Controller for internal combustion engine

A controller for an internal combustion engine, the controller comprising processing circuitry, wherein

• the processing circuitry is configured to execute an accumulation amount calculation process and a burn-off rate calculation process,
• the accumulation amount calculation process calculates an accumulation amount of particulate matter that has accumulated in a filter,
• the filter is provided in an exhaust passage of the internal combustion engine,
• the filter traps the particulate matter in exhaust gas in the exhaust passage,
• the accumulation amount is calculated based on a discharge rate of the particulate matter discharged from the internal combustion engine to the exhaust passage and a burn-off rate of the particulate matter burned in the filter,
• the accumulation amount varies along an exhaust gas flow direction within the filter, and
• the burn-off rate calculation process calculates the burn-off rate in accordance with a degree of variation in the accumulation amount along the exhaust gas flow direction.