Supervisory system using visible ray or infrared ray

• US 5,237,308 A
• Filed: 02/18/1992
• Issued: 08/17/1993
• Est. Priority Date: 02/18/1991
• Status: Expired due to Term

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Nakamura, Tetsuya
• Primary Examiner(s): Ng, Jin F.
• Assistant Examiner(s): TONG, NINA C
• Application Number:
  US07/837,495
• Time in Patent Office: 546 Days
• Field of Search: 340/588, 340/589, 340/555, 340/556, 340/521, 340/522, 340/630, 340/628, 340/506, 358/108, 358/110, 358/113
• US Class Current: 340/588
• CPC Class Codes: G08B 13/194 using image scanning and comparing systems
• CPC Class Codes: G08B 17/10 Actuation by presence of smoke or gases , e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means
• CPC Class Codes: G08B 17/125 by using a video camera to detect fire or smoke

Abstract

A smoke supervisory system comprising a visible image processor for calculating a differential image between a reference image and an input image and calculating parameters in the differential image; an address overlap detector for detecting whether the differential images overlap each other; an image element number change detector for detecting a change in the image element number of the differential image; and an address ratio change detector for calculating an address ratio of the differential image; or an equipment supervisory system comprising an image fetch device for fetching a reference image and an input image from an infrared image pick up device; a mask control device for masking the reference image and the input image; a differential operation device for calculating a differential image of an unmasked dividing image; a temperature distribution difference detector for detecting a maximum temperature and a mean temperature of a temperature distribution from the differential image and calculating a temperature distribution difference; and when the calculated temperature distribution difference is more than a predetermined level, detecting an abnormal sign. By using this invention, in any environmental conditions, early detection of smoke generation is automatically executed and early and accurate detection of an abnormal temperature can be realized.

Claims

1. A smoke supervisory system comprising:

a visible ray image pick up means for picking up an image at an arbitrary location;

a visible image processing means for fetching the picked up images from the visible ray image pick up means at a certain time interval;

the preceding fetching image being a reference image and the following fetching image being an input image to be supervised, for calculating a differential image from the input image and the reference image; and

for calculating a two dimensional address and an image element number on an image frame of the differential image;

an image change detection means for updating the reference image and the input image in the visible image processing means when the two dimensional address and image element number of the differential image is less than a predetermined level, and for fixing the reference image and updating only the input image when the two dimensional address and image element number of the differential image is more than a predetermined level;

an address overlap detection means for detecting whether the two dimensional addresses overlap each other on the two dimensional axis;

an image element number change detection means for detecting a change in the image element number;

an address ratio change detection means for detecting the change of the address ratio by calculating the address ratio on the two dimensional axis from the two dimensional address; and

a first degree smoke detection means for outputting an initial first degree smoke detection signal when each two dimensional addresses overlap by the address overlap detection means, each change of the image element number by the image element number change detection means, and each change of the address ratio by the address ratio change detection means are detected simultaneously.

2. A smoke supervisory system as set forth in claim 1 further comprising:

an infrared ray image pick up means for picking up an infrared ray at an arbitrary location;

an infrared image processing means for calculating a differential image between an input image and a reference image, which are infrared images different in pick up times in the infrared ray image pick up means;

a local temperature rise detection means for detecting a local temperature rise at a location from the differential image; and

a second degree smoke detection means for outputting a second degree smoke detection signal only when the first degree smoke detection signal from the first degree smoke detection means and the local temperature rise from the local temperature rise detection means are detected simultaneously.

3. A smoke supervisory system as set forth in claim 2, wherein

the local temperature rise detection means generates a temperature abnormal portion address;

the system comprises a smoke generation source calculator and a smoke source confirmation means;

the smoke generation source calculator specifies a smoke generation source address in accordance with a detection result of the address overlap from the address overlap detection means;

the smoke source confirmation means compares the smoke generation source address with the temperature abnormal portion address from the local temperature rise detection means, and outputs a coincidence signal to the second degree smoke detection means when the compared signals coincide; and

only when the second degree smoke detection means is supplied simultaneously with the coincidence signal, the first degree smoke detection signal, and the temperature abnormal rise detection signal from the local temperature rise detection means, the second degree smoke detection means outputs the second degree smoke detection signal.

4. An equipment supervisory system comprising:

an infrared ray image pick up means for picking up an infrared image from a supervisory object at an arbitrary location;

an image fetch means for fetching the picked up image from the infrared ray image pick up means at a certain time interval, and for storing the preceding fetched image as a reference image and the following fetched image as an input image;

a mask control means for dividing the fetched and stored reference image and the input image into a plurality of areas, for masking all other areas except one divided image, and for sequentially moving an unmasked divided image at a certain time interval;

a differential operation means for calculating the differential image between the unmasked divided images in the divided input image and the reference image;

a temperature distribution difference detection means for detecting a maximum temperature (T_MAX) and a mean temperature (T_AV) in a temperature distribution on an object from the differential image and for calculating a difference Δ

T of the temperature distribution; and

an abnormal sign detection means for calculating a predetermined number of mean values (Δ

T_AV) continuously in a predetermined time to confirm a continuous temperature rise characteristic of the temperature distribution difference Δ

T, for detecting an abnormal sign when the calculated temperature distribution difference (Δ

T) is more than a predetermined level, for updating the input image to the reference image, and for repeating the fetch of the next image as an input image when the abnormal sign is not detected or before the mean value (Δ

T_AV) is calculated.

5. An equipment supervisory system as set forth in claim 4 further comprising an abnormal prediction detection means for calculating a prediction time until the mean value of the temperature distribution difference (Δ

T_AV) attains a dangerous abnormal level by repeating the detection of the abnormal sign.

6. An equipment supervisory system as set forth in claim 5 further comprising a dangerous abnormality detection means for detecting a dangerous abnormality when the mean value of the temperature distribution difference (Δ

T_AV) is more than the dangerous abnormal level.