GB2533396A

GB2533396A - Monitoring system for railway embankment

Info

Publication number: GB2533396A
Application number: GB1422725.0A
Authority: GB
Inventors: Anthony Smith Bryn; Simon Maddison Michael
Original assignee: SENCEIVE Ltd
Current assignee: SENCEIVE Ltd
Priority date: 2014-12-19
Filing date: 2014-12-19
Publication date: 2016-06-22

Abstract

A monitoring system comprises movement sensors 100 distributed on a railway embankment; a camera 800 for imaging the railway near the embankment 31; a wireless network 301 linking the sensors and camera; and a backhaul 410 providing external communications to or from the wireless network. The backhaul may be a gateway node supporting GPRS for communication with a remote server 500. The sensors may be tilt meters attached to stakes embedded into the embankment and the wireless network may include a rain gauge. Outputs from the sensors may be processed remotely or by a node in the wireless network using a consensus algorithm to detect slippage in the embankment (e.g. a landslide). If earth movement is detected, a warning may be sent over the backhaul and the railway illuminated and camera activated for visual confirmation.

Description

MONITORING SYSTEM FOR RAILWAY EMBANKMENT

Field of the Invention

The present invention relates to a monitoring system for use on a railway embankment to detect movement or slippage.

Background of the Invention

Railway lines are often raised onto an embankment made of earth and/or other materials (e.g. stones, rocks, gravel, etc) in areas of low lying ground, or ground liable to flood, in order to allow the railway lines to pass at an acceptable level and gradient. In other circumstances, earth may be removed or cut out to make way for the railway line, in which case an embankment rises from the railway line up to the surrounding terrain (such a configuration is also known as a cutting). In any given rail network, there may be many miles of such embankments (including cuttings).

Earth movement in a raised embankment may cause significant problem with distortion of the rail geometry, such as lateral twist and longitudinal unevenness, and can also affect the stability of overhead gantries. The regular passage of trains will also make the problem worse. This may cause ride discomfort, and may be dangerous if too severe. In an extreme case, part of the embankment may subside, potentially leading to structural damage. In a cutting there is also the risk that earth or other materials (including vegetation) from the embankment can slide or fall onto the railway line, blocking the path for trains. The operational service impact of undertaking remedial maintenance work on embankments and tracks which have suffered damage from earth movement is typically very high.

A monitoring system may be used to detect slippage or other such movement of an embankment. If this slippage is identified at an early stage, before the problem is too severe, it may be feasible to repair or at least stabilise the situation at relatively reduced engineering maintenance and inspection costs, and if necessary to regulate or stop rail traffic on the affected line. Detecting more major slippage events is also valuable to avoid the risk of resulting interruption to railway traffic, damage to rolling stock, or in the worst case, accident through derailment or collision. Given the size of a railway network, it is attractive for such monitoring to be performed remotely (in addition to or instead of manual inspection), as potential problems can be detected much more quickly than through periodic manual inspections.

Senceive Ltd (see www.senceive.corn) provides wireless sensor devices that create and utilise a wireless mesh network for data communications, thereby allowing the nodes to work cooperatively to monitor (for example) environments, structures, plant and buildings. Senceive Ltd has provided monitoring solutions for railway embankments using tilt sensors mounted on steel or wooden beams, which are driven into the earth. The existing systems have focused primarily on data capture and analysis.

GB2510383A discloses a sensor device containing a tilt meter and a wireless communication facility, the sensor device also having a magnetic fixing for attaching the housing to a surface of a structure to be monitored by the tilt meter.

Summary of the Invention

The invention is defined in the appended claims.

One embodiment of the invention provides a railway embankment monitoring system comprising: a pattern of sensors distributed on the embankment, said sensors configured to detect movement or slippage of the earth in the embankment, a camera for imaging the embankment and the railway adjacent to the embankment; a wireless network linking the sensors and the camera; and a backhaul network for providing external communications to/from the wireless network.

Each sensor comprises a housing containing a tilt meter and a wireless communication facility configured to transmit data from the tilt meter, such as the Senceive Ltd FlatMesh Tilt Sensor (see WelikAl.serve ive c-rn). A sensor as described herein may be used to measure distortion or movement of embankment to which the sensor is attached. Typically multiple sensors are positioned in a pattern on the embankment, forming a network of such sensors, to provide a more accurate determination of any movement or distortion across a larger region of the embankment.

The sensors may be mounted individually onto a stake, beam or post embedded into the embankment to facilitate monitoring of the movement of the earth in the embankment. Mounting the sensors onto a stake allows the sensors to be rapidly and conveniently installed, and also rapidly and conveniently removed from the embankment (for potential redeployment elsewhere).

The wireless communication facility in the sensor may allow each sensor to function as a node within a wireless mesh network. The sensors may also be battery powered, so that the sensor does not require a fixed infrastructure for power supply. Thus the battery and wireless data communications obviate the need for a hard-wired or intrusively-fixed electrical installation. Accordingly, the sensors can be readily and conveniently reconfigured on a dynamic basis to satisfy ongoing needs.

External communication to/from the wireless network is provided by a backhaul, facilitated by a gateway node within the wireless network, such as a Senceive Ltd FlatMesh GPRS Gateway. The backhaul utilises a cellular network to provide communication between the wireless sensor network and a remote server. A database on the server is used to store data generated by the sensors and camera(s) within the wireless sensor network. Data stored on the database may then be transferred to the customer, such as the railway operator or maintenance group, via the internet or other means.

A remote monitoring system may also be able to access the server via the internet to receive diagnostic information about the network.

One or more nodes within the wireless mesh network may also comprise a camera positioned for imaging of the railway adjacent to the embankment. In some embodiments, one or more illuminators are linked to the camera to provide lighting of the field of vision of the camera and improve its performance in low light conditions or at night.

In some embodiments, rainfall information is also received through the wireless network from a rain gauge located on the embankment directly linked to the wireless network.

In some embodiments, data is sent from the sensors to the database via the backhaul for analysis. In other embodiments, each sensor communicates its data with the other sensors in the wireless network and computes levels of risk collectively using consensus algorithms before sending a status report to the database via the backhaul.

In some embodiments, when a pre-determined degree of earth movement has been detected, either from a single sensor or from multiple sensors, a signal is sent to a camera across the wireless network to generate an image. In other embodiments, the database analyses the data received from the sensors and determines when a signal should be sent to the camera to take an image. The signal is then sent to the camera, either directly to the camera or via the gateway node.

Additionally, the signal may instruct the camera to take a series of images over a pre-configured period of time. The images generated by the camera are then sent to the database via the backhaul (N.B. the camera may utilise the same backhaul as the monitoring system, or may have its own backhaul or other external connectivity). These images may then be transferred to the customer, alerting them to any issues there may be on the railway network due to earth movements in the embankment.

In some embodiments, the camera senses the light level and determines whether the illuminators are required. A signal is then sent to the illuminators to switch them on. In other embodiments, the illuminators are activated every time the camera takes a photo.

The embodiments described below relate to railways, but the monitoring system described herein could also be used for monitoring other engineering structures, such as roads, pipelines, and dams, that involve embankments, cuttings or similar structures which may be subject to slippage, ground movement, etc.

Brief Description of the Drawings

Various embodiments of the invention will now be described in detail by way of example only with reference to the following drawings: Figures 1-3 are images of existing sensor deployments on railway embankments. In Figure 1, the railway line is lower than the surrounding terrain, while in Figure 2, the railway line and associated gantries are higher than the surrounding terrain. In Figure 3, movement of earth around the sensor post has caused the post to which the sensor is attached to tilt.

Figure 4 is a schematic diagram of a railway embankment monitoring system in accordance with some embodiments of the invention.

Figure 5 is a schematic diagram of a railway embankment monitoring system in accordance with some other embodiments of the invention.

Figure 6 is a schematic diagram of a railway embankment monitoring system in accordance with some other embodiments of the invention.

Detailed Description

Figure 1 shows a railway embankment where the earth embankment 30 slopes down towards the railway line 40. In other locations, the railway line 40 is elevated above the local terrain and the embankment 30 slopes up towards the railway line 40, as shown in Figure 2. In some instances, earth movement in the embankment 30 can cause problems with distortion of the rail geometry, such as lateral twist and longitudinal unevenness, and can also affect the stability of overhead gantries 50. In other instances, earth from the embankment can slide or fall onto the railway line 40, blocking the path for trains. Meteorological events, for example recent heavy rain or long periods of dry weather, can accelerate the movement of the earth in the embankment.

Distributed along the embankment in a pattern are a number of sensors 100 to monitor the movement of the earth in the embankment. Each sensor 100 may be screwed, bolted, tie wrapped, glued or otherwise securely attached to a stake 110. Sensors 100 may be attached individually to a stake 110 or multiple sensors may be attached to some or all of the stakes.

Each stake 110 may comprise a pole, beam, tube, post etc. The stakes 110 may be constructed from steel, wood, carbon-fibre, fibreglass or any other suitably rigid material, such that movement detected by the sensor is that of the earth in the embankment and not of the stake (by itself). Each stake 110 is typically about two metres in length, with about half of its length embedded into the embankment 30. The sensors 100 are attached to the portion of the stake protruding from the embankment 30 -typically, close to the top of the stake 110 in order to optimise the wireless signal propagation.

The sensors 100 are arranged in a pattern along the embankment 30 to give sufficient coverage and distribution of measurements. Typical spacing between sensors is of the order of 5 meters, but may be up to 100 meters depending on the size of the embankment, vegetation and any previous records of large earth movements. The sensors 100 may be positioned anywhere on the embankment such that they do not interfere with normal operation of the railway line.

Each sensor 100 comprises a housing containing a tilt meter and a wireless communication facility configured to transmit data from the tilt meter. The wireless communication facility is also able to receive incoming messages for the sensor, as well as acting as an intermediate node to receive and then forward messages sent by or to other nodes in the mesh network. The mesh network is self-configuring, so does not require the sensors 100 to be positioned into any particular configuration. Each sensor 100 is powered by its own internal battery so that the sensor does not require a fixed infrastructure for power supply. The battery and wireless data communications therefore obviate the need for a hard wiring to individual sensors (for power and/or data communications). Accordingly, the sensors can be quickly and conveniently installed in their desired positions on an embankment, as well as reconfigured on a dynamic basis to satisfy ongoing needs.

In some embodiments, each sensor 100 is a Senceive Ltd FlatMesh Tilt Sensor (see vvvvi.senceive.com). The sensor is able to measure movements of the earth resulting in a movement of the stake of the order of 0.01°, although earth movements of the order of degrees are possible.

Further information about examples of sensor of this type can be found, inter alia, in GB2510383A.

Also positioned on the embankment 30 is a gateway node 200. The gateway node 200 provides a communications link between the network of sensors 100 and a remote server across a backhaul for the transfer of data to and from the sensors 100 on the railway embankment 30. In some embodiments the gateway node 200 is a Senceive Ltd FlatMesh GPRS Gateway. However, any other suitable communications facility may be used for linking the gateway node 200 to an external network, depending upon the services that are available locally to the gateway node 200 (e.g. wi-fi or a fixed data communication line).

The gateway node 200 may be bolted, tie wrapped, glued or otherwise securely attached to a stake 210. Stake 210 may be constructed from a similar material to that of stake 110 and may be of a similar length (although the gateway node may be located at a slightly greater height if this will help external communications). Depending upon the particular configuration of the sensor network, and also the positioning of the gateway node, the stake supporting the gateway node 200 may also have a sensor 100 attached to it and be installed as described in the paragraphs above.

The gateway node 200 may be powered by means of a solar charging panel 220 or other energy harvesting system, with a backup battery to provide a period of operation when power from its primary source is not available, for example at night or during a period of cloudy weather or low light weather. Sourcing power from such an energy source obviates the need for a hard-wired electrical installation.

The gateway node 200 and/or the solar charging panel 220 may in some cases be mounted on existing infrastructure (where available) or else on some structure, e.g. a post that is more substantial than the stakes 110 used for the individual sensors. This helps to ensure a more robust mounting for these devices.

Figure 3 shows a sensor 100 comprising a tilt meter and a wireless communication facility attached to a stake 110 which is embedded into a railway embankment 30 which has undergone significant earth movements. A spirit level 60 is provided in the figure to demonstrate the degree to which the sensor 100 and stake 110 have tilted due earth movement in the embankment 30. Figure 4 shows a railway embankment monitoring system in accordance with some embodiments of the invention. At least one sensor 100 and at least one gateway node 200 is positioned on each embankment 31, 32, 33. Embankments 31, 32, 33 may represent different locations along a single embankment, different embankments on the same railway, or separate sections of the railway network potentially separated by several hundred kilometres (or any combination thereof). It will be appreciated that a given railway monitoring system may have greater or fewer than three embankments under surveillance.

The sensors 100 and gateway node 200 form a set of nodes within a mesh network and communicate with one another via a wireless network 301, 302, 303. As shown in Figure 4, each wireless network 301, 302, 303 is specific to a given embankment 31, 32, 33. In some installations, multiple wireless networks 301, 302, 303 may be positioned on the same embankment. In such an arrangement, the wireless networks may be configured to operate independently of one another or the wireless networks may be configured to exchange data from sensors 100 between the wireless networks.

In some embodiments, the sensors 100 and gateway node 200 communicate at a frequency of 2.4 GHz within the ISM (industry, scientific and medical) band, in compliance with IEEE 802.15.4. The data rate is 250kbits per second, with a typical duty cycle of 1%. The point-to-point range between one sensor 100 and another sensor (or the gateway node 200) is generally tens of meters, but may be up to 'I km depending on the environment. It will be appreciated that other sensors 100 and gateway nodes 200 may have different communication parameters such as frequency, protocol, etc, according to the requirements and considerations of any particular implementation. For example, some implementations may operate in a different radio band from the one specified above. In some embodiments, the gateway node 200 may only communicate with one sensor 100 in order to be linked for data transmission with the entire network of sensors, since each node in the network can communicate directly or indirectly (via one or more other nodes) with every other node in the wireless network.

In some embodiments, the wireless sensor network 301, 302, 303 is based on a FlatMesh network from Senceive Ltd (see mov.senceve.corn). The FlatMesh network comprises multiple sensors 100 that can be positioned as desired in an environment to be monitored.

The use of a wireless network 301, 302, 303 for connecting the sensors 100 provides a robust communications architecture, in that even if one path might fail, for example, because a given sensor 100 fails (at least in part), or because of the presence of an obstacle along the path, sensors that were using this path may be able to maintain communications via an alternative path over different nodes in the wireless network 301, 302, 303. Furthermore, the wireless network 301, 302, 303 supports dynamic reconfiguration, for example, if the sensors 100 are moved with respect to one another or if one or more sensors are added to or removed from an existing wireless network. This dynamic reconfiguration may result in the wireless network 301, 302, 303 forming new links between sensors 100 that are now able to communicate with one another; conversely, the reconfiguration may result in the wireless network 301, 302, 303 breaking (ending) old links between sensors 100 that are no longer able to communicate with one another -for example, because they are now separated by some obstacle, or because one of the sensors 100 has been removed from the network. Note that such dynamic reconfiguration in terms of the wireless communications occurs automatically (it does not have to be controlled or specifically commanded by an operator). Further information about wireless sensor networks can be found, inter alia, in "The SECOAS Project -Development of a Self-Organising, Wireless Sensor Network for Environmental Monitoring" by Britton and Sacks, available at: httpliwww.lancs_ac.ukistaffirnarshai2Isecoas/SANPA-2004-81-thon.pdt and "Wireless Sensor Network Survey" by Yick et al, in Computer Networks, Volume 52, Issue 12, 22 August 2008, pages 2292-2330.

Also shown in Figure 4 is an interface application 510, which is able to communicate with any given sensor 100 in the wireless sensor network 301, 302, 303 from a remote location. This communication may occur via the gateway node 200 and using a backhaul 410, 412 a cellular (mobile telephone) network 400. In some embodiments, the cellular network 400 is a 2G GSM (Global System for Mobile Communications) network and the gateway node 200 uses GPRS (General Packet Radio Services) for data communications. It will be appreciated that other cellular networks 400 and gateway nodes 200 may have different transmission standards according to the requirements and considerations of any particular implementation, such as CDMA2000, 3G (third generation, or ITU IMT-2000) or 4G (fourth generation, or ITU IMT-Advanced).

Furthermore, other embodiments may utilise different communication networks for wired or wireless data transmission between a gateway node 200 and the interface app or application 510.

For example, gateway node 200 may have a wi-fi connection to the Internet (and from there to the interface application 510). Alternatively, the gateway node may connect to the interface application 510 over a fixed landline, or transmit a data signal modulated over a railway power line. It will be appreciated that the choice of communications link (or links) between the gateway node 200 and the interface application 510 will depend on which communications facilities are available locally to a given remote monitoring system (in many cases, GPRS will have the most widespread availability). As shown in Figure 4, the interface application 510 runs on a server 500, which includes or is linked to a database 520 for storing information. The database 520 can be remotely accessed across the internet 600 from a customer access point 710 and from a remote network management point 700. The network management point 700 can be used to access diagnostic information about the network whilst the customer access point 710 can be used to remotely receive data from any of the nodes within the wireless network 301, 302, 303 (that belong to the relevant customer). In this instance, the customer may be the railway operator or the railway maintenance organisation.

As also shown in Figure 4, one or more of the nodes within the wireless sensor network 301, 302, 303 is a camera 800, which is positioned to image the embankment on which the sensors 100 are located and also the adjacent railway. The camera may be powered by means of a solar charging panel and/or other energy harvesting system, with a backup battery to provide a period of operation when power from its primary source is not available, for example at night or during a period of cloudy weather or low light levels. Sourcing power from such an energy source obviates the need for a hard-wired electrical installation. Although Figure 4 shows only one camera, it will be appreciated that some monitoring installations may use multiple cameras, depending upon the area to be monitored, its topography, any obstructions (bridges, trees, etc), available lines of sight, and so on.

Multiple cameras 800 may be positioned along the railway embankment within a single wireless sensor network 301, 302, 303 to provide a larger area of coverage. The camera 800 may communicate with the interface application 510 using the backhaul 410 via the gateway node 200. In this case, the camera only has to be able to operate as a node within the wireless network 301, 302, 303. Alternatively, the camera may be able to communicate across the cellular network via its own backhaul link 411. In general, even if the camera 800 and the gateway node 200 communicate separately with the interface application 510, they are likely to use the same communications network (which is available at the location of the remote monitoring site). However, in some implementations the communications routes may be different, depending upon the particular capabilities of the gateway node 200 and the camera 800.

In some embodiments, the remote monitoring system also includes one or more light sources 850, located on the embankment 31, 32, 33, to provide additional lighting within the field of view of the camera 800. The light source(s) may be positioned next to a camera 800, or anywhere else along the embankment. The light source may be powered by means of a solar charging panel or other energy scavenging system, with a backup battery to provide a period of operation when power from its primary source is not available, for example at night or a period of cloudy weather or low light levels. Sourcing power from such an energy source obviates the need for a hard-wired or intrusively-fixed electrical installation. The light sources generally operated in the infra-red spectrum, in particular in a portion of the infra-red spectrum that is invisible to humans. This helps to ensure firstly that a train driver is not distracted or dazzled by a bright (visible) light source, and secondly that there is no risk of the light source being mistaken for, e.g. a red signal for controlling the train.

A light source 850 may be controlled directly by a camera 800 (especially if co-located with the camera). In this case, the control of the light source may be performed by the camera (or via the wireless node on which the camera is located). Alternatively a light source may be included as a separate node in the wireless network and therefore communicated with and controlled independently of the camera 800.

In some embodiments, one or more of the nodes within the wireless sensor network 301, 302, 303 comprises a rain gauge 900, located on the embankment 31, 32, 33, to measure and record the amount of rain that has fallen in the vicinity of the embankment. The rain gauge then transmits this rainfall data across the wireless sensor network 301, 302, 303. In other implementations, rainfall data may be obtained from a separate source, for example, by accessing a meteorological service over the Internet (or the two sources may be used in conjunction with one another). The rainfall data may be used as an additional input for assessing the stability of the earth on the embankment -for example, large scale earth movements may occur after a period of heavy or prolonged rainfall, so monitoring operations may be increased following such a rainfall. In other words, seeking to correlate earth movement with weather conditions, such as heavy rain, wind, or long dry spells, has the potential to aid in remote monitoring operations.

Similarly, in some embodiments the wireless networks may be provided with an anemometer (not shown in Figure 4) to measure wind speed, and/or the wind information can be sourced from another meteorological service. This information can be useful, for example, because very high winds might potentially trigger an alert from a tilt meter that movement has been detected, but such movement may in fact arise from the wind strength rather than from any earth movement (in general, the stakes are designed to be sufficiently robust to resist wind movement). On the other hand, high winds may also result in fallen trees or other debris being blown onto (or falling onto) the track, and this is also valuable for the monitoring system to be able to detect such situations. In addition, a falling tree may cause earth movement which again should be detected.

In some embodiments, the data from each sensor 100 is sent to the server 500 across the cellular network 400 via the backhaul 410 for analysis and for storage in database 520. The interface application 510 then takes on some or all of the responsibility for controlling the remote monitoring e.g. for determining when to take images of the railway using camera 800, or when to raise an alarm about possible land movement. A human operator of the interface application 510 may take some or all responsibility for such control decisions.

In other embodiments, the wireless network 301, 302, 303 itself is provided with some level of internal intelligence -for example, by designating one node 100 with a microprocessor as a control node. This control node then receives data from the other sensors in the wireless sensor network 301, 302, 303 and computes e.g. levels of risk collectively across the whole network. Alternatively, some or all of this intelligence or control processing may be distributed across the various nodes of the wireless network. For example, if any given node detects movement of more than a given amount, it may automatically instruct the camera to take a photograph. Another possibility would be for a node to instruct the camera to take a photograph whenever it has detected movement itself, and also has received notification of movement from a nearest neighbour node -this may help to discriminate against a false positive from an individual sensor. For example, a single sensor 100 showing movement may result from a system problem, an aberration or another cause, such as human or animal disturbance, or high winds, but a group of sensors in proximity to one another showing movement will generally indicate a genuine or more significant problem.

Accordingly, various forms of consensus algorithm may be employed within the sensor network requiring a detection event at a certain (absolute or relative) number of nodes (possibly positioned close to one another), typically within a given time interval, before triggering a particular action, such as instructing a photograph by the camera, or sending a status report to the server 500 across the cellular network 400. Note that the threshold of the consensus algorithm might be varied with circumstances, for example, the threshold for triggering a particular action might be reduced after a period of heavy rain in order to improve sensitivity at this more vulnerable time.

Overall, the analysis of data from the network of sensors 100 at the server 500 and/or within the wireless sensor network 301, 302, 303, helps to provide real-time monitoring of the state and stability of the earth on the embankment, based on the magnitude of any detected movement, the number of sensors showing movements and the proximity (or clustering) of sensors showing movement. When a pre-determined threshold has been reached, whether from a single sensor 100 or from multiple sensors as described above, one or more actions may be instructed automatically by the sensor network. For example, a command is sent to a camera 800 across the wireless sensor network 301, 302, 303 to acquire an image. If there are multiple cameras 800 within the wireless network 301, 302, 303, the signal may only be sent to one or a selection of the cameras, depending on where the potential earth movement has been detected. The signal may instruct the camera to take a series of images over a period of time (or the camera may be configured to do this anyway). The images acquired by the camera(s) are transmitted to the server 500 and the database 520 across the cellular network 400 via the backhaul 410, whether from the gateway node 200 or directly from the camera 800 (via its own communications link). The images may then be transferred to the customer access point 710 via the internet 600 to alert the customer, such as the railway operator or the railway maintenance organisation, to any issues there may be on the railway network due to earth movements in the embankment 31, 32, 33.

A detection of movement, with or without visual confirmation using the camera images, may trigger various resulting actions. For example, any detection of movement might generate an email and/or SMS alert (as appropriate), and also may automatically create a tracker ticket for issue reporting and management purposes. In the case of a relatively substantial detection, e.g. involving many sensors, or involving significant movement at a small number of sensors, this may trigger an on-site inspection by an engineer. In this way, the remote monitoring system, by providing an early detection of earth movement, as well as an assessment of scale, can help to make the most of limited human engineering resources by highlighting particular areas of potential concern. Such prioritisation can also extend to scheduling of maintenance operations: e.g. attention (such as engineering works) for an area which has experienced an ongoing series of movements may be more urgent than for an area which experienced one relatively small movement, but for which further movement has not been detected since (such an area may have now stabilised of its own accord).

The outputs from the monitoring network can also be used for making real-time decisions for controlling railway operations. For example, if severe movement is detected (or suspected, based on the sensor outputs), then trains may be prevented from travelling through the relevant section of track. For less severe situations, the speed of trains passing through the area may be restricted.

A further application of the monitoring network is to assess the outcome of engineering works.

For example, if such works are performed to stabilise a particular embankment, the sensor nodes 100 can be used to help provide confirmation that such works have been successful.

Figure 5 shows the railway embankment monitoring system in accordance with some other embodiments of the invention. In these embodiments, the interface application 510 on the server 500 communicates with the wireless sensor network 301, 302, 303 across a cellular network 400 via the backhaul 410 as described previously. Additionally, the interface application 510 on the server 500 communicates directly with a database 560 on a customer server 550. The communication link 620 may be wireless or via the internet or a local area network, etc. The database 560 passes the information to a data processing unit 570 on the customer server 550, which can be accessed by the customer via an access point 710. Monitoring of the network can then be carried out at a remote access point 700 via a communications link 610, 611 across the internet 600 to the server 500 as before. Using this configuration, data and diagnostic information about the network can be passed directly to the customer with little or no latency.

Analysis of the data from sensors 100 and signals to operate the camera(s) 800 may be sent from the server 500 or this functionality may be performed by the customer server 550. Alternatively, the analysis of data from the sensors 100 and the signal to operate the camera(s) 800 may be provided, at least in part, by the sensors 100 themselves within the wireless network 301, 302, 303 as described above.

Figure 6 shows the railway embankment monitoring system in accordance with some other embodiments of the invention. In these embodiments, the interface application 580 is positioned on the customer server 550 for communication with the wireless sensor networks 301, 302, 303 across the cellular network 400 via the backhaul 410. The interface application 580 communicates with the server 500 via a communication link 640 (server 500 typically belongs to the entity which runs the sensor networks, as opposed to the rail networks). The communication link 640 may be wireless or wired, e.g. via the internet. Data is passed from the interface application 580 to a database 560 and processing unit 570, both located on the customer server 550, which can be accessed by the customer via an access point 710. Monitoring of the network can be carried out at a remote access point 700 via a communications link 610, 611 across the internet 600 to the database 520 located on server 500 as described above. Using this configuration, all data and diagnostic information about the network is passed directly to the customer, with a backup copy sent to the server 500. Analysis of the data from sensors 100 and signals to operate the camera(s) 800 may be provided by the server 500, and/or this functionality may be performed the customer server 550. Alternatively, the analysis of data from the sensors 100 and the signal to operate the camera(s) 800 may be provided, at least in part, by the sensors 100 themselves within the wireless network 301, 302, 303 as described previously above.

Thus Figures 4, 5 and 6 provide different overall configurations, especially for how the outputs from the sensor networks are reported, and how the sensor networks may be controlled. However, the skilled person will appreciate that the functionality described in most detail in connection with the configuration of Figure 4 can also be readily implemented in the configurations of Figure 5 and 6 (as well as other possible configurations).

In summary, various embodiments described herein provide monitoring system for a railway embankment. The skilled person will appreciate that these embodiments are provided only by way of example, and different features from different embodiments can be combined as appropriate. Accordingly, the scope of the presently claimed invention is to be defined by the appended claims and their equivalents.

Claims

Claims A monitoring system for use on a railway embankment for detection of movement comprising: a pattern of sensors for detecting movement distributed on the embankment; a camera for imaging the railway in the vicinity of the embankment; a wireless network linking the sensors and the camera; and a backhaul for providing external communications to/from the wireless network; 2. 4. 5. 7. 9. 10. 11. 12.

The monitoring system of claim 1, wherein the sensors are tilt meters.

The monitoring system of any preceding claim, wherein the sensors are attached to stakes embedded into the embankment.

The monitoring system of any preceding claim, wherein the backhaul utilises a cellular network.

The monitoring system of any preceding claim, wherein the wireless network includes a gateway node to provide the backhaul communications link.

The monitoring system of claim 5 as dependent on claim 4, wherein the gateway node supports GPRS for the backhaul communications link.

The monitoring system of any preceding claim, further comprising one or more illuminators for lighting at least part of a field of view of the camera.

The monitoring system of any preceding claim, further comprising a rain gauge as part of the wireless network.

The monitoring system of any preceding claim, wherein the backhaul connects the wireless network to a remote server.

The monitoring system of claim 9, wherein data on the remote server is accessible from a computer via the internet.

The monitoring system of any preceding claim, wherein the camera is configured to operate based on a signal sent across the wireless network.

The monitoring system of claim 11, wherein the signal is generated based on data from one or more sensors.

13. The monitoring system of claim 12, wherein one or more nodes within the wireless network are operable to process outputs from multiple sensors to generate the signal.

14. The monitoring system of claim 13, wherein said processing of outputs from multiple sensors involves a consensus algorithm.

15. The monitoring system of any preceding claim, wherein the camera is configured to operate based on a signal sent directly to the camera from an external control system.

16. The monitoring system of any of claims 11-15, wherein the camera takes a series of images over a pre-determined time interval based on the signal received.

17. The monitoring system of any preceding claim, wherein the system is configured to send an alert or warning over the backhaul in the event that the sensors detect movement.

18. The monitoring system of claim 17, wherein said alert or warning includes information indicating the scale or significance of the movement detection.

19. A monitoring system substantially as described herein with reference to the accompanying drawings.