Fuel metering control system for internal combustion engine

A system for controlling fuel metering for an internal combustion engine having a plurality of cylinders, comprising:

• a first air/fuel ratio sensor installed upstream of a catalytic converter at an exhaust system of the engine for detecting a first air/fuel ratio of an exhaust gas of the engine;
• engine operating condition detecting means for detecting engine operating conditions at least including engine speed and engine load;
• fuel injection quantity determining means for determining a quantity of fuel injection for individual cylinders at least based on the detected engine operation conditions;
• a second air/fuel ratio sensor installed downstream of the catalytic converter for detecting a second air/fuel ratio of the exhaust gas passing through the catalytic converter;
• a desired air/fuel ratio correcting means for correcting a desired air/fuel ratio in response to the second air/fuel ratio detected by said second air/fuel ratio sensor;
• an adaptive correcting means for determining an adaptive correction coefficient to correct the quantity of fuel injection such that the detected first air/fuel ratio detected by the first air/fuel ratio sensor is adaptively brought to the corrected desired air/fuel ratio;
• output fuel injection quantity determining means for correcting the quantity of fuel injection by the adaptive correction coefficient to determine an output quantity of fuel injection;
• and
• a fuel injector for injecting fuel in the individual cylinders of the engine in response to the determined output quantity of fuel injection,
• wherein said adaptive correcting means includes an adaptive controller means and an adaptation means,
• said adaptation means adaptively estimating dynamic engine characteristic parameters based upon dynamic changes in the engine, and
• said adaptive controller means determining the adaptive correction coefficient based upon the dynamic engine characteristic parameters determined by the adaptation means such that the detected air/fuel ratio detected by the first air/fuel ratio sensor is adaptively brought to the corrected desired air/fuel ratio.

A system for controlling fuel metering for an internal combustion engine having a plurality of cylinders, comprising:

• a first air/fuel ratio sensor installed upstream of a catalytic converter at an exhaust system of the engine for detecting a first air/fuel ratio of an exhaust gas of the engine;
• engine operating condition detecting means for detecting engine operating conditions at least including engine speed and engine load;
• a second air/fuel ratio sensor installed downstream of the catalytic converter for detecting a second air/fuel ratio of the exhaust gas passing through the catalytic converter;
• control means for controlling fuel injected into said engine based upon the outputs from the first and second air/fuel ratio sensors and the engine operating condition detecting means, said control means including;
• a) fuel injection quantity determining means for determining a quantity of fuel injection for individual cylinders at least based on the detected engine operating conditions;
• b) desired air/fuel ratio correcting means for correcting a desired air/fuel ratio in response to the second air/fuel ratio detected by said second air/fuel ratio sensor;
• c) an adaptive correcting means for determining an adaptive correction coefficient to correct the quantity of fuel injection such that the detected first air/fuel ratio detected by the first air/fuel ratio sensor is adaptively brought to the corrected desired air/fuel ratio;
• and
• d) output fuel injection quantity determining means for correcting the quantity of fuel injection by the adaptive correction coefficient to determine an output quantity of fuel injection;
• and
• a fuel injector for injecting fuel in the individual cylinders of the engine in response to the determined output quantity of fuel injection,
• wherein said adaptive correcting means includes an adaptive controller means and an adaptation mechanism means,
• said adaptation mechanism means adaptively estimating dynamic engine characteristic parameters based upon dynamic changes in the engine;
• and
• said adaptive controller means determining the adaptive correction coefficient based upon the dynamic engine characteristic parameters determined by the adaptation mechanism means such that the detected air/fuel ratio detected by the first air/fuel ratio sensor is adaptively brought to the corrected desired air/fuel ratio.

A method for controlling fuel metering for an internal combustion engine having a plurality of cylinders, comprising the steps of:

• detecting a first air/fuel ratio of an exhaust gas of the engine by a first air/fuel ratio sensor installed upstream of a catalytic converter at an exhaust system of the engine;
• detecting a second air/fuel ratio of the exhaust gas passing through the catalytic converter by a second air/fuel ratio sensor installed downstream of the catalytic converter;
• detecting engine operating conditions at least including engine speed and engine load;
• determining a quantity of fuel injection for individual cylinders at least based on the detected engine operating conditions;
• correcting a desired air/fuel ratio in response to the second air/fuel ratio detected by the second air/fuel ratio sensor;
• adaptively determining an adaptive correction coefficient to correct the quantity of fuel injection such that the detected first air/fuel ratio detected by the first air/fuel ratio sensor is adaptively brought to the corrected desired air/fuel ratio;
• correcting the quantity of fuel injection by the adaptive correction coefficient to determine an output quantity of fuel injection;
• and
• injecting fuel for the individual cylinders of the engine in response to the determined output quantity of fuel injection,
• wherein said adaptive determination of the adaptive correction coefficient includes adaptively estimating dynamic engine characteristic parameters based upon dynamic changes in the engine and determining the adaptive correction coefficient based upon the dynamic engine characteristic parameters.

A computer system for controlling fuel metering for an internal combustion engine comprising:

• fuel injection quantity determining means for determining a quantity of fuel injection for individual cylinders at least based on detected engine operating conditions;
• desired air/fuel ratio correcting means for correcting a desired air/fuel ratio in response an air/fuel ratio detected by a second air/fuel ratio sensor installed downstream of a catalytic converter;
• an adaptive correcting mean for determining an adaptive correction coefficient to correct the quantity of fuel injection such that a detected first air/fuel ratio detected by a first air/fuel ratio sensor installed upstream of a catalytic converter is adaptively brought to the corrected desire air/fuel ratio;
• and
• output fuel injection quantity determining means for correcting the quantity of fuel injection by the adaptive correction coefficient to determine an output quantity of fuel injection, wherein individual cylinders of the engine are injected with fuel based upon the determined output quantity of fuel injection,
• wherein said adaptive correcting means includes an adaptive controller means and an adaptation mechanism means.
• said adaptation mechanism means adaptively estimating dynamic engine characteristic parameters based upon dynamic changes in the engine, and
• said adaptive controller means determining the adaptive correction coefficient based upon the dynamic engine characteristic parameters determined by the adaptation mechanism means such that the detected air/fuel ratio detected by the first air/fuel ratio sensor is adaptively brought to the corrected desired air/fuel ratio.