Yuh-Yih Wu

Adaptive Idle Speed Control for Spark-Ignition Engines

Due to the nonlinear time-varying nature of the sparkignition 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.

Using TiO2 nanofluid additive for engine lubrication oil

Purpose – Nanoparticles have been studied as additives to lubrication oils for reducing friction and wear. The purpose of this paper is to investigate the effect of nanofluid on engine oil and friction reduction in a real engine.Design/methodology/approach – The nanoparticles were prepared using a high‐temperature arc in a vacuum chamber to vaporize the Ti metal, and then condensed into a dispersant to form the TiO2 nanofluid, which was used as lubricant additive. Experiments were performed in both real engine running and test rig.Findings – It was found that the engine oil with nanofluid additive with an ethylene glycol dispersant of nanoparticles, had gelled after 10‐h of engine running. The problem of oil gelation (jelly‐like) was solved by replacing the dispersant with paraffin oil. The engine oil with TiO2 nanoparticle additive exhibited lower friction force as compared to the original oil. The experiment showed that a smaller particle size exhibits better friction reduction with particle size rangin...

Adaptive Power Split Control for a Hybrid Electric Scooter

An adaptive power split control for a rear-wheel-driven hybrid electric scooter (HES) is proposed in this paper. It is designed using the concept of total equivalent fuel consumption. The equivalence factor is used to transform the electric energy into the equivalent fuel energy and is often selected to be a predetermined function of the state of charge (SOC) of the battery. However, the predetermined function might not be optimal for different driving cycles. An adaptive fuzzy sliding mode controller is used to adjust the equivalence factor according to the SOC deviation. An instantaneous cost function, which consists of the total equivalent fuel consumption, is then minimized to obtain the optimal power split between the internal combustion engine and the electric motor. Deterministic dynamic programming (DDP) is used to offer the performance upper bound to benchmark the proposed control strategy. Preliminary results show that suboptimal fuel economy, which is close to the DDP performance, can be achieved for various driving cycles.

Producing Aluminum-oxide Brake Nanofluids Using Plasma Charging System

This study examines the characteristics of Aluminum-oxide brake nanofluids (AOBN) manufactured by a home-made machine, the plasma arc system. The plasma electric arc welding machine was specially modified to be a nanofluid production system in the experiment. Argon was chosen to be the plasma gas because it can be ionized very easily and needs only lower voltage to keep the production of plasma electric arcs continuous. The aluminum bulk specimen is then mixed with DOT3 break fluid. The AOBN thus obtained shows a higher boiling, higher viscosity and higher conductivity. Furthermore, they are affected by the synthesizing parameters such as cooling liquid temperature and vacuum pressure. The confirmed appearance of nanoparticles was determined by Transmission Electron Microscopy (TEM) and X-RAY. This study revealed that a home made plasma arc machine can produce AOBN which surpasses the boiling point to reduce the occurrence of vaporlock, higher viscosity, higher conductivity and circle geometry common to the superior performance of brake nanofluids.

Modeling and Control of Hybrid Electric Motorcycle with Direct-Driven Wheel Motor

A Hybrid Electric Motorcycle (HEM) with a direct-driven wheel motor is proposed in this paper. The rear wheel is driven by an internal combustion engine and a powertrain system of a traditional motorcycle with minor modifications. The front wheel is driven by a direct-driven wheel motor. The proposed HEM is a parallel configuration. Both wheels can supply tractive forces simultaneously to drive the motorcycle when necessary. A rule-based structure is used to design the power split controller of the proposed HEM. Fuel economy of the proposed design will be evaluated by a dynamic simulation model in Matlab /Simulink using ECE-R40 driving cycle.

Modulization of four-stroke single-cylinder spark-ignition air-cooled engine models

Abstract In order to satisfy different requirements for engine design and real-time simulation, modulization technology is used in this paper to establish the engine model for small-scale engines. The model consists of simple and complex modules of charging, torque, friction, and crankshaft dynamics, which are established in Matlab/Simulink and verified using the experimental data. Different sets of these modules can be selected for various applications. For engine design, a complex model, which consists of the wave-action charging module and the mean-value combustion module, is employed to study the effects of inlet and exhaust systems on torque output performance. For real-time simulation, different levels of complexity can be selected according to the hardware-in-the-loop requirement of the control verification.

Design of Multi-Mode Switch Strategy for Lean Burn Engine Using Driving Pattern Recognition Technique

A multi-mode switch strategy based on driving pattern recognition (DPR) technique used for lean burn engine is proposed in this paper. First, four representative driving patterns (RDP) are selected from nine Taiwan driving patterns. The single-mode switch strategy is then extracted and optimized for each RDP by analyzing the results of dynamic programming. The proposed strategy can select the appropriate single-mode switch strategy using the DPR technique, which is designed to classify the current driving scenario into one of the RDPs. Preliminary results show that the proposed strategy can significantly reduce the fuel consumption without excessive increment of NOx emission across all the test scenarios.

Estimation of engine rotational dynamics using a closed-loop estimator with stroke identification for engine management systems

Abstract In order to study the effect of the crank sensor noise on the engine management system (EMS), an algorithm using a closed-loop estimator with stroke identification is proposed to estimate the engine rotational dynamics. Estimated crank angle and engine speed are used for fuel injection and ignition control systems. The closed-loop estimator design is based on a linear model by assuming that the engine rotational inertia is constant. Since the effective inertia actually varies with different crank angles, the stability of the proposed algorithm is assessed using the Lyapunov stability theorem. Performances of the proposed and traditional algorithms are evaluated using a non-linear engine model with a four-plus-one-tooth crankshaft wheel in Matlab/Simulink. The estimated crank angle and engine speed of the traditional algorithm can be significantly affected by large sensor noises resulting from the poorly grounded ignition coil. It was found that the proposed algorithm can mitigate the noise impact and thus maintain the desired engine control performance.

Application of semi-direct injection for spark-ignition engine

This paper proposes an application of a motorcycle engine lean-burn system for improving engine efficiency and reducing exhaust emissions. This Semi-Direct Injection (SDI) system consists of a high swirl charge, injection during intake-valve opening, and air-assisted fuel injection. The fuel enters the cylinder directly through the intake valve near the middle intake stroke for a richer mixture around the spark plug. A 125 cc, 4-valve, Port-Fuel-Injection (PFI) engine was retrofitted by designing a control plate to enhance the swirl. The swirl ratio was increased to 3.8 and the lean limit was extended to 1.7 of lambda (excess air ratio). The engine was tested at the low-load region, which includes most operation points of the ECE-40 driving cycle. A complete engine performance map was conducted for comparison between SDI and original PFI engines. The results show that Brake-Specific Fuel Consumption (BSFC) decreased by 11.3%. Brake-specific exhaust emissions of NOx and CO decreased by 32.0% and 92.9%, respectively. The HC emission increased by 47.7%.

Estimation of Engine Rotational Dynamics Using Kalman Filter Based on a Kinematic Model

For a conventional scooter engine with a four-plus-one-tooth crankshaft wheel, not only is the crankshaft position estimation insufficient due to poor angle resolution, but the speed measurement might also be easily contaminated by the sensor noise. We proposed a Kalman filter with stroke identification to estimate the engine rotational dynamics. The design of the Kalman filter is based on a kinematic model that requires no engine parameters. A nonlinear engine model is used to evaluate the estimation performance of the conventional algorithm using a low-pass filter and the proposed algorithm at various operating conditions. Preliminary simulation and experimental results show that the proposed algorithm can mitigate the noise impact and result in estimations closer to the actual engine responses.