Real-time IMEP Estimation for Torque-based Engine Control using an In-cylinder Pressure Sensor

2009 ◽  
Author(s):  
Seungsuk Oh ◽  
Daekyung Kim ◽  
Junsoo Kim ◽  
Byounggul Oh ◽  
Kangyoon Lee ◽  
...  
Keyword(s):  
Real Time ◽  
Pressure Sensor ◽  
Engine Control ◽  
Cylinder Pressure

scholarly journals A Virtual In-Cylinder Pressure Sensor Based on EKF and Frequency-Amplitude-Modulation Fourier-Series Method

Sensors ◽  
2019 ◽  
Vol 19 (14) ◽  
pp. 3122
Author(s):  
Qiming Wang ◽  
Tao Sun ◽  
Zhichao Lyu ◽  
Dawei Gao
Keyword(s):  
Fourier Series ◽  
Real Time ◽  
Pressure Sensor ◽  
High Accuracy ◽  
Efficiency Coefficient ◽  
Cylinder Pressure ◽  
Cumulative Error ◽  
Optimal Output ◽  
Iteration Model ◽  
Error Percentage

As a crucial and critical factor in monitoring the internal state of an engine, cylinder pressure is mainly used to monitor the burning efficiency, to detect engine faults, and to compute engine dynamics. Although the intrusive type cylinder pressure sensor has been greatly improved, it has been criticized by researchers for high cost, low reliability and short life due to severe working environments. Therefore, aimed at low-cost, real-time, non-invasive, and high-accuracy, this paper presents the cylinder pressure identification method also called a virtual cylinder pressure sensor, involving Frequency-Amplitude Modulated Fourier Series (FAMFS) and Extended-Kalman-Filter-optimized (EKF) engine model. This paper establishes an iterative speed model based on burning theory and Law of energy Conservation. Efficiency coefficient is used to represent operating state of engine from fuel to motion. The iterative speed model associated with the throttle opening value and the crankshaft load. The EKF is used to estimate the optimal output of this iteration model. The optimal output of the speed iteration model is utilized to separately compute the frequency and amplitude of the cylinder pressure cycle-to-cycle. A standard engine’s working cycle, identified by the 24th order Fourier series, is determined. Using frequency and amplitude obtained from the iteration model to modulate the Fourier series yields a complete pressure model. A commercial engine (EA211) provided by the China FAW Group corporate R&D center is used to verify the method. Test results show that this novel method possesses high accuracy and real-time capability, with an error percentage for speed below 9.6% and the cumulative error percentage of cylinder pressure less than 1.8% when A/F Ratio coefficient is setup at 0.85. Error percentage for speed below 1.7% and the cumulative error percentage of cylinder pressure no more than 1.4% when A/F Ratio coefficient is setup at 0.95. Thus, the novel method’s accuracy and feasibility are verified.

Real-time NOx estimation in light duty diesel engine with in-cylinder pressure prediction

2021 ◽  
pp. 146808742110157
Author(s):  
Youngbok Lee ◽  
Seungha Lee ◽  
Kyoungdoug Min
Keyword(s):  
Prediction Model ◽  
Real Time ◽  
Pressure Sensor ◽  
Design Stage ◽  
Lean Nox Trap ◽  
Nox Emissions ◽  
Cylinder Pressure ◽  
Estimation Model ◽  
Light Duty ◽  
Light Duty Vehicle

Recently, there have been numerous efforts to cope with automotive emission regulations. Various strategies to reduce engine-out NOx emissions and proper after-treatment systems, such as selective catalytic reduction (SCR) and lean NOx trap (LNT), have been taken into account in the engine research field. In this study, real-time engine-out NOx prediction model was established where zero-dimensional NO and NO2 models were combined with in-cylinder pressure model. During the procedure for estimating NO and NO2 (NOx), a real-time prediction model of in-cylinder pressure was applied so that the inputs to the NOx prediction model could be provided only by the data acquired from the engine control unit (ECU). This implies that an in-cylinder pressure sensor is not necessarily required to properly predict the engine-out NOx in real time. The real-time NOx estimation model was validated through the worldwide harmonized light-duty vehicle test cycle (WLTC) without a pressure sensor, and the total NOx error during the mode was comparable with the total NOx error of the portable NOx sensor. This real-time NOx estimation model can ultimately contribute to minimizing tail-pipe NOx emissions by influencing both emission calibration at the engine design stage and the management of NOx after-treatment systems where NOx conversion efficiency is heavily affected by the NO2/NO ratio.

Combustion Trajectory Visualization Model for Study of Conventional and Advanced Direct Injection Combustion Modes

2015 ◽  
Author(s):  
Joshua A. Bittle ◽  
Timothy J. Jacobs
Keyword(s):  
Real Time ◽  
Equivalence Ratio ◽  
Sampling Rate ◽  
Flame Temperature ◽  
Operating Conditions ◽  
Engine Control ◽  
Cylinder Pressure ◽  
Real Time Control ◽  
Time Step ◽  
The Future

Many of the approaches to diagnostics of in-cylinder spatially resolved quantities (such as equivalence ratio, temperature, speciation, etc.) require either optical engines or computational fluid dynamics. These approaches are expensive (time or money) and will likely never be practical for on-board use in the future. The market trend towards real-time control and consumer grade in-cylinder pressure transducers suggest that relatively simple modeling techniques based on cylinder pressure and other standard engine sensors are well situated to be a part of the future engine control schemes. This work expands previous efforts to calculate combustion trajectories (path through equivalence ratio vs. temperature plane) based on cylinder pressure measurements in near real-time. This work incorporates the current state-of-the-art diesel fuel spray mixing models (Kattke and Musculus entrainment waves) and adds features to accounting for changing cylinder pressure, adaptive time step based on sampling rate of cylinder pressure, and optimizing spray axial resolution for reduced calculation time. Based on the predicted local fuel concentration, flame temperature and relating calculated heat release rates to the amount of fuel burned in each portion of the spray the combustion processes can be tracked to give a cumulative history of the ignition, subsequent mixing and heating/cooling that gives a picture of what combustion looks like on the equivalence ratio vs. temperature plane. Various engine operating conditions are explored including conventional diesel operation with and without EGR as well as highly dilute late injection low temperature combustion at different injection pressures. The results obtained in this work give encouragement that this type of approach may enable future engine control using these detailed yet computationally simple approaches.

Engine Control Using Estimated Parameters From a Real Time Model of an Engine With Variable Valve Actuation

2005 ◽  
Author(s):  
John L. Lahti ◽  
John J. Moskwa
Keyword(s):  
Real Time ◽  
Mass Fraction ◽  
Fuel Injection ◽  
Exhaust System ◽  
Time Estimation ◽  
Exhaust Gas ◽  
Engine Control ◽  
Cylinder Pressure ◽  
Time Model ◽  
Residual Mass

A real time model of an engine was developed and integrated with engine control software to provide better engine control with less calibration effort. The model uses one-dimensional compressible gas wave equations for the intake and exhaust system along with a thermodynamic model of the cylinder to provide real time estimation of the cylinder air charge, exhaust gas residual mass fraction, cylinder pressure, cylinder temperature, and various other states along the intake and exhaust system. Information from the model is used to control the fuel injection, spark advance, valve timing, and throttle position on the actual engine. The system does not use any volumetric efficiency tables. Since the real time model responds like the actual engine there is no need for transient fuel or transient spark advance correction factors. The estimated cylinder pressure is used to calculate the instantaneous indicated engine torque and engine efficiency. Using the model it is possible to optimize efficiency, control the torque output, and regulate the exhaust gas residual mass fraction. The system offers many control advantages and is easy to calibrate.

Sign in / Sign up

Export Citation Format

Share Document