Engine control device and engine control method

An engine control device comprising:

• a target torque calculation unit that calculates target torque of an engine for which torque-based engine control is performed using estimated torque;
• and
• an estimated torque calculation unit that calculates the estimated torque by performing primary delay processing on the target torque using a primary delay coefficient equivalent to a time constant calculated for each control cycle based on a change in an actual intake air amount with respect to a target intake air amount of air sucked into the engine,
• the estimated torque calculation unit includes:
• a target intake air amount calculation unit that calculates a target intake air amount based on the target torque input from the target torque calculation unit and a speed of the engine,
• a primary delay coefficient calculation unit that calculates that primary delay coefficient equivalent to the time constant calculated based on the target intake air amount and the actual intake air amount, and
• a primary delay processing unit that calculates the estimated torque by performing primary delay processing on the target torque based on the target torque and the primary delay coefficient, wherein
• the estimated torque calculation unit further includes a divergence prevention processing unit that switches the primary delay coefficient calculated by the primary delay coefficient calculation unit to a different value to prevent divergence of the primary delay coefficient when the divergence occurs in the calculation of the primary delay coefficient performed by the primary delay coefficient calculation unit.