Cylinder-Pressure-Based Combustion Analysis in Race Engines

1994 ◽  
Author(s):  
Andrew L. Randolph
Keyword(s):  
Cylinder Pressure ◽  
Combustion Analysis

Cylinder Pressure Information-Based Postinjection Timing Control for Aftertreatment System Regeneration in a Diesel Engine—Part I: Derivation of Control Parameter

2016 ◽  
Vol 138 (8) ◽  
Author(s):  
Hyunjun Lee ◽  
Manbae Han ◽  
Myoungho Sunwoo
Keyword(s):  
Phase Shift ◽  
Heat Release ◽  
Exhaust Emissions ◽  
Cylinder Pressure ◽  
Combustion Analysis ◽  
Operating Condition ◽  
Combustion Phase ◽  
Rate Of Heat Release ◽  
Engine Operating Condition ◽  
Aftertreatment Systems

The implementation of aftertreatment systems in passenger car diesel engines, such as a lean NOx trap (LNT) and a diesel particulate filter (DPF), requires an in-cylinder postinjection (POI) for a periodic regeneration of those aftertreatment systems to consistently reduce tail-pipe emissions. Although the combustion and emission characteristics are changed from the normal engine operating conditions due to the POI, POI is generally applied with a look-up table (LUT) based feedforward control because of its cost effectiveness and easy implementation into the engine management system (EMS). However, the LUT-based POI control necessities tremendous calibration work to find the optimal timing to supply high exhaust gas temperature or enough reductants such as carbon monoxide (CO) and hydrocarbon to regenerate the aftertreatment systems while maintaining low engine-out smoke emissions. To solve this problem, we propose a novel combustion analysis method based on the cylinder pressure information. This method investigates the relation between the POI timing with the exhaust emissions and compensates the combustion phase shift occurred by the engine operating condition changes, such as the engine speed and injection quantity. A burning rate of fuel after a location of the rate of heat release maximum (BRaLoROHRmax) was derived from the combustion analysis. A mass fraction burned X% after a location of the rate of heat release maximum (MFBXaLoROHRmax) was determined using the BRaLoROHRmax and main injection (MI) quantity. Nonlinear characteristics of the exhaust emissions according to POI timing variations and the combustion phase shift due to the engine operating condition changes can be easily analyzed and compensated in terms of the proposed MFBXaLoROHRmax domain. The proposed method successfully evaluated its utility through the engine experiments for the LNT and DPF regeneration.

Spark Advance Real-Time Optimization Based on Combustion Analysis

2010 ◽  
Author(s):  
Enrico Corti ◽  
Claudio Forte
Keyword(s):  
Real Time ◽  
Pressure Sensors ◽  
Heat Losses ◽  
Test Time ◽  
Cylinder Pressure ◽  
Combustion Analysis ◽  
Mean Values ◽  
Control Setting ◽  
Cycle Variation ◽  
Novel Approach

Future emission regulations could force manufacturers to install in-cylinder pressure sensors on production engines. The availability of such a signal opens a new scenario in terms of combustion control: many settings that previously were optimized off-line, can now be monitored and calibrated in realtime. One of the most effective factors influencing performance and efficiency is the combustion phasing: in gasoline engines Electronic Control Units (ECU) manage the Spark Advance (SA) in order to set the optimal combustion phase. SA optimal values are usually determined by means of calibration procedures carried out on the test bench by changing the ignition angle while monitoring Brake and Indicated Mean Effective Pressure (BMEP, IMEP) and Brake Specific Fuel Consumption (BSFC). The optimization process relates BMEP, IMEP and BSFC mean values with the control setting (SA). However, the effect of SA on combustion is not deterministic, 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. This paper presents a novel approach to SA optimization, with the objective of improving the performance analysis robustness, while reducing the test time. The approach can be either used in the calibration phase or in on-board applications, if the in-cylinder pressure signal is available: this would allow maintaining the optimization active throughout the entire engine life. The methodology is based on the observation that, for a given running condition, IMEP can be considered a function of a single combustion parameter, represented by the 50% Mass Fraction Burned (50%MFB). Due to cycle-to-cycle variation, many different MFB50 and IMEP values are obtained during a steady state test carried out with constant SA, but these values are related by means of a unique relationship. The distribution on the plane IMEP-MFB50 forms a parabola, therefore the optimization could be carried out by choosing SA values maintaining the scatter around the vertex. Unfortunately the distribution shape is slightly influenced by heat losses (i.e., by SA): this effect must be taken into account in order to avoid over-advanced calibrations. SA is then controlled by means of a PID (Proportional Integer Derivative) controller, fed by an error that is defined based on the previous considerations: a contribution is related to the MFB50-IMEP distribution, and a second contribution is related to the net Cumulative Heat Release (CHRNET)-IMEP distribution. The latter is able to take into account for heat losses. Firstly, the methodology has been tested on in-cylinder pressure data, collected from different SI engines; then, it has been implemented in real-time, by means of a programmable combustion analyzer: the system performs a cycle-to-cycle combustion analysis, evaluating the combustion parameters necessary to calculate the target SA, which is then actuated by the ECU. The approach proved to be efficient, reducing the number of engine cycles necessary for the calibration to less than 1000 per operating condition.

An Analysis of Next Cycle Control Based on Cylinder Pressure Derived Calculations

2009 ◽  
Author(s):  
Kristopher P. Quillen ◽  
Matthew Viele
Keyword(s):  
Peak Pressure ◽  
Combustion Engine ◽  
Single Point ◽  
Cylinder Pressure ◽  
Pressure Data ◽  
Combustion Analysis ◽  
Control Value ◽  
Crank Angle ◽  
Commercial Off The Shelf ◽  
Safety Systems

This paper examines the detailed timing requirements necessary to implement next cycle control of an internal combustion engine based on values derived from cylinder pressure. A controller consisting of two parts is presented. The first part is found in traditional combustion analysis systems. It records crank-angle resolved cylinder pressure data and reduces it to single point values such as location of peak pressure or location of 50% mass fraction burned. The second part is an engine controller capable of controlling one or more of these analysis parameters. The focus of this paper is on the execution time and latency of the data-path from the sensor to the control value with various engine configurations and calculation methods explored. Some discussion of the data acquisition to controller interface will be included with a focus on practical engine controller latencies and safety systems. An implementation of this system using commercial off the shelf (COTS) hardware and an open software platform are presented.

Cycle-by-Cycle Exhaust Temperature Monitoring for Detection of Misfiring and Combustion Instability in Reciprocating Engines

2007 ◽  
Author(s):  
David P. Gardiner ◽  
William D. Allan ◽  
Marc LaViolette ◽  
Michael F. Bardon
Keyword(s):  
Electromagnetic Interference ◽  
Combustion Instability ◽  
Pressure Sensors ◽  
Combustion Stability ◽  
Cylinder Pressure ◽  
Combustion Analysis ◽  
Exhaust Temperature ◽  
Reciprocating Engines ◽  
Temperature Signal ◽  
Combustion Monitoring

This paper describes a means of achieving cycle-by-cycle combustion monitoring of reciprocating engines without the use of cylinder pressure sensors. This approach is intended primarily for engines that are not equipped with indicator passages (that would facilitate the installation of cylinder pressure sensors) but are (or can be) equipped with fittings for individual cylinder exhaust thermocouples. The monitoring system uses rugged exhaust temperature probes and advanced signal processing and analysis to detect cycle-by-cycle variations in exhaust temperatures and correlates these with conventional combustion analysis parameters. The system is particularly useful for detecting the deteriorations in combustion stability that precede misfiring as well as individual misfire events if they occur. Engine test results are presented showing the correlation between the exhaust temperature signal and parameters based upon cylinder pressure measurements. The ability to detect low level combustion instability and isolated, individual misfires has been demonstrated on a 95 liter V12 industrial natural gas engine. It as also been shown that successful acquisition of high fidelity exhaust temperature signals for the combustion analysis can be achieved in the presence of the high levels of electromagnetic interference typical of a power generation facility.

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