Prediction method for engine mass air flow per cylinder

In an engine fuel control system having apparatus for measuring values of manifold absolute pressure (MAP) and a throttle position signal (TPS) and for detecting values of an exhaust gas recirculation valve signal (EGR) and an idle air control signal (IAC) at reference times during each engine revolution, a method of controlling engine fueling by predicting air flow into an engine cylinder comprising the steps of:

• measuring MAP, TPS, EGR and IAC values at each point of at least one set of points uniformly spaced relative to each dead center;
• calculating trends of each of the measured values from a difference of respective values at successive points;
• determining a base MAP value;
• predicting a future MAP value from the base MAP value and the calculated trends by multiplying each calculated trend by a respective gain to form a series of products and adding such products to the base MAP value;
• predicting air flow into said cylinder from the predicted MAP value;
• calculating a desired amount of fuel to be delivered to the engine cylinder as a predetermined function of the predicted air flow;
• and
• controlling a fuel injector to deliver the desired amount of fuel to the engine cylinder.

In an engine fuel control system having apparatus for measuring mass air flow (MAF) throttle position signal (TPS), exhaust gas recirculation valve signal (EGR) and an idle air control signal (IAC), a method of controlling engine fueling by predicting the air flow into each cylinder comprising the steps of:

• measuring MAF at each point of at least one set of points uniformly spaced from each dead center;
• detecting values of EGR and IAC at each of the points;
• calculating mass air flow per cylinder (MAC) at each point from MAF and engine speed;
• measuring TPS at each of said points;
• calculating trends of MAC values and TPS values from the measurements at consecutive recent points;
• calculating trends of EGR and IAC from their respective values at the most recent points;
• determining a base average MAC value from at least a most recent dead center MAF measurement;
• predicting air flow into each cylinder from the base MAC value and the calculated trends;
• calculating a desired amount of fuel to be delivered to each cylinder as a predetermined function of the predicted air flow into the respective cylinder;
• and
• controlling at least one fuel injector to deliver the desired amount of fuel to each respective cylinder.

In an engine fuel control system having apparatus for measuring values of mass air flow (MAF), absolute manifold pressure (MAP) and a throttle position signal (TPS) and for detecting values of engine speed, an exhaust gas recirculation valve signal (EGR) and an idle air control signal (IAC) at reference times during each engine revolution, the method of controlling engine fueling by predicting the air flow into an engine cylinder comprising the steps of:

• measuring MAF, MAP, TPS, EGR and IAC values at each point of at least one set of points uniformly spaced relative to each dead center;
• calculating air mass flow per cylinder MAC from MAF and engine speed at each point;
• calculating trends of each of the values MAC, MAP, TPS, EGR, and IAC from a difference of respective values at successive points;
• determining a base value of air mass per cylinder;
• predicting air mass into said cylinder from the base value and the calculated trends by multiplying each calculated trend by a respective gain to form a series of products and adding said products to the base value;
• calculating a desired amount of fuel to be delivered to said cylinder as a predetermined function of the predicted air mass into said cylinder;
• and
• controlling a fuel injector to deliver the desired amount of fuel to said cylinder.