Method and apparatus for controlling intake airflow rate of an engine and method for controlling output

Abstract

There is provided an air flow meter for detecting the flow rate of air, an electronically controlled throttle for opening and closing a throttle valve and a calculating device to which a target engine intake air flow rate, a value detected by the air flow meter, the position of a throttle valve detected by a throttle position sensor, and a value detected by an engine speed sensor are input. The calculating device calculates a time constant of a delay of response of the air flow rate into the engine, and a air flow rate passing through the throttle valve to compensate for the delay of response, and drives the throttle valve such that the flow rate of air passing through the throttle valve agrees with the calculated value.

What is claimed is:  
     
         1 . A method for controlling the flow rate of intake air to an engine by controlling the opening of an electronically controlled throttle comprising the steps of: 
 calculating a command value for the flow rate of intake air to the engine from a throttle position signal of the electronically controlled throttle provided in a suction pipe, an air flow rate signal detected by an air flow meter provided upstream of the electronically controlled throttle valve and an engine speed signal; and    calculating a target engine intake air flow rate by finding an over-shooting amount for said electronically controlled throttle valve.    
     
     
         2 . A method according to  claim 1 , wherein an over-shooting operation includes; 
 determining a time constant of a delay of response based on the throttle position signal from the electronically controlled throttle, the signal of the air flow meter, the engine speed signal and the target engine intake air flow rate to be taken into the cylinders of the engine by a calculating device;    calculating a target signal for an air flow meter for compensating for the delay of response based on the determined time constant of the delay of response; and    driving the electronically controlled throttle such that the signal of the air flow rate meter agrees with the target signal.    
     
     
         3 . A method for controlling the flow rate of intake air to an engine by controlling the opening of an electronically controlled throttle comprising the steps of: 
 calculating an engine intake air flow rate from a throttle valve position signal, an air flow rate signal of air flowing through a suction pipe and an engine speed signal;    calculating an intake air flow rate command value in accordance with an amount of fuel injection determined based on said intake air flow rate;    calculating a throttle valve position signal by adding an over-shooting amount to said intake air flow rate command value; and    repeating above calculations by calculating an engine intake air flow rate from the throttle valve position signal, air flow rate signal and the engine speed signal.    
     
     
         4 . A method for controlling the flow rate of intake air to an engine by controlling the opening of an electronically controlled throttle comprising the steps of: 
 calculating an exhaust gas recirculation flow rate of exhaust gas recirculation for introducing the exhaust gas of the engine into the intake pipe based on a throttle valve position signal, an air flow rate signal of air flowing through the intake pipe and an engine speed signal;    calculating a position signal of an exhaust gas recirculation flow rate adjusting valve (referred to as “EGR valve”) by adding an over-shooting amount to a value corresponding to said exhaust gas recirculation flow rate; and    repeating said calculation by calculating an exhaust gas recirculation flow rate from said throttle valve position signal, air flow rate signal and engine speed signal.    
     
     
         5 . A method according to  claim 3  or  4 , wherein said over-shooting amount is a compensating value determined in advance for the delay of change of the intake air flow rate relative to the operation of the electronically controlled throttle.  
     
     
         6 . A method for controlling the flow rate of intake air to an engine having an electronically controlled throttle provided in a suction pipe for introducing air in the internal combustion engine for controlling air flow rate, an air flow meter provided upstream of the electronically controlled throttle for detecting the air flow rate, an engine speed meter for detecting engine speed, a calculating device and a flow rate adjusting valve for an exhaust gas recirculation device for introducing exhaust gas from the internal combustion engine into the intake pipe comprising the steps of: 
 determining a time constant for a first delay of response based on a throttle position signal from the electronically controlled throttle, an air flow meter signal, an engine speed signal, the flow rate of intake air to be taken into the cylinders of the engine and the flow rate of the exhaust gas to be taken into the cylinder of the engine by a calculating device;    calculating a target signal for the air flow rate meter to compensate for the delay of response based on the determined time constant for the first delay of response;    driving the electronically controlled throttle such that the signal from the air flow rate meter agrees with the target signal;    determining a time constant for a second delay of response; and    driving the flow rate adjusting valve based on the determined time constant for the second delay of response to compensate for the delay of response of the exhaust gas that flows into the engine.    
     
     
         7 . A device for controlling the flow rate of intake air to an engine comprising: 
 an electronically controlled throttle provided in a suction pipe for introducing air in the engine to control air flow rate;    an air flow rate meter provided upstream of the electronically controlled throttle valve to detect the air flow rate    an engine speed meter to detect engine speed; and    a calculating device which calculates the flow rate of intake air to the engine based on a throttle valve position signal, an air flow rate signal and an engine speed signal, calculates an intake air flow rate command value based on said intake air flow rate, calculates a throttle valve position signal by adding an over-shooting amount to said intake air flow rate command value and repeats said calculation by calculating an engine intake flow rate based on the throttle valve position signal, the air flow rate signal and engine speed signal.    
     
     
         8 . A device according to  claim 7 , wherein said calculating device calculates an amount of fuel injection based on said engine intake air flow rate and calculates said intake air flow rate command value in accordance with said amount of fuel injection.  
     
     
         9 . A device for controlling the flow rate of intake air to an engine comprising: 
 an electronically controlled throttle provided in a suction pipe for introducing air in the internal combustion engine to control air flow rate;    an air flow rate meter provided upstream of the electronically controlled throttle to detect the air flow rate;    an engine speed meter to detect engine speed;    a flow rate adjusting valve for an exhaust gas recirculation device to introduce exhaust gas from the engine into the suction pipe;    a calculating device which determines a time constant for a first delay of response based on a throttle position signal from the electronically controlled throttle, an air flow meter signal, an engine speed signal, the flow rate of intake air to be taken into the cylinders of the engine and the flow rate of the exhaust gas to be taken into the cylinder of the engine, calculates a target signal for the air flow meter to compensate for the delay of response based on the determined time constant for the first delay of response, drives the electronically controlled throttle such that the signal from the air flow meter agrees with the target signal, determines a time constant for a second delay of response and drives the flow rate adjusting valve based on the determined time constant for the second delay of response to compensate for the delay of response of the exhaust gas that flows into the engine.    
     
     
         10 . A method for controlling the output of an engine in which output required for an engine is controlled by a command from an acceleration pedal comprising the steps of: 
 determining an amount of fuel injection in advance based on an intake air flow rate;    determining an intake air flow rate command value based on said amount of fuel injection; and    determining a target intake air flow rate by adding an over-shooting amount transiently to said intake air flow rate command value to control the opening of an electronically controlled throttle.