AU2004201723B2

AU2004201723B2 - Signaling System with an Imaging Sensor

Info

Publication number: AU2004201723B2
Application number: AU2004201723A
Authority: AU
Inventors: Thomas Brupbacher; Dieter Wieser
Original assignee: Siemens AG; Siemens Corp
Current assignee: Siemens AG
Priority date: 2003-05-12
Filing date: 2004-04-23
Publication date: 2009-07-23
Anticipated expiration: 2024-04-23
Also published as: CN1551054A; NO330180B1; EP1477948A1; ES2298446T3; DE50308965D1; KR20040097943A; CN100483471C; DK1477948T3; EP1477948B1; PL367913A1; AU2004201723A1; ATE383631T1; NO20041935L

Abstract

An image sensor such as a video camera (1) picks up images of the monitored space. A processor (2) processes the image signals. A communication connection with a central office allows two-way communication. A control and/or communication device, such as a loudspeaker (6) for announcements, or an exit indicator (7), is provided in the region of the image sensor, its control and/or operation being based on the picked up images.

Description

S&F Ref: 674295 AUSTRALIA PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name and Siemens Building Technologies AG Address Bellerivestrasse 36 of Applicant: 8008 Zurich Switzerland Actual Thomas Brupbacher Inventor(s): Dieter Wieser Address for Spruson & Ferguson Service: St Martins Tower Level 35 31 Market Street Sydney NSW 2000 (CCN 3710000177) Invention Title: Signaling System with an Imaging Sensor The following statement is a full description of this invention, including the best method of performing it known to me/us:- Signaling system with an imaging sensor 5 Description The present invention relates to a signaling system for the occurrence of events in a region which is referred to in the following text as a monitoring area, having 10 an imaging sensor for recording images of the monitoring area, having a processor for processing the image signals which are supplied from the imaging sensor, having a control center and having a communication link to the control center. 15 Signaling systems of this type are primarily used for fire and intrusion monitoring (see, for example, WO-A-01/67415) , with the image of the imaging sensor being evaluated in a processor which, in the event of 20 an alarm, sends an alarm signal to the control center via the communication means. For example, if the monitoring area is a road tunnel, it is also known for the image of the imaging sensor to be transmitted to the control center, and for the traffic to be observed 25 there by the operator (see, for example, WO-A-02/054364) . It is also possible for the operator to verify the fact when an alarm occurs, and to direct the emergency services to the appropriate location. 30 While, in the past, specific signaling device types were used for the individual events, such as a fire, intrusion or else traffic monitoring, modern image processing allows the use of a single signaling device type, specifically an imaging sensor, for example a 35 video camera, for the various types of events with the image signal from the imaging sensor being evaluated on the basis of various criteria.

- 2 All of the types of events described so far have the common feature that the signaling device which is formed by the imaging sensor initiates an alarm locally and signals this back to the control center, and 5 possibly also transmits the sensor images to the control center, where although the personnel can view the images, they cannot interactively communicate with the imaging sensor. The latter is a disadvantage if one considers further possible applications of the 10 signaling device having an imaging sensor. For example, WO-A-00/14693 describes a fire alarm which is designed to detect two levels of different magnitude of a fire characteristic variable, the lower of which indicates the occurrence of smoke, while the higher level 15 indicates that the relevant escape route cannot be used. This fire alarm may have an associated camera for monitoring the area surrounding the signaling device. The camera transmits the recorded images to the control center, providing the emergency services with the 20 capability to monitor the escapes routes visually, and to determine their usability. In the case of this fire alarm, it would be advantageous if the emergency services additionally had 25 the capability to use the supplied images to take measures in the relevant escape route, and/or if the escape routes could be automatically blocked. It would also be advantageous to replace the combination of a fire alarm and camera by a signaling system of the type 30 mentioned initially, and thus to simplify the hardware complexity. The aim of the invention is now to provide a cost effective signaling system of said type with as wide a 35 range of applications as possible. According to the invention, this object is achieved in that said communication link is designed for two-way communication, and in that control and/or communication means are provided in the area of the imaging sensor, 3 which means are controlled and/or operated on the basis of the images recorded by the imaging sensor. A signaling system for the occurrence of events in a region which is referred to in the following text as a monitoring area, having an imaging sensor for 5 recording images of the monitoring area, having a processor for processing the image signals which are supplied from the imaging sensor, having a control center and having a communication link to the control center, characterized in that said communication link is designed for two-way communication, and in that control and/or communication means are provided in the area of the imaging 10 sensor, which means are controlled and/or operated on the basis of the recorded images, in which the said communication means comprise a visual display for escape routes, and the said control means relate to the viability of the escape routes. A first preferred embodiment of the signaling system according to the 15 invention is characterized in that said control and/or communication means have a loudspeaker for announcement to people who are located in the relevant monitoring area. This preferred embodiment upgrades the signaling system to form a so-called voice system, which is a system for announcement of evacuation instructions to people who are located in an endangered building. 20 According to a second preferred embodiment, said control and/or communication means have means for initiation/activation of a stationary extinguishing system. A further preferred embodiment is characterized in that the visual conditions in the monitoring area are determined automatically. This preferred 25. embodiment is extremely advantageous in particular for use in an -4 evacuation system, because the visual conditions represent a reliable criterion for the usability of escape routes, on the basis of which the relevant escape route can be blocked either by an action from 5 the control center, or else, possibly, automatically. When the visibility falls below a minimum value, an appropriate announcement is preferably made on a loudspeaker, or an indication is provided that the relevant escape route is not usable. 10 A further preferred embodiment of the signaling system according to the invention is characterized by a microphone which is arranged in the monitoring area and allows the control center to deliberately listen to the 15 monitoring area. A further preferred embodiment of the signaling system according to the invention is characterized in that the imaging sensor is formed by a camera, and the processor 20 is installed in the camera or is connected directly to it, in that the processing and evaluation of the image signals which are supplied from the camera are carried out locally at the location of the camera, and in that it is possible to post-process the image signals 25 centrally. The camera and the processor are preferably combined with a microphone and a loudspeaker to form an appliance unit, which forms a multifunctional signaling device for the measurement of visual perturbation, the detection of movements and/or noise, and the 30 compression of the image signals. This multifunctional signaling device is designed for fire detection, movement detection, noise detection and evacuation control. 35 Noise detection allows a particularly interesting application of the multifunctional signaling device according to the invention at locations where there is a risk of accidents, for example in underpasses and multistory car parks. If the noise detector is formed 5 by a scream detector, on whose response the images which are supplied from the camera are connected to the control center or other suitable actions are initiated, the probability of accidents is drastically reduced, and personnel safety is correspondingly increased. 5 Other aspects and preferred aspects are disclosed in the specification and/or defined in the appended claims, forming a part of the description of the invention. The invention will be explained in more detail in the following text with reference to an exemplary embodiment and the single drawing; the drawing 10 shows a schematic block diagram of a signaling system according to the invention. According to the illustration, the signaling system essentially comprises an event signaling device, which is formed by a camera 1 and a processor 2, a control center 3 and a bidirectional communication link 4 between the processor 2 15 and the control center 3. The expression camera refers in general to an imaging sensor and should not be understood in a restrictive manner. The camera 1 is, for example, a video camera whose signals are digitized and are transmitted to the processor 2, in which case the processor 2 may be provided both in the camera 1 and in the control center 3 as well as between the camera I and the 20 control center 3. The processor 2 is preferably located in or immediately adjacent to the camera 1, in order to allow local processing and evaluation of the image signals supplied from the camera 1, in situ. The communication link 4 allows bidirectional communication between a control station, which is physically separate from the event signaling device, for example the control center 2, and 25 the event signaling device which is formed by the camera 1 and the process or 2. The camera I may itself have a digital output, for example in accordance with IEEE Standard 1394. The signal which is transmitted to the control center 3 may be an image signal or a purely digital data stream, in both cases generally in compressed form. The 30 -6 transmission of the image signal to the control center 3 allows its central post-processing, the verification of decisions made by the local evaluation, and the initiation of suitable measures. 5 The camera 1 may also be a CMOS micro-camera module of the type provided for use in mobile telephones, with optics and with a single chip, which carries out the functions of an image sensor and image processor. The 10 dimensions of the camera module are less than 10 x 10 x 5 mm; the image sensor is distinguished by very low power consumption. The image recorded by the camera 1 is then a pixel image of the monitoring area, which is processed to form brightness information for the rows 15 and columns of the pixels. The evaluation is preferably carried out in the processor 2, with a common processor 2 in each case being associated with a specific number, for example 8 to 10, cameras 1. 20 The event signaling device which is formed by the camera 1 and processor 2 preferably contains an addressable, bidirectional, digital communication link, in which context the expression IP signal (IP = Internet Protocol) is also used, thus allowing the 25 integration of the described signaling system in existing communication networks. Inter alia, the bidirectional communication link 4 means that the monitoring area can be viewed from the 30 control center 3 and, for example, an alarm signal can be verified and/or specific actions can be initiated in the monitoring area. The expression monitoring area is used to describe the region which is monitored by the event signaling device and which may be located within 35 a building or in the open air, or else may extend from an internal area to the outside, or vice versa. A microphone 5 which is connected to the processor 2 is preferably provided in the monitoring area, so that audio signals can also be processed and transmitted to -7 the control center 3. The latter function may, for example, be in the form of a so-called "listen in", with the microphone 5 being switched on from the control center 3 in the event of an alarm, so that the 5 monitoring area can be listened to. This function is particularly highly suitable for movement and intrusion monitoring, because intruders generally produce typical noise. 10 As can also be seen from the drawing, further devices, which are referred to in the following text as control and/or communication means, are associated with the event signaling device which is formed by the camera 1 and processor 2, and these control and/or communication 15 means are controlled and/or operated on the basis of the images which are recorded by the camera 1, to be precise automatically or from the control center. These control and/or communication means 5 may, for 20 example, be loudspeakers 5 or visual displays 7, such as markings of escape routes, or means 8 for initiation/activation of a stationary extinguishing system, or means for operation of a closing mechanism for sealing off the relevant monitoring area, and more 25 such items. The described signaling system is designed for one or more, or else all, of the following applications: 30 * Detection of smoke or flames: When the system is in the armed operating state, camera 1 in each case records an image of the monitoring area at intervals of fractions of a second. This is compared with reference images which are 35 characteristic of the occurrence of specific danger characteristic variables. Such reference images may, for example, be images of flames, objects, states or movements. Furthermore, the image is compared with one or more successive -8 images, in order to make it possible to identify a change in the image sequence. A change such as this may, for example, comprise the structure of the monitoring area becoming fuzzy, which would be 5 an indication of the occurrence of smoke. In order to identify a fuzzy structure in the monitoring area, the brightness of groups of pixels in the images from the camera 1 is 10 determined. This is done by means of a process in which a value which is representative of the brightness is obtained, and its time profile is investigated for a change that is characteristic of the occurrence of smoke. For example, the 15 brightness of the pixels is determined by means of an edge extraction process, in which each pixel is associated with an edge value and is compared with a mean value. With regard to the edge extraction process, reference should be made to 20 WO-A-02/054364. Another possibility for smoke detection is for the camera 1 to measure the scattered light caused by the occurrence of smoke. This method corresponds 25 to the measurement principle as used in the scattered light smoke alarms that are widely used nowadays, but with the difference that the measurement area in which the scattered light is measured is not itself a measurement camera 30 provided in the interior of the signaling device, but is the monitoring area itself. Light sources (not illustrated), for example LEDs or IREDs which illuminate the monitoring area intermittently or continuously, may be provided on or adjacent to 35 the camera, in order to intensify the scattered light. The system may also be operated in such a way that, with adequate illumination, the structure of the monitoring area is monitored using the method which has just been described, -9 and the scattered light is measured when it becomes dark. For this purpose, the brightness in the monitoring area is determined from the image from the camera 1, and the camera 1 is switched to 5 the appropriate mode on the basis of the brightness. e Movement signaling: A further important danger characteristic variable which can be monitored by 10 means of the signaling system is the movement of people in the monitoring area. Foreign objects can be located by comparison of the images from the camera 1 with a reference image which reproduces the monitoring area without any foreign objects, 15 and their movement can be tracked by comparing successive images. Detailed investigation of the image area with the foreign object allows classification of the object and, in particular, makes it possible to distinguish between people 20 and animals. * Detection of the presence of persons (presence detection): The movement signaling provides an unambiguous indication that someone who is not 25 sleeping is located in the relevant area. Since people who are not sleeping may on the one hand do something which may trigger a false alarm and on the other hand can reach even the smallest smouldering fire considerably earlier than the 30 best smoke alarm can detect it, it is worthwhile setting the sensitivity of the fire detection at a lower level when people are present in the relevant area than when no-one is present. The described signaling system can carry out this 35 sensitivity switching automatically by monitoring for people moving in the monitoring area. * Evacuation of people from an endangered, for example burning, building: Since the image signal - 10 from the camera 1 supplies information that a fire has broken out, that people are present in a building and about the usability of areas, this represents an excellent aid for evacuation of 5 people from a burning building in a specific manner. For this purpose, the signaling system is connected to controllable escape route indications 7, which can be controlled on the basis of the image signal. In this way, impassable passages or 10 stairwells can be blocked automatically, and the people to be evacuated can be guided to safe escape routes. The loudspeakers 6 which have been mentioned can be used to make announcements to the people to be rescued and to inform them of the 15 danger situation, to request them to take actions, and to inform them of the evacuation process. The microphones 5 can be used to listen to the monitored areas, and this is, of course, also advantageous in conjunction with presence 20 detection and movement signaling. The microphones provide means for detection of help calls and screaming, and this is particularly suitable, for example, in underground garages, 25 train stations (underground or on the surface), underpasses, underground passages or the like. As soon as a scream is detected, which is preferably done on the basis of the frequency, the relevant imaging sensor 1 is automatically connected to the 30 control center 3, from where the necessary assistance measures are initiated for the endangered people. In this case, it may be very helpful to the endangered people to be able to speak into the monitoring area so that the person 35 involved is informed of the monitoring and of what is being done. The signal from the camera 1 may also be used to analyze the behavior of people, for example in - 11 hotel passages, at cash machines or in halls in an entirely general manner, in order to make it possible to draw conclusions about potential dangers. In order to improve the acceptance of 5 this video monitoring, it may be helpful to detect faces and to make the faces of the people appearing in the image unrecognizable. The detection of screams and calls for help that has 10 been mentioned is an application of the described signaling system which can be used widely and satisfies a broader requirement, in which case it is possible to speak in a general form of noise detection and to monitor widely differing noise signatures and 15 frequencies. In addition to the already mentioned calls for help and screams for help, this also relates primarily, for example, to the typical crackling of a fire or to the typical noise when using a spray can (graffiti). All of these noises can be used for 20 detection of the relevant events, to initiate countermeasures, and/or for evidence. For use as a noise detector, it is advantageous for the camera 1, the processor 2, the microphone 5 and the 25 loudspeaker 5 to be integrated in a multifunctional signaling device 9, which forms an apparatus unit, for measurement of visual turbidity, for detection of movement and noise, and for the compression of image signals. This multifunctional signaling device 9 would 30 be a video camera 1 with a processor 2, a microphone 5 and a loudspeaker 6, which could either be connected to a control center 3 or, possibly, could also be in the form of a stand-alone appliance. In addition, a light source for shock illumination and/or a siren could be 35 connected to the signaling device 9. If the signaling device 9 is used as a stand-alone apparatus, it is advantageous to connect it to a station which is installed in the vicinity of the signaling device 9 and allows secure and reliable storage of the events 12 recorded by the signaling device 9, thus providing good evidence and allowing the relevant data to be read easily. A device of this type is described in EP-A-1 233 385, to which reference is hereby expressly made. "Comprises/comprising" when used in this specification is taken to specify 5 the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. 10

Claims

1. A signaling system for the occurrence of events in a region which is referred to in the following text as a monitoring area, having an imaging sensor for 5 recording images of the monitoring area, having a processor for processing the image signals which are supplied from the imaging sensor, having a control center and having a communication link to the control center, characterized in that said communication link is designed for two-way communication, and in that control and/or communication means are provided in the area of the imaging 10 sensor, which means are controlled and/or operated on the basis of the recorded images, in which the said communication means comprise a visual display for escape routes, and the said control means relate to the viability of the escape routes. 15

2. The signaling system as claimed in claim 1, characterized in that said control and/or communication means have a loudspeaker for announcement to people who are located in the relevant monitoring area.

3. The signaling system as claimed in claim 1 or 2 characterized in that said 20 control and/or communication means have means for initiation/activation of a stationary extinguishing system.

4. The signaling system as claimed in claim 2, characterized in that the visual conditions in the monitoring area are determined automatically. 25

5. The signaling system as claimed in claim 4, characterized in that, when the visibility fails below a minimum level, an appropriate announcement is made on the or a loudspeaker. 30

6. The signaling system as claimed in claim 4, characterized in that, if the visibility falls below a minimum level, the non-usability of the relevant escape route is indicated. 14

7. The signaling system as claimed in any one of claims 1 to 6, characterized by a microphone which is arranged in the monitoring area and allows the control center to deliberately listen to the monitoring area. 5

8. The signaling system as claimed in claim 7, characterized in that the microphone forms part of a noise detector, on whose response an action is initiated.

9. The signaling system as claimed in claim 8, characterized in that the noise 10 detector is formed by a scream detector.

10. The signaling system as claimed in claim 9, characterized in that the response of the scream detector connects the images which are supplied from the imaging sensor to the control center, and/or results in an announcement 15 being initiated in a loudspeaker and/or in shock illumination being initiated.

11. The signaling system as claimed in any one of claims 1 to 10, characterized in that the presence of people in the monitoring area is determined automatically. 20

12. The signaling system as claimed in any one of claims I to 11, characterized in that the monitoring area is monitored for people entering it.

13. The signaling system as claimed in any one of claims 1 to 12, 25 characterized in that the imaging sensor is formed by a camera, and the processor is installed in the camera or is connected directly to it, in that the processing and evaluation of the image signals which are supplied from the camera are carried out locally at the location of the camera, and in that it is possible to post-process the image signals centrally. 30

14. The signaling system as claimed in claim 13, characterized in that the camera and the processor are combined with a microphone and a loudspeaker to form an appliance unit, which forms a multifunctional signaling device for the 15 measurement of visual perturbation, the detection of movements and/or noise, and the compression of image signals.

15. The signaling system as claimed in claim 14, characterized in that the 5 multifunctional signaling device is designed for smoke detection, movement detection, noise detection and evacuation control.

16. The signaling system as claimed in claim 15, characterized in that the multifunctional signaling device contains a ring memory for the storage of the 10 image signals which have been recorded immediately before and after an event, and an addressable, bidirectional, digital communication link.

17. The signaling system substantially as described herein with reference to the accompanying drawing. 15