Fuel metering control system for internal combustion engine

Claim 1

A system for controlling fuel metering for an internal combustion engine having a plurality of cylinders and 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 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 operatively 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; (d) a feedback loop means having a controller means for calculating a feedback correction coefficient using a control law expressed in a recursion formula, to correct the quantity of fuel injection such that the detected air/fuel ratio detected by said air/fuel ratio sensor is brought to a desired air/fuel ratio; (e) fuel injection quantity correcting means for correcting the quantity of fuel injection based on the feedback correction coefficient; (f) fuel adhesion correction means for determining a fuel correction based upon a quantity of fuel adhered on an intake manifold wall of the engine; (g) output fuel injection quantity determining means operatively coupled to said fuel correction means, for correcting the corrected fuel injection based on the output of the fuel injection quantity determining means, to determine an output quantity of fuel injection; and (h) fuel injector means operatively coupled to said output fuel injection quantity determining means for injecting fuel in the individual cylinders of the engine based on the determined quantity of fuel injection.

Claim 2

A system for controlling fuel metering for an internal combustion engine having a plurality of cylinders and 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 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 operatively 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; (d) a feedback loop means having a controller means for calculating a feedback correction coefficient using a control law expressed in a recursion formula, to correct the quantity of fuel injection such that the detected air/fuel ratio detected by said air/fuel ratio sensor is brought to a desired air/fuel ratio; (e) fuel injection quantity correcting means for correcting the quantity of fuel injection based on the feedback correction coefficient; (f) fuel adhesion correction means for determining a fuel correction based upon a quantity of fuel adhered on an intake manifold wall of the engine; (g) output fuel injection quantity determining means operatively coupled to said fuel correction means, for correcting the corrected fuel injection based on the output of the fuel injection quantity determining means, to determine an output quantity of fuel injection; and (h) fuel injector means operatively coupled to said output fuel injection quantity determining means for injecting fuel in the individual cylinders of the engine based on the determined quantity of fuel injection.

Claim 6

A system for controlling fuel metering for an internal combustion engine having a plurality of cylinders and 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 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 operatively 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; (d) a first feedback loop means having a controller means for calculating a first feedback correction coefficient using a control law expressed in a recursion formula, to correct the quantity of fuel injection such that the detected air/fuel ratio detected by said air/fuel ratio sensor is brought to a desired air/fuel ratio; (e) a second feedback loop means having a second controller means for calculating a second feedback correction coefficient using a control law whose control response is less than that of the first controller, to correct the quantity of fuel injection such that the detected air/fuel ration is brought to the desired air/fuel ratio; (f) selecting means for selecting one of the first feedback correction coefficient and the second feedback correction coefficient in response to the detected engine operating conditions; (g) fuel injection quantity correcting means for correcting the quantity of fuel injection based on the selected feedback correction coefficient; (h) fuel adhesion correction means for determining fuel correction based upon a quantity of fuel adhered on an intake manifold wall of the engine; (i) output fuel injection quantity determining means operatively coupled to the fuel adhesion correction means, for correcting the corrected quantity of fuel injection based on of the output of the fuel adhesion correction means, to determine an output quantity of fuel injection; and (j) fuel injector means coupled to the output of the output fuel injection quantity determining means for injecting fuel in the individual cylinders of the engine based on the determined output quantity of fuel injection.

Claim 7

A system for controlling fuel metering for an internal combustion engine having a plurality of cylinders and 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 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 operatively 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; (d) a first feedback loop means having a controller means for calculating a first feedback correction coefficient using a control law expressed in a recursion formula, to correct the quantity of fuel injection such that the detected air/fuel ratio detected by said air/fuel ratio sensor is brought to a desired air/fuel ratio; (e) a second feedback loop means having a second controller means for calculating a second feedback correction coefficient using a control law whose control response is less than that of the first controller, to correct the quantity of fuel injection such that the detected air/fuel ration is brought to the desired air/fuel ratio; (f) selecting means for selecting one of the first feedback correction coefficient and the second feedback correction coefficient in response to the detected engine operating conditions; (g) fuel injection quantity correcting means for correcting the quantity of fuel injection based on the selected feedback correction coefficient; (h) fuel adhesion correction means for determining fuel correction based upon a quantity of fuel adhered on an intake manifold wall of the engine; (i) output fuel injection quantity determining means operatively coupled to the fuel adhesion correction means, for correcting the corrected quantity of fuel injection based on of the output of the fuel adhesion correction means, to determine an output quantity of fuel injection; and (j) fuel injector means coupled to the output of the output fuel injection quantity determining means for injecting fuel in the individual cylinders of the engine based on the determined output quantity of fuel injection.

Claim 14

A method for controlling fuel metering for an internal combustion engine having a plurality of cylinders and an exhaust system, said method comprising the steps of: (a) detecting an air/fuel ratio of the engine; (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; (d) calculating a feedback correction coefficient using a control law expressed in a recursion formula to correct the quantity of fuel injection such that the detected air/fuel ratio is brought to a desired air/fuel ratio; (e) correcting the quantity of fuel injection as a function of the feedback correction coefficient; (f) determining a fuel correction based upon a quantity of fuel adhered on an intake manifold wall of the engine; (g) correcting the corrected fuel injection based on the adhered fuel correction to determine an output quantity of fuel injection; and (h) injecting fuel in the individual cylinders of the engine based on the determined output quantity of fuel injection.

Claim 15

A method for controlling fuel metering for an internal combustion engine having a plurality of cylinders and an exhaust system, said method comprising the steps of: (a) detecting an air/fuel ratio of the engine; (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; (d) calculating a feedback correction coefficient using a control law expressed in a recursion formula to correct the quantity of fuel injection such that the detected air/fuel ratio is brought to a desired air/fuel ratio; (e) correcting the quantity of fuel injection as a function of the feedback correction coefficient; (f) determining a fuel correction based upon a quantity of fuel adhered on an intake manifold wall of the engine; (g) correcting the corrected fuel injection based on the adhered fuel correction to determine an output quantity of fuel injection; and (h) injecting fuel in the individual cylinders of the engine based on the determined output quantity of fuel injection.

Claim 18

A method for controlling fuel metering for an internal combustion engine having a plurality of cylinders, said method comprising the steps of: (a) detecting an air/fuel ratio of the engine; (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; (d) calculating a first feedback correction coefficient using a control law expressed in a recursion formula to correct the quantity of fuel injection such that the detected air/fuel ratio is brought to a desired air/fuel ratio; (e) calculating a second feedback correction coefficient using a control law whose control response is less than that of the first feedback correction coefficient, to correct the quantity of fuel injection such that the detected air/fuel ratio is brought to the desired air/fuel ratio; (f) selecting one of the first feedback correction coefficient and the second feedback correction coefficient in response to the detected engine operating conditions; (g) correcting the quantity of fuel injection according to the selected feedback correction coefficient; (h) determining a fuel correction based upon a quantity of fuel adhered on an intake manifold wall of the engine; (i) correcting the corrected quantity of fuel injection based on the fuel adhesion correction, to determine an output quantity of fuel injection; and (j) injecting fuel in the individual cylinders of the engine based on the determined output quantity of fuel injection.

Claim 19

A method for controlling fuel metering for an internal combustion engine having a plurality of cylinders, said method comprising the steps of: (a) detecting an air/fuel ratio of the engine; (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; (d) calculating a first feedback correction coefficient using a control law expressed in a recursion formula to correct the quantity of fuel injection such that the detected air/fuel ratio is brought to a desired air/fuel ratio; (e) calculating a second feedback correction coefficient using a control law whose control response is less than that of the first feedback correction coefficient, to correct the quantity of fuel injection such that the detected air/fuel ratio is brought to the desired air/fuel ratio; (f) selecting one of the first feedback correction coefficient and the second feedback correction coefficient in response to the detected engine operating conditions; (g) correcting the quantity of fuel injection according to the selected feedback correction coefficient; (h) determining a fuel correction based upon a quantity of fuel adhered on an intake manifold wall of the engine; (i) correcting the corrected quantity of fuel injection based on the fuel adhesion correction, to determine an output quantity of fuel injection; and (j) injecting fuel in the individual cylinders of the engine based on the determined output quantity of fuel injection.