Sensitivity Study of a NOx Estimation Model for On-Board Applications

Proceedings of the Institution of Mechanical Engineers, Part D:

Climent

Plá

et al. 2014

Self Cite

The implantation of NO x sensors in diesel engines is necessary in order to track emissions at the engine exhaust for diagnosing and control of the after-treatment devices. However, the use of models is still necessary since the sensor outputs are delayed and filtered. The present paper deals with the problem of the NO x estimation in two parts, the first part deals with a controloriented model for the NO x estimation, while the second part presents data fusion of the model and sensor to improve the estimation, which is presented in the next. The use of models for the NO x estimation is an alternative but the drift and ageing are still an issue. In order to overcome this problem, the fusion of different signals can be made in a smart way by means of a Kalman filter. There exist different ways of presenting this fusion, from directly tracking the bias to updating the model parameters. According to that, different algorithms are proposed in this paper with the aim of correcting the model output. Furthermore, the estimation of the actual NO x , by preventing sensor delay and filtering, is also integrated in the algorithm, being a suitable strategy for combining NO x sensors and models in an on-board basis.

Section: Online Updating Of the No X Modelmentioning

confidence: 99%

Section: Online Observation Of the Actual No Xmentioning

confidence: 99%

ECU-oriented models for NO_x prediction. Part 2: adaptive estimation by using an NO_x sensor

Proceedings of the Institution of Mechanical Engineers, Part D:

Climent

Plá

et al. 2014

Self Cite

“…This selection is justified by the availability of mass flow and pressure sensors with high accuracy and reliability at affordable costs. However, some studies suggest the use of lambda sensors as an alternative to improve fuel consumption while controlling emissions [26,27,28].…”

Section: Sensor Selectionmentioning

confidence: 99%

Considerations on the low-pressure exhaust gas recirculation system control in turbocharged diesel engines

Luján

International Journal of Engine Research

Plá

et al. 2013

Although high pressure exhaust gas recirculation has been commonly used in turbocharged diesel engines for controlling the NOx formation, recent advances in after-treatment and material technology make possible using a low pressure architecture, which recirculates the exhaust gas upstream the compressor. This brief paper presents a basic study of control aspect related to the low pressure architecture, emphasising the similarities and differences with the high pressure system. Data coming from experimental tests with both configurations, and from a one-dimensional wave action model simulations, are combined for the analysis of the input-output paring, linearity and the transient performance of both systems.

“…In case of steady-state data, the following 10 measurement channels could be elicited as the most important ones: injected fuel mass (m f ), recirculated gas temperature (T egr ), start of injection (SOI), gas composition at the intake manifold (which is estimated through the product of the EGR ratio and the fuel-to-air ratio, EGR · F r ), intake gas temperature (T int ), atmospheric pressure (p atm ), engine coolant temperature T w , atmospheric temperature T atm and two factors which normalise the variation of the engine charge (admitted air mass plus EGR mass) and of the coolant temperature. This automatic selection of channels concentrates on the physical quantities being responsible of the NOx formation: injected fuel and injection settings, and also of the engine charge composition, quantity and temperature, being all of them of great importance in the NOx formation mechanisms [5].…”

Section: Selected Featuresmentioning

confidence: 99%

“…There are several ways for estimating the amount of a given pollutant that reaches the after-treatment device [5]:…”

Section: Introductionmentioning

confidence: 99%

Identifying static and dynamic prediction models for NOx emissions with evolving fuzzy systems

Lughofer

Macián

et al. 2011

Applied Soft Computing

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ElsevierLughofer, E.; Macian Martinez, V.; Guardiola García, C.; Klement, EP. (2011) AbstractAntipollution legislation in automotive internal combustion engines requires active control of pollutant formation and emissions. In addition to new technologies, like selective catalyst systems or diesel particulate filters, predictive emission models are needed. These models are of great use in the system calibration phase, and also can be integrated for the engine control and on-board diagnosis tasks. In this paper, fuzzy modelling of the NOx emissions of a diesel engine is investigated, which overcomes some drawbacks of pure engine mapping or analytical physical-oriented models. For building up the fuzzy NOx prediction models, the FLEXFIS approach (short for FLEXible Fuzzy Inference Systems) is applied, which automatically extracts an appropriate number of rules and fuzzy sets by an evolving version of vector quantization (eVQ) and estimates the consequent parameters of Takagi-Sugeno fuzzy systems with the local learning approach in order to optimize the least squares functional. The predictive power of the fuzzy NOx prediction models is compared with that one achieved by physical-oriented models based on high-dimensional engine data recorded during steady-state and dynamic engine states.