Dynamic fuel control

Claim 1

A method of controlling the air/fuel ratio of an internal combustion engine including the steps of: predicting the air charge to enter the engine in two engine events using the equation M.sub.i+2.sup.c =(2-k)k [2 M.sub.i.sup.tb -M.sub.i-1.sup.tb ]+(1-k).sup.2 M.sub.i.sup.c wherein M c =Cylinder air charge M tb =Air charge from throttle flow ##EQU4## ncyl=Number of cylinders N=Engine speed (RPM) Vd=Engine displacement(cu.in.) Vm=Manifold volume(cu.in.) η v =Volumetric efficiency.

Claim 2

A method of controlling the air/fuel ratio of an internal combustion engine including the steps of: predicting the air charge to enter the engine in two engine events using the equation M.sub.i+2.sup.c =(2-k)k [2 M.sub.i.sup.tb -M.sub.i-1.sup.tb ]+(1-k).sup.2 M.sub.i.sup.c wherein M c =Cylinder air charge M tb =Air charge from throttle flow ##EQU4## ncyl=Number of cylinders N=Engine speed (RPM) Vd=Engine displacement(cu.in.) Vm=Manifold volume(cu.in.) η v =Volumetric efficiency.

Claim 4

A method of controlling the air/fuel ratio of an internal combustion engine including the steps of: determining air flow into the engine during every induction event; integrating the air meter reading over the last two samples; storing the integrated value; predicting the air charge to enter the engine in two engine events using the equation M.sub.i+2.sup.c =(2=k)k ] 2 M.sub.i.sup.tb -M.sub.i-1.sup.tb ]+(1-k) .sup.2 M.sub.i.sup.c wherein M c =Cylinder air charge M tb =Air charge from throttle flow ##EQU5## ncyl=Number of cylinders N=Engine speed (RPM) Vd=Engine displacement(cu.in.) Vm=Manifold volume(cu.in.) η v =Volumetric efficiency. determining the amount of fuel to be injected into a cylinder to determine a desired air/fuel ratio; injecting a first fuel injection pulse; determining if the first fuel injection pulse is sufficient to meet the desired air/fuel ratio; and injecting a second fuel injection pulse if there is a shortfall of the amount injected by the first fuel injection pulse to achieve the desired air/fuel ratio.

Claim 5

A method of controlling the air/fuel ratio of an internal combustion engine including the steps of: determining air flow into the engine during every induction event; integrating the air meter reading over the last two samples; storing the integrated value; predicting the air charge to enter the engine in two engine events using the equation M.sub.i+2.sup.c =(2=k)k ] 2 M.sub.i.sup.tb -M.sub.i-1.sup.tb ]+(1-k) .sup.2 M.sub.i.sup.c wherein M c =Cylinder air charge M tb =Air charge from throttle flow ##EQU5## ncyl=Number of cylinders N=Engine speed (RPM) Vd=Engine displacement(cu.in.) Vm=Manifold volume(cu.in.) η v =Volumetric efficiency. determining the amount of fuel to be injected into a cylinder to determine a desired air/fuel ratio; injecting a first fuel injection pulse; determining if the first fuel injection pulse is sufficient to meet the desired air/fuel ratio; and injecting a second fuel injection pulse if there is a shortfall of the amount injected by the first fuel injection pulse to achieve the desired air/fuel ratio.

Claim 6

A method of controlling the air/fuel ratio an internal combustion engine including the steps of: reading an air meter indicating airflow into the engine during every induction event; integrating the air meter reading over the last two samples and adding a leakage factor; storing the integrated value; determining a multiplication factor as a function of load for computing a new value of an estimated cylinder air charge; predicting air charge two induction events into the future; computing the equivalent fuel charge at the current desired air/fuel ratio; computing the injector pulse width corresponding to the desired fuel charge; scheduling the pulse width for the fuel pulse to be applied to the next cylinder to fuel; determining the need for an additional fuel pulse; if additional fuel is needed, calculating a dynamic fuel pulse width for a second fuel pulse; and scheduling a second fuel pulse to occur on an open intake valve.

Claim 7

A method of controlling the air/fuel ratio an internal combustion engine including the steps of: reading an air meter indicating airflow into the engine during every induction event; integrating the air meter reading over the last two samples and adding a leakage factor; storing the integrated value; determining a multiplication factor as a function of load for computing a new value of an estimated cylinder air charge; predicting air charge two induction events into the future; computing the equivalent fuel charge at the current desired air/fuel ratio; computing the injector pulse width corresponding to the desired fuel charge; scheduling the pulse width for the fuel pulse to be applied to the next cylinder to fuel; determining the need for an additional fuel pulse; if additional fuel is needed, calculating a dynamic fuel pulse width for a second fuel pulse; and scheduling a second fuel pulse to occur on an open intake valve.