Fuel metering control system for internal combustion engine

A method for controlling fuel metering for a multi-cylinder internal combustion engine, said method comprising the steps of:

• (a) detecting an air/fuel ratio;
• (b) detecting engine operating conditions including at least engine speed and engine load;
• (c) determining a quantity of fuel injection for individual cylinders based on at least the detected engine operating conditions at a predetermined crank angle of the individual cylinders;
• (d) using an adaptive control process for correcting the quantity of fuel injection to bring a controlled variable based on at least the detected air/fuel ratio, to a desired value;
• (e) providing estimated adaptive control parameters;
• and
• (f) providing the controlled variable in synchronism with the predetermined crank angle of at least one of the cylinders, and estimating the controller parameters based on at least the controlled variable that is at least one of the detected air/fuel ratio and an estimated quantity of cylinder-intake fuel obtained based on at least an air/fuel ratio output.

A system for controlling fuel metering for a multi-cylinder internal combustion engine, said engine having an exhaust system, said system comprising:

• (a) an air/fuel ratio sensor located in the exhaust system of the engine for detecting an air/fuel ratio;
• (b) engine operating condition detecting means for detecting engine operating conditions including at least engine speed and engine load;
• (c) fuel injection quantity determining means coupled to said engine operating condition detecting means for determining a quantity of fuel injection for individual cylinders based on at least the detected engine operating conditions at a predetermined crank angle of the individual cylinders;
• (d) fuel injector means coupled to said fuel injection quantity determining means, for injecting fuel into the individual cylinders of the engine based on the determined quantity of fuel injection;
• and
• (e) a feedback loop means having a controller means using a control law expressed in a recursion formula, for calculating a feedback correction coefficient to correct the quantity of fuel injection to bring a controlled variable based on at least an output of said air/fuel ratio sensor, to a desired value, said controller means operating synchronously with a cycle longer than an interval between the predetermined crank angles.

A computer program embodied on a computer-readable medium for controlling fuel metering for a multi-cylinder internal combustion engine, said computer program comprising the steps of:

• (a) determining a quantity of fuel injection for individual cylinders based on the detected engine operating conditions at a predetermined crank angle of the individual cylinders;
• (b) using an adaptive control process for correcting the quantity of fuel injection to bring a controlled variable based on a detected air/fuel ratio, to a desired value;
• (c) providing estimated adaptive control parameters;
• and
• (d) providing the controlled variable in synchronism with the predetermined crank angle of at least one of the cylinders, and estimating the controller parameters based on at least the controlled variable that is at least one of the detected air/fuel ratio and an estimated quantity of cylinder intake fuel based on at least the detected air/fuel ratio.

A computer program embodied on a computer-readable medium for controlling fuel metering for a multi-cylinder internal combustion engine, said computer program comprising the steps of:

• (a) determining a quantity of fuel injection for individual cylinders based on detected engine operating conditions at a predetermined crank angle of the individual cylinders;
• (b) determining an adaptive control correction coefficient for correcting the quantity of fuel injection to bring a controlled variable based on a detected air/fuel ratio, to a desired air/fuel ratio,
• (c) applying an input of the controlled variable to the determining of the adaptive control correction coefficient synchronously with a predetermined crank angle of at least one of the individual cylinders;
• and
• (d) estimating adaptive control parameters based on at least the controlled variable of a detected air/fuel ratio and utilizing the control parameters in determining the adaptive control correction coefficient.

A computer program embodied on a computer-readable medium for controlling fuel metering for a multi-cylinder internal combustion engine, said computer program comprising the steps of:

• (a) determining a quantity of fuel injection for individual cylinders based on engine operating conditions at a predetermined crank angle of the individual cylinders;
• (b) utilizing an adaptive control process for correcting the quantity of fuel injection to bring a controlled variable of an estimated quantity of cylinder intake fuel to a desired value of the quantity of fuel injection;
• (c) applying an input with the controlled variable to the determining of the adaptive control process in synchronism with a predetermined crank angle of at least one of the individual cylinders;
• and
• (d) estimating the adaptive control parameters based on at least the controlled variable and utilizing the control parameters in determining an adaptive control correction coefficient.

A method for controlling fuel metering for a multi-cylinder internal combustion engine, said method comprising the steps of:

• (a) detecting an air/fuel ratio;
• (b) detecting engine operating conditions including at least engine speed and engine load;
• (c) determining a quantity of fuel injection for individual cylinders based on at least the detected engine operating conditions at a predetermined crank angle of the individual cylinders;
• and
• (d) calculating a feedback correction coefficient using a control law expressed in a recursion formula, to correct the quantity of fuel injection to bring a controlled variable obtained based on at least the air/fuel ratio to a desired value;
• wherein the calculation of the feedback correction coefficient is in synchronism with a cycle longer than an interval between the predetermined crank angles.

A computer program embodied on a computer-readable medium for controlling fuel metering for a multi-cylinder internal combustion engine, said computer program comprising the steps of:

• (a) determining a quantity of fuel injection for individual cylinders based on detected engine operating conditions at a predetermined crank angle of the individual cylinders;
• and
• (b) calculating a feedback correction coefficient using a control law expressed in a recursion formula, to correct the quantity of fuel injection to bring a controlled variable obtained based on a detected air/fuel ratio to a desired value;
• wherein the calculation of the feedback correction coefficient is in synchronism with a cycle longer than an interval between the predetermined crank angles.

A system for controlling fuel metering for a multi-cylinder internal combustion engine, said engine having an exhaust system, said system comprising:

• (a) an air/fuel ratio sensor located at an exhaust system of the engine;
• (b) engine operating condition detecting means for detecting engine operating conditions including at least engine speed and engine load;
• (c) fuel injection quantity determining means coupled to said operating condition detecting means, for determining a quantity of fuel injection for individual cylinders based on at least the detected engine operating conditions at every predetermined crank angle;
• (d) a fuel injector means coupled to said fuel injection quantity determining means, for injecting fuel into the individual cylinders of the engine based on the determined quantity of fuel injection;
• and
• (e) a feedback loop means having an adaptive controller means and an adaptation mechanism means that estimates controller means parameters, said adaptive controller means correcting the quantity of fuel injection to bring a controlled variable based on at least an output of said air/fuel ratio sensor, to a desired value,
• wherein an operation cycle of at least one of the adaptive controller means and the adaptation mechanism means is varied based on least one of the parameters in the detected engine operating conditions.

A method for controlling fuel metering for a multi-cylinder internal combustion engine, said engine having an exhaust system, said method comprising the steps of:

• (a) sensing an air/fuel ratio in the exhaust system of the engine;
• (b) detecting operating conditions including at least engine speed and engine load;
• (c) determining a quantity of fuel injection for individual cylinders based on at least the detected engine operating conditions at every predetermined crank angle;
• (d) injecting fuel into the individual cylinders of the engine in response to the determined quantity of fuel injection;
• and
• (e) using an adaptive process for correcting the quantity of fuel injection to bring a controlled variable based on at least the detected air/fuel ratio to a desired value, wherein:
• providing estimated adaptive control parameters;
• and wherein the operation cycle of at least one of correcting the quantity of fuel injection and providing estimated control parameters is varied as a function of least one of parameters in the detected engine operating conditions.

A computer program embodied on a computer-readable medium for controlling fuel metering for a multi-cylinder internal combustion engine, said engine having an exhaust system, said computer program comprising the steps of:

• (a) determining a quantity of fuel injection for individual cylinders based on the detected engine operating conditions at every predetermined crank angle;
• (b) using an adaptive process for correcting the quantity of fuel injection to bring a controlled variable based on a detected air/fuel ratio to a desired value,
• wherein:
• providing estimated adaptive control parameters;
• and wherein the operation cycle of at least one of correcting the quantity of fuel injection and providing estimated control parameters is varied as a function of least one of parameters in the detected engine operating conditions.