Electronic Control Unit Calibration Research Articles

ECU calibration for gaseous dual fuel supply system in compression ignition engines

The dual fuel (DF) combustion mode is proven solution that allows to improve or get at the same level engine performance and reduce toxic compounds in exhaust gases which is confirmed by researchers and end-users. DF combustion mode uses two fuels gaseous fuel as a primary energy source and a pilot quantity of diesel fuel as ignition source. However, in order, to fully take advantage of the potential of the dual fuel mode, DF system must be proper calibrated. Despite the existence of commercial control systems for dual fuel engines on the market, the literature on the important parameters for the engine's operation introduced during calibration is scarce. This article briefly describes a concept of working algorithm and calibration strategy of a dual fuel electronic control unit (ECU) The purpose of calibration is to achieve the greatest possible use of an alternative gaseous fuel without causing accelerated engine wear.

Engine Valvetrain Lift Prediction Using a Physic-based Model for The Electronic Control Unit Calibration

The electronic control has an increasingly important role in the evolution of the internal combustion engine (ICE) and the vehicle. Research in the automotive sector, in this historical period, is dictated by three main guidelines: reducing polluting emissions and fuel consumption while maintaining high performance. The Electronic Control Unit (ECU) has made it possible, complicating the engine both in terms of architecture and in terms of strategies, controlling, through simplified functions, physical phenomena in an ever more precise way. The ECU functions are experimentally calibrated, reducing the error between the quantity estimated by the function and the experimental quantity over the entire operating range of the engine, developing extensive experimental campaigns. The calibration process of the ECU functions is one of the longest and most expensive processes in the development of a new vehicle. Some lines of research have been explored to reduce the experimental tests to be carried out on the test bench. The use of neural networks (NN) has proven to be effective, leading to a reduction in experimental tests from 40 to 60%. Another methodology consists in the use of 1D/0D Thermo-fluid dynamic models of the ICE. These models are used as virtual test benches and through them it is possible to carry out the experimental campaigns necessary for the calibration of the control unit functions. At the real test bench, only the few experimental tests necessary for the validation of the model must be carried out. One of the simplifications that is usually made in the 1D/0D ICE models consists in assigning a single intake and exhaust valve lift, without taking into account the effect of the engine speed on the valve lift in early intake valve closure (EIVC) mode for engines equipped with VVA. This phenomenon has a not negligible effect on engine performance, especially at high engine speeds. In the case of engine models equipped with VVA, the valve lift cannot be imposed, since it is unique for each closing angle at each engine speed. Indeed, in order to assign the correct valve lift for a given engine speed and EIVC, numerous experimental tests should be carried out, making vain the beneficial effects of the method. In this work, the authors propose the use of a 0D/1D CFD model of the entire electro-hydraulic valvetrain VVA module, coupled with 1D lumped mass for reproducing the linear displacements of the intake valve, and for simulating the interactions between flow and mechanical systems of the solenoid hydro-mechanical valve. Thus, model simulations allow to predict the valve lift in all the necessary conditions in the experimental campaigns for the calibration of the control unit functions. Starting from geometric valvetrain data, the model has been validated with a parametric analysis of some variables on which there was greater uncertainty, by comparing the valve lift obtained by the model with the experimental ones in certain engine speeds. Subsequently, the authors have obtained the valve lifts in conditions not used for model validation, comparing them with their respective experimental lifts. The model has proven to be sensitive to the effect of the variation of the engine speed, reproducing the valve lift with a low error. In this way it is possible to reduce the experimental effort aimed to the calibration process considering that the virtual experimental campaign has proven to be reliable.

Performance and emissions of a Euro5 small diesel engine fuelled with biodiesel

This article describes the effects of using neat biodiesel on a modern small displacement passenger car diesel engine, highlighting the need for a specific adjusted electronic control unit (ECU) calibration for biodiesel. Engine performance were evaluated at full load with a standard ECU calibration as well as with an ECU calibration specifically adjusted for biodiesel; Break Specific Fuel Consumption (BSFC) and exhaust emissions was then evaluated at seven part load operating conditions, representative of the New European Driving Cycle (NEDC). Tests showed that through recalibration it is possible to obtain the same performance measured under diesel operation, with benefits in terms of engine-out emissions, especially as far as smoke emissions are concerned. Moreover, particle number and size distribution at engine outlet were also evaluated at part load operating conditions, showing a significant reduction of particle number and mass with biodiesel.

Case-based adaptation for automotive engine electronic control unit calibration

The automotive engine performance is greatly affected by the calibration of its electronic control unit (ECU). The method for ECU calibration is traditionally done by trial-and-error. This traditional method consumes a large amount of time and money. To resolve this problem, case-based reasoning (CBR) is employed, so that an existing and effective ECU setup can be adapted to fit another similar class of engines. The adaptation procedure is done through a more sophisticated step called case-based adaptation (CBA) ( Craw, Jarmulak, & Rowe, 2001; Craw, Wiratunga, & Rowe, 2006; Leake, Kinley, & Wilson, 1996, 1997). CBA is an effective knowledge management tool, which can interactively learn the expert adaptation knowledge. The paper briefly reviews the methodologies of CBR and CBA. Then the application to ECU calibration is described via a case study. With CBR and CBA, the efficiency of calibrating an ECU can be enhanced. A prototype system has also been developed to verify the usefulness of CBR in ECU calibration.

Data preprocessing and modelling of electronically-controlled automotive engine power performance using kernel principal components analysis and least squares support vector machines

Modern automotive engines are controlled by the Electronic Control Unit (ECU). The engine ECU calibration is done empirically through tests on the dynamometer because no exact mathematical engine model is yet available. With Least Squares Support Vector Machines (LS-SVM), the approximate engine power performance model can be determined by training the sample data acquired from the dynamometer. Besides, Kernel Principal Components Analysis (KPCA) is proposed to transform unimportant adjustable variables into a compact subset for shortening model construction time and improving model accuracy. Experimental results show that KPCA+LS-SVM can really improve the training time and accuracy of an engine model.