| Summary: | 博士 === 國立臺灣科技大學 === 機械工程系 === 102 === This thesis presents the modeling and control of homogeneous charge compression
ignition (HCCI) engines, common rail (CR) diesel Engines and selective
catalytic reduction (SCR) systems. First of all, for stability of HCCI engines,
A model reference adaptive controller (MRAC) is designed based on a simplified
bilinear parametric model to regulate the combustion timing CA50 in the presence
of uncertainty or unknown variation in plant parameters such as cylinder
charge properties. The adaptive controller is developed based on a simplified
control-oriented HCCI cycle-to-cycle ignition timing dynamics model. The simulation
results show that the controller is able to regulate the combustion timing
CA50 to desired set-point via controlling the rebreathing lift of exhaust valve when
a cylinder charge properties are changing with time. Secondly, an engine management
system (EMS) is developed for a common-rail diesel engine to achieve
precise and flexible control of the rail pressure, fuel injection timing and injected
fuel amount. Real-time calculation of the combustion heat release rate (HRR)
is conducted based on the cylinder pressure measurement to examine the effect
of various fuel types and injection parameters on engine brake power and NOx
emission. To reduce the tail-pipe NOx emission of diesel engine, a controller for
selective catalytic reduction (SCR) system is developed. Experimental tests in
European Stationary Cycle (ESC) and European Transient Cycle (ETC) driving
modes are conducted to demonstrate the performance and reliability of the SCR
system with a rule-based feedforward plus PI feedback controller. A SCR model
is then developed and is validated against experimental data. Finally, an effective
method that identifies the cross-sensitivity of SNS to ammonia is proposed on the
basis of a periodic modulation of the urea dosage rate and Fast Fourier Transform
(FFT) of the SNS signal. This method enables us to measure the true NOx
concentration correctly even if the NOx is overkilled by excessive ammonia.
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