Knocking detection of a gasoline engine by utilizing an optical fiber with specific refractive-index composition

摘要

Abnormal combustion of a gasoline engine is often accompanied by a sharp metallic noise called knocking. A recently proposed method of in-cylinder pressure measurement is applied to detect the knocking, where the bending power loss of a single-mode fiber with specific refractive-index composition is utilized, The high-frequency response of a prototype sensor is obtained with a small structure to utilize the bending mechanism that is installed into an engine head gasket. Knocking signals are detected in a wide range of trace-to heavy-knock conditions. (C) 1998 Optical Society of America. [References: 25]