Search

Abstract: Methods for diagnosing misfire in internal combustion engines are presented in this paper. Crank-angle domain digital filters are used to extract features from the measured engine speed signal that are characteristic of misfire. Features for intermittent and continuous misfires are developed separately, since the engine speed responses for intermittent and continuous misfires are distinctly different. Also, the influence of crankshaft torsional vibration and repeatable measurement errors must be addressed differently in each case. The outputs from the digital filters serve as inputs to a pattern recognition network based on linear parametric classifiers. Experimental results from implementation on a Ford 4.6L V-8 engine are provided. [Copyright &y& Elsevier]

Abstract: The vibrational characteristics of an internal combustion engine crankshaft are investigated from a cylinder health diagnostics point of view. Experimental results from a six-cylinder industrial diesel engine are presented to demonstrate the effects of cylinder imbalance on the individual harmonic components of the engine speed signal. A crank-angle domain numerical model of the crankshaft dynamics for a six-cylinder industrial diesel engine is also adopted to establish the effects of continuous low-power production in individual cylinders of a multi-cylinder engine. Outline of a diagnostics algorithm that makes use of the properties of crankshaft vibration behaviour is provided. In particular, crank-angle domain notch filters are employed to extact the harmonic components of engine speed. The outlined method can be implemented for individual cylinder health diagnostics across a family of multi-cylinder engines and can be formulated to handle changes in crankshaft characteristics due to replacement of mechanical components and/or wear. [Copyright &y& Elsevier]

Studies a feedforward controller identification process for the transient fueling control of spark ignition (SI) engines. Objective of the SI fueling control system; Controller identification process; Design and implementation of a repetitive feedback controller; Feedforward fueling controller identified using standard parametric system identification tools; Experimental validation provided on a 1999 Ford V-8 fuel injected engine with sequential port injection.

Studies a method for designing repetitive feedback controllers using nonparametric frequency response plant models. Comparison with zero-phase-error controllers; Optimal equiripple filter that is useful when designing high-order filters; Validation of the process on an engine control application; Use of a repetitive controller to determine the dynamic fueling requirements of a fuel injected, spark-ignition engine subjected to periodic changes in the throttle position.

The article presents a design methodology of a multi-variable linear feedback controller for the constant speed control of spark-ignition engines. The feedback control system utilizes throttle and ignition timing to control the speed and roughness of the engine. It likewise proposes a loop shaping approach to design the feedback controller. Moreover, it provides the experimental results in the use of a Ford 4.6 liter V-8 engine.