NO330180B1 - Alert system with imaging sensor - Google Patents

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

The present invention relates to a notification system for the occurrence of events in an area which is hereinafter referred to as a surveillance room, with an imaging sensor for recording images of the surveillance room, a processor for processing the image signals delivered from the imaging sensor, a central and a communication connection with the central office.

Alarm systems of this type are primarily used for fire and burglary monitoring (see, for example, WO-A-01/67415), where the image from the imaging sensor is used in a processor, which in the event of an alarm sends an alarm message over the means of communication to the central office. When it concerns a road tunnel as a monitoring room, it is also known to transfer the image from the imaging sensor to the control center and thus monitor traffic incidents through the operating staff (see, for example, WO-A-02/054364). One can also imagine that the operating staff, when an alarm is triggered, verifies it and directs emergency forces to the emergency site.

While in the past special detector types were used for individual incidents, such as fire or burglary or traffic monitoring, modern image processing makes the use of a single detector type possible, namely an imaging sensor, for example a video camera, for the various types of incidents, where the image signal from the imaging sensors is utilized based on different criteria.

All the previously described types of events have in common that the detector, provided with an image-providing sensor, triggers an alarm at a location and reports this to the control center, and possibly also transmits sensor images to the control center, where the staff can, of course, view the images, but cannot communicate interactively with the imaging sensor. The latter is a disadvantage, when one further thinks about possible applications of a detector that exhibits an imaging sensor. For example, WO-A-00/14693 describes a fire detector, which has been developed for the detection of two different high values of fire parameters, where the first shows the appearance of smoke and the second shows whether the relevant escape route is unusable. This fire detector can be assigned to a camera for monitoring the room surrounding the detector. The camera transmits the captured images to the control center, through which the emergency forces have the opportunity to visually monitor the escape routes and determine their usability.

WO 99/10855 describes an evacuation alarm system for use in buildings and within small outdoor areas. The system includes a two-way digital transmission via a cable to allow the implementation of additional functions, and when power-consuming alarm components are used, and then power supply to such components via the cable. The functions of the alarm components can be controlled using a signal that is transmitted to the component in the form of background music from a speaker.

WO 97/08896 describes a security system with an acoustic sensor device. A camera placed near this device can be automatically directed towards a detected, sound-producing event. Event data can be stored in a memory and the system can learn from the nature of the event.

With these fire alarms, it would have been beneficial to have the emergency forces in addition

could make it possible to take precautions regarding the relevant escape route with the help of the supplied images and/or whether the escape route could be automatically blocked. It would also have been advantageous to replace the combination of fire alarms and camera through a reporting system of the type mentioned at the outset and through this simplify the apparatus-related equipment.

With the help of the present invention, a cost-friendly reporting system of the aforementioned type will now be provided with the widest possible range of application. This task is solved in accordance with the invention, in that the aforementioned communication connection is provided for two-way communication, and in that control and/or communication means are placed in the area of the imaging sensor, whose control and/or activation takes place with the help of the images captured by the imaging sensor.

The proposed reporting system also includes an imaging sensor for observation of a monitoring room, which is connected to a central through a communication link. The communication connection has been developed for two-way communication, so that the control panel can communicate with the imaging sensor to trigger actions in the monitoring room. Such actions can be control of optical signals and/or communication with persons who are in the monitoring room. Through this, the reporting system becomes an essential component of an evacuation system, with which people in dangerous areas can be rescued. There is an automatic determination of the visibility conditions in the monitoring room. Visibility is a reliable criterion for the usability of escape routes, with the help of this the relevant escape route can be blocked by intervention from the control center or possibly also automatically. Preferably, corresponding notification of the non-usability of the relevant escape route occurs in a speaker or a signal when Ise falls below a minimum value for the visibility value.

A first preferred embodiment of the reporting system in accordance with the invention is characterized by the aforementioned control and/or communication means comprising a loudspeaker for messages to persons who are in the relevant monitoring room. This preferred embodiment expands the notification system to a so-called "Voice-System", which is a system for communicating evacuation instructions to people who are in a dangerous building.

A second preferred embodiment of the reporting system in accordance with the invention is characterized by the aforementioned control and/or communication means comprising an optical signal for the escape route and/or its usability. In accordance with a third preferred embodiment, the aforementioned control and/or communication means comprise means for triggering/activating a stationary extinguishing system.

A further preferred embodiment of the reporting system in accordance with the invention is characterized by the fact that a microphone is arranged in the monitoring room, which makes targeted listening of the monitoring room possible from the central office.

A further preferred embodiment of the reporting system in accordance with the invention is characterized in that the imaging sensor is provided with a camera, and the processor is built into the camera or directly connected to it, that the processing and utilization of the image signals delivered by the camera is decentralized at the location at the camera, and that there is an option for central post-processing of the image signal. Preferably, the camera and the processor are built together with a microphone and a speaker into a unified device, which forms a multifunctional detector for measuring visibility turbidity, detection of movements and/or noise and compression of image signals. This multifunctional detector is provided for fire detection, motion detection, noise detection and evacuation control.

Noise detection enables a particularly interesting application of a multifunctional detector for places where there is a risk of assault in accordance with the invention, such as e.g. in underpasses and car parks. When the noise detector is provided as a scream detector, which by reaction is connected to the control center and delivers images using a camera or triggers other suitable actions, the probability of an attack is drastically reduced and the safety of people correspondingly increased.

In the following, the invention is described in more detail with the help of an embodiment and drawings; the drawing shows a schematic block diagram of a reporting system in accordance with the invention.

The reporting system in accordance with the description essentially consists of an incident report formed by a camera 1 and a processor 2, as well as a control panel 3 and a two-way communication connection 4 between the processor 2 and the control panel 3. The term camera generally denotes here an image-producing sensor and must shall not be construed as restrictive. The camera is e.g. a video camera, the signal of which is digitized and transmitted to the processor 2, whereby the processor 2 can be placed in the camera 1 as well as in the control panel 3 or also between the camera 1 and the control panel 3. Preferably, the processor 2 is located in the immediate vicinity of the camera 1, to enable a decentralized processing and utilization of the image signals from the location provided by the camera 1. The communication connection 4 enables a two-way connection between a control station spatially separated from the incident detector, for example the control center 2 and the incident detector formed with the help of the camera 1 and the processor 2.

The camera 1 itself can also include a digital output, for example according to the standard IEEE 1394. The signal that is transmitted to the central 3 can be an image signal or a pure digital data stream, which in both cases is usually in compressed form. The transmission of the image signals to the central 3 enables central post-processing, verification of determinations made through the decentralized utilization, as well as initiation of suitable precautions.

The camera 1 can also be a CMOS micro camera module used in mobile phones, with an optic and with a separate chip, which performs the function of the image sensor and the image processor. The dimension of the camera module is approximately 10 x 10 x 5 mm;

and the image sensor is characterized by its negligible power consumption. The captured image of the camera 1 is a pixel image of the monitoring room, which is processed into light density information consisting of lines and columns of pixels. The utilization preferably follows in the processor 2, whereby a certain number from, for example, 8-10 cameras 1 are arranged to a common processor 2 at any time.

Preferably, the event detector, which is formed by the camera 1 and the processor 2, contains an addressable, two-way digital communication connection, in this context we also talk about an IP signal (IP = Internet Protocol), which enables the integration of the present event system into an existing communication network.

The two-way communication connection 4 means, among other things, that one can look into the monitoring room from the central 3 and, for example, verify an alarm signal and/or trigger specific actions in the monitoring room. The area monitored by the event detector is called the monitoring room, and is located in a building or in the open or can also extend from an indoor room to the outside or vice versa. Preferably, the monitoring room is equipped with a microphone 5 connected to the processor 2, so that audio signals can also be processed and transmitted to the control panel 3. The latter function can follow, for example, as mentioned ("listen in"), where the microphone 5 is connected from the control panel in the event of an alarm 3 and the monitoring room is overheard. This function is particularly well suited for motion and break-in monitoring, because break-ins usually create noise.

As will further be understood from the drawing, the event detector which is formed by the camera 1 and the processor 2 is further assigned to a device, which is hereinafter referred to as control and/or communication means, whose control and/or operation takes place with the help of images captured by camera 1, automatically or from the control panel. This control and/or communication means 5 can for example be a speaker 5 or optical signals 7, which e.g. instructions for an escape route, or a means 8 for releasing/activating a stationary fire extinguisher or a means for activating a locking mechanism for closing the monitoring room in question, and the like.

The present reporting system is provided for one, several or all of the following applications: • Detection of smoke or flames: in sharply connected operating mode, the system causes the camera 1 to take pictures of the monitoring room at intervals in fractions of seconds. These are compared with reference images, which appear to be characteristic of certain hazard parameters. Such reference images can, for example, be images of flames, objects, conditions or movements. In addition, the image is compared with one or more temporally following images, in order to be able to recognize a change in the image order. Such a change can e.g. consist of the structure in the monitoring room becoming blurred, which may be a sign that smoke is present.

In order to recognize a blurred structure in the monitoring room, a determination is made of the light density of groups of pixels from the images from camera 1. These go through a process, where a representative value for the light density is derived, the temporal course of which is examined for the occurrence of characteristic changes which indicates smoke. For example, the determination of the light density of the pixels goes through an edge extraction process, where each pixel is assigned an edge value and is compared with a mean value. Regarding the edge extraction process, reference is made to WO-A-02/054364.

Another possibility for smoke detection consists in the camera 1 measuring stray light caused by the presence of smoke. This method originates from the today widespread measurement principle used in scattered light smoke detectors, but with the difference that the measuring room in which the scattered light is measured is not a measuring chamber inside the detector, but is the monitoring room itself. To amplify the scattered light, light sources (not shown), for example LED or IRED can be provided at or next to the camera, which illuminate the surveillance room constantly or periodically. You can also operate the system so that with sufficient lighting, as in the procedure just described, the monitoring room is monitored and the darkness of the scattered light is measured. For this purpose, the light density in the monitoring room is also determined from the image from camera 1 and camera 1 performs switching using the light density in the relevant mode. • Movement notification: a further important hazard parameter that can be monitored using the notification system is the movement of people in the monitoring room. By comparing images from the camera 1 with a reference image of the surveillance room without foreign objects, foreign objects can be located and their movement can be tracked by means of a comparison of subsequent images. A more accurate examination of the image area with foreign objects enables a classification of the objects and in particular the separation of humans from animals. • Detection and presence of people (presence detection): The movement message provides a clear indication that there is a non-sleeping person in the room in question. As non-sleeping people can on the one hand do something that can trigger a false alarm and on the other hand can also smell the smallest smoldering fire significantly earlier than the best smoke detector can detect it, it is useful to be able to set the sensitivity of fire detection in presence of people in the room in question than in their absence. The existing reporting system can automatically make these sensitivity adjustments by means of monitoring people moving in the monitoring room. • Evacuation of people from a dangerous, for example burning building: When the image signal from camera 1 delivers information about the outbreak of a fire, about the presence of people in a building and about the usability of escape routes, these constitute an excellent aid for targeted evacuation of people from a burning building. For this purpose, the reporting system is connected to controllable escape route instructions 7, whose control takes place using image signals. In this way, impassable corridors or stairwells can be blocked automatically and the people to be evacuated can be directed to safe escape routes. Through the aforementioned loudspeaker 6, announcements can be made to the people who are to be rescued and give references in the event of danger, call for action and inform about the progress of the evacuation. The microphone 5 enables eavesdropping of the monitored room, which is of course also advantageous in connection with presence detection and motion notification. • Through the microphone, a means of detecting calls for help and screams has been provided for disposal, which is, for example, very well suited for use in underground garages, railway stations (under and above ground), underpasses, underground passages and the like. As soon as a scream is detected, which preferably happens with the help of the frequency, the relevant imaging sensor 1 is automatically connected to a central 3, from which the necessary auxiliary measures can be initiated for the persons exposed to danger. At the same time, a message can be made to the monitoring room with references from the manager of the monitoring and the ongoing efforts, which will be very helpful for the person exposed to danger. • You can also use the signal from camera 1 to analyze the behavior of people, for example in hotel corridors, at ATMs or at counters in communal cupboards, in order to rule out potential dangers. In order to increase the acceptance of such video surveillance, it may be helpful to prevent face detection and to be able to make the face of a person appearing in the image unrecognizable.

The mentioned detection of screams and calls for help is a versatile, applicable application of the described reporting system, which satisfies a widespread need, where we are talking about noise detection in general and can monitor various noise signatures and frequencies. Next to the mentioned calls for help and screams for help, there is, for example, the typical sparking from flames, or the typical noise that arises from the use of a spray can (graffiti). All these types of noise can be used for detection of the aforementioned incidents, triggering of countermeasures and/or securing evidence.

When used as a noise detector, it is advantageous to integrate the camera 1, the processor 2, the microphone 5 and the speaker 6 in an apparatus unit which forms a multifunctional detector 9 for measuring visibility turbidity, detection of movements and noise and compression of image signals. This multifunctional detector 9 can be developed with a video camera 1 with a processor 2, a microphone 5 and a speaker 6, which is either connected to a central 3 or possibly also a stand-alone device. In addition, the detector 9 can be connected to a light source for shock lighting and/or a siren. When using the detector 9 as a stand-alone device, it is advantageous that this is connected to a station in the vicinity of the detector 9, which enables secure storage of events recorded by the detector 9 and thus an impeccable security of evidence and a simple readout of the relevant the data. A device of this type is described in EP-A-1 233 385, which is hereby expressly incorporated as a reference.

Claims (16)

1. Reporting system for the occurrence of incidents in an area which is hereinafter referred to as a surveillance room, with an imaging sensor (1) for recording images of the surveillance room, a processor (2) for processing the image signals delivered from the imaging sensor, a central ( 3) and a communication connection (4) with the central unit (3), where the communication connection (4) is provided for two-way communication, and that it is arranged with a control and/or communication means in the area of the imaging sensor (1), whose control and/or activation takes place using the captured images, characterized by an automatic determination of the visibility conditions in the surveillance room. 2. Reporting system in accordance with patent claim 1, characterized in that the control and/or communication means comprises a loudspeaker (6) for messages to persons who are in the relevant monitoring room. 3. Reporting system in accordance with patent claim 1 or 2, characterized in that the control and/or communication means comprise an optical indicator (7) for escape routes and/or their usability. 4. Reporting system in accordance with one of the patent claims 1-3, characterized in that the control and/or communication means comprise a means (8) for triggering/activating a stationary extinguishing system. 5. Reporting system in accordance with patent claim 1, characterized in that when a minimum value for the sight value is undershot, a corresponding message occurs in a loudspeaker (6). 6. Reporting system in accordance with patent claim 1, characterized by falling below a minimum value for the visibility value, an indication of the non-usability of the escape route in question occurs. 7. Reporting system in accordance with one of patent claims 1-6, characterized in that a microphone (5) is arranged in the monitoring room, which makes targeted monitoring of the monitoring room possible from the central office (3). 8. Reporting system in accordance with patent claim 7, characterized in that the microphone (5) forms part of a noise detector, which triggers an action upon notification. 9. Reporting system in accordance with patent claim 8, characterized in that the noise detector is provided by means of a scream detector. 10. Reporting system in accordance with patent claim 9, characterized in that the imaging sensor (1) which delivers images to the control center (3) is switched on and/or a message is triggered in a loudspeaker (6) and/or a shock light is triggered by a charge in the scream detector. 11. Reporting system in accordance with one of the patent claims 1-10, characterized in that an automatic determination of the presence of persons in the monitoring room occurs. 12. Reporting system in accordance with one of patent claims 1-11, characterized in that a monitoring of the intrusion of persons in the monitoring room occurs. 13. Reporting system in accordance with one of patent claims 1-12, characterized in that the imaging sensor (1) is provided with the help of a camera, and the processor (2) is built into the camera or connected in the immediate vicinity of it, that the processing and utilization of the image signals delivered from the camera takes place decentralized at the location at the camera, and that the possibility of a central post-processing of the image signals exists. 14. Reporting system in accordance with patent claim 13, characterized in that the camera and the processor (2) are built together with a microphone (5) and a speaker (6) into one device unit, which forms a multifunctional detector (9) for measuring visibility turbidity, detection of movements and/or noise and compression of image signals. 15. Reporting system in accordance with patent claim 14, characterized in that the multifunctional detector (9) is designed for smoke detection, motion detection, noise detection and evacuation control. 16. Reporting system in accordance with patent claim 15, characterized in that the multifunctional detector (9) contains a ring storage for storing image signals immediately before and after an event and an addressable two-way digital communication connection.