# US 10,864,927 B2 · Monitoring system and monitoring method

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- Number: US 10,864,927 B2
- Document ID: US10864927B2
- Status: Granted
- Kind: B2
- Application number: 16/493,371
- Filed: 2018-03-07
- Published: 2020-01-30
- Granted: 2020-12-15
- Earliest claimed: 2017-03-28
- Assignees: Hitachi Kokusai Electric Inc.
- Applicants: Hitachi Kokusai Electric Inc.
- Inventors: Kana Ohki
- Web page: https://patentgrep.com/patent/US10864927B2

## CPC

- B61K 13/04: Passenger-warning devices attached to vehicles; Safety devices for preventing accidents to passengers when entering or leaving vehicles
- B61L 15/0081: {On-board diagnosis or maintenance}
- B61B 1/02: General arrangement of stations and platforms including protection devices for the passengers {(B61B1/005 takes precedence)}
- H04N 7/183: {for receiving images from a single remote source}
- H04N 7/186: {Video door telephones}
- H04N 23/61: based on recognised objects
- B61L 23/041: {Obstacle detection}
- B61K: AUXILIARY EQUIPMENT SPECIALLY ADAPTED FOR RAILWAYS, NOT OTHERWISE PROVIDED FOR
- B61L: GUIDING RAILWAY TRAFFIC; ENSURING THE SAFETY OF RAILWAY TRAFFIC (brakes or auxiliary equipment B61H, B61K; point or crossing construction E01B)
- B61B: RAILWAY SYSTEMS; EQUIPMENT THEREFOR NOT OTHERWISE PROVIDED FOR (lifts or hoists, elevators, escalators, moving walkways B66B)
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

Provided is a technology for monitoring train doors which improves the accuracy of detection of trapping in vehicle doors. A server compares the difference between a static image (reference image 91), from each monitoring camera, of a normal state in which there is no trapping in vehicle doors, said static images being held in the server in advance, and a static image (an observation image 92) first acquired in a prescribed acquisition time. If a difference is present, the difference (difference image 94) between the reference image 91 and the observation image 92 acquired in the acquisition time is acquired. A quadrilateral F which covers the four sides of an object constituting the difference is subsequently rendered, the centre point of the quadrilateral is obtained, it is determined that trapping has occurred if movement of a centre coordinate C1, C2, . . . Cn, i.e. the difference between the centre coordinates C, is lower than a prescribed threshold value, and red frame rendering of video is indicated on a monitor.

## Claims

### Claim 1

A monitoring system including a monitoring camera that images a door of a train, a control device that detects trapping by the door based on a video obtained by the monitoring camera, and a monitor that displays the video of the monitoring camera, wherein
when the door has changed from an opened state to a closed state, the control device determines a trapping determination state that trapping by the door has occurred based on a difference image between a reference image captured by the monitoring camera and an observation image captured by the monitoring camera after elapse of a prescribed time since the capturing of the reference image,
the monitor displays, in a highlighted mode, the video of the monitoring camera that captures the door determined as causing the occurring of the trapping and further displays a cancellation button for cancelling the trapping determination state, and
if the cancellation button is pressed, the highlighted mode of the video of the monitoring camera is cancelled.

### Claim 2 (depends on 1)

The monitoring system according to claim 1, wherein the monitoring camera captures a plurality of the observation images after capturing the reference image, and the control device acquires a difference image between the reference image and each observation image, obtains the movement of a central coordinate from central coordinates of the plurality of difference images, and determines that trapping by the door has occurred if it is determined that the central coordinate has not moved.

### Claim 3

A monitoring method for detecting trapping by a door of a train, based on a video of a monitoring camera that images the door of the train, comprising:
a difference calculation step of calculating a difference between a reference image captured by the monitoring camera and an observation image captured by the monitoring camera after elapse of a prescribed time since the capturing of the reference image, when the door has changed from an opened state to a closed state;
a trapping determination step of obtaining the movement of a central coordinate of the difference, and determining trapping determination state that trapping by the door has occurred if it is determined that the central coordinate has not moved;
an alarm ringing step of starting an alarm ringing if the trapping determination state that the trapping has occurred is determined in the trapping determination step;
a cancelling step of receiving an operation of a cancellation button for cancelling the trapping determination state; and
a stoning step of stooping the alarm ringing.