STATE DETECTION SYSTEM FOR INTERNAL COMBUSTION ENGINE, DATA ANALYSIS DEVICE, AND VEHICLE

A state detection system for an internal combustion engine includes: a memory configured to store mapping data, the mapping data being data that defines a detection mapping, the detection mapping being a mapping between an input and an output, the input being a rotation waveform variable and a drive system rotation speed variable and the output being a value of a combustion state variable, and the detection mapping including a joint operation of the rotation waveform variable and the drive system rotation speed variable based on a parameter learned by machine learning; and a processor configured to execute an acquisition process and a determination process, the acquisition process being configured to acquire a value of the drive system rotation speed variable, the determination process being configured to determine whether or not the internal combustion engine is in a predetermined operating state.