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The goal of this research was to study and quantify the effect of exhaust valve timing and residual gas dilution on in-cylinder flow patterns, flame propagation and heat release characteristics in a spark ignition engine. Experiments were carried out in a recently developed single cylinder optical engine. Particle image velocimetry (PIV) was applied to measuring and evaluating the in-cylinder flow field. Detailed analysis of flame images combined with heat release data was presented for several engine operating conditions, giving insight into the combustion process in terms of visible flame area and flame expansion speed. Results from PIV measurement indicates that the limited alteration of the in-cylinder bulk flow could be observed with the variation of exhaust valve timing. The in-cylinder fluctuating kinetic energies and their Coefficient of Variations (COVs) decrease with the advance of the exhaust valve timing.

SI-CAI hybrid combustion, also known as spark-assisted compression ignition (SACI), is a promising concept to extend the operating range of CAI (Controlled Auto-Ignition) and achieve the smooth transition between spark ignition (SI) and CAI in the gasoline engine. In order to stabilize the hybrid combustion process, the port fuel injection (PFI) combined with gasoline direct injection (GDI) strategy is proposed in this study to form the in-cylinder fuel stratification to enhance the early flame propagation process and control the auto-ignition combustion process. The effect of bowl piston shapes and fuel injection strategies on the fuel stratification characteristics is investigated in detail using three-dimensional computational fluid dynamics (3-D CFD) simulations. Three bowl piston shapes with different bowl diameters and depths were designed and analyzed as well as the original flat piston in a single cylinder PFI/GDI gasoline engine.

More than ever, microcontroller performance in cars has a direct impact on the driving experience, on compliance with improved safety, ever-stricter emissions regulations, and on fuel economy. The simple microcontrollers formerly used in automobiles are now being replaced by powerful number-crunchers with incredible levels of peripheral integration. As a result, performance can no longer be measured in MIPS (Millions of Instructions Per Second). A microcontroller's effectiveness is based on coherent partitioning between analog and digital, hardware and software, tools and methodology. To make an informed choice among the available devices, the designer needs benchmarks that are specific to automotive applications, and which provide a realistic representation of how the device will perform in the automotive environment.

More than ever, microcontroller performance in cars has a direct impact on the driving experience, on compliance with improved safety, ever-stricter emissions regulations, and on fuel economy. The simple microcontrollers formerly used in automobiles are now being replaced by powerful number-crunchers whose performance can no longer be measured in MIPS. Instead, their effectiveness is based on a coherent partitioning between analog and digital, hardware and software, tools and methodology. To make an informed choice among the available devices, what the designer needs are benchmarks that are specific to automotive applications, and which provide a realistic representation of how the device will perform in the automotive environment. This presentation will explore the role of new benchmarks in the development of complex automotive applications.

Homogeneous Charge Compression Ignition (HCCI) has the potential of reducing fuel consumption as well as NOx emissions. However, it is still confronted with problems in real-time control system and control strategy for the application of HCCI, which are studied in detail in this paper. A CAN-bus-based distributed HCCI control system was designed to implement a layered close loop control for HCCI gasoline engine equipped with 4VVAS. Meanwhile, a layered management strategy was developed to achieve high real-time control as well as to simplify the couplings between the inputs and the outputs. The entire control system was stratified into three layers, which are responsible for load (IMEP) management; combustion phase (CA50) control and mechanical system control respectively, each with its own specified close loop control strategy. The system is outstanding for its explicit configuration, easy actualization and robust performance.

A great deal of effort has been directed towards Gasoline HCCI engines, which have the potential of providing better fuel economy and emission characteristics than conventional SI engines. For stable HCCI engine operation, cycle-by-cycle based closed-loop control is needed. Such a control scheme requires an accurate and reliable sensor to monitor the combustion and provide a feedback signal. At present, the general method used to measure the combustion parameters is to monitor in-cylinder pressure with a cylinder pressure sensor. However, using in-cylinder pressure transducers is not feasible for use in mass production of HCCI engines. A good substitute to get information about combustion is the knock sensor, which is already equipped on engines on a large scale. In this paper, the knock signal from an HCCI engine equipped with 4VVAS is analyzed in detail to find the relationship between the combustion parameters and the knock sensor signal.

In terms of modern technical systems, the automotive sector is characterized by escalating complexity and functionality requirements. The development of embedded control systems has to meet highest demands regarding process-, time- and cost-optimization. Hence, the efficiency of software development becomes a crucial competitive advantage. Systems design engineers need effective tools and methods to achieve exemplary speed and productivity within the development phase. To obtain such tools and methods, semiconductor manufacturers and tool manufacturers must work closely together. Within the joint efforts of ETAS and Infineon, the software tool suite ASCET-SD was enhanced to generate efficient C code for Infineon's TriCore architecture mapped on ETAS's real-time operating system ERCOSEK. The processor interface to application & calibration tools was realized using the ETK probe based on a JTAG/Nexus link at very high bandwidth.

FIRCRI-a flexible injection rate common rail injector was developed. This paper presents the working principle and the configuration of the injector. As key technologies in development of the injector, a new fast response solenoid valve was developed and 4 dimensionless design parameters of hydraulic system were presented by through computer simulation and experimental study. The solenoid valve was deliberately designed so as to eliminate the hydraulic force acting on the valve. Other configuration parameters were also optimized so that the response time of the solenoid valve is 0.3 ms. It is interesting to find that the response time of the injector is not only determined by the solenoid valve, but all parameters of the hydraulic system of the injector. The injector can realize pilot injection, which is less than 2.5mm3, at a controllable phase and multi-injections.

Infineon proposes a Quasi-Autonomous Gate Driver (QAGD) to manage an electrically actuated component, whether electromechanical, electromagnetic, or electrohydraulic. This paper examines some current control strategies that can be implemented within the QAGD, such as: Synchronous Sampling (SYSA), Hysteresis, Improved Synchronous Sampling-Hysteresis (ISSH), Suboscillation, Suboscillation with Back EMF Feedforward (SBEF) and Synchronous Control in Rotation Coordinates (SCRC). Analysis and simulation of these strategies indicate their advantages and disadvantages, which are then summarized in a comparison chart, from which the best solution for a given application can be determined. The QAGD IC proposed by Infineon adopts this solution by integrating the current controller and the driver unit for the MOSFETs in a single package. The inverter function can therefore be implemented using one QAGD and several MOSFETs, which greatly simplify the system and decrease the costs.

Increasing fuel costs and emission regulations are driving the car manufacturers to develop powerful but efficient engines. The 3-liter car (3-liter/100 km fuel consumption → 80 miles/gallon) is one achievement of these developments. Beside the pure mechanics electronics for fuel and air management are getting the key element for further improvement. Direct Injected (DI) engines are the standard for Diesel and are looking very promising for Gasoline. This SAE paper will discuss the differences of the operation principle of a solenoid and a Piezo based injector as well as the impact and the requirements for the semiconductors on the ECU especially under respect of future emission standards. A solution from Infineon Technologies will be presented.

The aim of this paper is to compile the state of the art of engine control and develop scenarios for improvements in a number of applications of engine control where the pace of technology change is at its most marked. The first application is control of downsized engines with enhancement of combustion using direct injection, variable valve actuation and turbo charging. The second application is electrification of the powertrain with its impact on engine control. Various architectures are explored such as micro, mild, full hybrid and range extenders. The third application is exhaust gas after-treatment, with a focus on the trade-off between engine and after-treatment control. The fourth application is implementation of powertrain control systems, hardware, software, methods, and tools. The paper summarizes several examples where the performance depends on the availability of control systems for automotive applications.

The spark ignition-controlled auto-ignition (SI-CAI) hybrid combustion is promising in achieving smooth transition between SI and CAI combustion but, it is limited by the combustion cyclic-variation at late combustion phasing to avoid too high pressure rise rate (PRR). In this paper, to stabilize the combustion and reduce PRR, the in-cylinder fuel-stratification strategy is investigated in a gasoline engine, equipped with port fuel injection combined with single pulse direct injection (PFI-DI). Experimental results confirm the benefits of employing PFI-DI in comparison with PFI and single-pulse DI strategy. The influence of DI timing (Start of injection, SOI) on the combustion process is found to be quite complicated, in terms of combustion phasing, combustion stability, PRR and thermal efficiency. It makes the optimal-SOI calibration time-intensive, since complex trade-off between PRR and thermal efficiency is needed.

The spark-assisted compression ignition (SACI) is widely used to expend the high load limit of homogeneous charge compression ignition (HCCI), as it can reduce the high heat release rate effectively while partially maintain the advantage of high thermal efficiency and low NOx emission. But as engine load increases, the SACI combustion traditionally using negative valve overlap strategy (NVO) faces the drawback of higher pumping loss and limited intake charge availability, which lead to a restricted load expansion and a finite improvement of fuel economy. In this paper, research is focused on the SACI combustion using positive valve overlap (PVO) strategy. The characteristics of SACI combustion employing PVO strategy with external exhaust gas recirculation (eEGR) are investigated. Two types of PVO strategies are analyzed and compared to explore their advantages and defects, and the rules of adjusting SACI combustion with positive valve overlap are concluded.

Homogeneous charge compression ignition (HCCI) technology is promising to reduce engine exhaust emissions and fuel consumption in gasoline engine. However, it is still confronted with the problem of its limited operation range. High load is limited by the tradeoff between the quantity of working charge and dilution charge. Low load is limited by the high residual gas fraction and low temperature in the cylinder. One of the highlights of HCCI combustion research at present is to expand the low load limit of HCCI combustion by developing HCCI idle operation. The main obstacle in developing HCCI idle combustion is too high residual gas fraction and low temperature to misfire in cylinder. This paper relates to a method for achieving the appropriate environment for auto-ignition at idle and the optimal tradeoff between the combustion stability and fuel consumption by employing EIVO valve strategy with an equivalent air-fuel ratio.

Chemical reaction kinetics plays an important role in homogeneous charge compression ignition (HCCI) combustion. In order to control the combustion process, the underlying mechanism of auto-ignition must be explored, especially for the HCCI combustion using negative valve overlap (NVO) strategy, in which the residual gas affects the auto-ignition of next cycle remarkably. In this research, experimental research was carried out in a single cylinder gasoline engine equipped with an in-cylinder sampling system which mainly consists of a special spark plug, a sampling tube and a high-speed electromagnetic valve. In-cylinder charge was sampled at compression stroke and analyzed by FTIR with two types of fuel injection strategy, such as port fuel injection (PFI) solely and port fuel injection combined with injection during negative valve overlap (PFI & NVO-Injection).

Homogeneous charge compression ignition (HCCI) technology is promising to reduce engine exhaust emissions and fuel consumption. However, it is still confronted with the problem of its narrow operation range that covers only the light and medium loads. Therefore, to expand the operation range of HCCI, mode switching between HCCI combustion and transition SI combustion is necessary, which may bring additional problems to be resolved, including load fluctuation and increasing the complexity of control strategy, etc. In this paper, a continuously adjustable load strategy is proposed for gasoline engines. With the application of the strategy, engine load can be adjusted continuously by the in-cylinder residual gas fraction in the whole operation range. In this research, hybrid combustion is employed to bridge the gaps between HCCI and traditional SI and thus realize smooth transition between different load points.

Controlled Auto-Ignition (CAI), also known as Homogeneous charge compression ignition (HCCI), has been the subject of extensive research because of their ability to providing simultaneous reduction in fuel consumption and NOx emissions in a gasoline engine. However, due to its limited operation range, combustion mode switching between CAI and spark ignition (SI) combustion is essential to cover the overall operational range of a gasoline engine for passenger car applications. Previous research has shown that the SI-CAI hybrid combustion has the potential to control the ignition timing and heat release process during both steady state and transient operations. However, it was found that the SI-CAI hybrid combustion process is often characterized with large cycle-to-cycle variations, due to the flame instability at high dilution conditions.

SI-CAI hybrid combustion, also known as spark-assisted compression ignition (SACI), is a promising concept to extend the operating range of CAI (Controlled Auto-Ignition) and achieve the smooth transition between spark ignition (SI) and CAI in the gasoline engine. In order to investigate the effect of the thermal boundary condition on the hybrid combustion, the experiments with different coolant temperatures are performed to adjust the chamber wall temperature in a gasoline engine. The experimental results indicate that increasing wall temperature would advance the combustion phasing, enlarge the peak heat release rate and shorten the combustion duration. While the capacity of the wall temperature effect on the hybrid combustion characteristics are more notable in the auto-ignition dominated hybrid combustion.

Homogeneous charge compression ignition (HCCI) is a promising internal combustion engine concept, but suffers from its high sensitivity to operation conditions and disturbances, such as the intake temperature fluctuation, the load fluctuation or the in-cylinder temperature distribution variation. In this paper, a novel control method is proposed for a port-fuel-injected stoichiometric HCCI engine equipped with variable valve actuation (VVA). A first principle model is developed for controller synthesis with intake valve closing (IVC), exhaust valve closing (EVC), and injected fuel quantity as inputs and combustion timing (CA50), Gross IMEP and Lambda as outputs. The proposed method combines the features of model-based feedforward, decoupling, and active disturbance rejection control (ADRC), named MDDC for short, where the easily modeled cross-coupling and disturbances are compensated directly, while all the remaining uncertainties are estimated and mitigated in real time by ADRC.

In the last few years, residual gas trapping has been widely used to achieve CAI combustion operation in the four-stroke gasoline engine by means of the negative valve overlap period. In this paper, a flexible mechanical variable valve actuation system based on the production technologies is described. The 4VVAS system is capable of independent control of intake valve lift and its timing, exhaust valve lift and its timing and it has been incorporated in a specially designed cylinder head for a single cylinder research engine. In addition, an engine simulation program has been developed to investigate the potential of the 4VVAS system for CAI engine operation and the switch between CAI and SI operations on the same engine. The engine simulation program is written with Matlab Simulink and incorporates an engine block, a newly developed CAI ignition and heat release model, a valve profile generator, and an engine control module for spark ignition and fuelling control.