Physical quantity detecting apparatus and internal combustion engine control apparatus each utilizing optical fiber.

摘要

A pressure detecting apparatus mounted on a cylinder head gasket of a combustion engine comprises at least one optical fiber (3;500), at least one light emitting means (1) for emitting an incident light beam on the optical fiber, and at least one light receiving means (5) for detecting an outgoing light beam from the optical fiber. A position information generating means (14) provides information indicative of the position of the applied pressure at a plurality of sites along the optical fiber. An operating means (12;12b) calculates a change in the pressure over time at the respective optical fiber positions from the received position informations and measured pressures. Thus different physical quantities (e.g. temperture, pressure) can be simultaneously sensed by one single fiber at multiple locations by using different polarization modes.