Thermodynamic Based Modeling for Nonlinear Control of Combustion Phasing in HCCI Engines

Thermodynamic Based Modeling for Nonlinear Control of Combustion Phasing in HCCI Engines PDF Author: Joshua Bradley Bettis
Publisher:
ISBN:
Category : Chemical kinetics
Languages : en
Pages : 0

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Book Description
"Low temperature combustion modes, such as Homogeneous Charge Compression Ignition (HCCI), represent a promising means to increase the efficiency and significantly reduce the emissions of internal combustion engines. Implementation and control are difficult, however, due to the lack of an external combustion trigger. This thesis outlines a nonlinear control-oriented model of a single cylinder HCCI engine, which is physically based on a five state thermodynamic cycle. This model is aimed at capturing the behavior of an engine which utilizes fully vaporized gasoline-type fuels, exhaust gas recirculation and intake air heating in order to achieve HCCI operation. The onset of combustion, which is vital for control, is modeled using an Arrhenius Reaction Rate expression which relates the combustion timing to both charge dilution and temperature. To account for a finite HCCI combustion event, the point of constant volume combustion is shifted for SOC to a point of high energy release based on experimental heat release data. The model is validated against experimental data form a single cylinder CI engine operating under HCCI conditions at two different fueling rates. Parameters relevant to control such as combustion timing agree very well with the experiment at both operating conditions. The extension of the model to other fuels is also investigated via the Octane Index (OI) of several different gasoline-type fuels. Since this nonlinear model is developed from a controls perspective, both the output and state update equations are formulated such that they are functions of only the control inputs and state variables, therefore making them directly applicable to state space methods for control. The result is a discrete-time nonlinear control model which provides a platform for developing and validating various nonlinear control strategies"--Abstract, leaf iv

Thermodynamic Based Modeling for Nonlinear Control of Combustion Phasing in HCCI Engines

Thermodynamic Based Modeling for Nonlinear Control of Combustion Phasing in HCCI Engines PDF Author: Joshua Bradley Bettis
Publisher:
ISBN:
Category : Chemical kinetics
Languages : en
Pages : 0

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Book Description
"Low temperature combustion modes, such as Homogeneous Charge Compression Ignition (HCCI), represent a promising means to increase the efficiency and significantly reduce the emissions of internal combustion engines. Implementation and control are difficult, however, due to the lack of an external combustion trigger. This thesis outlines a nonlinear control-oriented model of a single cylinder HCCI engine, which is physically based on a five state thermodynamic cycle. This model is aimed at capturing the behavior of an engine which utilizes fully vaporized gasoline-type fuels, exhaust gas recirculation and intake air heating in order to achieve HCCI operation. The onset of combustion, which is vital for control, is modeled using an Arrhenius Reaction Rate expression which relates the combustion timing to both charge dilution and temperature. To account for a finite HCCI combustion event, the point of constant volume combustion is shifted for SOC to a point of high energy release based on experimental heat release data. The model is validated against experimental data form a single cylinder CI engine operating under HCCI conditions at two different fueling rates. Parameters relevant to control such as combustion timing agree very well with the experiment at both operating conditions. The extension of the model to other fuels is also investigated via the Octane Index (OI) of several different gasoline-type fuels. Since this nonlinear model is developed from a controls perspective, both the output and state update equations are formulated such that they are functions of only the control inputs and state variables, therefore making them directly applicable to state space methods for control. The result is a discrete-time nonlinear control model which provides a platform for developing and validating various nonlinear control strategies"--Abstract, leaf iv

Thermodynamic and Chemical Kinetic Coupled Modeling for the Determination of Cyclic Combustion Phasing in HCCI Engines

Thermodynamic and Chemical Kinetic Coupled Modeling for the Determination of Cyclic Combustion Phasing in HCCI Engines PDF Author: Krishawn Michele Goodwin
Publisher:
ISBN:
Category : Carbon monoxide
Languages : en
Pages : 171

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Book Description
"Homogeneous charge compression ignition (HCCI) is a low temperature combustion mode that contains great potential for decreasing emissions while increasing efficiency in internal combustion engines. The limitation is in that it is inherently difficult to control based on the lack of an external combustion trigger. This thesis outlines the potential of using the combustion residual species of carbon monoxide as a method of controlling the location of combustion by using data from a computer model. The model is a nonlinear five-state thermodynamic model that is coupled with a skeletal chemical kinetic model for PRF96. The model computes the amount of carbon monoxide within the cylinder during partial burn, which is when the engine is most difficult to control, and also calculates the amount of carbon monoxide residual that will be fed forward into the next cycle. The model is verified by comparing experimental data at the steady state and at the onset of partial burn collected from a Hatz 1D50Z engine located on the Missouri S&T campus. The impact of the carbon monoxide on the cyclic dynamics of the engine is observed through return maps displaying cyclic dependence generated by using data from the model. These return maps are created to determine the effects of the naturally produced amounts of carbon monoxide during partial burn, artificially increased amount of carbon monoxide during partial burn and complete combustion, and the effects of the intake temperature on several important engine parameters. These effects observed can be used to determine the relevance of using carbon monoxide as a control for HCCI."--Abstract, page iii.

Combustion Timing Control of Natural Gas HCCI Engines Using Physics-based Modeling and LQR Controller

Combustion Timing Control of Natural Gas HCCI Engines Using Physics-based Modeling and LQR Controller PDF Author: Marwa Abdelgawad
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Homogeneous Charge Compression Ignition (HCCI) Engines hold promises of being the next generation of internal combustion engines due to their ability to produce high thermal efficiencies and low emission levels. HCCI combustion is achieved through the auto-ignition of a compressed homogenous fuel-air mixture, thus making it a "fusion" between spark-ignition and compression-ignition engines. The main challenge in developing HCCI engines is the absence of a combustion trigger hence making it difficult to control its combustion timing. The aim of this research project is to model and control a natural gas HCCI engine. Since HCCI depends primarily on temperature and chemical composition of the mixture, Exhaust Gas Recirculation (EGR) is used to control ignition timing. In this research, a thermodynamical, physics-based nonlinear model is developed to capture the main features of the HCCI engine. In addition, the Modified Knock Integral Model (MKIM), used to predict ignition timing, is optimized. To validate the nonlinear model, ignition timing under varying conditions using the MKIM approach is shown to be in accordance with data acquired from a model developed using a sophisticated engine simulation program, GT-Power. Most control strategies are based on a linear model, therefore, the nonlinear model is linearized using the perturbation method. The linear model is validated by comparing its performance with the nonlinear model about a suitable operating point. The control of ignition timing can be defined as a regulation process where the goal is to force the nonlinear model to track a desired ignition timing by controlling the EGR ratio. Parameters from the linear model are used to determine the gains of the LQR controller. The performance of the controller is validated by implementing it on the nonlinear model and observing its ability to track the desired timing with 0.5% error within a certain operating range. To increase the operating range of the controller and reduce steady-state error, an integrator is added to the LQR. Finally, it is shown that the LQR controller is able to successfully reject disturbance, parameter variation, as well as noise.

Nonlinear Systems and Circuits in Internal Combustion Engines

Nonlinear Systems and Circuits in Internal Combustion Engines PDF Author: Ferdinando Taglialatela-Scafati
Publisher: Springer
ISBN: 3319671405
Category : Technology & Engineering
Languages : en
Pages : 89

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Book Description
This brief provides an overview on the most relevant nonlinear phenomena in internal combustion engines with a particular emphasis on the use of nonlinear circuits in their modelling and control. The brief contains advanced methodologies —based on neural networks and soft-computing approaches among others— for the compensation of engine nonlinearities by using the combustion pressure signal and proposes several techniques for the reconstruction of this signal on the basis of different engine parameters, including engine-block vibration and crankshaft rotational speed. Another topic of the book is the diagnosis of the nonlinearities of injection systems and their balancing, which is a mandatory task for the new generation of gasoline direct injection engines. The authors come from both industrial and academic backgrounds, so the brief represents an important tool both for researchers and practitioners in the automotive industry.

Modeling and Control of Single Cylinder HCCI Engine

Modeling and Control of Single Cylinder HCCI Engine PDF Author: Varun Tandra
Publisher:
ISBN:
Category :
Languages : en
Pages : 218

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Book Description
With growing environmental concern, energy consumption has become a key element in the current debate on global warming. Over the past two decades, Homogeneous Charge Compression Ignition (HCCI) engine technology has aroused a great deal of interest in the automotive sector owing to its fuel flexibility and ability to generate ultra-low exhaust emissions. One of the strategies to achieve ultra-low emissions in HCCI engines is to retain some exhaust gas/burnt products in the cylinder by dynamically actuating/varying valve opening and closing timings and lifts. This can be achieved by recent advancements in microprocessor, actuators and controller technologies. The first step in the synthesis of control algorithms involves developing simple system-level mathematical models. This thesis presents two such mathematical models of HCCI combustion. In the first part of this thesis, a control-oriented two-zone thermo-kinetic model of a single cylinder HCCI engine is presented. Earlier control laws were derived using single zone mathematical models of HCCI combustion; however, such models fail to accurately capture the combustion dynamics of an HCCI engine owing to the assumption of homogeneous composition and temperature in the cylinder. Certain multi-zone models of HCCI engines emphasizing the shortcomings of these single zone models have also been reported in literature. However, such models are far too complex and unwieldy for the development of fast and efficient controllers for HCCI engines. The present work outlines the modeling approach of a physics based two-zone model of a single-cylinder HCCI engine by incorporating the first law of thermodynamics and the temperature and concentration inhomogeneities within the cylinder in order to better predict emissions, peak pressures, and timing. A comparative analysis between the single zone and two-zone models is also discussed. The nonlinear model was linearized about an operating point to facilitate the development of an effective LQR regulator. The model inputs include variable valve timing to effectively control peak pressures, exhaust temperatures and ignition timing. In the second part of the thesis we address the shortcomings of control analysis which to date has been done by developing models that are engine specific, such models often rely on extensive parameters which are to be experimentally identified. Moreover, further investigation revealed that these models were valid only for a narrow operating range. Therefore, a detailed mathematical model of an HCCI engine, which is fuel flexible and valid for transitions in engine speed, is developed based on ideal gas laws and basic thermodynamics and conservation principles. The different engine subsystems and engine phenomena discretized into eight stages are modeled in a "control-oriented sense" to address the combustion timing, peak pressure and heat release rate control issues. The model has been implemented in MATLAB® to facilitate simulation studies and requires minimum tuning parameters to be experimentally recognized. Model validation is based on three sets of engine data, obtained from literature. The validation suggests that the model, once tuned properly, shows a fair agreement between the simulation and experimental data for a given engine and operating conditions.

Reinforcement Learning and Approximate Dynamic Programming for Feedback Control

Reinforcement Learning and Approximate Dynamic Programming for Feedback Control PDF Author: Frank L. Lewis
Publisher: John Wiley & Sons
ISBN: 1118453972
Category : Technology & Engineering
Languages : en
Pages : 498

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Book Description
Reinforcement learning (RL) and adaptive dynamic programming (ADP) has been one of the most critical research fields in science and engineering for modern complex systems. This book describes the latest RL and ADP techniques for decision and control in human engineered systems, covering both single player decision and control and multi-player games. Edited by the pioneers of RL and ADP research, the book brings together ideas and methods from many fields and provides an important and timely guidance on controlling a wide variety of systems, such as robots, industrial processes, and economic decision-making.

Nonlinear Model Predictive Control of Combustion Engines

Nonlinear Model Predictive Control of Combustion Engines PDF Author: Thivaharan Albin Rajasingham
Publisher: Springer Nature
ISBN: 303068010X
Category : Technology & Engineering
Languages : en
Pages : 330

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Book Description
This book provides an overview of the nonlinear model predictive control (NMPC) concept for application to innovative combustion engines. Readers can use this book to become more expert in advanced combustion engine control and to develop and implement their own NMPC algorithms to solve challenging control tasks in the field. The significance of the advantages and relevancy for practice is demonstrated by real-world engine and vehicle application examples. The author provides an overview of fundamental engine control systems, and addresses emerging control problems, showing how they can be solved with NMPC. The implementation of NMPC involves various development steps, including: • reduced-order modeling of the process; • analysis of system dynamics; • formulation of the optimization problem; and • real-time feasible numerical solution of the optimization problem. Readers will see the entire process of these steps, from the fundamentals to several innovative applications. The application examples highlight the actual difficulties and advantages when implementing NMPC for engine control applications. Nonlinear Model Predictive Control of Combustion Engines targets engineers and researchers in academia and industry working in the field of engine control. The book is laid out in a structured and easy-to-read manner, supported by code examples in MATLAB®/Simulink®, thus expanding its readership to students and academics who would like to understand the fundamental concepts of NMPC. Advances in Industrial Control reports and encourages the transfer of technology in control engineering. The rapid development of control technology has an impact on all areas of the control discipline. The series offers an opportunity for researchers to present an extended exposition of new work in all aspects of industrial control.

Modeling Engine Spray and Combustion Processes

Modeling Engine Spray and Combustion Processes PDF Author: Gunnar Stiesch
Publisher: Springer Science & Business Media
ISBN: 3662087901
Category : Computers
Languages : en
Pages : 293

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Book Description
The utilization of mathematical models to numerically describe the performance of internal combustion engines is of great significance in the development of new and improved engines. Today, such simulation models can already be viewed as standard tools, and their importance is likely to increase further as available com puter power is expected to increase and the predictive quality of the models is constantly enhanced. This book describes and discusses the most widely used mathematical models for in-cylinder spray and combustion processes, which are the most important subprocesses affecting engine fuel consumption and pollutant emissions. The relevant thermodynamic, fluid dynamic and chemical principles are summarized, and then the application of these principles to the in-cylinder processes is ex plained. Different modeling approaches for the each subprocesses are compared and discussed with respect to the governing model assumptions and simplifica tions. Conclusions are drawn as to which model approach is appropriate for a specific type of problem in the development process of an engine. Hence, this book may serve both as a graduate level textbook for combustion engineering stu dents and as a reference for professionals employed in the field of combustion en gine modeling. The research necessary for this book was carried out during my employment as a postdoctoral scientist at the Institute of Technical Combustion (ITV) at the Uni versity of Hannover, Germany and at the Engine Research Center (ERC) at the University of Wisconsin-Madison, USA.

Dynamic Modeling and Predictive Control of a Multi-Mode Combustion Engine

Dynamic Modeling and Predictive Control of a Multi-Mode Combustion Engine PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
Abstract : Low temperature combustion (LTC) offers high thermal efficiency and low engine-out nitrogen oxides (NOx) and particulate matter (PM) emissions. Homogeneous charge compression ignition (HCCI), partially premixed charge compression ignition (PPCI) and reactivity-controlled compression ignition (RCCI) are the common LTC modes studied in this research. The primary barrier to implementing the LTC modes in on-road vehicles is their limited operating range due to high cyclic variability and excessive pressure rise rates. The feasible operating range of the LTC modes is only a subset of the speed-load range of the conventional spark ignition (SI) engine. Therefore, a multi-mode engine concept operating in one or more LTC modes and SI mode is a viable option to improve engine performance in terms of efficiency and emissions. The goal of this dissertation is to develop model-based closed loop control of an SI-RCCI-SI multi-mode engine. Control-oriented models and predictive controllers for HCCI, PPCI and RCCI modes are developed to simultaneously control combustion phasing and engine load for an optimal operation of a multi-mode engine. Cyclic variability in HCCI and RCCI modes are modeled using machine learning classification algorithms. Nonlinear model predictive controllers are developed for HCCI and RCCI modes to control combustion phasing and engine load while constraining cyclic variability below 3%. Furthermore, LTC engine operation faces challenges of excessive pressure rise rates that can damage the hardware. To this end, supervised machine learning classification algorithms are developed to model the heat release type which is used as a scheduling variable to develop data-driven model for an LTC engine. Model predictive controller is then developed to control combustion phasing and engine load while constraining maximum pressure rise rate below 8 bar/CAD. RCCI mode offers good control over the combustion event by modulating the start of injection timing of high reactivity fuel and adjusting the premixed ratio of the dual fuels. Therefore, this research focuses on SI-RCCI-SI multi-mode engine concept. The aim of this research is to achieve smooth SI-RCCI-SI mode switching operation at different engine loads and speed. A dynamic model for SI-RCCI-SI multi-mode engine is developed and validated for different transient conditions. The model includes the mode switching dynamics as well as actuator dynamics. A model-based predictive controller framework is developed for SI-RCCI-SI mode switching. The mode switching controller showed good performance during mode transitions and steady state engine operation. The controller is capable of tracking the desired combustion phasing and engine load during mode switching while maintaining $\lambda$ near stoichiometry in SI mode and constraining maximum pressure rise rate below 8 bar/CAD in RCCI mode.

A Simple HCCI Engine Model for Control

A Simple HCCI Engine Model for Control PDF Author: S. Aceves
Publisher:
ISBN:
Category :
Languages : en
Pages : 8

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Book Description
The homogeneous charge compression ignition (HCCI) engine is an attractive technology because of its high efficiency and low emissions. However, HCCI lacks a direct combustion trigger making control of combustion timing challenging, especially during transients. To aid in HCCI engine control we present a simple model of the HCCI combustion process valid over a range of intake pressures, intake temperatures, equivalence ratios, and engine speeds. The model provides an estimate of the combustion timing on a cycle-by-cycle basis. An ignition threshold, which is a function of the in-cylinder motored temperature and pressure is used to predict start of combustion. This model allows the synthesis of nonlinear control laws, which can be utilized for control of an HCCI engine during transients.