ABNORMALITY DETECTING ELECTRONIC CONTROL UNIT, VEHICLE-MOUNTED NETWORK SYSTEM AND ABNORMALITY DETECTING METHOD

摘要

An anomaly detection is connected to a communication path, including an electronic control unit that periodically transmits a first-type message including data to be monitored, and an electronic control unit that periodically transmits a second-type message including data for comparison. The anomaly detection electronic control unit includes: a receiver that successively receives first-type messages and second-type messages from the communication path; a determining unit that determines whether a first-type message received by the receiver is normal or anomalous, based on content of the first-type message, content of a second-type message received last by the receiver at the time of receiving this first-type message, and either one of content of a first-type message received by the receiver further in the past than this first-type message, and content of a second-type message received by the receiver further in the past than the second-type message received last; and a transmitter that transmits in accordance with results of the determination by the determining unit.