Ignition timing control device for internal combustion engine

An ignition timing control device for an internal combustion engine, the ignition timing control device comprising:

• a storage unit that stores:
• a pre-learned normal signal generation model configured to output, upon receiving an output value of a knocking sensor that detects vibration of a body of the internal combustion engine, a noise-removed output value from which an unlearned noise component value included in the output value of the knocking sensor has been removed;
• and
• a first learned neural network pre-learned to output, upon receiving one of the output value of the knocking sensor and the noise-removed output value of the normal signal generation model, an estimated value for a value representing knocking intensity, originally obtained from an output value of a pressure sensor that detects a combustion pressure of an air-fuel mixture generated by ignition;
• and
• a processor configured to:
• acquire the estimated value for the value representing knocking intensity output from the first learned neural network by inputting the output value of the knocking sensor, during operation of the internal combustion engine, to the normal signal generation model read out from the storage unit and inputting the noise-removed output value output from the normal signal generation model to the first learned neural network read out from the storage unit;
• and
• execute retarding control of an ignition timing of the internal combustion engine based on the acquired estimated value for the value representing knocking intensity.