CLAIMS
1. An in-vehicle monitoring system that comprises: a
plurality of monitoring cameras and a plurality of
emergency call devices mounted on a vehicle of a train; a
display unit that displays information transferred within
the vehicle; and an information control device that
transmits imaging data from the monitoring cameras to the
display unit, and that monitors inside of the vehicle by
using images taken by the monitoring cameras, wherein
a table, in which IP addresses of the emergency call devices and IP addresses of the monitoring cameras are stored in association with each other in a one-to-one relationship or a one-to-many relationship, is set in the information control device, and
upon receiving a call signal from an operated emergency call device, the information control device specifies an IP address of a monitoring camera corresponding to the operated emergency call device from IP addresses of the monitoring cameras on a basis of the table, selects imaging data from specified monitoring camera from pieces of imaging data from the monitoring cameras, and transmits selected imaging data to the display unit.
2. An in-vehicle monitoring system that comprises: a
plurality of monitoring cameras and a plurality of
emergency call devices mounted on a vehicle of a train; a
display unit that displays information transferred within
the vehicle; and an information control device that
transmits imaging data from the monitoring cameras to the
display unit, and that monitors inside of the vehicle by
using images taken by the monitoring cameras, wherein
a first table, in which IP addresses of the emergency call devices and multicast addresses are stored in

association with each other in a one-to-one relationship or a one-to-many relationship, is set in the information control device,
a second table, in which IP addresses of the monitoring cameras and multicast addresses are stored in association with each other, is set in the monitoring camera,
the monitoring camera transmits imaging data to a multicast address corresponding to an IP address in the second table, and
upon receiving a call signal from an operated emergency call device, the information control device specifies a multicast address corresponding to the operated emergency call device from a plurality of multicast addresses on a basis of the first table and transmits imaging data in a multicast packet transmitted from specified multicast address to the display unit.
3. The in-vehicle monitoring system according to claim 1 or 2, wherein
graphic data schematically expressing an installation state of emergency call devices and monitoring cameras in a vehicle is set in the information control device for each vehicle,
upon receiving the call signal, the information control device outputs the graphic data corresponding to a vehicle in which an emergency call device as a source of the call signal is installed to the display unit, and
the display unit displays emergency call devices and monitoring cameras in the vehicle on a basis of the graphic data, and when a monitoring camera displayed on a screen is operated, displays an image taken by the monitoring camera.

4. The in-vehicle monitoring system according to claim 1, wherein the information control device attaches a flag indicating not to delete imaging data taken during a certain period before and after a start point when the emergency call device is operated to imaging data from the specified monitoring camera and causes a data recording device mounted on a train to record the imaging data.
5. The in-vehicle monitoring system according to claim 2, wherein the information control device attaches a flag indicating not to delete imaging data taken during a certain period before and after a start point when the emergency call device is operated to the imaging data in a multicast packet transmitted from the specified multicast address and causes a data recording device mounted on a train to record the imaging data.
6. An in-vehicle monitoring method executed in an in-vehicle monitoring system that comprises a plurality of monitoring cameras and a plurality of emergency call devices mounted on a vehicle of a train and a display unit that displays information transferred within the vehicle, and that monitors inside of the vehicle by using images taken by the monitoring cameras, the method comprising:
an IP-address specifying step of specifying, upon receiving a call signal from an operated emergency call device, an IP address of a monitoring camera corresponding to the operated emergency call device from IP addresses of the monitoring cameras on a basis of a table in which IP addresses of the emergency call devices and the IP addresses of the monitoring cameras are stored in association with each other in a one-to-one relationship or a one-to-many relationship;

an imaging-data selecting step of selecting, from pieces of imaging data from the monitoring cameras, imaging data transmitted from a monitoring camera having an IP address specified at the IP-address specifying step; and
a transmitting step of transmitting imaging data selected at the imaging-data selecting step to the display unit.
7. An in-vehicle monitoring method executed in an in-vehicle monitoring system that comprises a plurality of monitoring cameras and a plurality of emergency call devices mounted on a vehicle of a train and a display unit that displays information transferred within the vehicle, and that monitors inside of the vehicle by using images taken by the monitoring cameras, the method comprising:
a step of transmitting imaging data to a multicast address corresponding to an IP address in a table, in which IP addresses of the monitoring cameras and multicast addresses are stored in association with each other, on a basis of the table;
a multicast-address specifying step of specifying, upon receiving a call signal from an operated emergency call device, a multicast address corresponding to the operated emergency call device from a plurality of multicast addresses on a basis of a table in which IP addresses of the emergency call devices and multicast addresses are stored in association with each other in a one-to-one relationship or a one-to-many relationship; and
a transmitting step of transmitting imaging data in a multicast packet transmitted from a multicast address specified at the multicast-address specifying step to the display unit.