Alcohol discriminator and fuel control for an internal combustion engine fueled with alcohol-gasoline fuel mixtures

A discriminator apparatus for identifying the type of alcohol contained in an alcohol-gasoline fuel mixture delivered to an internal combustion engine, where the alcohol is from the group consisting of ethanol and methanol, the discriminator apparatus comprising;

• a resistive sensor for measuring the electrical resistivity of the fuel mixture and for developing a resistance signal having a value indicative of the fuel mixture resistivity;
• means for deriving a threshold resistance value;
• means for comparing the value of the resistance signal with the threshold resistance value;
• means for providing an output signal indicating that ethanol is contained in the fuel mixture when value of the resistance signal is greater than the threshold resistance value and indicating that methanol is contained in the fuel mixture when the value of the resistance signal is less than the threshold resistance value.

A fuel control system for an internal combustion engine operated on an alcohol-gasoline fuel mixture, the control system comprising:

• a sensor for identifying the type of alcohol contained in the alcohol-gasoline fuel mixture;
• means for determining the relative concentration of alcohol to gasoline in the fuel mixture in accordance with identified type of alcohol in the fuel mixture;
• and
• means for controlling the quantity of fuel delivered to the engine based upon the identified type and concentration of alcohol in the fuel mixture.

A fuel control system for an internal combustion engine operated on an alcohol-gasoline fuel mixture, the fuel control system comprising:

• a resistive sensor for measuring the resistivity of the fuel mixture and for developing a resistance signal indicative of fuel mixture resistivity;
• a capacitive sensor for measuring the dielectric constant of the fuel mixture and for developing a capacitance signal indicative of the fuel mixture dielectric constant;
• means responsive to the resistance and capacitance signals for determining the type and concentration of alcohol in the fuel mixture;
• means for controlling the quantity of fuel mixture delivered to the engine in accordance with the determined type and concentration of alcohol in the fuel mixture.