WO2008038288A2

WO2008038288A2 - System and method for reducing power consumption in a detection system

Info

Publication number: WO2008038288A2
Application number: PCT/IL2007/001201
Authority: WO
Inventors: Gil Pogozelits; Alexander Pikus
Original assignee: Soniclynx Ltd.
Priority date: 2006-09-28
Filing date: 2007-10-07
Publication date: 2008-04-03
Also published as: WO2008038288A3

Abstract

A method and a system for reducing power consumption and bandwidth use in a detection system (100) having a plurality of locally positioned sensors (110, 120) and a remotely positioned workstation (140). The sytem comprises a plurality of sensors (110, 120) supplied with processing means (112) such that some of the processing is performed in situ - before the data transmission. In addition, the remote control unit is configured to process data from the various sensors (110, 120) and consequently produce feedback to the sensors (110, 120) such that only relevant data from the sensors is transmitted. The disclosed method starts with obtaining signals from local sensors (110, 120). Then, for each signal data relevant for detection is extracted. The method goes on by representing said data in a compact format for transmission. Then after transmitting the compacted data to the workstation (140), non-relevant data is removed by comparing the data arriving form different sensors.

Description

SYSTEM AND METHOD FOR REDUCING POWER CONSUMPTION IN A DETECTION

SYSTEM

FIELD OF THE INVENTION [0001] The present invention relates generally to alarm and detection systems. More specifically, the present invention relates to reducing power consumption in such systems.

BACKGROUND OF THE INVENTION

[0002] Alarm and detection systems are required to operate non-stop and to deliver a large amount of data, the majority of which in non relevant. When the sensors are located in a specific position and a workstation is located in another remote position, said large amount of data need to be transmitted. Transmitting large amount of data where only a small portion of which is relevant is not cost effective as it increases, without any benefit, the power consumption and the bandwidth use of the system.

SUMMARY OF THE INVENTION

[0003] The disclosed invention is a method and a system for reducing power consumption and bandwidth use in a detection system having a plurality of locally positioned sensors and a remotely positioned workstation. The disclosed system comprises a plurality of sensors supplied with processing means such that some of the processing is performed in situ — before the data transmission. In addition, the remote control unit is configured to process data from various sensors and consequently to produce feedback to the sensors such that only relevant data from the sensors is transmitted. [0004] The disclosed method starts with obtaining signals from local sensors. Then, for each signal the data relevant for detection is extracted. The method goes on by representing said data in a compact format for transmission. Then after transmitting the compacted data to workstation, non-relevant data is removed by comparing the data arriving from different sensors. BRIEF DESCRIPTION OF DRAWINGS

[0010] The subject matter regarded as the invention will become more clearly understood in light of the ensuing description of embodiments herein, given by way of example and for purposes of illustrative discussion of the present invention only, with reference to the accompanying drawings (Figures, or simply "FIGS."), wherein:

[0011] FIG. 1 is a schematic illustration of a power and/or bandwidth saving intrusion and/or damage detection system according to an embodiment of the invention;

[0012] FIG. 2 is a schematic illustration of the data flow in the system, according to an embodiment of the invention; [0013] FIG. 3 is a schematic illustration of a method for saving power and/or bandwidth in an intrusion and/or damage detection system, according to an embodiment of the invention; and [0014] FIG. 4 is a schematic illustration of a continuation of the method for saving power and/or bandwidth in an intrusion and/or damage detection system, according to an embodiment of the invention. [0015] The drawings together with the description make apparent to those skilled in the art how the invention may be embodied in practice. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.

DETAILED DESCRIPTION OF THE INVENTION [0016] The present invention discloses an intrusion and/or damage detection system and a method for protecting a region or compound such as an airport, a military base, and a prison from unauthorized access and to enable detection of damages on an installation such as an oil pipeline, a water pipeline, a high-voltage electricity line. [0017] The detection system comprises one or more sensors or alternatively, may be adaptable to one or more sensors that are configured to detect physical stimuli such as a person's or an animal's gait, an explosion and the like. Such sensors may be for example, geophones, pressure sensors, sound sensors, active sensors, passive sensors, fiber optic sensors or any other suitable type of sensor. The system processes and/or analyzes the signals after their detection, i.e., the system classifies and/or locates the origin of at least some of the signals and generates a suitable output at a workstation to make a user aware of occurrences near or in the compound or installation. [0018] However, the workstation may be located remotely from the compound or the installation. Therefore, the signals have to be transmitted to the workstation via wire or wireless communication infrastructure. In order to transmit substantially all signals representing the physical stimuli from the sensor(s) to the workstation, high bandwidth and high power consumption may be required. High bandwidth and high power consumption may increase complexity of system requirements.

[0019] The present invention provides a system and method that enable preprocessing of the detected signals locally at the sensors, i.e., the signals are preprocessed prior to their transmission to the workstation, such that both power and bandwidth required by the system for the transmission of the signal(s) from the sensor(s) to the workstation are substantially reduced. [0020] FIG. 1 schematically illustrates a power and/or bandwidth saving intrusion and/or damage detection system according to an embodiment of the invention. FIG. 2 schematically illustrates the data flow in the system, according to an embodiment of the invention. The detection system 100 may include or may be adapted to operate in conjunction with one or more sensors such as sensor 110 and/or sensor 120. Each sensor may include a sensing element 117 that senses physical stimuli (hereinafter referred to as "occurrences"), such as drilling, a person's gait, an explosion and the like. The sensors are configured to process and represent the physical stimuli in the form such as electronic signal(s). For example, sensing element 117 and/or processor 112 are configured to process and represent a physical stimulus (hereinafter referred to as "Input 1") by a signal 50.

[0021] The sensor 110 may further include a power source 111, which is operatively associated to a processor 112 and to a storage device 113, which may store instructions 114 and comprises a buffer 115. The processor 112 is operatively associated with a storage device 113 and may run instructions 114 resulting in one or more applications such as Preprocessing application 116a and Post processing application 1 116b, as will be outlined below.

[0022] In some embodiments of the invention, each sensor or group of sensors may have its transmitter operatively associated therewith to transmit signals representing the physical stimuli to a workstation 140. For example, a transmitter 131 and a transmitter 132 may be operatively associated to sensor 110 and 120, respectively. In some other embodiments of the invention, the system 100 may include only one transmitter such as transmitter 131, which is operatively associated to a plurality of sensors. [0023] According to some embodiments of the invention, preprocessing application 116a and/or post processing application I 116b may perform various processes like filtering, such that substantially only the portion of a signal 50 is actually carrying relevant information about damage and/or intrusion, is transmitted from transmitter 131 to a receiver 142. As a result, the probability that a false alarm is triggered is substantially reduced. In addition, bandwidth and power required for transmitting data representing the signal is substantially reduced. [0024] For example, a signal 50 may carry information representing gait of a human person as well as gait of a dog. However, preprocessing application 116a and/or post processing application I 116b may process the signal 50 in a manner such that signal 181 carries information representing the gait of the human being only.

[0025] According to some embodiments of the invention, the workstation 140 includes a display 141, a processor 143, an input device 146, a power source 147 and a storage device 144 storing therein instructions 145. Receiver 142, display 141, processor 143, storage device 144, input device 146 and power source 147 are operatively associated with each other. [0026] According to some embodiments of the invention, the processor 143 may execute instructions 145 resulting in an application, hereinafter referred to as post processing application II 148, which may compare information carried by the signal 181 with information received at the workstation 180 from other sensors and trigger an alarm accordingly. For example, post processing application II 148 may compare signal 181 with signal 182 received from sensors 110 and 120, respectively, in order to ensure that the signal received from sensor 110 was not generated due to an accidental occurrence, noise, randomly generated signal, and the like.

[0027] FIG. 3 schematically illustrates a method for saving power and/or bandwidth in an intrusion and/or damage detection system, according to an embodiment of the invention. [0028] According to some embodiments of the invention, processor 112 may execute instructions 114 resulting in preprocessing application 116a, which may include the steps indicated by box 305-315.

[0029] As indicated by box 305, the method may include, for example, the step of handling physical stimuli, such as input 1, received at sensing element 117. In some embodiments of the invention, handling input 1 may include performing analog to digital (A/D) conversion and/or normalizing of the analog signal representing input 1, thereby obtaining signal 50. Input 1 may be handled, for example, by sensing element 117 and/or processor 112. [0030] As indicated by box 310, the method may include, for example, the step of determining the energy level of signal 50. The energy level may be determined, for example, by executing suitable instructions such as instructions 114 by processor 112.

[0031] As indicated by box 315, the method may include, for example, the step of determining whether the energy level of signal 50 exceeds a predetermined energy threshold value. If the energy level exceeds the predetermined energy threshold value, then signal 50 may be further processed and/or analyzed. On the other hand, if the energy level does not exceed the predetermined energy threshold value, signal 50 will not be further processed. In one embodiment, signal 50 is further processed in case said signal 50 is equal to the predetermined energy threshold value. In another embodiment, signal 50 will not be further processed in case said signal 50 is equal to the predetermined threshold value.

[0032] According to some embodiments of the invention, processor 112 may execute instructions 114 resulting in a post processing application 1 116b, which may include the steps indicated by box 325-350. [0033] As indicated by box 325, the method may include, for example, the step of classifying a signal such as signal 50 by applying a classifying function. Classifying signal 50 may include the steps of, e.g., high pass filtering signal 50 and determining the Hubert spectrum on the high pass filtered signal 50, thereby generating a signal 60. The Hubert spectrum may be computed by performing on signal 50 Principal Components Analysis (PCA), i.e. by a Singular Value Decomposition (SVD), which generates singular vectors, and by applying the Hubert transform on said singular vectors, thereby enabling time-frequency localization. Time-frequency correlation may facilitate determining correlation of signal 60 with other known and classified signals stored in the system 100. If for example, correlation of signal 60 with another signal representing human gait is the highest compared to other correlations, then said signal 60 may be classified as representing human gait as well.

[0034] As indicated by box 330, the method may include, for example, representing signal 60 in a tagged form by determining a vector wherein each number or group of numbers represents a certain attribute of signal 60. For example, signal 60 may be represented by the following vector: 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 1, 0, 1 ,1, 1, 1. The first four members of the vector may represent an identification of signal 60, the fifth to the eighth member may represent classification of the signal such as, gait, explosion and the like, the ninth to the twelfth member may represent location of sensor and the thirteenth to the sixteenth member of the vector may represent the time at which input 1 was received. Other methods for representing signal 60 may be used.

[0035] As indicated by box 335, the method may include, for example, the step of storing the vector representing the information carried on signal 60 in, e.g., buffer 115. [0036] As indicated by box 340, the method may include, for example, the step of determining whether the number of vectors that have similar attributes to the vector representing input 1, exceeds a predetermined threshold. This may be accomplished by post processing application I. Said predetermined threshold may be any number equal or higher than 1 such as, for example, 1, 2, 10 and the like. [0037] In some embodiments of the invention, as indicated by box 345, the method may include, for example, erasing the vector that represents input 1 and the vectors that are substantially equal to vector 1 from, e.g., a buffer 115. The vectors may be erased in case the number of said vectors does not exceed the predetermined threshold within a certain period. Such a period may last, for example, 0.5 seconds, 1 seconds, 10 seconds or 30 minutes. Erasing said vectors from, e.g., buffer 115, might occur substantially immediately after the time period has passed or at any time later.

[0038] As indicated by box 350, the method may include, for example, sending the vector representing the signal of input 1 to workstation 140 via signal 181. Step 345 may occur if the number of inputs similar or equal to input 1, i.e., if the number of vectors representing inputs similar to input 1, exceeds a predetermined threshold. In consequence, randomly generated signals may be filtered out, thereby reducing the probability of triggering false alarms. [0039] According to some embodiments of the invention, post processing application I may check similarity like, e.g., correlation, only between vectors that are received subsequently at workstation 140. [0040] FIG. 4 schematically illustrates a continuation of the method for saving power and/or bandwidth in the intrusion and/or damage detection system, according to an embodiment of the invention.

[0041] According to some embodiments of the invention, processor 112 may execute instructions 114 resulting in post processing application II 148, which may include the steps as indicated by boxes 405-430.

[0042] As indicated by box 405, the method may include, for example, the step of comparing the vector of sensor 110 with vector(s) of one or more other sensors, which are in vicinity of sensor 110. For example, only vectors of sensors that are located at a distance of up to 100 meters from sensor 110 may be taken into account by post processing application II. For example, post processing application II 148 may compare the vector representing input 1 with a vector representing input 2 received from sensor 120 by, e.g., determining the correlation between said vectors.

[0043] As indicated by box 410, the method may include, for example, the step of determining whether an intruder and/or damage are detected at another sensor such as sensor 120. This may be accomplished by determining whether the comparison performed at step 305 yields a result, e.g., a correlation value, that indicates that the input 1 and input 2 detected at, e.g., sensor 110 and 120, respectively, are substantially equal or not.

[0044] In the case that an intruder and/or damage are detected, the method may include, for example, the step of triggering an alarm or provide the user with any other suitable message to indicate the user that an intruder and/or damage were detected, as indicated by box 420. [0045] As indicated by box 425, the method may include, for example, the step of determining whether the same intruders and/or damages were detected for more than a predetermined number of times.

[0046] In case the same intruder and/or damage was detected for more than a predetermined number of times, the method may include, for example, the step of transmitting a feedback signal to the sensor. The feedback signal may carry data representing a command to stop sending signals carrying data that represent input l.The feedback signal may be sent from workstation 140 to sensor 110 from transceiver 142 to transmitter 131. For example, in case input 1 caused by water leaking from the piping, system 100 may trigger an alarm until the water leak is stopped or unless a suitable feedback signal is sent to sensor 110. In some embodiments, the user may stop the alarm, which may an audible signal, a pop-up window appearing on display 141 and the like.

[0047] While the invention has been described with respect to a limited number of embodiments, these should not be construed as limitations on the scope of the invention, but rather as exemplifications of some of the embodiments. Those skilled in the art will envision other possible variations, modifications, and applications that are also within the scope of the invention. Accordingly, the scope of the invention should not be limited by what has thus far been described, but by the appended claims and their legal equivalents. Therefore, it is to be understood that alternatives, modifications, and variations of the present invention are to be construed as being within the scope and spirit of the appended claims.

Claims

CLAIMSWhat is claimed is:

1. A method for reducing power consumption and bandwidth use in a detection system having a plurality of locally positioned sensors and a remotely positioned workstation, said method comprising the steps of:

- obtaining signals from local sensors;

- for each signal extracting data relevant for detection;

- representing said data in a compact format for transmission; - transmitting said compacted data to workstation;

- for all received signals: removing non-relevant data by comparing the data arriving from different sensors.

2. The method according to claim 1, wherein extracting data relevant to detection comprises early local detection.

3. The method according to claim 1, wherein extracting data relevant to detection comprises analyzing the energy level of said signals in view of a predetermined threshold.

4. The method according to claim 1, wherein extracting data relevant to detection comprises applying a classifying function on said signals.

5. The method according to claim 4, wherein said classifying function comprises a correlation with a predetermined know signal.

6. The method according to claim 5, wherein said correlation is computed by determining the Hubert spectrum on the high pass filtered signal.

7. The method according to claim 1, wherein representing said data in a compact format for transmission comprises representing the relevant data to detection from said signals in a form of a vector.

8. The method according to claim 7, wherein said vector comprise information regarding at least one of the following: relevant data for detection, location of sensors that detected relevant data, duration of detection.

9. The method according to claim 1, wherein representing said data in a compact format for transmission is followed by refraining from transmitting data whose representation does not account for a detection occurrence in accordance with predefined criteria.

10. The method according to claim 1, wherein removing non-relevant data by comparing the data arriving from different sensors comprises detecting common data from all sensors.

11. The method according to claim 1, wherein removing non-relevant data by comparing the data arriving from different sensors comprises detecting common data from all sensors.

12. The method according to claim 1, wherein removing non-relevant data by comparing the data arriving from different sensors comprises confirming data by comparing data arriving from physically proximate sensors.

13. A system for reducing power consumption and bandwidth use in a detection system having a plurality of locally positioned sensors and a remotely positioned workstation, said system comprising:

- means for obtaining signals from local sensors;

- means for extracting data relevant for detection for each signal; said means for extracting data are located in close proximity to said sensors;

- means for representing said data in a compact format for transmission;

- means for transmitting said compacted data to workstation;

- means for removing non-relevant data by comparing the data arriving from different sensors for all received signals and providing feedback to said means for extracting data relevant for detection such that only relevant data from the sensors is transmitted.

14. The system according to claim 13, wherein means for extracting data relevant to detection comprises means for analyzing the energy level of said signals in view of a predetermined threshold.

15. The system according to claim 14, wherein means for extracting data relevant to detection comprises means for applying a classifying function on said signals.

16. The system according to claim 13, wherein said means for representing data from the sensor in a compact format for transmission results in a vector comprising information regarding at least one of the following: relevant data for detection, location of sensors that detected relevant data, duration of detection.

17. The system according to claim 13, wherein means for removing non-relevant data by comparing the data arriving from different sensors comprises means for detecting common data from all sensors.

18. The system according to claim 13, wherein sad means for removing non-relevant data by comparing the data arriving from different sensors comprises means for confirming data by comparing data arriving from physically proximate sensors.

19. An article of manufacture comprising an electric signal implementing a method comprising the steps of: - obtaining signals from local sensors;

- for each signal: extracting data relevant for detection;

- representing said data in a compact format for transmission;

- transmitting said compacted data to a workstation;