Controller for internal combustion engine, control method for internal combustion engine, and storage medium

A method for controlling an internal combustion engine, the method comprising:

• determining, by processing circuitry of a controller, whether a pressure sensor is correctly detecting a pressure value, the internal combustion engine being mounted on a vehicle, an exhaust passage of the internal combustion engine being provided with a filter for trapping particulate matter in exhaust gas in the exhaust passage, a pressure pipe being connected to an upstream section of the exhaust passage with respect to the filter and a downstream section of the exhaust passage with respect to the filter, and the pressure sensor being disposed in the pressure pipe and configured to detect, as the pressure value, a differential pressure between a pressure of the upstream section and a pressure of the downstream section;
• calculating, by the processing circuitry, a reference ratio when it is determined that the pressure sensor is correctly detecting the pressure value, the reference ratio being a ratio between the pressure value detected by the pressure sensor and a reference pressure that is a reference value of the pressure value, the reference pressure being calculated based on an operating parameter relating to the pressure value;
• storing the reference ratio as a value to be used in a next trip of the vehicle, the next trip being a trip subsequent to the trip in which the reference ratio is stored;
• calculating, by the processing circuitry, the reference pressure based on the operating parameter in the next trip;
• and
• calculating, by the processing circuitry, the pressure value by multiplying the calculated reference pressure by the stored reference ratio.

A non-transitory computer-readable storage medium that stores a program code for causing a processor to execute a control process for an internal combustion engine, the control process includes:

• determining, by processing circuitry of the processor, whether a pressure sensor is correctly detecting a pressure value, the internal combustion engine being mounted on a vehicle, an exhaust passage of the internal combustion engine being provided with a filter for trapping particulate matter in exhaust gas in the exhaust passage, a pressure pipe being connected to an upstream section of the exhaust passage with respect to the filter and a downstream section of the exhaust passage with respect to the filter, and the pressure sensor being disposed in the pressure pipe and configured to detect, as the pressure value, a differential pressure between a pressure of the upstream section and a pressure of the downstream section;
• calculating, by the processing circuitry, a reference ratio when it is determined that the pressure sensor is correctly detecting the pressure value, the reference ratio being a ratio between the pressure value detected by the pressure sensor and a reference pressure that is a reference value of the pressure value, the reference pressure being calculated based on an operating parameter relating to the pressure value;
• storing the reference ratio as a value to be used in a next trip of the vehicle, the next trip being a trip subsequent to the trip in which the reference ratio is stored;
• calculating, by the processing circuitry, the reference pressure based on the operating parameter in the next trip;
• and
• calculating, by the processing circuitry, the pressure value by multiplying the calculated reference pressure by the stored reference ratio.