Universal tracking air-fuel regulator for internal combustion engines

A method for controlling fuel supply to an engine, comprising:

• generating a desired equivalence ratio (EQR) signal based on a dither signal and a desired EQR of an exhaust gas;
• determining an offset indicating a change in the desired EQR signal;
• generating an expected EQR signal based on a model that relates the expected EQR signal to a sum of the desired EQR signal and the offset and that adjusts a fuel command based on the expected EQR signal;
• and
• generating the expected EQR signal independently of a feedback from an exhaust gas oxygen (EGO) sensor.

A fuel control system of an engine, comprising:

• a setpoint generator module that generates a desired equivalence ratio (EQR) signal based on a dither signal and a desired EQR of an exhaust gas;
• an offset module that generates an offset indicating a change in the desired EQR signal;
• and
• a control module that generates an expected EQR signal based on a model that relates the expected EQR signal to a sum of the desired EQR signal and the offset and that adjusts a fuel command to meet the expected EQR signal,
• wherein the control module generates the expected EQR signal using an open-loop control based on the model instead of using a closed-loop control based on calibration.

A method for controlling fuel supply to an engine, comprising:

• generating a desired equivalence ratio (EQR) signal based on a dither signal and a desired EQR of an exhaust gas;
• determining an offset indicating a change in the desired EQR signal;
• generating an expected EQR signal based on a model that relates the expected EQR signal to a sum of the desired EQR signal and the offset and that adjusts a fuel command based on the expected EQR signal;
• and
• generating the expected EQR signal using an open-loop control based on the model instead of using a closed-loop control based on calibration.