Air Fuel Ratio Estimation Using In-Cylinder Pressure Frequency Analysis

2003 ◽  
Vol 125 (3) ◽  
pp. 812-819 ◽  
Author(s):  
N. Cavina ◽  
F. Ponti
Keyword(s):  
Frequency Analysis ◽  
Closed Loop ◽  
Fuel Injection ◽  
Combustion Engine ◽  
Control Strategies ◽  
Feedback Signal ◽  
Exhaust Gas ◽  
Cylinder Pressure ◽  
Passenger Cars ◽  
Fuel Ratio

This paper presents an original approach to estimate the air-fuel ratio (AFR) of the mixture that burned inside a given cylinder of a spark-ignited (SI) internal combustion engine, using the information hidden in the corresponding in-cylinder pressure signal. In modern closed-loop fuel injection control strategies, the feedback signal is usually given by one (or more) heated exhaust gas oxygen (HEGO) sensor(s), mounted in the exhaust manifold(s). The information that such sensors give is related to the stoichiometry of the mixture that burned inside the cylinders. The HEGO sensor is not able to evaluate the AFR value precisely, being only able to determine whether the mixture was rich or lean. This information is sufficient to allow the implementation of a closed-loop strategy for injection time control. Generally speaking, such strategy could be improved in terms of readiness and precision by directly measuring (or by estimating) the actual AFR. Universal exhaust gas oxygen (UEGO) sensors are still considered expensive and their use is mostly limited to laboratory and racing applications, even if some automotive manufacturers have started installing such sensors on board passenger cars, as part of an effort to comply with ULEV (ultra low emission vehicles) regulations. For this reason the idea of estimating AFR values from other signals has received great attention in the past few years. A new approach based on in-cylinder pressure frequency analysis is presented here.

scholarly journals Energy Harvesting Technology for turbocompounding automotive engines with waste-gate valve

2019 ◽  
Vol 113 ◽  
pp. 03020
Author(s):  
Vittorio Usai ◽  
Silvia Marelli ◽  
Avinash Renuke ◽  
Alberto Traverso
Keyword(s):  
Fuel Consumption ◽  
Environmental Protection Agency ◽  
Gate Valve ◽  
Combustion Engine ◽  
Power Level ◽  
Electrical Power ◽  
Residual Energy ◽  
Exhaust Gas ◽  
Passenger Cars ◽  
Automotive Engines

The reduction of CO2 and, more generally, GHG (Green House Gases) emissions imposed by the European Commission (EC) and the Environmental Protection Agency (EPA) for passenger cars has driven the automotive industry to develop technological solutions to limit exhaust emissions and fuel consumption, without compromising vehicle performance and drivability. In a mid-term scenario, hybrid powertrain and Internal Combustion Engine (ICE) downsizing represent the present trend in vehicle technology to reduce fuel consumption and CO2 emissions. Concerning downsizing concept, to maintain a reasonable power level in small engines, the application of turbocharging is mandatory for both Spark Ignition (SI) and Diesel engines. Following this aspect, the possibility to recover the residual energy of the exhaust gases is becoming more and more attractive, as demonstrated by several studies around the world. One method to recover exhaust gas energy from ICEs is the adoption of turbo-compounding technology to recover sensible energy left in the exhaust gas by-passed through the waste-gate valve. In the paper, an innovative option of advanced boosting system is investigated through a bladeless micro expander, promising attractive cost-competitiveness. The numerical activity was developed on the basis of experimental data measured on a waste-gated turbocharger for downsized SI automotive engines. To this aim, mass flow rate through the by-pass valve and the turbine impeller was measured for different waste-gate settings in steady-state conditions at the turbocharger test bench of the University of Genoa. The paper shows that significant electrical power can be harvested from the waste-gate gases, up to 94 % of compressor power, contributing to fuel consumption reduction.

Influence of exhaust gas temperature and air-fuel ratio on NOx aftertreatment performance of five large passenger cars

2021 ◽  
Vol 244 ◽  
pp. 117878
Author(s):  
Zamir Mera ◽  
Natalia Fonseca ◽  
Jesús Casanova ◽  
José-María López
Keyword(s):  
Exhaust Gas ◽  
Gas Temperature ◽  
Passenger Cars ◽  
Fuel Ratio ◽  
Exhaust Gas Temperature

scholarly journals Closed-loop control of a dual-fuel engine working with different combustion modes using in-cylinder pressure feedback

2019 ◽  
Vol 21 (3) ◽  
pp. 484-496 ◽  
Author(s):  
Carlos Guardiola ◽  
Benjamín Pla ◽  
Pau Bares ◽  
Alvin Barbier
Keyword(s):  
Closed Loop ◽  
Combustion Engine ◽  
Fuel Combustion ◽  
Operating Conditions ◽  
Dual Fuel ◽  
Maximum Pressure ◽  
Cylinder Pressure ◽  
Pressure Derivative ◽  
Combustion Modes ◽  
Dual Fuel Combustion

This work presents a closed-loop combustion control concept using in-cylinder pressure as a feedback in a dual-fuel combustion engine. At low load, reactivity controlled compression ignition combustion was used while a diffusive dual-fuel combustion was performed at higher loads. The aim of the presented controller is to maintain the indicated mean effective pressure and the combustion phasing at a target value, and to keep the maximum pressure derivative under a limit to avoid engine damage in all the combustion modes by cyclically adapting the injection settings. Various tests were performed at steady-state conditions showing good abilities to fulfil the expected operating conditions but also to reject disturbances such as intake pressure or exhaust gas recirculation variations. Finally, the proposed control strategy was tested during a load transient resulting in a combustion switching-mode and the results exhibited the closed-loop potential for controlling such combustion concept.

On-Board Indicated Pressure and Torque Estimation in Engines With a High Number of Cylinders

2002 ◽  
Author(s):  
Enrico Corti ◽  
Davide Moro
Keyword(s):  
Control Strategy ◽  
Engine Speed ◽  
Fuel Injection ◽  
Control Strategies ◽  
Engine Control ◽  
Cylinder Pressure ◽  
Signal Processing Algorithm ◽  
Operating Condition ◽  
Torque Estimation ◽  
Speed Fluctuations

In recent years engine control development focused the attention on torque-based models, that allow improving driveability and implementing traction control strategies. The design of such a torque-based engine control strategy requires the knowledge of the torque produce by the engine, which depends on fuel injection time, spark advance, throttle opening, EGR command, … In the actual engine control strategies this is mainly done by means of static maps stored in the ECU memory. The real engine torque production under every operating condition can be evaluated by means of the in-cylinder pressure estimation, thus allowing a torque based closed loop control strategy. Many approaches are present in the literature showing the possibility of on-board estimating the actual torque produced by the engine not simply by using static maps, but estimating it through other measured signals. Most of the methodologies that do not require a specific sensor placed on the engine are based either on the engine speed fluctuations (measured by a pick-up facing the flywheel teeth) or on the engine block vibrations (measured by the knock sensor), performing better for engines with a low number of cylinders. The paper presents an original methodology based on the instantaneous engine speed fluctuations, that has been usefully applied to engines with higher number of cylinders. The methodology is based on the observation of the speed fluctuations in a crankshaft window inside the expansion stroke and on the hypothesis that there exists a strong correlation between these engine speed fluctuations and pressure inside the selected cylinder. This relationship has been characterized using Frequency Response Functions (FRF) for each steady-state engine operating condition. In the following the FRFs have been used to perform in-cylinder pressure and then indicated torque estimation under every operating condition, and a specific signal processing algorithm has been developed in order to apply the procedure during speed and load engine transients. The experimental tests have been conducted mounting a six-cylinder turbo-charged spark-ignited engine in a test cell. The application on-board a vehicle of the same methodology seems to be feasible due to the quickness of the algorithm employed and the presence on-board of all the sensors required for the implementation.

Cylinder Pressure Information-Based Postinjection Timing Control for Aftertreatment System Regeneration in a Diesel Engine—Part II: Active Diesel Particulate Filter Regeneration

2016 ◽  
Vol 138 (8) ◽  
Author(s):  
Hyunjun Lee ◽  
Jaesik Shin ◽  
Manbae Han ◽  
Myoungho Sunwoo
Keyword(s):  
Diesel Particulate Filter ◽  
Fuel Injection ◽  
Control Method ◽  
Particulate Filter ◽  
Exhaust Gas ◽  
Cylinder Pressure ◽  
Gas Temperature ◽  
Diesel Particulate ◽  
Dpf Regeneration ◽  
Exhaust Gas Temperature

The successful utilization of a diesel particulate filter (DPF) to reduce particulate matter (PM) in a passenger car diesel engine necessitates a periodic regeneration of the DPF catalyst without deterioration of the drivability and emission control performance. For successful active DPF regeneration, the exhaust gas temperature should be over 500 °C to oxidize the soot loaded in the DPF. Previous research increased the exhaust gas temperature by applying early and late post fuel injection with a look-up table (LUT) based feedforward control implemented into the engine management system (EMS). However, this method requires enormous calibration work to find the optimal timing and quantity of the main, early, and late post fuel injection with less certainty of accurate torque control. To address this issue, we propose a cylinder pressure based multiple fuel injection (MFI) control method for active DPF regeneration. The feedback control of the indicated mean effective pressure (IMEP), lambda, and DPF upstream temperature was applied to precisely control the injection quantity of the main, early, and late post fuel injection. To determine their fuel injection timings, a mass fraction burned 60% after location of the rate of heat release maximum (MFB60aLoROHRmax) was proposed based on the cylinder pressure information. The proposed control method was implemented in an in-house EMS and validated at several engine operating conditions. During the regeneration period, the exhaust gas temperature tracked the desired temperature, and the engine torque fluctuation was minimized with minimal PM and NOx emissions.

Cycle-to-Cycle Control of HCCI Engines

2003 ◽  
Author(s):  
Gregory M. Shaver ◽  
J. Christian Gerdes
Keyword(s):  
Fuel Injection ◽  
Molar Ratio ◽  
Exhaust Gas ◽  
Cylinder Pressure ◽  
Isentropic Compression ◽  
Detailed Model ◽  
Loop Control ◽  
Modeling And Control ◽  
Control Approach ◽  
Variable Valve Actuation

With stated benefits ranging from increased thermal efficiency to significantly reduced NOx emissions, Homogeneous Charge Compression Ignition (HCCI) represents a promising combustion strategy for future engines. When achieved by reinducting exhaust gas with a variable valve actuation (VVA) system, however, HCCI possesses nonlinear cycle-to-cycle coupling through the exhaust gas and lacks an easily identified trigger comparable to spark or fuel injection. This makes closed-loop control decidedly nontrivial. To develop a controller for HCCI, the engine cycle is partitioned into five stages: adiabatic, constant pressure induction of re-inducted product and reactant charge; isentropic compression to the point just prior to combustion initiation; constant volume combustion; isentropic expansion of product gases; isentropic exhaust of product gases. Using this framework, a nonlinear low-order model of HCCI combustion is formulated, where the input is the molar ratio of reinducted products to fresh reactants and the output is the peak in-cylinder pressure. Comparison with experimental in-cylinder pressure data shows that the model, while simple, offers reasonable fidelity. Using the nonlinear model, a linearized model and an accompanying LQR controller are formulated and implemented on a more detailed model presented in previous work. Results from these simulations show that the modeling and control approach is indeed successful at tracking a varying desired work output while maintaining a constant desired combustion phasing.

Analysis of Reentrant Combustion Chamber on Combustion Process and Exhaust Emissions Based on FIRE

2014 ◽  
Vol 543-547 ◽  
pp. 425-428
Author(s):  
Jian Ying Dai ◽  
Dong Ling Xiao
Keyword(s):  
Working Condition ◽  
Fuel Injection ◽  
Combustion Engine ◽  
Noise Analysis ◽  
Combustion Process ◽  
Simulation Software ◽  
Cylinder Pressure ◽  
Development Cycle ◽  
Engine Cylinder ◽  
Engine Combustion

In the paper firstly analyzes the engine combustion theory, for the numerical analysis for engine cylinder pressure to provide the basis. This paper makes use of the FIRE simulation software to analyze the shrinkage mouth combustion engine under different working condition of the fuel injection advance Angle of the characteristics of the combustion process and exhaust process, after got the mixture combustion in cylinder gas pressure range and emissions, for the next step muffler simulation model is established by applying the method of finite element and acoustical noise analysis provides the basis of the parameters, shorten product development cycle.

Closed-Loop Temperature Control of Material Plasticisation during Friction Stir Welding

2014 ◽  
Vol 1019 ◽  
pp. 120-125
Author(s):  
D.G. Hattingh ◽  
Theo I. van Niekerk ◽  
Raymond Pothier
Keyword(s):  
Friction Stir Welding ◽  
Temperature Control ◽  
Closed Loop ◽  
Control Strategies ◽  
Industrial Process ◽  
Traverse Speed ◽  
Feedback Signal ◽  
Monitoring And Control ◽  
Friction Stir ◽  
Tool Geometries

This research presents the potential for improved joint integrity of friction stir welding by controlling the plasticisation temperature in the weld nugget. During a typical FSW, temperature fluctuates with position along the length of the weld. Working from a basis that for all material and tool geometries, there is an Optimal Plasticisation Temperature (OPT), this paper provides a strategy for maintaining this optimal weld temperature by adjusting selected weld input parameters ensuring consistent joint quality, irrespective of component geometry or clamp configuration. This proposed methodology can also be used to determine the OPT for different FSW tool geometries and material combinations. Advanced monitoring and control strategies are essential to ensure that FSW can be made a more robust industrial process that can keep pace with the modern demand for more consistent production and reliability of welded structures. The potential lies in the possibility for an operator to now select an OPT point for a specific approved welding program and allow the welding platform to maintain the OPT via closed-loop temperature control which adjusts tool rotation and or tool traverse speed. This paper further reports on the potential of integration of a closed-loop temperature control algorithm for FSW. The system measures the temperature inside the FSW tool using thermocouple sensors (creating the feedback signal). The controller then applies a PID algorithm which in turn drives the spindle speed (and if necessary, tool traverse speed) in order to change the energy input rate to the weld for controlling plasticisation temperature.

Sliding Mode Control of a Dual-Fuel System Internal Combustion Engine

2009 ◽  
Author(s):  
Stephen Pace ◽  
Guoming G. Zhu
Keyword(s):  
Sliding Mode Control ◽  
Fuel Injection ◽  
Sliding Mode ◽  
Combustion Engine ◽  
Direct Injection ◽  
Fuel Mixture ◽  
Dual Fuel ◽  
Sliding Mode Controller ◽  
Fuel Ratio ◽  
Mode Control

Air-to-fuel (A/F) ratio is the mass ratio of air-to-fuel mixture trapped inside a cylinder before combustion begins, and it affects engine emissions, fuel economy, and other performances. Using an A/F ratio and dual-fuel ratio control oriented engine model, a multi-input-multi-output (MIMO) sliding mode control scheme is used to simultaneously control the mass flow rate of both port fuel injection (PFI) and direct injection (DI) systems. The control target is to regulate the A/F ratio at a desired level (e.g., at stoichiometric) and fuel ratio (ratio of PFI fueling vs. total fueling) to a given desired level between zero and one. A MIMO sliding mode controller was designed with guaranteed stability to drive the system A/F and fuel ratios to the desired target under various air flow disturbances. The performance of the sliding mode controller was compared with a baseline multi-loop PID (Proportional-Integral-Derivative) controller through simulations and showed improvements over the baseline controller.

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