Transient Spark Advance Calibration Approach

Abstract Combustion control is assuming a crucial role in reducing engine tailpipe emissions while maximizing performance. The effort in the calibration of control parameters affecting the combustion development can be very demanding. One of the most effective factors influencing performance and efficiency is the combustion phasing: in Spark Ignition (SI) engines it is affected by factors such as Spark Advance (SA), Air-Fuel Ratio (AFR), Exhaust Gas Recirculation (EGR), Variable Valve Timing (VVT). SA optimal values are usually determined by means of calibration procedures carried out in steady state conditions on the test bench by changing SA values while monitoring performance indicators, such as Brake and Indicated Mean Effective Pressure (BMEP, IMEP), Brake Specific Fuel Consumption (BSFC) and pollutant emissions. The effect of SA on combustion is stochastic, due to the cycle-to-cycle variation: the analysis of mean values requires many engine cycles to be significant of the performance obtained with the given control setting. Moreover, often the effect of SA on engine performance must be investigated for different settings of other control parameters (EGR, VVT, AFR). The calibration process is time consuming involving exhaustive tests followed by off-line data analysis. This paper presents the application of a dynamic calibration methodology, with the objective of reducing the calibration duration. The proposed approach is based on transient tests, coupled with a statistical investigation, allowing reliable performance analysis even with a low number of engine cycles. The methodology has been developed and tested off-line, then it has been implemented in Real-Time. The combustion analysis system has been integrated with the ECU management software and the test bench controller, in order to perform a fully automatic calibration.

[1]  Anthony J. Lawrance,et al.  Engine-mapping experiments: a two-stage regression approach , 1998 .

[2]  Lars Eriksson.  Spark advance for optimal efficiency , 1999 .

[3]  Shugang Jiang,et al.  Implementation of Model-Based Calibration for a Gasoline Engine , 2012 .

[4]  Mark Paul Gravesend Guerrier,et al.  The Development of Model Based Methodologies for Gasoline IC Engine Calibration , 2004 .

[5]  A. Thomas Shenton,et al.  Peak Pressure Position Control of Four Cylinders through the Ion Current Method , 2009 .

[6]  Gary J. Patterson.  A Technique for Processing Cylinder Pressure and Test Bed Data Sets for Engine Speed-Sweep Tests to Allow Reduced Testing Time with Enhanced Interpretation of Results , 2008 .

[7]  R. Lyman Ott.,et al.  An introduction to statistical methods and data analysis , 1977 .

[8]  Jeffrey Naber,et al.  Analysis of Combustion Knock Metrics in Spark-Ignition Engines , 2006 .

[9]  Enrico Corti,et al.  A Statistical Approach to Spark Advance Mapping , 2010 .

[10]  John B. Heywood,et al.  Internal combustion engine fundamentals , 1988 .

[11]  Vittorio Ravaglioli,et al.  Torsional Analysis of Different Powertrain Configurations for Torque and Combustion Phase Evaluation , 2011 .

[12]  Johann F. Böhme,et al.  IMEP-Estimation and In-Cylinder Pressure Reconstruction for Multicylinder SI-Engine by Combined Processing of Engine Speed and One Cylinder Pressure , 2005 .

[13]  M. D. Cesare,et al.  Development and Validation of a Methodology for Real-Time Evaluation of Cylinder by Cylinder Torque Production Non-Uniformities , 2011 .

[14]  Yannis Hardalupas,et al.  Flame chemiluminescence studies of cyclic combustion variations and air-to-fuel ratio of the reacting mixture in a lean-burn stratified-charge spark-ignition engine , 2004 .

[15]  Ulrich Spicher,et al.  Application of Different Cylinder Pressure Based Knock Detection Methods in Spark Ignition Engines , 2002 .

[16]  Gabriele Serra,et al.  MFB50 On-Board Evaluation Based on a Zero-Dimensional ROHR Model , 2011 .

[17]  Gabriele Serra,et al.  Instantaneous Engine Speed Measurement and Processing for MFB50 Evaluation , 2009 .

[18]  N. Cavina,et al.  Individual Cylinder Combustion Control Based on Real-Time Processing of Ion Current Signals , 2007 .

[19]  Jonathan Chauvin,et al.  Combustion Parameters Estimation Based on Knock Sensor for Control Purpose Using Dedicated Signal Processing Platform , 2008 .

[20]  Tao Xu,et al.  The engine knock analysis – An overview , 2012 .