IMBALANCE DETECTION DEVICE, IMBALANCE DETECTION SYSTEM, DATA ANALYSIS DEVICE, AND CONTROLLER FOR INTERNAL COMBUSTION ENGINE

摘要

An imbalance detection device, an imbalance detection system, a data analysis device, and a controller for an internal combustion engine are provided. An obtainment process (S12) includes obtaining a rotation waveform variable (T30(1)-T30(24)) based on a detection value of a sensor (86) that detects a rotational behavior of a crankshaft (24), and an air-fuel ratio detection variable (Afuave) in each of a plurality of first intervals. A calculation process (S14, S16) includes calculating an imbalance variable (Riv(i)) based on an output (f(x)) of a mapping having a value obtained by the obtainment process (S12) as an input (x(1)-x(24), x(25)-x(48)). The imbalance variable indicates a degree of variations in an air-fuel ratio of the internal combustion engine (10). The rotation waveform variable (T30(1)-T30(24)) indicates a difference between instantaneous speed variables (T30) that are variables corresponding to the rotational speed (NE) of the crankshaft (24) in each of the second intervals