DISPOSITIF DE RELAIS MONTÉ SUR VÉHICULE, DISPOSITIF DE SURVEILLANCE MONTÉ SUR VÉHICULE, SYSTÈME DE RÉSEAU DE COMMANDE MONTÉ SUR VÉHICULE, PROCÉDÉ DE SURVEILLANCE DE COMMUNICATION ET PROGRAMME

摘要

An in-vehicle relay device prevents the occurrence of an anomaly of a control command exchanged over networks having different transmittable data sizes in a frame. The in-vehicle relay device relays communication between a plurality of control devices in a vehicle over the networks to which the control devices are connected. The in-vehicle relay device receives control data from a first control network in the plurality of networks, where the control data includes, in a frame, a plurality of control commands to be executed by at least some of the control devices, makes a first determination as to whether types of the control commands included in the frame form a first combination preset as a combination of control commands executable simultaneously and thereafter makes a second determination as to whether the control data is anomalous by using the result of the first determination, and outputs the result of the second determination.