Patent Application
20080100705
The present invention relates generally to surveillance and monitoring systems, and more particularly to surveillance and monitoring systems that employ two or more surveillance cameras that communicate over a data network.
Electronic surveillance and monitoring systems are becoming more common and important in residential and commercial environments. Individuals and families, in particular, desire a security system that monitors a defined premises and/or environment, to prevent or deter theft, burglary and robbery. In addition, there is a desire to monitor and detect other defined conditions and, in response to a detected condition, generate a warning. These other potentially hazardous conditions or threats include, for example, fire hazards, carbon monoxide and power failure and electricity outages.
Surveillance and monitoring systems often include video cameras, which allow activity to be monitored for alerting the occurrence of unwanted activity or intrusions, for identification, for facilities management, and/or for providing a signal that may be recorded for later reference or potential use as evidence. Generally individual cameras are dedicated to different field of views such as different rooms, passageways, doors, and stairwells. The video cameras may be in continuous operation so that they are always recording what is in their field of view. However, because of the prodigious volume of data that may be recorded, the video cameras alternatively may be configured so that they only begin recording when motion is detected. Since there can be a latency between the time motion is detected and the camera begins recording, potentially valuable video data may be missed. For instance, sometimes one camera will begin recording before any others because it is the first to detect motion while a neighboring camera may be better situated to record important information that may be lost because it has not yet detected motion. Under such circumstances it could be helpful to reduce the response time of any of the cameras that may be able to record useful information, regardless of when they first detect motion.
A simple example will now be presented to facilitate a better understanding of the problem discussed above. If an intruder enters a residence through a living room window, but the living room camera only captures the intruder's back and not his face, little useful information is obtained. If the intruder then quickly crosses through the hallway and enters the dining room, the hallway camera may not respond sufficiently rapidly to begin recording before the intruder has left the hallway and entered the dining room. In this case valuable information that could have been obtained while the intruder is in the hallway will be missed. Accordingly, it would be helpful if when motion is first detected, thereby triggering the first camera in the living room, the hallway camera is also instructed to begin recording so that by the time the intruder has entered the hallway the hallway camera will be recording.
If surveillance system 100 operates over a wireless network, any of a variety of different physical and data link communication standards may be employed. For example, such systems may use, without limitation, IEEE 802.11 (e.g., 802.11a; 802.11b; 802.11g), IEEE 802.15 (e.g., 802.15.1; 802.15.3, 802.15.4), DECT, PWT, pager, PCS, Wi-Fi, Bluetooth™, cellular, and the like. While the surveillance system may encompass any of these standards, one particularly advantageous communication protocol that is currently growing in use is ZigBee , which is a software layer based on the IEEE standard 802.15.4. Unlike the IEEE 802.11 and Bluetooth standards, ZigBee offers long battery life (measured in months or even years), high reliability, small size, automatic or semi-automatic installation, and low cost. With a relatively low data rate, 802.15.4 compliant devices are expected to be targeted to such cost-sensitive, low data rate markets as industrial sensors, commercial metering, consumer electronics, toys and games, and home automation and security.
Hub 110 may be implemented as a base station, router, switch, access point, or similar device that couples network devices. While the IP protocol suite is used in the particular implementations described herein, other standard and/or communication protocols are suitable substitutes. For example, X.25, ARP, RIP, UPnP or other protocols may be appropriate in particular installations. The IP protocol suite operates within the network layer of the International Standard Organization's Open System Interconnect model. In this system, packets of data transmitted through a network are marked with addresses that indicate their destination. Established routing algorithms determine an appropriate path through the network such that the packet arrives at the correct device. Packets also contain information that indicates the address of the sending device that the receiving device may use to reply to the transmitter. Even within the IP protocol suite, a variety of different standard and/or proprietary transport protocols may be employed (e.g., TCP, UDP, RTP, DCCP).
Hub 110 may implement any number of ports to meet the needs of a particular application, and may be implemented by a plurality of physical devices to provide more ports and/or a more complex network including sub-networks, zones, and the like. Hub 110 may also include additional functionality such as those normally offered by a conventional surveillance system controller. Alternatively, the functionality of the controller may be provided by one or more separate components. If cameras 120 and 130 transmit video and/or audio data to the hub 110 (as opposed to storing the data locally in the individual cameras), other devices that may associated with hub 110 includes a server for storing the data and a monitor that provides an operator with a centralized location from which to view the scenes from the various cameras
In the particular example of
A monitoring terminal 60 is also associated with hub 110. The monitoring terminal 60 may be used to view in real time the audio and video captured by any of the cameras 120 and 130 as well as video and audio stored on server 72.
In
Alternatively, instead of network-enabled cameras such as cameras 120, some or all of the cameras may be analog cameras that communicate with hub 110 using an analog subsystem interface that implements control functions and provides a network interface for cameras that do not communicate using standard network protocols. For example, in
Some or all of the cameras 120 and 130 may be fixed in position or they may be tracking cameras that are secured to a pan-tilt positioning unit (not shown in
IP cameras 120 are configured to generate a message that is transmitted to hub 110 whenever the camera is activated by detecting motion or by other means such as the activation of a co-located mechanical sensor (indicating that a door or window has been opened), thermal detector, glass breakage sensor, environmental sensor or monitor and the like. The message may conform to any transport or application layer protocol in the IP protocol suite that can be used to control and configure network devices such as UDP, TCP, FTP, SMTP and the like. If a different communication protocol is employed, the messages may be transmitted in any format appropriate for that protocol. For example, if the UPnP protocol is employed, the messages may be sent as XML messages.
In operation, when any of the cameras 120 and 130 are activated or otherwise undergo a change in imaging status (e.g., on/off, change in orientation such as a pan or tilt) by detecting motion or other means, a message is transmitted by the camera to the hub 110. The message identifies the camera that has undergone a change in imaging status and possibly provides other pertinent information, if available. For instance, if the camera that is activated has pan and tilt mechanisms, the message may include the camera orientation or the coordinates identifying the precise location that the camera was viewing when it was activated. Such information could assist other cameras in rapidly orienting themselves to view the scene that caused the first camera to be activated. For instance, if a stairwell camera located at the top of the stairs receives a message indicating that a camera on the first floor has been activated or has otherwise undergone a change in imaging status, the stairwell camera may be instructed to tilt downward.
The operation of the cameras as discussed above can be further illustrated using
Upon receipt of a message from the hub 110, hub 110 forwards the information to one or more of the other cameras, either by forwarding the original message or generating a new message. Instead of forwarding all or part of the information itself, the hub 110 may simply forward a command instructing one or more of the cameras to begin recording, or more generally, undergo some change in its imaging status. The cameras that are selected to receive the message can be determined in any of a number of different ways. For example, only those cameras in the same vicinity (e.g., the same room or same side of a building) or that have overlapping fields of view as the initially activated camera may receive the message. In this case the hub 110 can be preprogrammed, either by the user or a technician, with a distribution list that is appropriate for each camera. The distribution list can be stored, for example, in ROM 88 so that it is available for access by processor 86. The hub 110 can be programmed by downloading the distribution list using, for instance, either ROM port 100 or programming port 92. For instance, if camera “A” is activated, hub 110 may have a distribution list stored in ROM 88 instructing it to inform cameras “B” and “D.” Likewise, if camera “E” is activated, hub 110 may have a distribution list stored in ROM 88 instructing it to inform cameras “A” “F” and “G.” In the particular example shown in
The distribution list may be a static distribution list or a dynamic distribution list. In a static distribution list, the cameras that are selected to receive the message always remains the same (unless reprogrammed, of course). For example, the distribution list for a given camera may list all adjacent rooms. In a dynamic distribution list, the cameras included on the distribution list may vary depending on the particular circumstances or conditions under which the camera maintaining the list is activated. For instance, returning to the floor plan shown in
The hub 110 may include a memory that stores an electronic map or relational database of the premises so that it can correlate the cameras to be included in the dynamic distribution list. Of course, such an electronic map or relational database can be used for other purposes as well. For instance, the electronic map or relational database may be used to correlate the orientation information that is to be forwarded from one camera to another.
Alternatively, instead of using a distribution list, hub 110 may simply forward the information to all the cameras or even determine the cameras to be notified on some dynamic basis (e.g., the particular coordinates of the event being observed, the time of day, a likely path through the premises that may be traversed by a hypothetical intruder).
As previously mentioned, if orientation information is available in the message from the initially activated camera, the hub 110 may forward on this information in its subsequent messages to the other cameras, thereby allowing the individual cameras to determine its corresponding coordinates of the appropriate location that is to be viewed. Alternatively, the hub may use the orientation information from the initially activated camera to determine the appropriate orientation to be taken by the other cameras that are notified by the hub 110. This can be accomplished using, for instance, a relational database (e.g., the aforementioned electronic map of the premises) stored in hub 110 and accessible to processor 86, which relates corresponding coordinates of the various cameras 120 and 130 when viewing the same location. Instead of a database relating coordinates of each camera to one another, this information may be provided in terms of a coordinate transformation that the processor 86 can perform between any two of the cameras to ensure that they view the same location. In any case, once the hub determines the appropriate orientation for each of the cameras, this information can be included in the messages they are sent instructing them to begin recording.
It should be noted that if the orientation information (e.g., coordinates) that is transmitted in the message is specific to the camera receiving the message, the content included in the messages will generally differ from camera to camera. Of course, the content that is transmitted to the various cameras may differ in other ways as well and is not limited to different orientation information.
Upon receipt of a message from the hub 110, the receiving camera(s) is activated and begins recording. If the message includes the coordinates of the location that the initial camera was viewing when it was activated, the receiving camera may orient itself to view the same location or even a different but generally nearby location that may yield more useful information.
In some cases it may be desirable to turn off or otherwise deactivate the cameras so that they stop recording if a period of time have elapsed during which there has been no subsequent detection of motion or other activity that may have been used to initiate the recording process. If there has been no such activity for say, ten or fifteen minutes (or some other timeout period) the recording process can be terminated since presumably the intruder has already left the premises. Alternatively, the motion or other activity that first triggered or activated the cameras may have been due to some event other than an intruder such as a tree falling through a window, a loud noise or the like, in which case there once again is no reason to continuing the recording process.
