| Summary: | 碩士 === 中華大學 === 機械與航太工程研究所 === 89 === 英文摘要
The thesis presents a LabVIEW-aided engine condition monitoring design system. The analog signals of engine running parameters are acquired and converted to digital signals by data acquisition board, respectively. These data can be recorded and stored simultaneously in the LabVIEW environment and displayed on the screen. In this approach, the technique potentially provides a friendly graphical interface with the operator for the real-time monitoring of engine parameters and illustrates the concepts that could form the basis of any future on-line engine health monitoring facility.
The engine model includes intake manifold dynamics, actuator dynamics, sensor dynamics, and cycle delay inherent in a four-stroke engine process. Since the exhaust sensor only provides a delayed and lagged AFR signal to the controller, the conventional proportional and integral (PI) feedback control will slow down the system response. To achieve a high bandwidth closed-loop control of AFR, modern observer-based control can be used as a feed-forward control.
As the parameters of fuel-injected engines depend on the engine operating conditions, as well as engine wear, aging or lack of maintenance, the engine model suffers from model uncertainty. Two control methodologies are used to deal with the engine parameter uncertainties. One is the gain-scheduling technique in which feed-forward and feedback controls are designed under different operating conditions. The other is the adaptive technique in which the control parameters are tuned on-line during various operating conditions. Simulation results indicate that adaptive method or gain-scheduling method can improve AFR transient behavior.
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