WEAR AMOUNT DETECTION DEVICE FOR AUTOMOBILE TIRES

Provided is a wear amount detection device that is able to detect that a tire is in a worn state, during running, without a special sensor while suppressing an increase in cost. The device includes: a rotation sensor (2) detecting rotation of a wheel (1) to measure a speed of an automobile; a signal processing (3) extracting rotation speed fluctuations synchronized with rotation, from a rotation signal detected by the rotation sensor, and obtain a rotation speed fluctuation pattern synchronized with rotation, from rotation speed fluctuations over a plurality of rotations; and a wear state determination (4) configured to: obtain, from the obtained pattern, a value of a component induced by a characteristic embodied in a tire (1a) of the wheel (1), the value varying in accordance with a wear state of the tire (1a); estimate a wear state of the tire (1a); and output the state.