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In this research, with proposed design of hydraulic-controlled variable valve lift system, a feed pump is used to supply the low-pressure oil into the hydraulic pump which will compress low-pressure oil as high-pressure oil and pumps the high-pressure oil into the hydraulic cylinder. In the meanwhile, the intake valve opened in accordance with the plunger is pushed by the hydraulic cylinder. To achieve the change of intake valve lift, a DC motor connected with the control rack that is used for controlling oil-drain time of the hydraulic pump. In addition, a solenoid valve is installed in order that the intake valve will be closed quickly without controlling the drain flow when the maximum valve lift is reached. Commonly, the throttle is not required with variable valve lift system, but the throttle is kept for engine start. Hence, except for engine cranking condition, the throttle maintains in wide open (WOT) under different test conditions.

Butanol is deemed as a potential alternative fuel for vehicle, but there are few studies about applying butanol in engine combustion. This paper focuses on application of butanol-gasoline blend fuel on scooter engine. In this research, different volume percentage of butanol-gasoline blend fuel, B10, B20, B40, B60, B80 and B100 are applied on 125cc scooter engine to conduct engine experiment, and higher than B60 blend fuel is declared as high butanol concentration blend fuel. The test conditions are set at 4000 and 6000rpm under partial load and full load. After executing engine experiment, engine performance, brake specific fuel consumption (BSFC), emissions and combustion analysis are discussed. Furthermore, viscosity and fuel spray are tested with high butanol concentration blend fuel. The engine experimental result shows that B100 fuels can increase engine performance under engine 4000 and 6000rpm.

This paper develops an adaptive idle speed control strategy for a V2, 1000 cc four-stroke, water-cooled, port injection SI engine. In order to verify the proposed strategy, the non-dimensional engine model including charging and torque dynamics is established in Matlab/Simulink software based on previously experimental verification. The integration of dynamics above will be a multi-input-single-output (MISO) system, which inputs are throttle angle and spark advance angle, and the output is engine speed. The proposed adaptive controller is developed on the model-based structure. The system parameters are updated by recursive least square (RLS) method so the system is able to represent the actual operation. The updated system parameters adjust control gain by derivation of closed-loop gain and pole placement.

Butanol is deemed as the potential alternative fuel for future development, and the previous researches show poor injection spray atomization when high butanol concentration blended fuel applying on stock small scooter engines. In this research, a platform is built to observe the spray atomization phenomena with 2.5kg/cm2 (2.452bar) 、 3.5kg/cm2(3.433bar) injection pressures and various n-butanol volume percent concentration blended fuels, B60, B80 and B100. After that, engine experiments are undergone with above conditions under wide open throttle (WOT) with stoichiometric air fuel ratio (AFR) at 4000rpm. The experiment results are analyzed and discussed from different aspects eventually. Injection spray observation shows that worse spray atomization appears accompanied with higher concentration blended fuel. But when the injection pressure increases, higher shear force acting on the injection spray improves the breakup of fuel and enhances the effect of fuel spray atomization.

In this paper, the off-line analysis method is applied to develop three-way catalytic converter (TWC) diagnostic strategy including oxygen sensor (O2 sensor) diagnostic strategy with common narrow band oxygen sensor (EGO sensor) in Matlab/Simulink software. Moreover, Mototron ECU (Engine Control Unit) is used for monitoring catalyst deterioration. However, aged catalyst is difficult to possess so the different catalytic conversion efficiency (CCE) is simulated by using exhaust by-pass valve. The CEC (China Engine Corporation) 1L V2, four stroke, water-cooled engine is selected as target engine to conduct engine dynamometer test. After making sure O2 sensor operates normally, the catalyst diagnostic strategy test is executed. The experimental result shows that the catalyst deterioration accurately can be detected when the failure phenomenon takes place.

Fuel film dynamics in the intake manifold are considered to develop air fuel ratio (AFR) control strategy with on-line system identification for a V2 engine in this paper. A1000 cc four-stroke two-cylinder, water-cooled port injection SI engine is used as the target engine to develop the engine model in Matlab/Simulink. The model which consists of charging, fueling, combustion, friction, and engine rotational dynamics is used to verify the proposed AFR control. Since the fuel film dynamics changes with different engine operating conditions, the fuel film parameters are often listed as look-up tables for fuel film dynamics calculation in the conventional AFR control. However, those parameters might be inaccurate during transient engine operation. Different intake port temperature will affect the accuracy of those fuel film parameters as well. In order to solve this problem, recursive least square (RLS) is used to identify those parameters on-line.

This paper develops an engine model for the model-in-the-loop (MIL) and hardware-in-the-loop (HIL) application to shorten the time duration and reduce the costs of developing and verifying the engine management system (EMS). The target engine is a 1.0L V-type two cylinder water-cooled spark-ignition engine. The engine model is developed using a so-called modulization method, which includes to: (1) separate the sub-models according to the different physical phenomena; (2) collect the sub-models to establish a library; (3) execute the component modules based on a pre-determined sequence by a more flexible way. The engine model is then applied in MIL structure for testing and verifying the control strategies in the developed EMS. After all strategies are verified, the HIL structure is constructed by a hardware controller and a virtual engine in the xPC target. The execution time-step of engine model is analyzed to keep enough accuracy and numeric stability for real-time simulation.

The fossil fuel is consumed faster than last century. However, the fossil fuel reserves might be depleted due to its limited resources. Many researchers have started to seek alternative of fossil fuels for vehicles. Biofuels are regarded as a shorten-solution which synthesizes some additive fuel from bio-materials into fossil fuel to reduce fossil fuel consumption and can be applied on original fuel supplying system of vehicles that becomes another advantage. This paper focuses on studying the operation characteristics of using gasohol biofuel in a production motorcycle engine. Engine experiments with various test conditions are designed to investigate the operation characteristics with different concentration of ethanol. The ethanol concentrations considered in this paper include 10%, 20%, 50%, 65%, and 80% by weight, which are then compared with the results from pure gasoline.

This study focuses on developing a cranking torque reduction strategy for a motorcycle with idling-stop system. At first, experiments are done to measure the electric current consumption of starting motor which is then converted into cranking torque by the motor torque constant. The experimental results also indicate that the piston position, after the engine is stopped, always remains at the bottom dead center of compression stroke. This will further increase the cranking torque for the next engine start due to static friction and compression pressure. This paper, therefore, proposes to retrofit the original generator of motorcycle as a motor/generator with the same operation power. The motor/generator could be worked in motor mode to assist the starting motor to crank the engine, and hence the instantaneous power provided by the starting motor could be reduced to extend its life time.

For vehicles with intake manifold absolute pressure (MAP) sensor, the intake air mass is obtained using speed-density method. Since the analog MAP signal will contain high frequency noise with uncertain amplitude, the MAP value obtained in the engine management system using angle based sampling will result in MAP value variation even for engine steady-state operation. In order to properly obtain a MAP value under nonlinear time-varying characteristics, a MAP estimation method based on a closed-loop model is proposed. First, an adaptive two-input single-output intake manifold model is constructed. The Recursive Least Square technique is utilized to on-line identify the intake manifold model with throttle opening angle and engine speed as inputs. The identified intake manifold model is then employed to estimate the MAP using the Kalman Filter.

The on-board diagnostic (OBD) technologies for automobiles have been well-developed; however, it could not be carried out on motorcycles directly since the operation conditions are quite different between automobiles and motorcycles. In this research, we propose a misfire detection strategy for motorcycles based on the characteristics of crankshaft rotational dynamics. At first, experiments were done on a 125cc motorcycle to investigate the variation of instantaneous crankshaft rotational speed in power stroke while the misfire events are injected at different engine operation conditions. In order to generate misfire events for the engine, a misfire generator is established for providing specific misfire rates. If a misfire takes place at higher engine speed, the instantaneous rotational speed will decline continuously during power stroke due to higher friction losses, which leads to the reduction of average crankshaft rotational speed as well.

Range extender (RE), combined by an engine and a generator, charges the battery on the electric vehicle. Power management strategy of a range extended electric vehicle (REEV) will determine the required charging power according to battery state of charge (SOC) and driver demands. The charging power demand will be further converted into required operation torque and rotational speed demands from engine. Torque-based engine management system (EMS) is, therefore, required to receive the torque command from power management strategy for controlling the engine at required torque. This research develops a torque-based EMS for a RE engine which is a 125cc four-stroke semi-direct injection engine and fueled by liquefied petroleum gas (LPG). The RE engine is operated to provide stable power output for driving generator, so we only select two operating points for this engine. The first operating point is for higher power output and better fuel economy.

Engine control units manage various conditions in an operating engine, including fuel injection, spark ignition and valve timing, in order to achieve the goals of high performance, high fuel efficiency and low emissions. Typically, engine models are necessary for developing engine control systems. Most mean value engine models (MVEM) are based on empirical volumetric efficiency, which contributes to calculating intake air flow rate. Therefore, they are not capable of simulating changes in valve lift and valve timing, and cannot be used for a variable valve train (VVT) engine. A method of calculating intake air flow rate with variable valve lift and valve timing is needed to adapt to the demands on VVT engine models. An engine model is proposed that focuses on a charging model, developed by using a filling-and-emptying model to simulate the air exchange in an engine, including intake- and exhaust-air flows.

The phenomenon of fuel-film dynamics for four-stroke small-scale spark-ignition engines is investigated in this paper. A first-order fuel-film model, so-called tau-x model, is used to represent the fuel dynamics. The parameters of fuel-film model, which consists of the portion of fuel that deposited on the manifold wall and the time constant of the fuel evaporation process, are identified using the recursive least squared technique. Performances of the proposed algorithm are evaluated using a nonlinear engine model in Matlab/Simulink. The preliminary simulation results show that the proposed algorithm can accurately be used to identify the parameters of fuel-film model. The experimental data are then utilized to study the characteristics of fuel-film dynamics, and show that the fuel-film dynamics is significantly affected by engine speed, throttle opening, injection timing, and intake temperature.

This paper constructed a parallel type hybrid-electric bus model based on GM-Allison system which is consisted of three planetary gear-sets and two motors. The simulation model is modified from the backward-looking simulation of ADVISOR. The hybrid-electric bus (HEB) is simulated to compare with a conventional diesel bus. Four different driving cycles are employed: Taipei City Bus Cycle, New York Bus Cycle, Manhattan Cycle, and Central Business District Cycle. Three different control strategies, namely speed control, torque control, and power control are studied. The simulation results show that the GM-Allison hybrid-electric bus with good control strategy can improve fuel economy by 66% compared to a conventional diesel bus. As for exhaust emissions, CO, HC, NOx and PM are reduced by 83%, 59%, 66% and 62%, respectively.

A heat transfer model for small-scale spark-ignition engines has been proposed by authors in previous study. However, this model is only based on single engine, it may not be suitable for the others. In order to improve the accuracy of predicted heat transfer rate for different small-scale engines, another heat transfer model using Stanton number based on two engines is proposed. Prediction results of instantaneous heat flux and global heat transfer based on the proposed model are compared with the experimental results and prediction results of previous model. It is found that the proposed model has prediction results closer to the measured data than the previous models.

This paper established a hardware-in-the-loop (HIL) system for developing the engine management system (EMS) of a motorcycle, which combines xPC target real-time simulator and PC based controller. An engine model of 125cc four-stroke gasoline engine that included the calculation of cylinder pressure is employed to be a control plant. A proposed control strategy developed with application of this HIL is verified to be superior to the conventional EMS of motorcycles. The proposed controller can send fuel injection and spark ignition control signals every two revolutions accurately via stroke identification method. During the engine running period, perhaps the ignition coil or other electronic equipment will conduct noise that interfere crankshaft tooth signal. Therefore, a Kalman filter is designed to improve the robustness of controller. Under interference, the performance of proposed controller is more satisfied than that without Kalman filter.

In order to improve the performance of a small gasoline engine, a part of oxygen is added to the intake air when the engine is operated at wide open throttle. The combustion process can be enhanced by using an oxidant that contains a higher proportion of oxygen than that in normal air. This paper studies the combustion characteristics and engine performance of such engine. Engine testing is performed on a 50 cc four-stroke spark-ignition engine with the oxygen concentration of intake air ranging from 21% to 25% by volume. The engine torque is increased with increasing oxygen concentration. The HC and CO emissions are decreased with oxygen enrichment, but the NOx emission is increased.

Due to the nonlinear time-varying nature of the spark-ignition engine, an adaptive multi-input single-output (MISO) controller based on self-tuning regulator (STR) is proposed for idle speed control in this paper. The spark timing and idle air control are simultaneously employed as control inputs for maintaining the desired idle speed, and are designed based on P and PI type STR, respectively. The Recursive Least Square technique is employed to identify the engine as a first-order MISO linear model. Pole placement technique is then used to design the adaptive MISO controller. Performances of the proposed algorithm are evaluated using a nonlinear engine model in Matlab/Simulink. The system parameters with 10% uncertainties are also utilized to perform the associated robustness analysis. Preliminary simulation results show significant reduction of speed deviations under the presence of torque disturbances and model uncertainties.

This work studies the potential to use nanoparticles as additives in lubrication oil to improve friction and wear properties. The friction coefficient, electrical contact resistance and wear depth are experimentally measuring using a reciprocating sliding tribo-tester at various temperatures, contact pressures and sliding velocities. The test results show that the nanoparticle as additive in base oil can reduce friction and wear by up to 50% in mixed and boundary regimes, but in a commercial engine oil, it has a relatively minor effect. The material properties, size and shape of nanoparticles affect their tribological properties. The mechanisms of friction and wear behavior improved are briefly discussed.