In-vehicle sensor, in-vehicle sensor system, and method of setting identifiers of in-vehicle sensors in in-vehicle sensor system

An identifier setting method for an in-vehicle sensor system comprising a communication bus constructed in the vehicle, and a plurality of in-vehicle sensors mounted in the vehicle and connected to the communication bus, the method setting identifiers for the plurality of in-vehicle sensors, wherein

• each of the in-vehicle sensors includes
• a bus connection connector used for connection to the communication bus and including one or a plurality of communication external terminals to be connected to a communication line of the communication bus through which communication data flow, and one or a plurality of external terminals for setting, outside the in-vehicle sensor, each external terminal for setting being brought into one of two connection states composed of an open state in which the terminal is not connected to any potential and one potential connected state in which the terminal is connected to a predetermined potential, being brought into one of three or more connection states composed of the open state and a plurality of potential connected states in which the terminal is selectively connected to predetermined potentials different from one another, or being brought into one of two or more potential connected states in which the terminal is selectively connected to predetermined potentials different from one another,
• a nonvolatile storage section for storing the identifier, and
• communication means for performing communications through the communication bus by using the identifier stored in the storage section;
• the in-vehicle sensor system includes a plurality of connection paths which connect the in-vehicle sensors to the communication bus and each of which includes a sensor connection connector provided for each of the plurality of in-vehicle sensors and mated with the bus connection connector of the corresponding in-vehicle sensor, each of the plurality of connection paths including a connection path for communication for connecting the one or plurality of communication external terminals to the communication line of the communication bus, and one or a plurality of setting paths provided for the one or plurality of external terminals for setting so as to set the connection state(s) thereof, wherein the one or plurality of setting paths differ among the connection paths in terms of the combination of the connection state(s) of the external terminal(s) for setting set by the setting path(s);
• and
• the identifier setting method comprises:
• a judgment step of judging the connection state(s) of the one or plurality of external terminals for setting when electric power is supplied to the in-vehicle sensor in a state in which the bus connection connector is connected to the communication bus;
• an identifier generation step of generating an identifier of the in-vehicle sensor on the basis of the connection state(s) of the one or plurality of external terminals for setting judged by the judgment step;
• and
• a storing step of storing an initial identifier first generated by the identifier generation step in the storage section as the identifier, wherein the judgment step, the identifier generation step, and the storing step are performed for each of the plurality of in-vehicle sensors.