System and related methods for fuel pressure monitoring

A system for monitoring rail pressure, the system comprising:

• an internal combustion engine;
• a plurality of fuel injectors configured to inject fuel for the internal combustion engine;
• a fuel rail configured to provide the fuel to the plurality of fuel injectors;
• a rail pressure sensor configured to detect a pressure of the fuel within the fuel rail;
• and
• a controller configured to:
• determine a desired rail pressure;
• determine a rail pressure error based on a rail pressure measured with the rail pressure sensor and the desired rail pressure;
• calculate a high rail pressure moving threshold and a low rail pressure moving threshold;
• calculate a difference between the rail pressure and one of the low rail pressure moving threshold and the high rail pressure moving threshold;
• monitor a cumulative difference based on the calculated difference between the rail pressure and one of the low rail pressure moving threshold and the high rail pressure moving threshold;
• and
• reset or suspend monitoring of the cumulative difference when the internal combustion engine is in a transient state.

A method for monitoring rail pressure, the method comprising:

• receiving, from a pressure sensor, a rail pressure of a fuel injector of an internal combustion engine;
• determining a desired rail pressure;
• calculating a rail pressure error based on the rail pressure from the rail pressure sensor and the desired rail pressure;
• calculating a high rail pressure moving threshold and a low rail pressure moving threshold;
• incrementing a high rail pressure numerical value when the difference of the rail pressure and the high rail pressure moving threshold is a positive value;
• incrementing a low rail pressure numerical value when the difference of the rail pressure and the low rail pressure moving threshold is a negative value;
• monitoring the high rail pressure numerical value and the low rail pressure numerical value;
• determining whether the internal combustion engine is in a transient state;
• when the internal combustion engine is in the transient state, suspending monitoring of the high rail pressure numerical value or resetting the high rail pressure value upon the high rail pressure numerical value exceeding a first trip threshold;
• and
• when the internal combustion engine is in the transient state, suspending monitoring of the low rail pressure numerical value or resetting the low rail pressure value upon the low rail pressure numerical value exceeding a second trip threshold.