Patent Application
20080030328
The foregoing summary, as well as the following detailed description of certain embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. To the extent, that the figures illustrate diagrams of the functional blocks of various embodiments, the functional blocks are not necessarily indicative of the division between hardware circuitry. Thus, for example, one or more of the functional blocks (e.g., processors or memories) may be implemented in a single piece of hardware (e.g., a general purpose signal processor or a block or random access memory, hard disk, or the like). Similarly, the programs may be stand alone programs, may be incorporated as subroutines in an operating system, may be functions in an installed software package, and the like. It should be understood that the various embodiments are not limited to the arrangements and instrumentality shown in the drawings.
The system 100 has one or more infrared (IR) sensors, such as first IR sensor 104, second IR sensor 106 and N IR sensor 108 connected to the network 110 and in communication with the system control panel 102. The first, second, through N IR sensors 104-108 may be configured to control and/or monitor a first door 112, second door 114, through N door 116, respectively. The first through N IR sensors 104-108 may receive power from, and communicate with, the system control panel 102 over the network 110. Each of the first through N IR sensors 104-108 may have a unique address on the network 110.
Alarm condition detectors 118, 120 and 122 may be connected on the network 110 and are monitored by the system control panel 102. The detectors 118-122 may detect fire, smoke, temperature, chemical compositions, or other hazardous conditions. When an alarm condition is sensed, the system control panel 102 transmits an alarm signal to one or more notification device 124, 126 and/or 128 through the network 110. The notification devices 124, 126 and 128 may be horns and/or strobes, for example, and may be addressable or non-addressable notification devices as discussed further below.
The system control panel 102 is connected to a power supply 130 which provides one or more levels of power to the system 100. One or more batteries 132 may provide a back-up power source for a predetermined period of time in the event of a failure of the power supply 130 or other incoming power. Other functions of the system control panel 102 may include indicating the status of the system 100, resetting a component, a portion, or all of the system 100, silencing signals, turning off strobe lights, and the like.
The network 110 is configured to carry power and communications to the addressable notification devices from the system control panel 102. Each addressable notification device 124-128 has a unique address and may be capable of bidirectional communication with the system control panel 102. The addressable notification devices 124-128 may communicate their status and functional capability to the system control panel 102 over the network 110. In contrast, a notification signal sent on the network 110 from the system control panel 102 may be received and processed by each non-addressable notification device.
The system control panel 102 has a control module 134 which provides control software and hardware to operate the system 100. Operating code 136 may be provided on a hard disk, ROM, flash memory, stored and run on a CPU card, or other memory. An input/output (I/O) port 138 provides a communications interface at the system control panel 102 with external communication devices 160 such as a laptop computer, personal digital assistant and the like.
A central monitoring station 146 may receive communications from the system control panel 102 regarding security alerts and alarm conditions. The central monitoring station 146 is typically located remote from the system 100 and provides monitoring functions to more than one security system.
The first IR sensor 104 may be installed on a wall proximate to the first door 112, such as at one of wall positions 168 and 169, to the top or side, respectively, of the first door 112, and at distances of D2 and D3, respectively, from a reflecting surface associated with the first door 112. The reflecting surface may be a front, back, or edge surface side of the first door 112 or the reflector 190 may be mounted on the first door 112.
The first IR sensor 104 may also be installed within or mounted on door frame 150, such as at one of door frame positions 166 and 167 which are positioned at distances D4 and D5, respectively, from the reflecting surface, such as a top edge 194 or side edge 196, respectively. The first IR sensor 104 may be installed to be flush, recessed, or slightly protruding with respect to an inner surface 192 of the door frame 150. The positioning of the first IR sensor 104 may depend on one or more factors such as available clearance between the inner surface 192 of the door frame 150 and the top or side edge 194 or 196 of the first door 112. For example, it may be desirable to recess the first IR sensor 104 into the door frame 150 to at least partially obscure the first IR sensor 104 from view.
When the first IR sensor 104 is installed at one of the door frame positions 166 and 167, the distance D4 and D5 to the reflecting surface may be less than the distances D1, D2 and D3 when the first IR sensor 104 is installed in the panel 148 or on the wall. Therefore, a lens 202 and 204 may optionally be used when installing the first IR sensor 104 within the door frame 150 to optimize reflections of the IR signal off of a near-field object.
Returning to
An interface device 156 with an optional backlight 158 may be installed on the panel 148. The interface device 156 may provide one or more of a keypad, fingerprint reader, card reader, Radio Frequency Identification (RFID) reader, alpha/numeric (A/N) display, speaker, or other device. For example, if a keypad is available, a user may enter access codes and/or manually change settings at the panel 148. If installed in the panel 148, the first IR sensor 104 may be used to detect the presence of an object, such as a hand, in close proximity to the panel 148, and in response may turn on the backlight 158, activate one or more of the available interface devices, or activate interface circuitry, such as enable the RFID reader.
By quickly flashing the first IR sensor 104, data packets may be transmitted which may be used to detect proximity of an object (the first door 112) as well as detect the presence of a foreign reflective object. The processor 152 may define a duty cycle having an active period and an idle period for the IR transmitter 154. The IR transmitter 154 transmits a control data packet during the active period. The IR receiver 155, however, is always active and is always receiving IR data and/or reflected data packets. IR data may be infrared background noise, while the reflected data packet is the control data packet which has been reflected off an object.
The first IR sensor 104 is calibrated to store IR reflectivity data in the memory 162 that is associated with the desired reflective surface, such as the reflective surface of the first door 112 or the reflector 190 at one or more desired positions. Each surface which reflects IR has a different level of reflectivity and creates a different reflectivity signature. The IR reflectivity data may comprise one or both of diffuse or specular reflectance which may change based on the angle of incidence and distance.
For detecting the proximity of the first door 112 with the first IR sensor 104, the first IR sensor 104 is positioned so that the control data packet may be reflected off the first door 112 (or the reflector 190) as a reflected data packet when the first door 112 is closed. The reflected data packet will have a known door reflectivity which was determined during calibration. Therefore, if an object such as a thin piece of wood or metal were inserted between the first IR sensor 104 and the first door 112, the reflectivity of the reflected data packet would be different and a trouble indication may be generated.
When the first door 112 is open, however, the control data packet may not be reflected and thus the IR receiver 155 does not receive a reflected data packet. In another embodiment, the first IR sensor 104 may be configured to receive a reflected data packet which may be reflected off another object, such as a hand or an identification item, such as a badge, which has a different reflectivity than the door reflectivity. In this configuration, a trouble signal may not be generated.
The filter 164 samples IR data acquired by the IR receiver during the idle period of the duty cycle when the IR transmitter 154 is not transmitting to determine a level of background noise. When the IR receiver 155 detects a reflected data packet, the filter 164 filters the reflected data packet to remove background noise based on a previously determined level of background noise. Using the filter 164 may remove extraneous noise, such as increased sunlight or attempted tampering by shining a light at the IR receiver 155.
At 250, the first door 112 is placed in a desired position, such as closed. At 252, the IR transmitter 154 transmits a control data packet 206 which is reflected by the reflector 190 as reflected data packet 208. At 254, the IR receiver 155 receives the reflected data packet 208 which has an associated packet IR reflectivity. At 256, the processor 152 determines a level of door IR reflectivity based on the packet IR reflectivity of the reflected data packet 208. At 258, IR reflectivity data, which may also be referred to as the door IR reflectivity and is associated with control data packets reflected by the reflector 190 when the first door 112 is closed, is stored in the memory 162.
At 260, the processor 152 optionally determines whether another IR sensor associated with the first door 112 is to be calibrated or if IR reflectivity data is to acquired with the first door 112 in a different door position. If Yes, the method returns to 250. For example, more than one IR sensor may be used to monitor a single door for additional security. Also, if may be desirable to establish an IR range of IR reflectivity which may further ensure that the first door 112 is completely closed and/or latched and/or secured. It may be possible to position the first door 112 in a position which is not secured or latched that still reflects the control data packet 206. Therefore, additional IR reflectivity data may be acquired by placing the first door 112 in the unacceptable position. In 262, the processor 152 may then determine an IR range which indicates that the first door 112 is closed, latched and/or secured. (Optionally, no IR range may be determined.) IR reflectivity data outside the IR range, such as that detected when the first door 112 is in the unacceptable position, would indicate a door open position even if the first door 112 is not visibly open.
At 274, the IR transmitter 154 transmits the control data packet. The control data packet may be a beacon or broadcast signal, or any other type of data packet. In this configuration, the IR reflectivity of the reflected data packet is of interest but the content of the control data packet may or may not be verified.
At 276, the IR receiver 155 may detect a reflected data packet which has an associated packet IR reflectivity. If the first door 112 is closed, the IR receiver 155 will receive a reflected data packet virtually simultaneously as the IR transmitter 154 transmits the control data packet. If the first door 112 is open, however, the control data packet is not reflected by the first door 112 or the reflector 190, if present. If the first IR sensor 104 is configured to detect proximity of an object, such as a hand, the IR receiver 155 will detect the reflected data packet when the object is present and within a predefined distance from the first IR sensor 104, such as within three inches. Line 294 indicates that 272-276 are continually performed as discussed above to maintain an accurate level of background noise and to detect a current position of the first door 112 and/or proximity of an object, if so configured.
At 276, if the IR receiver 155 receives a reflected data packet, the method passes to 278, where the filter 164 filters the reflected data packet based on the most recent level of background noise (272). At 280, the processor 152 compares the reflectivity of the reflected data packet to the door IR reflectivity data (258 of
If the packet IR reflectivity of the reflected data packet 208 (
Returning to 284, if the first IR sensor 104 is being used as a door sensor but not as a proximity sensor to detect other objects, the method flows to 288. The processor 152 may determine that a foreign object has been held inserted between the first IR sensor 104 and the reflector 190, and may initiate a trouble signal to indicate a suspected tampering with the security system 100 and/or the first IR sensor 104. The trouble signal may be sent to the system control panel 102 over the network 110, forwarded to the central monitoring station 146, and/or may initiate activation of one or more of the notification devices 124-128. The method then returns to 272.
Returning to 276, if a reflected data packet is not received, the method flows to 290 where the processor 152 determines that the first door 112 is open. In 292, the processor 152 may initiate at least one of a door open signal and a trouble signal that is sent to the system control panel 102 over the network 110. The system control panel 102 may optionally log the trouble signal, send the trouble signal to the central monitoring station 146, and/or activate one or more of the notification devices 124-128. Alternatively, the processor 152 may log the door openings and closings in memory 162, and may initiate the trouble signal if the first door 112 remains open longer than a predetermined amount of time. Alternatively, the processor 152 may initiate a trouble signal during periods of time when it has been determined that the first door 112 should not be open, such as outside of predefined business hours.
While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.
