 7 publications

References 5 publications

Composite adaptive and input observer‐based approaches to the cylinder flow estimation in spark ignition automotive engines

Composite adaptive and input observer‐based approaches to the cylinder flow estimation in spark ignition automotive engines

Numerical model of variable valve timing distribution for a supercharged diesel engine

Comparison of Engine Simulation Software for Development of Control System

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