Optical fuel composition sensor.

摘要

An engine control system for operating an internal combustion engine with any mixture of alcohol and gasoline. The control system includes an air/fuel ratio control system providing a desired fuel charge in relation to the alcohol and gasoline content of the fuel which is indicated by an optical sensor. In one embodiment, the optical sensor includes an optical sensor for determining the ratio for each of two constituents in a fluid mixture wherein each constituent has a different index of refraction, the optical sensor comprising, a hemispherical lens portion (74) having an axis (88), a hemispherical surface surrounded by the fluid mixture, and a base (82), a light emitting source (98) aligned with said axis and positioned adjacent to said base (82) for transmitting light against substantially all of said hemispherical surface, and a light detector (94) aligned with said axis and positioned on said base adjacent said light emitting source, said light detector collecting light which is reflected from substantially all of said hemispherical surface such that the optical sensor has an effective aperture of nearly 2 Pi steradians, said light detector (94) providing an electrical signal related to the proportion of the constituents in the fluid mixture..