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With fuel efficiency becoming an increasingly critical aspect of internal combustion engine (ICE) vehicles, the necessity for research on efficient generation of electric energy has been growing. An energy management (EM) system controls the generation of electric energy using an alternator. This paper presents a strategy for the EM using a control mode switch (CMS) of the alternator for the (ICE) vehicles. This EM recovers the vehicle’s residual kinetic energy to improve the fuel efficiency. The residual kinetic energy occurs when a driver manipulates a vehicle to decelerate. The residual energy is commonly wasted as heat energy of the brake. In such circumstances, the wasted energy can be converted to electric energy by operating an alternator. This conversion can reduce additional fuel consumption. For extended application of the energy conversion, the future duration time of the residual power is exploited. The duration time is derived from the vehicle’s future speed profile.

A Light Detection And Ranging (LiDAR) is now becoming an essential sensor for an autonomous vehicle. The LiDAR provides the surrounding environment information of the vehicle in the form of a point cloud. A decision-making system of the autonomous car is able to determine a safe and comfort maneuver by utilizing the detected LiDAR point cloud. The LiDAR points on the cloud are classified as dynamic or static class depending on the movement of the object being detected. If the movement class (dynamic or static) of detected points can be provided by LiDAR, the decision-making system is able to plan the appropriate motion of the autonomous vehicle according to the movement of the object. This paper proposes a real-time process to segment the motion states of LiDAR points. The basic principle of the classification algorithm is to classify the point-wise movement of a target point cloud through the other point clouds and sensor poses.

Controlled Auto-Ignition (CAI) combustion is a new combustion concept. Unlike the conventional internal combustion engine, CAI combustion takes place homogeneously throughout the fuel/air mixture with self ignition, and the mixture is burned without flame propagation. The start of combustion (SOC) is a critical factor in the combustion because SOC affects exhaust gas emissions, engine power, fuel economy and combustion characteristics. This paper presents a control oriented SOC detection method using a 10 bar of difference pressure, and proposes 50 percent normalized difference pressure for SOC detection parameter. Difference pressure is defined as the difference between the in-cylinder firing pressure and the in-cylinder motoring pressure. These methods were determined by CAI combustion experiments. Managing the difference pressure is a fast and precise method for SOC detection.

In CRDI diesel engines, the piezo injector is gradually replacing the solenoid injector due to the quick response of the actuator. Operating performance of the injectors in the CRDI diesel engine has an influence on engine emissions. Therefore, accurate injector control is one of the most important parts of the CRDI engine control. The objective of this paper is the development of a piezo injector driver for CRDI diesel engines. Electrical characteristics of the piezo injector were analyzed. A control strategy for charging and discharging the actuator are proposed. The developed injector driver is verified by experiments under various fuel pressures, injection durations and driving circuit voltages.

The successful monitoring of the combustion process depends on the accurate measurement of in-cylinder pressure. Piezoelectric transducers are normally used for in-cylinder pressure measurement. However, rapid changes in the temperature of the transducer housing and the quartz sensing element can change the transducer offset voltage. Therefore, piezoelectric transducers require referencing the output to the absolute pressure (pegging). This study reviews several pegging methods and proposes a modified method based on a variable polytropic coefficient. The feasibility of the proposed method was validated using both the simulated and the experimental pressure data from a common-rail direct injection (CRDI) diesel engine.

This paper presents a start of combustion (SOC) control for a common rail direct injection (CRDI) diesel engine, which is achieved by utilizing in-cylinder pressure signals. The difference pressure (DP), which is the difference between the in-cylinder firing pressure and motoring pressure, is selected as the variable for SOC detection. An adaptive feedforward controller was applied in order to improve the performance of the feedback controller. The feedforward controller consists of the radial basis function network (RBFN) and the feedback error learning method that is for training of the network. In this paper, the RBFN has two inputs which are engine speed and target SOC, and has one output, start of energizing. The feasibility and performance of the proposed controller were validated by transient engine operation experiments.

A control method using an in-cylinder pressure sensor can directly and precisely control engine combustion, lowering harmful emissions and fuel consumption levels. However, this method cannot be applied to a conventional engine management system because of its inaccuracy and the high cost of the pressure sensor, as well as the high computational load. In this study, we propose a real-time IMEP estimation method for a common rail direct injection diesel engine using the difference pressure integral as a cylinder pressure variable. The proposed method requires less computational load, enabling the IMEP to be estimated in real-time. In addition, we validated the estimation algorithm through simulation and engine experiments. The IMEP was accurately estimated with a small root mean square error of below 0.2305 bar.

In this paper, a nonlinear dynamic engine model is introduced, which is developed to represent an SI engine over a wide range of operating conditions. The model includes intake manifold dynamics, fuel film dynamics, and engine rotational dynamics with transport delays inherent in the four-stroke engine cycles, and can be used for designing engine controllers. The model is validated with engine-dynamometer experimental data. The accuracy of the model is evaluated by the comparison of the simulated and the measured data obtained from a 2.0 L inline four-cylinder engine over wide operating ranges. The test data are obtained from 42 operating conditions of the engine. The speed range is from 1500 (rpm) to 4000 (rpm), and the load range is from 0.4 (bar) to WOT. The results show that the simulation data from the model and the measured data during the engine test are in good agreement.

In a multi-cylinder variable valve lift (VVL) engine, in spite of its high efficiency and low emission performance, operation of the variable valve lift brings about not only variation of the air-fuel ratio at the exhaust manifold, but also individual cylinder air-fuel ratio maldistribution. In this study, in order to reduce the air-fuel ratio variation and maldistribution, we propose an individual cylinder air-fuel ratio estimation algorithm for individual cylinder air-fuel ratio control. For the purpose of the individual cylinder air-fuel ratio estimation, air charging dynamics are modeled according to valve lift conditions. In addition, based on the air charging model, individual cylinder air-fuel ratios are estimated by multi-rate sampling from single universal exhaust gas oxygen (UEGO) sensor located on the exhaust manifold. Estimation results are validated with a one-dimensional engine simulation tool.

Cylinder air charge is an important parameter to reduce generation of visible emissions by adjusting the amount of fuel injected into a diesel engine. In this study, we propose a cylinder air charge estimation algorithm for a diesel engine equipped with variable geometry turbocharger (VGT), exhaust gas recirculation (EGR), and swirl control valve (SCV). The estimation algorithm predicts the cylinder air charge using a mean value air path model and measurable signals available in mass produced engines. The estimation algorithm addresses effects of the VGT, EGR, and SCV on the cylinder air charge. The proposed estimation algorithm was validated with a 1-D engine model simulation.

In this paper, a control oriented cylinder-by-cylinder engine model (CCEM) and ECU-in-the-loop simulation (EILS) of common-rail direct injection (CRDI) diesel engine are presented. The CCEM includes the combustion model of torque production so that it is possible to acquire the in-cycle information, such as cylinder pressure. EILS environment using the CCEM is proposed for cylinder pressure based controller design. It allows real-time engine simulation available, and is applicable for developing the control logic and validating prototype ECUs. Finally, the accuracy of the CCEM is evaluated by the engine experimental data.

A controller is introduced for air-to-fuel ratio management, and the control scheme is based on the feedback error learning method. The controller consists of neural networks with linear feedback controller. The neural networks are radial basis function network (RBFN) that are trained by using the feedback error learning method, and the air-to-fuel ratio is measured from the wide-band oxygen sensor. Because the RBFNs are trained by online manner, the controller has adaptation capability, accordingly do not require the calibration effort. The performance of the controller is examined through experiments in transient operation with the engine-dynamometer.

This paper presents an exhaust gas recirculation (EGR) rate estimation algorithm for a turbocharged diesel engine. Accurate estimation of the EGR rate is important for precise air system control of a diesel engine. In order to estimate the EGR rate accurately, we developed an adaptive observer using a model reference identification scheme (MRIS). A linear parameter varying model for the intake manifold pressure dynamics is derived as the reference model for the adaptive observer. The intake and exhaust temperature models are developed through an empirical approach. The MRIS is used to design an update rule for the adaptive observer. Convergence of the proposed observer is proven by using the Lyapunov stability criterion. The proposed observer is implemented in a real-time embedded system and validated via engine experiments.

Increasing demands on the emission reduction of high speed direct injection (HSDI) diesel engines require more accurate control of injection parameters such as the injection timing, injection rate, and injection quantity. In order to meet injection requirements, the piezo injector, which has a piezoelectric element as an actuator, has been recently developed. Compared with solenoid-actuated injectors, piezo-actuated injectors yield greater force and give faster response times, resulting in more accurate and faster injections. In this study, a mathematical model of a piezo-actuated injector is developed. The injector model consists of three subsystems: the piezo-actuator subsystem, the mechanical subsystem, and the hydraulic subsystem. The constitutive relations of piezoelectricity are used for modeling the piezo-actuator subsystem. An estimation method of the injection timing and rate is introduced based on the proposed model.

Emission regulations for diesel engines have steadily become more stringent in the past decade, and there is no indication that this trend will change. As a result, the use of electronic engine control systems will be indispensable to diesel-powered vehicles. The conventional map-based control scheme is inadequate to meet the emission requirements. A mathematical model-based control scheme for a turbocharged diesel engine, on the other hand, can improve performance in terms of power and emissions during the steady state and the transient engine operations. In this study, a dynamic model of a turbocharged common-rail direct injection diesel engine is developed for control applications. This model is composed of differential and algebraic equations, which are derived from the filling and emptying method and the quasi-steady method, respectively.

In spark ignition engines, the mechanism of transferring electrical energy from an ignition system into the mixture in the spark gap is controlled by many aspects. The major parameters of these aspects are inputs of electrical energy, combustion energy release, and heat transfers. Heat caused by combustion energy is transferred to the spark plug, cylinder head, unburned mixture, and others. This study presents the development and validation of a flame kernel initiation and propagation model in SI engines, and most of the aspects described above are considered during the course of the model development. Furthermore, the model also takes into account the strain rate of the initial kernel and residual gas fraction. The model is validated by the engine experiments, which are conducted in a constant volume combustion chamber.

The introduction of inexpensive cylinder pressure sensors provides new opportunities for precise engine control. This paper presents a control strategy of spark advance and air-fuel ratio based upon cylinder pressure for spark ignition engines. In order to extend the cylinder pressure based engine control to a wide range of engine speeds, the appropriate choice of control parameters is important as well as essential. For this control scheme, peak pressure and its location for each cylinder during every engine cycle are the major parameters for controlling the air-fuel ratio and spark timing. However, the conventional method requires the measurement of cylinder pressure at every crank angle degree to determine the peak pressure and its location. In this study, the peak pressure and its location were estimated, using a multi-layer feedforward neural network, which needs only five cylinder pressure samples at -40°, -20°, 0°, 20°, and 40° after TDC.

The electrical power system is the vital lifeline to most of the control systems on modern vehicles. The demands on the system are highly complex, and a detailed understanding of the system behavior is necessary both to the process of systems integration and to the economic design of a specific control system or actuator. The vehicle electric power system, which consists of two major components: a generator and a battery, has to provide numerous electrical and electronic systems with enough electrical energy. A detailed understanding of the characteristics of the electric power system, electrical load demands, and the driving environment such as road, season, and vehicle weight are required when the capacities of the generator and the battery are to be determined for a vehicle. An easy-to-use and inexpensive simulation program may be needed to avoid the over/under design problem of the electric power system. A vehicle electric power simulator is developed in this study.

The effect of ignition energy, ignition system and spark plug electrode on initial flame kernel development in a constant volume combustion chamber has been studied. The experiment was done in a quiescent and lean condition. Two different ignition systems are designed and evaluated, and several kinds of spark plugs are also made. The spark time controller is also developed to regulate dwell time and to synchronize ignition time with data acquisition time. The ignition energy is measured at each experimental condition, and the flame propagation is measured by piezoelectric type pressure sensor. The heat release rate and the mass fraction burnt are derived from the combustion pressure. The results show that as the dwell time or the spark plug gap are increased, the ignition energy is increased, which derives higher heat release rate and faster the mass fraction burnt.

This paper presents a strategy to improve fuel atomization during warm-up. Heating the fuel inside the fuel-rail plans improvement on fuel atomization. In this experiment, the heated fuel-rail system is constructed to investigate the reduction effects on the size of the fuel droplet by fuel heating. The fuel atomization is examined by measuring Sauter Mean Diameter (SMD) of the fuel droplets from the three different types (two-hole, pintle, and six-hole) of injectors based upon the returnless heated fuel-rail system. The results show that the six-hole type injector with the heated fuel provides the best fuel atomization results in terms of SMD among three different types of injectors.