Closure protection apparatus, system and method

Abstract

The invention provides a sensor system for monitoring unauthorised access to a hatch, the system comprising a sensor apparatus having a motion sensor and at least one processor configured to process signals from the motion sensor. The processor is configured to sample the signals from the motion sensor to determine a motion amplitude, compare the amplitude to a predetermined threshold, and, increase a variable if the threshold is exceeded, or decrease the variable if the threshold is not exceeded, sample the variable and produce an alert if the variable exceeds a predetermined maximum value.

Description

Closure protection apparatus, system and methodTechnical Field

[0001] The present invention is concerned with an apparatus, a system and a method for protection of a closure. More specifically, the present invention is concerned with a sensor device and associated system and method for the detection of attacks on access hatches to restricted areas such as utility supplies.Background Art

[0002] Closures in the form of hatches are often provided to allow access to important equipment, typically for the purposes of inspection and service. In many infrastructure installations secure hatches are used to permit access to conduits, pipes, monitoring equipment and control equipment to ensure the ongoing uninterrupted supply of utilities to end users. For example in the water supply industry hatches are provided to allow access to water pipes and associated equipment to carry out inspection and maintenance. These hatches typically comprise a frame and a closure panel attached to the frame in a pivotable manner (much like a door). The closure panel is normally secured in the closed condition with a lock (particularly if the hatch is located in an area accessible to the public).

[0003] Even though this is the case, there are several instances of such hatches being attacked to gain unauthorised access to the restricted area. This may be simply due to vandalism, or to interrupt or interfere with the supply of the underlying utility. It is therefore important that the hatches are made as secure as possible.

[0004] Although hatches can be made out of strong materials (metals) and secured with high quality locks, all materials are vulnerable to sustained attack. Secure hatches are often in remote areas where a sustained attack may not be immediately detected. Therefore irrespective of the materials and techniques used to mechanically secure the hatch, there is always a risk of unauthorised entry given enough time and the right equipment.

[0005] Attacks may take place using convention tools such as hand-powered saws and hammers. Various methods have been proposed in the prior art to counter such attacks. One such system is disclosed in WO 201 0 / 1 25374 in which a seismic / acoustic sensor is used to detect a brute force attack. The system is desensitised to what the application calls "tank generic" signals produced by e.g., pumping and filling and uses a signal analyser todetect vibrations and sounds which fit the profile of a brute force attack using conventional mechanical tools.

[0006] A problem is the detection ofthe use oftools which may produce a higher frequency and lower amplitude signal. Power tools such as drills and disc cutters are examples of this. The problem is that high frequency, low amplitude vibrations may be caused by rain or hail on the hatch, which makes avoidance of false alarms difficult. WO 2010 / 125374 attempts to differentiate the signals using frequency and / or amplitude with signal processing. This is a delicate balancing act. The filter of WO'374 is 300 Hz to 3.3kHz, and looks for signals in the 1 kHz to 2kHz region.

[0007] A further problem with the prior art system is that it remains vulnerable to more specialist equipment such as cutting torches. Such equipment is not mechanical- rather uses a sustained and concentrated source of heat to damage the hatch and gain access to the restricted area. Any attempt to detect cutting torch use with a vibration sensor would be ineffective, not least because the level of sensitivity required would produce a high number of false alarms due to the aforementioned "tank generic" signals.

[0008] The present invention aims to eliminate, or at least mitigate, the above problems.Summary of Invention

[0009] According to a first aspect of the invention there is provided a sensor system for monitoring unauthorised access to a hatch, the system comprising: a sensor apparatus having a motion sensor; at least one processor configured to process signals from the motion sensor; the at least one processor configured to: sample the signals from the motion sensor to determine an acceleration amplitude; compare the amplitude to a predetermined threshold; and, increase a variable if the threshold is exceeded, or decrease the variable if the threshold is not exceeded; sample the variable; andproduce an alert if the variable exceeds a predetermined maximum value.

[0010] Preferably the motion sensor comprises a first accelerometer.

[0011] Preferably the first accelerometer signals are sampled at a frequency of at least 1 kHz.

[0012] Preferably the sensor apparatus comprises a housing containing the motion sensor.

[0013] Preferably: the housing contains a light sensor, and the housing comprises a transparent portion to allow light to reach the light sensor; and, wherein the processor is configured to compare data from the light sensor representative of a light level to a predetermined threshold, and to produce an alert if the light level exceeds a predetermined value.

[0014] Preferably: the housing contains a heat sensor; wherein the processor is configured to compare data from the heat sensor representative of a temperature to a predetermined threshold, and to produce an alert if the temperature exceeds a predetermined value.

[0015] Preferably the motion sensor comprises a tilt sensor wherein the processor is configured to compare data from the tilt sensor representative of a rotation of the sensor apparatus to a predetermined threshold, and to produce an alert if the rotation exceeds a predetermined value.

[0016] The tilt sensor may comprise a second accelerometer and / or a gyroscope. Preferably a gyroscope is used to obtain the spatial (rotation) orientation of the sensor and therefore the housing.

[0017] Preferably the motion sensor comprises an impact sensor; wherein the processor is configured to compare data from the impact sensor representative of an acceleration of the sensor apparatus to a predetermined threshold, and to produce an alert if the acceleration rotation exceeds a predetermined value.

[0018] Preferably the impact sensor comprises a third accelerometer.

[0019] Preferably the third accelerometer has a higher range of detectable acceleration than the first sensor.

[0020] Preferably the third accelerometer has a lower sampling frequency than the first sensor.

[0021] Preferably the processor is provided assembled with the sensor apparatus.

[0022] Preferably the processor is provided remote to the sensor apparatus.

[0023] Preferably the processor is provided at a control station.

[0024] Preferably the system comprises a plurality of sensor apparatuses reporting to a central controller.

[0025] Preferably the central controller is configured to write predetermined threshold data to each sensor of each sensor apparatus.

[0026] According to a second aspect there is provided a method of monitoring a hatch sensor apparatus attached to a hatch, comprising the steps of: attaching a motion sensor to a hatch; sampling signals from the motion sensor to determine an acceleration amplitude; comparing the amplitude to a predetermined threshold; and, increasing a variable if the threshold is exceeded, or decreasing the variable if the threshold is not exceeded; sampling the variable; and producing an alert if the variable exceeds a predetermined maximum value.

[0027] According to a third aspect there is provided a monitoring system comprising: a plurality of sensor apparatuses, each sensor apparatus comprising: a housing containing; a motion sensor; and, a light sensor; and,a processing unit configured to compare data from each sensor to a predetermined threshold, and to produce an alert if the predetermined threshold is exceeded.

[0028] Preferably the system comprises a controller, wherein the controller is configured to write threshold data to each processor of each processing unit.

[0029] Preferably each processing unit is configured to send alert data to the controller.

[0030] Preferably the housing comprises a transparent portion to allow light external to the housing to reach the light sensor.

[0031] Preferably the motion sensor comprises at least two of: a first accelerometer configured to detect a sustained attack; a second accelerometer configured to detect tilt; a third accelerometer configured to detect impact; and, a gyroscope to detect global angular orientation.

[0032] Preferably the processing unit is configured to: sample signals from the first accelerometerto determine an acceleration amplitude; compare the amplitude to a predetermined threshold; and, increase a variable if the threshold is exceeded, or decrease the variable if the threshold is not exceeded; sample the variable; and produce an alert if the variable exceeds a predetermined maximum value.

[0033] Preferably each sensor apparatus comprises a temperature sensor,.

[0034] Preferably, any of the sensors can be deactivated to suit the application.Brief Description of Drawings

[0035] An embodiment of the present invention will now be described with reference to the following figure in which:FIGURE 1 is a schematic view of a system incorporating a sensor apparatus according to the present invention;FIGURE 2a is a side view of the sensor apparatus of Figure 1 ;FIGURE 2b is a plan view of the sensor apparatus of Figure 1 ;FIGURES 3a and 3b are flow diagrams of methods in accordance with the present invention;FIGURES 4a to 4c are illustrative, quantitative data plots according to the present invention.Description of the first embodiment

[0036] Referring to Figure 1 there is shown a hatch security monitoring system 100. The system 100 is configured to monitor a plurality of hatches 200, each of which have a respective sensor apparatus 300, 300', 300", 300"', 300"" installed thereon.System W0

[0037] The monitoring system 100 comprises a power supply unit 102 configured to deliver power to each of the sensor apparatuses 300 via power cables 103. An SB400 controller unit 104 is provided which is connected via a RS485 data connection 106 to each of the apparatuses 300. A power supply 108 supplies the controller 104 and the output cards 1 10. The controller 104 is connected to a plurality of SB401 output cards 1 10 via RS485 data connection 1 12.

[0038] The controller has a first data output 1 14 in the form of an ethernet port which is configured to handle a TCP socket via an ethernet cable 1 18. Figure 1 shows two alternatives: i. in which the output 1 14 is linked to a first computer 1 16 (which is in a static location) and ii. linked to a second, mobile computer device 120.

[0039] The aforementioned equipment (with the exception of the sensor apparatuses 300) is positioned within a control room 122 (although it will be noted that the mobile device 120 may be moved elsewhere and remain connected e.g., by wireless connection, VPN etc).Hatch 200

[0040] The hatch 200 comprises a frame 202 and a closure 204. The frame 202 is mounted to a surface 206 through which an aperture 208 leads to a restricted area 210. The frame 202 is generally rectangular in shape and the closure 204 is mounted thereto via a hinge mechanism to rotate between an open and closed position about an axis A. The closure 204 has an exterior side 212 and an interior side 214. The hatch 200 has a lock (not shown) for securing the closure 204 in the closed position 202 and only permitting access by authorised persons (e.g., via a key, RFID tag, numerical combination etc.).

[0041] The sensor apparatus 300 is mounted to the interior side 214 of the closure 204, distal to the hinge.Sensor apparatus 300

[0042] Referring to Figures 2a and 2b a sensor apparatus 300 in accordance with the present invention is shown. The apparatus 300 comprises a housing 302 surrounding a cavity 304. The housing 302 has a lid 306, which in this embodiment is constructed from a transparent material.

[0043] Within the cavity 304, and attached to the housing 302 there are provided the following sensors:• A MEMS accelerometer array 308, comprising three individual accelerometers: o 308a a "high impact" accelerometer having a high detection range (400g) but a relatively low sampling frequency (1 kHz); o 308b, a tilt sensor having a maximum range of 16g, but a higher sampling frequency of 1 ,6kHz; and, o 308c, a sustained attack sentor having a maximum range of 16g, and a higher sampling frequency of 1 ,6kHz;• A heat sensor 310; and,• A light sensor 312.

[0044] Each of the sensors 308a, 308b, 308c, 310, 312 is connected to a local processing unit 313, which in turn is connected to an I / O module 314 which in turn communicates with the controller 104 via the data link 106.

[0045] The local processor 313 is programmed with a set of threshold values and is configured to poll each sensor and to compare each reading with the relevant threshold value. The processor 313 is configured to produce alert signals which can be sent via the I / O module 314 to the controller 104. The processor is also configured to receive updated threshold values from the controller 104 if desired.

[0046] Each processor 313 for each apparatus 300 is independently and uniquely addressable, and as such the threshold values on each processor can be changed independent of each other as required. It should also be noted that any individual sensor can be deactivated (for example by setting an unrealistically high threshold value).

[0047] It is also within the scope of the present invention for all or part of the data processing and analysis to be carried out at the controller 104. It is also within the scope of the invention for a local alert (audible or visual) to be produced at the hatch, and for the sensor apparatus to trigger anti-tampering countermeasures such as a loud siren, or tracer fluid.Use

[0048] The present invention utilises two different methods of detecting attack.

[0049] Turning to Figure 3a, a first method 1000 of operation ofthe sensor 300 and / or the system 100 is shown. The first method is relevant to the sensors 308a, 308b, 310, 312. The system starts in a primed condition in which the closure is in the closed (and locked) condition. The sensors are active and gathering data. The accelerometers (308a, 308b) gather data at their frequencies mentioned above.

[0050] The local processor 313 polls the sensors for new information on a periodic basis.

[0051] At step 1002 data is read by the processor 313 from each sensor. At step 1004, at the processor 313 the data from each sensor is compared to a sensitivity (or threshold) value. For example:

[0052] The sensitivity values of G1 , A, T and L are set by the controller 104 communicating with the local processing unit 313. It will be noted that the light alarm is configured to be triggered the artificial light of a cutting torch penetrating the enclosure.

[0053] If a reading from one of the sensors exceeds the relevant sensitivity I threshold value, this indicates that an attack may be taking place. An alert is produced by the processing unit 313, and sent to the controller 104. This in turn sends the alertto the output cards 1 10 to produce alarms of a desired type (audible etc).

[0054] The present invention also provides a feature for detection of a sustained attack with a drill or disc cutter. Due to the fact that bad weather (e.g., hail) may trigger such an alarm, having potentially similar frequency and amplitude of vibration, the present invention features the second method 2000 shown in Figure 3b.

[0055] The accelerometer 308c (for sustained attack) records at high frequency (i.e. 1 .6 kHz). Instead of simply relying on detection of a specific characteristic as a threshold (per Figure 3a) the present invention also requires the impact to be sustained over a predetermined time period.

[0056] Referring to Figure 3b, the system is in the primed condition and the local processing unit 313 is reading data from all sensors at step 2002. At step 2004, the vibration data from the sensor 308 is compared against a sensitivity threshold. If the amplitude (i.e. the "g" value) detected is below a predetermined amplitude, branch 2006 is followed in which a Accumulator variable AV is decreased (where AV>0). AV is decreased at a fixed rate (i.e., per unit time). If the amplitude detected is above a predetermined amplitude (i.e., above threshold) branch 2008 is followed in which the accumulator variable AV is increased. RAV is increased at a fixed rate (i.e., per unit time).

[0057] At step 2010, AV is compared to a predetermined maximum value AVLIM- If AV exceeds that value, a sustained attack alarm is triggered at step 2012. If not, the sensors are sampled again.

[0058] In this way, it is made less likely that weather events will trigger the alarm. Weather events (hail in particular) tends to be sporadic, and of intermittent frequency compared to a cutting tool which is constant and sustained.

[0059] Referring to Figures 4a to 4c, illustrative data is provided. In each case, the sampled g data (indicative of acceleration) is depicted by the solid line ("Samples"). The parameter AB is indicated by dashed lines (AV = "Accumulator"). AVLIM is shown in dot-dash lines.

[0060] Referring to Figure 4a, normal activity is shown. Minor accelerations are recorded, but only due to environmental vibrations.

[0061] Referring to Figure 4b, a hailstorm is shown, which is characterised by short, intermitted g-forces acting on the hatch. Due to the silent spaces between impacts (when hail is missing the lid) the variable AV quickly and repeatedly reduces, remaining well below AVLIM-

[0062] Referring to Figure 4c, the profile of a drill attack is shown. The drill is uses in bursts- but they are sustained and of longer duration than the hail impacts. As can be seen, AV increases with each burst, and only has a short time to recover. As it accumulates on the third burst, it exceeds AVLIM and an alarm is produced.Variations

[0063] In one alternative embodiment, the sensor apparatus 300 is mounted within the frame 202 rather than on the lid 204. It is therefore static. In this embodiment, it is not possible to detection opening of the lid with motion detection, and instead a switch whose state is influenced by opening of the lid (for example a magnetic contact) is used.

[0064] The size of the sensor enclosure and the material it is made from can be varied to fit specific scenarios. It could be a solid metal enclosure if no light detection is needed but it needs to be vandal proof.

[0065] The device 300 can be either bolted to a bracket, glued in place or it could be fitted to masonry etc.

[0066] As well as hatches, the sensor can be mounted on any superstructure that needs monitoring.

[0067] The sensors may be integrated onto a common PCB. For example the heat I temperature sensor may be integrated into the same PCB as the acclereometers.

[0068] The system may be used to secure doors and windows, roof hatches, walls / vaults. the sensors that are active may be delected to suit the application- for example some just need the tilt detection such as animal cage doors.

[0069] The temperature sensor may be omitted.

[0070] It is possible that after programming the behaviour of the sensor, it can then be disconnected from the RS485 bus and act stand-alone and just use the on-board output for alarms. It doesn't need the controller to function.

Claims

Claims1 . A sensor system for monitoring unauthorised access to a hatch, the system comprising: a sensor apparatus having a motion sensor; at least one processor configured to process signals from the motion sensor; the at least one processor configured to: sample the signals from the motion sensor to determine an acceleration amplitude; compare the amplitude to a predetermined threshold; and, increase a variable if the threshold is exceeded, or decrease the variable if the threshold is not exceeded; sample the variable; and produce an alert if the variable exceeds a predetermined maximum value.

2. A sensor system according to claim 1 , wherein the motion sensor comprises a first accelerometer.

3. A sensor system according to claim 2, wherein the first accelerometer signals are sampled at a frequency of at least 1 kHz.

4. A sensor system according to any preceding claim, wherein the sensor apparatus comprises a housing containing the motion sensor.

5. A sensor system according to claim 4, wherein: the housing contains a light sensor, and the housing comprises a transparent portion to allow light to reach the light sensor; and, wherein the processor is configured to compare data from the light sensor representative of a light level to a predetermined threshold, and to produce an alert if the light level exceeds a predetermined value.

6. A sensor system according to claim 4 or 5, wherein: the housing contains a heat sensor;wherein the processor is configured to compare data from the heat sensor representative of a temperature to a predetermined threshold, and to produce an alert if the temperature exceeds a predetermined value.

7. A sensor system according to any preceding claim, wherein the motion sensor comprises a tilt sensor; wherein the processor is configured to compare data from the tilt sensor representative of a rotation of the sensor apparatus to a predetermined threshold, and to produce an alert if the rotation exceeds a predetermined value.

8. A sensor system according to claim 7, wherein the tilt sensor comprises a second accelerometer and / or a gyroscope.

9. A sensor system according to any preceding claim, wherein the motion sensor comprises an impact sensor; wherein the processor is configured to compare data from the impact sensor representative of an acceleration of the sensor apparatus to a predetermined threshold, and to produce an alert if the acceleration rotation exceeds a predetermined value.1 0. A sensor system according to claim 8, wherein the impact sensor comprises a third accelerometer.1 1 . A sensor system according to claim 1 0, wherein the third accelerometer has a higher range of detectable acceleration than the first sensor.

12. A sensor system according to claim 1 1 , wherein the third accelerometer has a lower sampling frequency than the first sensor.1 3. A sensor system according to any preceding claim, wherein the processor is provided assembled with the sensor apparatus.1 4. A sensor system according to any preceding claim, wherein the processor is provided remote to the sensor apparatus.1 5. A sensor system according to claim 1 4, wherein the processor is provided at a control station.1 6. A sensor system according to any preceding claim, comprising a plurality of sensor apparatuses reporting to a central controller.

17. A sensor system according to claim 16, wherein the central controller is configured to write predetermined threshold data to each sensor of each sensor apparatus.

18. A method of monitoring a hatch sensor apparatus attached to a hatch, comprising the steps of: attaching a motion sensor to a hatch; sampling signals from the motion sensor to determine an acceleration amplitude; comparing the amplitude to a predetermined threshold; and, increasing a variable if the threshold is exceeded, or decreasing the variable if the threshold is not exceeded; sampling the variable; and producing an alert if the variable exceeds a predetermined maximum value.

19. A monitoring system comprising: a plurality of sensor apparatuses, each sensor apparatus comprising: a housing containing; a motion sensor; and, a light sensor; and, a processing unit configured to compare data from each sensor to a predetermined threshold, and to produce an alert if the predetermined threshold is exceeded.

20. A monitoring system according to claim 19, comprising a controller, wherein the controller is configured to write threshold data to each processor of each processing unit.21 . A monitoring system according to claim 20, wherein each processing unit is configured to send alert data to the controller.

22. A monitoring system according to any of claims 19 to 21 , wherein the housing comprises a transparent portion to allow light external to the housing to reach the light sensor.

23. A monitoring system according to claim 19, wherein the motion sensor comprises at least two of:a first accelerometer configured to detect a sustained attack; a second accelerometer configured to detect tilt; a third accelerometer configured to detect impact; and, a gyroscope configured to detect global angular orientation.

24. A monitoring system according to claim 23, wherein the processing unit is configured to: sample signals from the first accelerometer to determine an acceleration amplitude; compare the amplitude to a predetermined threshold; and, increase a variable if the threshold is exceeded, or decrease the variable if the threshold is not exceeded; sample the variable; and produce an alert if the variable exceeds a predetermined maximum value.

25. A monitoring system according to any of claims 1 9 to 24, wherein each sensor apparatus comprises a temperature sensor.

Images