Dynamic Modelling and Controller Design of Combustion Phasing for an RCCI Engine

2016 ◽  
Author(s):  
Kaveh Khodadadi Sadabadi ◽  
Mahdi Shahbakhti
Keyword(s):  
Controller Design ◽  
Dynamic Modelling ◽  
Mean Value ◽  
Operating Conditions ◽  
Combustion Model ◽  
Transient Operation ◽  
Real Time Control ◽  
Fuel Blend ◽  
Engine Operation ◽  
Model Based

Reactivity controlled compression ignition (RCCI) is an advanced low temperature combustion strategy introduced to achieve near-zero NOx and soot emissions while maintaining diesel-like efficiencies. Precise control of RCCI combustion phasing is necessary in realizing high fuel conversion efficiency as well as meeting stringent emission standards. Model-based control of combustion phasing provides a powerful tool for real-time control during transient operation of the RCCI engine, which requires a computationally efficient combustion model that encompasses factors such as, injection timings, fuel blend composition and reactivity. In this work, physics-based models are developed to predict the combustion phasing of a 1.9-liter RCCI engine. A mean value control-oriented model (COM) of RCCI is developed by combining the auto-ignition model, the burn duration model, and a Wiebe function to predict combustion phasing. Development of a model-based controller requires a dynamic model which can predict engine operation, i.e., estimation of combustion phasing, on a cycle-to-cycle basis. Hence, the mean-value model is extended to encompass the full-cycle engine operation by including the expansion and exhaust strokes. In addition, the dynamics stemming from the thermal coupling between cycles are accounted for, that results in a dynamic RCCI control-oriented model capable of predicting the transient operation of the engine. This model is then simplified and linearized in order to develop a linear observer-based feedback controller to control the combustion phasing using the premixed ratio (the ratio of the port injected gasoline fuel to the total gasoline/diesel fuel injected). The designed controller depicts an accurate tracking performance of the desired combustion phasing and successfully rejects external disturbances in engine operating conditions.

Model-Based Combustion Duration and Ignition Timing Prediction for Combustion Phasing Control of a Spark-Ignition Engine Using In-Cylinder Pressure Sensors

2019 ◽  
Author(s):  
Xin Wang ◽  
Amir Khameneian ◽  
Paul Dice ◽  
Bo Chen ◽  
Mahdi Shahbakhti ◽  
...  
Keyword(s):  
Pressure Sensors ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Combustion Model ◽  
Ignition Timing ◽  
Model Based ◽  
Crank Angle ◽  
Si Engines ◽  
Phasing Control

Abstract Combustion phasing, which can be defined as the crank angle of fifty percent mass fraction burned (CA50), is one of the most important parameters affecting engine efficiency, torque output, and emissions. In homogeneous spark-ignition (SI) engines, ignition timing control algorithms are typically map-based with several multipliers, which requires significant calibration efforts. This work presents a framework of model-based ignition timing prediction using a computationally efficient control-oriented combustion model for the purpose of real-time combustion phasing control. Burn duration from ignition timing to CA50 (ΔθIGN-CA50) on an individual cylinder cycle-by-cycle basis is predicted by the combustion model developed in this work. The model is based on the physics of turbulent flame propagation in SI engines and contains the most important control parameters, including ignition timing, variable valve timing, air-fuel ratio, and engine load mostly affected by combination of the throttle opening position and the previous three parameters. With 64 test points used for model calibration, the developed combustion model is shown to cover wide engine operating conditions, thereby significantly reducing the calibration effort. A Root Mean Square Error (RMSE) of 1.7 Crank Angle Degrees (CAD) and correlation coefficient (R2) of 0.95 illustrates the accuracy of the calibrated model. On-road vehicle testing data is used to evaluate the performance of the developed model-based burn duration and ignition timing algorithm. When comparing the model predicted burn duration and ignition timing with experimental data, 83% of the prediction error falls within ±3 CAD.

Model-Based Control of Combustion Instabilities

2005 ◽  
Author(s):  
Aimee S. Morgans ◽  
Ann P. Dowling
Keyword(s):  
Transfer Function ◽  
Controller Design ◽  
Open Loop ◽  
Operating Conditions ◽  
Combustion Instabilities ◽  
Lean Premixed Combustion ◽  
Model Based Control ◽  
Model Based ◽  
Loop Transfer Function ◽  
Mathematical Approximation

Model-based control has been successfully implemented on an atmospheric pressure lean premixed combustion rig. The rig incorporated a pressure transducer in the combustor to provide a sensor measurement, with actuation provided by a fuel valve. Controller design was based on experimental measurement of the open loop transfer function. This was achieved using a valve input signal which was the sum of an identification signal and a control signal from an empirical controller to eliminate the non-linear limit cycle. The transfer function was measured for the main instability occurring at a variety of operating conditions, and was found to be fairly similar in all cases. Using Nyquist and H∞-loop shaping techniques, several robust controllers were designed, based on a mathematical approximation to the measured transfer function. These were implemented experimentally on the rig, and were found to stabilise it under a variety of operating conditions, with a greater reduction in the pressure spectrum than had been achieved by the empirical controller.

Diesel engine control optimization for transient operation with lean/rich switches

2003 ◽  
Vol 4 (3) ◽  
pp. 219-231 ◽  
Author(s):  
N. P. Kyrtatos ◽  
E. I. Tzanos ◽  
C. I. Papadopoulos
Keyword(s):  
Diesel Engine ◽  
Direct Injection ◽  
Optimization Procedure ◽  
Combustion Model ◽  
Transient Operation ◽  
Simulation Code ◽  
Engine Operation ◽  
Control Optimization ◽  
Management Schemes ◽  
Engine Components

Transient operation of a direct injection heavy duty (DI HD) diesel engine equipped with an NOx storage catalyst (NSC) was simulated using a ‘virtual powerplant’ simulation code with a zero-dimensional multizone combustion model. For the regeneration of the NSC the engine is required to work with lean/rich operation switches, which necessitates advanced engine management schemes for the fuelling, throttle and turbocharger wastegate. An optimization procedure, using the simulation model, resulted in a proposed schedule for the control of the various engine components involved in such engine operation.

Study on Design Method of Combustion Reference Values for Model-Based Control of Advanced Diesel Engine

2020 ◽  
Author(s):  
Jihoon Kim ◽  
Yudai Yamasaki
Keyword(s):  
Heat Release ◽  
Control Systems ◽  
Reference Values ◽  
Model Prediction ◽  
Design Method ◽  
Operating Conditions ◽  
Compression Ignition ◽  
Transient Operation ◽  
Model Based Control ◽  
Model Based

Abstract Model-based control systems are drawing attention in relation to implementing next-generation combustion technologies with high thermal efficiency and low emissions, such as homogeneous charge compression ignition (HCCI) and premixed charge compression ignition (PCCI) combustion, which have low robustness. A model-based control system derives control inputs according to reference values and operating conditions during every cycle and has potential to replace the conventional control map, which requires a large number of experiments. However, model-based control for engines requires reference values for combustion, such as heat release peak timing and heat release peak value; such values represent the combustion state. Therefore, the reference for the transient condition is important for utilizing the benefit of model-based control systems, given that such systems derive control outputs cycle by cycle. In this study, a design method for the combustion reference values for the transient operating condition is described for advanced diesel combustion, which uses premixed compression ignition combustion by multiple fuel injections. Specifically, a statistical method and a method based on model prediction considering the driving characteristics are proposed and compared in engine control experiments. These proposed methods were evaluated under defined simple transient operation conditions and worldwide harmonized light vehicles test cycles (WLTC) mode considering real road conditions. Results showed that designing the combustion reference values for transient operation by model prediction is effective, and such method has the potential to reflect the driving characteristics.

Model-based advanced process control of coagulation

2002 ◽  
Vol 45 (4-5) ◽  
pp. 9-17 ◽  
Author(s):  
C.W. Baxter ◽  
R. Shariff ◽  
S.J. Stanley ◽  
D.W. Smith ◽  
Q. Zhang ◽  
...  
Keyword(s):  
Water Treatment ◽  
Process Control ◽  
New Technology ◽  
Drinking Water Treatment ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Ann Model ◽  
Real Time Control ◽  
Advanced Process Control ◽  
Model Based

The drinking water treatment industry has seen a recent increase in the use of artificial neural networks (ANNs) for process modelling and offline process control tools and applications. While conceptual frameworks for integrating the ANN technology into the real-time control of complex treatment processes have been proposed, actual working systems have yet to be developed. This paper presents development and application of an ANN model-based advanced process control system for the coagulation process at a pilot-scale water treatment facility in Edmonton, Alberta, Canada. The system was successfully used to maintain a user-defined set point for effluent quality, by automatically varying operating conditions in response to changes in influent water quality. This new technology has the potential to realize significant operational cost saving for utilities when applied in full-scale applications.

A two-zone reaction-based combustion model for a spark-ignition engine

2019 ◽  
Vol 22 (1) ◽  
pp. 109-124 ◽  
Author(s):  
Ruixue C Li ◽  
Guoming G Zhu ◽  
Yifan Men
Keyword(s):  
Real Time ◽  
Combustion Process ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Combustion Model ◽  
Individual Species ◽  
Cylinder Pressure ◽  
Model Based ◽  
Modeling Approach ◽  
Real Time Simulations

This article presents a control-oriented two-zone reaction-based zero-dimensional model to accurately describe the combustion process of a spark-ignited engine for real-time simulations, and the developed model will be used for model-based control design and validation. A two-zone modeling approach is adopted, where the combustion chamber is divided into the burned (reaction) and unburned (pre-mixed) zones. The mixture thermodynamic properties and individual chemical species in two zones are taken into account in the modeling process. Instead of using the conventional pre-determined Wiebe-based combustion model, a two-step chemical reaction model is utilized to predict the combustion process along with important thermodynamic parameters such as the mass-fraction-burned, in-cylinder pressure, temperatures, and individual species mass changes in both zones. Sensitivities of model parameters are analyzed during the model calibration process. As a result, one set of calibration parameters is used to predict combustion characteristics over all engine operating conditions studied in this article, which is the major advantage of the proposed method. Also, the proposed modeling approach is capable of modeling the combustion process under different air-to-fuel ratios, ignition timings, and exhaust-gas-recirculation rates for real-time simulations. As the by-product of the model, engine knock can also be predicted based on the Arrhenius integral in the unburned zone, which is valuable for model-based knock control. The proposed combustion model is intensively validated using the experimental data with a peak relative prediction error of 6.2% for the in-cylinder pressure.

Review of engine control-oriented combustion models

2021 ◽  
pp. 146808742199295
Author(s):  
Jian Tang ◽  
Guoming G Zhu ◽  
Yifan Men
Keyword(s):  
Real Time ◽  
Physical System ◽  
Mean Value ◽  
Combustion Model ◽  
Engine Control ◽  
Model Group ◽  
Model Based Control ◽  
Model Based ◽  
Combustion Models ◽  
Engine Combustion

As requirements for continuously improving internal combustion engine fuel economy with satisfactory emissions, model-based control strategies are often used to optimize the combustion process. To apply advanced control techniques for closed-loop engine combustion control, control-oriented engine combustion models are necessary and they are physics-based, accurate enough for model-based control, computationally low cost, and capable of real-time simulations. In addition, control-oriented combustion model with adequate fidelity may need to adapt to physical system and environment changes over time to maintain model-based control performance, such as model-reference (guided) control, where the control-oriented combustion model runs in real-time to generate an error signal between physical system and reference-model output for feedback control. This paper provides a review of existing control-oriented engine combustion models, along with their associated applications. Three main groups of control-oriented combustion models are reviewed from simple to sophisticated physics-based dynamic models, including mean-value, Wiebe function-based, and reaction-based models. The fundamental principle of each model group is reviewed briefly and its applications are also addressed. At the macro level, a control-oriented engine model can be used for crank angle-based and/or cycle-based control. As the engine control hardware performance continuous improving with reduced cost, model-reference (guided) combustion control shall become reality since now it is feasible to run a physics-based control-oriented engine combustion model inside an engine control module. On the other hand, each model group, even for the simple mean-value model, has its own applicable scenarios.

scholarly journals Modelling liquid film in modern GDI engines and the impact on particulate matter emissions – Part 1

2021 ◽  
pp. 146808742110244
Author(s):  
Federico Biagiotti ◽  
Fabrizio Bonatesta ◽  
Sadjad Tajdaran ◽  
Davide Domenico Sciortino ◽  
Sunny Verma ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Liquid Film ◽  
Operating Conditions ◽  
Gasoline Direct Injection ◽  
Injection System ◽  
Published Data ◽  
Injection Timing ◽  
Fuel Blend ◽  
Engine Operation ◽  
The Impact

This paper presents the details of a Computational Fluid Dynamics methodology to accurately model the process of mixture preparation in modern Gasoline Direct Injection engines, with particular emphasis on liquid film as one of the main causes of Particulate Matter formation. The proposed modelling protocol, centred on the Bai-Onera approach of droplets-wall interaction and on multi-component surrogate fuel blend models, is validated against relevant published data and then applied to a modern small-capacity GDI engine, featuring centrally-mounted spray-guided injection system. The work covers a range of part-load, stoichiometric and theoretically-homogeneous operating conditions, for which experimental engine data and engine-out Particle Number measurements were available. The results, based on the parametric variation of start of injection timing and injection pressure, demonstrate how both fuel mal-distribution and liquid film retained at spark timing, may contribute to PN emissions, whilst their relative importance vary depending on operating conditions and engine control strategy. Control of PN emissions and compliance with future, more stringent regulations remain large challenges for the engine industry. Renewed and disruptive approaches, which also consider the sustainability of the sector, appear to be essential. This work, developed using Siemens Simcenter CFD software as part of the Ford-led APC6 DYNAMO project, aims to contribute to the development of a reliable and cost-effective digital toolset, which supports engine development and diagnostics through a more fundamental assessment of engine operation and emissions formation.

Control-Oriented Model-Based Burn Duration and Ignition Timing Prediction With Recursive-Least-Square Adaptation for Closed-Loop Combustion Phasing Control of a Spark Ignition Engine

2019 ◽  
Author(s):  
Xin Wang ◽  
Amir Khameneian ◽  
Paul Dice ◽  
Bo Chen ◽  
Mahdi Shahbakhti ◽  
...  
Keyword(s):  
Operating Conditions ◽  
Least Square ◽  
Prediction Algorithm ◽  
Combustion Model ◽  
Model Errors ◽  
Ignition Timing ◽  
Recursive Least Square ◽  
Adaptation Algorithm ◽  
Model Based ◽  
Si Engines

Abstract In homogeneous spark-ignition (SI) engines, ignition timing is used to control the combustion phasing (crank angle of fifty percent of fuel burned, CA50), which affects fuel economy, engine torque output, and emissions. This paper presents a model-based adaptive ignition timing prediction strategy using a control-oriented dynamic combustion model for real-time closed-loop combustion phasing control. The combustion model predicts the burn duration from ignition timing to CA50 (ΔθIGN-CA50) at Intake Valve Closing (IVC) for the upcoming cycle based on current engine operating conditions, including variable valve timing, predicted ignition timing, air-fuel ratio, engine speed, and engine load. To maintain the accuracy of combustion model and ignition timing prediction during the engine lifetime, a Recursive-Least-Square (RLS) with Variable Forgetting Factor (VFF) based adaptation algorithm is developed to handle both short term (operating-point-dependent) and long term (engine aging) model errors. Due to short term model errors and stochastic characteristics of cycle-to-cycle combustion variations, large model errors may occur during severe transient operating conditions (tip-in/tip-out), which can result in wrong adjustments and excessive adaptations. Since on-road SI engines are always operating in transient conditions, the ‘Heavy Transient Detection’ algorithm is developed to avoid fault adaptation and assist the adaptation algorithm to be stable. On-road vehicle testing data is used to evaluate the performance of the entire model-based adaptive burn duration and ignition timing prediction algorithm. With only 64 calibration points, a mean ignition timing prediction error of 0.2 Crank Angle Degree (CAD) and average iteration number of 2 shows the capability of adaptive ignition timing prediction, a significant reduction of calibration efforts, and potential of real-time application of the developed adaptive ignition timing prediction algorithm.

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