Radio Frequency Control of Air-Fuel Ratio

摘要

Methods are disclosed for determining an oxidation state of a catalyst using RF signals. The method may include introducing radio-frequency signals into a resonant chamber including a catalyst, modulating an air-fuel ratio of an engine upstream of the catalyst to generate a sequence of uniform pulses and at least one altered pulse that differs from the uniform pulses, and comparing a frequency response of two or more resonant modes of the radio-frequency signals during the sequence to determine an oxidation state of the catalyst. The method may further include adjusting the air-fuel ratio based on the comparing step. Two or more altered pulses may be inserted into the air-fuel ratio sequence. The altered pulse may have a pulse width and/or amplitude that differs from the uniform pulses. The methods may be used to adjust an air-fuel ratio to correct or impart a bias.

主权项

1. A method comprising:
introducing radio-frequency signals into a resonant chamber including a catalyst; modulating an air-fuel ratio of an engine upstream of the catalyst to generate a sequence of uniform pulses and at least a first altered pulse that differs from the uniform pulses; and comparing a frequency response of two or more resonant modes of the radio-frequency signals during the sequence to determine an oxidation state of the catalyst.