Hazard alert system for railways

Abstract

Disclosed is a rail vehicle detection and warning system for providing a warning alert. The system comprises at least one rail vehicle detection unit comprising at least one rail vehicle detector for detecting an approaching rail vehicle based on a rail vehicle signal; at least one warning alert unit, and at least one control unit. The warning alert unit is configured to provide the warning alert in response to the rail vehicle detector sensing the rail vehicle signal. Through a feedback loop between the control unit and the warning alert unit, the system is configured to determine if the warning alert unit is in a safe state indicating that the warning alert unit is functioning or an unsafe state indicating that the warning alert unit is not functioning.

Description

[0001] Hazard Alert System for Railways

[0002] Field

[0003] This invention relates to a hazard detection and warning system and a method of detecting a hazard and providing a warning alert. More particularly, the invention relates to a rail vehicle (e.g. train) detection and warning system and a method of detecting a rail vehicle (e.g. train) and providing a warning alert.

[0004] Background

[0005] Maintenance and construction may need to be carried out on railways in areas where trains are still running on the railways tracks (i.e. a live railway). This avoids railway tracks being closed for the maintenance causing excessive disruption to the train network. However, due to the trains running on the track, a person or persons (e.g. track workers) on the railway may be exposed to unsafe working environments in which near miss incidents and fatalities occur. In other words, approaching trains (including any items / vehicles moving along the rails, such as a trolley or road rail vehicle) may be considered a hazard to the track workers.

[0006] Manual detection and warning may be a method used when railway track work (e.g. maintenance) has to be performed on tracks on which trains are operating. One or more of the track workers have to supervise the track at a remote location relative to the work location, and inform (e.g. call) their colleagues working at the work location if a train should appear.

[0007] There are methods available to detect the presence of an approaching train as a hazard. Furthermore, there are methods available to alert workers of approaching trains.

[0008] It is desired to improve safety for the track workers as well as reduce set up time for the safety equipment and reduce closure time of the railway. The present invention seeks to overcome or ameliorate at least some of the problems associated with the known art. This background serves only to set a scene to allow a skilled reader to better appreciate the following description. Therefore, none of the above discussion should necessarily be taken as an acknowledgement that that discussion is part of the state of the art or is common general knowledge. One or more aspects / embodiments of the disclosure may or may not address one or more of the background issues.

[0009] Summary

[0010] According to a first aspect of the invention, there is provided a rail vehicle detection and warning system for providing a warning alert, the system comprising: at least one rail vehicle detection unit comprising at least one rail vehicle detector for detecting an approaching rail vehicle based on a rail vehicle signal; at least one warning alert unit, and at least one control unit, wherein the warning alert unit is configured to provide the warning alert in response to the rail vehicle detector sensing the rail vehicle signal, wherein, through a feedback loop between the control unit and the warning alert unit, the system is configured to determine if the warning alert unit is in a safe state indicating that the warning alert unit is functioning or an unsafe state indicating that the warning alert unit is not functioning.

[0011] Advantages include improving worker safety when working on the railway (e.g. improving reliability of the safety system), and reducing the time required to establish protection methods as part of the declared safe system of work on the railway (e.g. improving the ratio of ‘set up time’ to ‘time on tools’).

[0012] The warning alert may be provided when the at least one warning alert unit is determined to be in the unsafe state. The system may comprise a plurality of warning alert units.

[0013] The control unit may be configured to determine if the warning alert unit is in the safe state or the unsafe state. The control unit may be separate to the warning alert unit and / or the rail vehicle detection unit or at least part of the control unit may be considered to form part of or be within the warning alert unit and / or rail vehicle detection unit. The control unit may comprise at least one signal processor. The control unit may comprise at least one data acquisition signal processor. The control unit may comprise a computing apparatus. The computing apparatus may comprise a processing apparatus for processing of data. The processing apparatus may comprise a central processing unit (CPU). The computing apparatus may also include a hard drive and other components of a PC including RAM, ROM, a data bus, an operating system including various device drivers, and hardware devices.

[0014] The rail vehicle detection unit (e.g. the control unit at the rail vehicle detection unit) may comprise a signal processor arranged for receiving the rail vehicle signal from the at least one rail vehicle detection unit and determining if an approaching rail vehicle has been detected based on the rail vehicle signal. The rail vehicle detection unit (e.g. the control unit) may be configured to determine, dependent on the rail vehicle signal being detected by the at least one rail vehicle detector, that the rail vehicle detection unit is in an unsafe state indicating that the rail vehicle detection unit has detected a rail vehicle. This unsafe state may be sent to the control unit (or another part of the control unit).

[0015] The control unit may comprise a signal processor arranged for receiving rail vehicle detector output signals representing the rail vehicle signal from the at least one rail vehicle detection unit. The control unit may be configured to process the rail vehicle detector output signals, determine if an approaching rail vehicle has been detected and, if so, may be configured to send an indication to the warning alert unit that a rail vehicle has been detected. The indication that a rail vehicle has been detected may take the form of an indication to the warning alert unit of an unsafe state of the rail vehicle detection unit indicating that the rail vehicle detection unit has detected a rail vehicle.

[0016] The warning alert may be provided to at least one person working in an area, to a device, to a worker, to equipment, to machinery, and / or to a robotic I autonomous vehicle. It will be appreciated that, where person is used in this text, one or more of these other options may be used instead of (or additionally) to person, as applicable.

[0017] The area that the at least one person is working in may be considered to be a danger or hazard area, e.g. an area that the moving rail vehicle may pass through that may constitute a danger or hazard to the person.

[0018] It will be appreciated that rail vehicle may cover objects moving or rolling along rails or railway rails. For example, rail vehicle may be considered to be a rail mounted or mountable object or vehicle with wheels, an item or vehicle configured to move or moving along rails via wheels, an object comprising rail wheels (wheels configured to move on rails), a trolley configured to or rolling on a rail (i.e. rail mounted or mountable trolley), a train, a passenger train, a freight train, a tram, rollercoaster, and / or a road rail vehicle (RRV).

[0019] The rail vehicle detection or warning system may be considered to be a rail wheel movement detection and warning system.

[0020] The rail vehicle detection or warning system may be considered to be a train detection and warning system.

[0021] The warning alert unit may comprise at least one alert generator for generating the warning alert and at least one alert detector for detecting the warning alert, wherein the warning alert unit may be configured to output, from the at least one alert generator, a predetermined control signal alert corresponding to the warning alert, wherein, the system may be configured to determine, dependent on the predetermined control signal alert being detected by the at least one alert detector, that the warning alert unit is in the safe state.

[0022] The predetermined control signal alert corresponding to the warning alert may be considered to be similar to the warning alert, the same type of signal as the warning alert, be representative of the warning alert and / or be characteristic of the warning alert.

[0023] The alert generator may be an alert (generating) transducer. The alert detector may be an alert detection transducer. The alert transducer and the alert detection transducer may be considered to be a transducer and detection transducer (or sensor) coupling. The system may comprise a plurality of transducer and sensor couplings. The system may comprise a plurality of alert transducer and alert detection transducer couplings. The alert generator and / or transducer may be considered to be a signal transmission unit and the alert detector and / or detection transducer may be considered to be a signal reception unit. The alert transducer may be a sound creating transducer (e.g. a speaker). The alert transducer may be an audible sound (e.g. able to be heard by the person) creating transducer. The alert detection transducer may be a sound detection transducer or sensor (e.g. a microphone). The alert detection transducer may be a sensor.

[0024] The alert transducer may be an electromagnetic radiation creating transducer (e.g. a light emitting diode). The alert transducer may be a light (e.g. visible light) creating transducer. The alert detection transducer may be an electromagnetic radiation transducer. The alert detection transducer may be a light transducer (e.g. a light dependent resister).

[0025] Through an additional feedback loop between the control unit and the rail vehicle detection unit, the system may be configured to determine if the rail vehicle detection unit is in a safe state indicating that the rail vehicle detection unit is functioning or an unsafe state indicating that the rail vehicle detection unit is not functioning.

[0026] The control unit may be configured to determine if the rail vehicle detection unit is in the safe state or the unsafe state.

[0027] The warning alert may be provided when the at least one rail vehicle detection unit is determined to be in the unsafe state. The unsafe state of the rail vehicle detection unit may comprise the unsafe state indicating that the rail vehicle detection unit is not functioning and / or the unsafe state indicating that the rail vehicle detection unit has detected a rail vehicle. The system may comprise a plurality of rail vehicle detection units.

[0028] The rail vehicle detection unit may comprise at least one rail vehicle generator for generating a predetermined control rail vehicle signal, wherein the rail vehicle detection unit may be configured to output, from the at least one rail vehicle generator, a predetermined control rail vehicle signal corresponding to the rail vehicle signal, wherein, the system may be configured to determine, dependent on the predetermined control rail vehicle signal being detected by the at least one rail vehicle detector, that the rail vehicle detection unit is in the safe state. The predetermined control rail vehicle signal corresponding to the rail vehicle signal may be considered to be similar to the rail vehicle signal, the same type of signal as the rail vehicle signal, be representative of the rail vehicle signal and / or be characteristic of the rail vehicle signal.

[0029] The rail vehicle generator may be a rail vehicle transducer. The rail vehicle detector may be a rail vehicle detection transducer. The rail vehicle transducer and the rail vehicle detection transducer may be considered to be a transducer and detection transducer (or sensor) coupling. The system may comprise a plurality of transducer and sensor couplings. The system may comprise a plurality of rail vehicle transducer and rail vehicle detection transducer couplings. The rail vehicle transducer may be considered to be a signal transmission unit and the rail vehicle detection transducer may be considered to be a signal reception unit. The rail vehicle transducer and / or the rail vehicle detection transducer may comprise a piezoelectric element.

[0030] The rail vehicle transducer may be a vibration creating transducer. The rail vehicle detection transducer may be a vibration detecting transducer. The rail vehicle detection transducer may be a sensor. The rail vehicle detecting transducer may comprise an acoustic transducer.

[0031] The rail vehicle transducer and / or the rail vehicle detection transducer may be fixed to at least one rail of a rail track. The rail vehicle detection transducer may be arranged for detecting the rail vehicle signal induced by a moving rail vehicle and propagated through the rail from the rail vehicle.

[0032] The predetermined control rail vehicle signal may be used for calibration of the system. That is, the system may be configured to calibrate at least part of the system by using (the reception of) the predetermined control rail vehicle signal. A transfer function may be determined. Changes in the predetermined control rail vehicle signal (e.g. due to travel through the rail) may be measured, e.g. to characterise particular section of rail in use. The transfer function may enable calibration of the system for optimised rail vehicle detection.

[0033] The control unit may be configured to output an alert trigger signal to the warning alert unit to trigger the warning alert unit to output the predetermined control signal alert. The alert trigger signal may form part of an evaluation cycle driven by the control unit. The alert trigger signal may be provided in a predetermined timescale.

[0034] The control unit may be configured to output a rail vehicle trigger signal to the rail vehicle detection unit to trigger the rail vehicle detection unit to output the predetermined control rail vehicle signal.

[0035] The rail vehicle trigger signal may form part of an evaluation cycle driven by the control unit. The rail vehicle trigger signal may be provided in a predetermined timescale.

[0036] Through at least one control feedback loop between the control unit and the warning alert unit and / or the control unit and the rail vehicle detection unit, the system may be configured to determine if the respective warning alert unit and / or rail vehicle detection unit is in a safe state indicating that communication between the control unit and the respective warning alert unit and / or rail vehicle detection unit is functioning or an unsafe state indicating that communication between the control unit and the respective warning alert unit and / or rail vehicle detection unit is not functioning.

[0037] The warning alert may be provided when the control unit is determined to be in the unsafe state. The system may comprise a plurality of control units.

[0038] The system may be configured to determine, dependent on the alert trigger signal and / or the rail vehicle trigger signal from the control unit being received by the warning alert unit and / or the rail vehicle detection unit respectively within a predetermined timescale, that the respective warning alert unit and / or rail vehicle detection unit is in the safe state.

[0039] The predetermined timescale may be e.g. 5 seconds. The warning alert unit and / or the rail vehicle detection unit may be configured to communicate to the control unit whether the alert trigger signal and / or the rail vehicle trigger signal respectively has been received or not.

[0040] The system may be configured to determine that the system is in an overall safe state when no rail vehicle has been detected and the warning alert unit and the rail vehicle detection unit are in the safe state, or an overall unsafe state when an approaching rail vehicle has been detected and / or at least one of the warning alert unit and the rail vehicle detection unit are in the unsafe state.

[0041] Advantages include providing a fail-safe system for detecting rail vehicles and providing warning alerts, e.g. to workers on a railway track.

[0042] Individual safety systems (e.g. safety system that that allows confirmation to be made that the rail vehicle detection system is functioning or safety system that allows confirmation to be made that a warning alert system is functioning) may be connected together to form a larger system. Furthermore, a plurality of systems or parts of systems (e.g. a plurality of control units, a plurality of warning alert units and / or a plurality of rail vehicle detection units) may be combined together to form an even larger system.

[0043] The safe state of the warning alert unit may comprise the safe state indicating that the warning alert unit is functioning and / or the safe state indicating that communication between the control unit and the warning alert unit is functioning. The unsafe state of the warning alert unit may comprise the unsafe state indicating that the warning alert unit is not functioning and / or the unsafe state indicating that communication between the control unit and the warning alert unit is not functioning.

[0044] The safe state of the rail vehicle detection unit may comprise the safe state indicating that the rail vehicle detection unit is functioning and / or the safe state indicating that communication between the control unit and the rail vehicle detection unit is functioning.

[0045] The unsafe state of the rail vehicle detection unit may comprise the unsafe state indicating that the rail vehicle detection unit is not functioning, the unsafe state indicating that communication between the control unit and the rail vehicle detection unit is not functioning, and / or the unsafe state indicating that the rail vehicle detection unit has detected a rail vehicle. The system may be configured to communicate the overall state of the system to the warning alert unit such that the warning alert unit provides the warning alert when the rail vehicle detection unit and / or another warning alert unit is in an unsafe state.

[0046] The overall state of the system may be communicated to the warning alert unit from the control unit.

[0047] The system may be configured such that the at least one warning alert unit may be removable from operating in the system without the system being considered to be in an overall unsafe state.

[0048] This may allow a person or persons to leave an area where they are working whilst maintaining the integrity of the system.

[0049] The system may be configured to communicate with equipment such that, if the overall state of the system is unsafe and / or the warning alert has been provided, the equipment stops working or moves autonomously to position of safety.

[0050] The equipment may comprise tools and machinery, e.g. in use by the person or persons. The equipment may comprise a robotic I autonomous vehicle. The warning alert unit may be linked with the equipment such that, when the warning alert is provided, a kill-switch is activated for the equipment. This may provide further notification to the person that there is an overall unsafe state or a rail vehicle is approaching.

[0051] The warning alert unit may comprise a worker status monitor, such as a health monitor (e.g. a wearable health monitor). The worker status monitor and / or the health monitor may comprise an accelerometer. The worker status monitor may provide information on the health and / or movement of the worker (i.e. determining movement of the warning alert unit).

[0052] The system may be configured to receive additional and / or remote information from external sources in at least one external feedback loop for triggering an overall unsafe state in the system. The additional and / or remote information from external sources may include Global Positioning System (GPS) location, Rail Traffic Management Systems (RTMS), European Train Control System (ETCS) or other information sources that may provide the necessary properties of trains approaching the workers, for example location, direction, routed path and speed of approach.

[0053] The system may be configured to default to use the local component or components (e.g. the rail vehicle detection unit) to avoid a false-negative outcome, e.g. if the additional and / or remote information from external sources is inaccurate or erroneous. This element of redundancy may enhance the safety of the system whilst providing various ways of detecting approaching rail vehicles as hazards.

[0054] The system may be configured to function without requiring any external information and / or any other safety or signalling system.

[0055] The system may operate independently, e.g. from any other safety or signalling system.

[0056] The system may be configured to be installed or is installable in an area where work is being carried out.

[0057] The area may be where at least one person is working. The warning alert unit, the control unit and / or the rail vehicle detection unit may be installed or installable in the area. The warning alert unit, the control unit and / or the rail vehicle detection unit may be considered to be local components. The system may provide workers with a safe working environment. The system may increase the available working time.

[0058] The system, the rail vehicle detection unit, the warning alert unit and / or the control unit may be mobile and / or portable.

[0059] The at least one rail vehicle detector may be configured to detect the rail vehicle at a distance sufficient to provide suitable warning time.

[0060] The suitable warning time may be for at least one person to move to a safe location, for example, the sufficient distance may be in a range of 50m to 3km. This means that that a person or persons are not required to walk relatively large distances to set up the safe system of work.

[0061] The feedback loop, the additional feedback loop, the at least one control feedback loop, and / or the at least one external feedback loop may be continuous.

[0062] More generally, all or any of the feedback loops may be continuous.

[0063] The warning alert may comprise at least one of audible, visual, electric, electromagnetic, electronic, digital, and / or tactile alerts.

[0064] The electromagnetic alert may comprise an electromagnetic signal. The electromagnetic signal (or signals) may include, but not be limited to, optical fibre signal(s) and radio frequency signal(s).

[0065] The warning alert unit may be a loudspeaker. The warning alert unit may be located with the control unit and / or the rail vehicle detection unit. The warning alert unit, the control unit and / or the rail vehicle detection unit may be integrated into the same unit or may be separate components. The warning alert unit may be or form part of personal protective equipment or wearable equipment (such as a helmet) or may be or form part of a smart device (e.g. a mobile phone) that may be held by the person.

[0066] The at least one warning alert unit may have a power source and the system may be configured such that, if the warning alert unit is in an unsafe state, the warning alert unit may have enough power from the power source to produce the warning alert.

[0067] This means that the warning alert unit may be able to provide the warning alert to a person whilst, when the system comprises more a plurality of warning alert unit, the rest of the system may defaults to an overall unsafe state and triggers the other warning alert unit or units to produce respective warning alerts.

[0068] The power source may be at least one battery. There may be one or more batteries.

[0069] That is, the warning alert unit may be battery powered. According to a second aspect of the present invention, there is provided a method of detecting a rail vehicle and providing a warning alert, the method comprising: detecting an approaching rail vehicle based on a rail vehicle signal sensed by at least one rail vehicle detector of at least one rail vehicle detection unit; providing a warning alert from at least one warning alert unit in response to the rail vehicle detector sensing the rail vehicle signal, and determining if the warning alert unit is in a safe state indicating that the warning alert unit is functioning or an unsafe state indicating that the warning alert unit is not functioning based on a feedback loop between a control unit and the warning alert unit.

[0070] The method may further comprise determining if the rail vehicle detection unit is in a safe state indicating that the rail vehicle detection unit is functioning or an unsafe state indicating that the rail vehicle detection unit is not functioning based on an additional feedback loop between the control unit and the rail vehicle detection unit.

[0071] The method may further comprise determining that the system is in an overall safe state when no rail vehicle has been detected and the control unit, the warning alert unit and the rail vehicle detection unit are in safe state or an overall unsafe state when an approaching rail vehicle has been detected and / or at least one of the control unit, the warning alert unit and the rail vehicle detection unit are in an unsafe state.

[0072] According to a third aspect of the present invention, there is provided a computer program comprising computer readable instructions configured to cause a processor to carry out a method as described above.

[0073] According to a fourth aspect of the present invention, there is provided a computer readable medium carrying a computer program as described above.

[0074] According to a fourth aspect of the present invention, there is provided a computer apparatus comprising: a memory storing processor readable instructions; and a processor arranged to read and execute instructions stored in said memory; wherein said processor readable instructions comprise instructions arranged to control the computer to carry out a method as described above. The rail vehicle detection or warning system may be considered to be a hazard detection and warning system. It will be appreciated that, where rail vehicle or train is used in this text, hazard may be used instead of (or additionally) to rail vehicle or train, as applicable.

[0075] According to another aspect of the present invention, there is provided a hazard detection and warning system for providing a warning alert, the system comprising: at least one hazard detection unit comprising at least one hazard detector for detecting a hazard based on a hazard signal; at least one warning alert unit, and at least one control unit, wherein the warning alert unit is configured to provide the warning alert in response to the hazard detector sensing the hazard signal, wherein, through a feedback loop between the control unit and the warning alert unit, the system is configured to determine if the warning alert unit is in a safe state indicating that the warning alert unit is functioning or an unsafe state indicating that the warning alert unit is not functioning.

[0076] According to a further aspect of the present invention, there is provided a method of detecting a hazard and providing a warning alert, the method comprising: detecting a hazard based on a hazard signal sensed by at least one hazard detector of at least one hazard detection unit; providing a warning alert from at least one warning alert unit in response to the hazard detector sensing the hazard signal, and determining if the warning alert unit is in a safe state indicating that the warning alert unit is functioning or an unsafe state indicating that the warning alert unit is not functioning based on a feedback loop between a control unit and the warning alert unit.

[0077] Features in one aspect may be applied as features in any other aspect, in any appropriate combination. For example, apparatus features may be applied as method features and vice versa.

[0078] It should be understood that the individual features and / or combinations of features defined above in accordance with any aspect of the present invention or below in relation to any specific embodiment of the invention may be utilised, either separately and individually, alone or in combination with any other defined feature, in any other aspect or embodiment of the invention. Furthermore, the present invention is intended to cover apparatus configured to perform any feature described herein in relation to a method and / or a method of using or producing, using or manufacturing any apparatus feature described herein.

[0079] The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.

[0080] Brief Description of the Figures

[0081] These and other aspects will now be described with reference to the accompanying drawings.

[0082] Figure 1 shows a schematic view of a train detection and warning system according to a first embodiment of the invention;

[0083] Figure 2 shows a more detailed schematic view of the train detection and warning system according to the first embodiment of the invention;

[0084] Figure 3 shows a detailed schematic view of a warning alert unit of the train detection and warning system according to the first embodiment of the invention;

[0085] Figure 4 shows a detailed schematic view of a train detection unit of the train detection and warning system according to the first embodiment of the invention;

[0086] Figure 5 shows a schematic view of the train detection and warning system according to a second embodiment of the invention;

[0087] Figure 6 shows a logic diagram of the train detection and warning system according to a third embodiment of the invention.

[0088] Detailed Description

[0089] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following embodiments, identical or common portions are identically denoted in the figures, and will not be described repeatedly.

[0090] Figure 1 shows a train detection and warning system (TDWS) 1 of the first embodiment for detecting a train 2 which is travelling in the direction shown by arrow 2a. More generally, the TDWS 1 may be considered to be a rail vehicle detection and warning system. It will be appreciated that, where train is mentioned in this text may be replaced with rail vehicles and vice versa, as applicable. The train 2 comprises a train wheel 3 which has a contact point 4 between train wheel 3 and a train track 5. The train track 5 may comprise two rails connected by sleepers (not shown).

[0091] The train 2 being in contact with the train track 5 and moving on the train track 5 induces vibrations 6 in the rails of the train track 5. The vibrations 6 propagate from the train 2 along the rails and are able to be detected a distance along the rails. The vibrations 6 may be considered be a train signal.

[0092] The TDWS 1 (shown in dashed lines) comprises a train detection unit (TDU) 7 for detecting the vibrations 6 propagating through the rail. More generally, the TDU 7 may be considered to be a rail vehicle detection unit. Data 8 may be sent, e.g. wirelessly, from the TDU 7 to a control unit 9. Alternatively, or additionally, the data 8 may be sent via a wired connection.

[0093] A person 10 (e.g. railway track worker or operative) is shown working in an area, e.g. on, adjacent to, or in the vicinity of, the railway track 5. The area that the person 10 is working in may be considered to be a danger or hazard area, e.g. an area that the moving train 2 may pass through that may constitute a danger or hazard to the person 10. The person 10 may be at risk of collision with the approaching train 2. The TDWS 1 includes a warning alert unit (WAU) 11 which is configured to provide a warning alert to the person 10. More generally, the WAU 11 may be considered to be a rail vehicle warning alert unit. It will be appreciated that, in other embodiments, the warning alert may be provided to something other than a person, e.g. to a device, to equipment, to machinery, and / or to a robotic I autonomous vehicle. It will be appreciated that, where person is used in this text, one or more of these other options may be used instead of (or additionally) to person, as applicable. The control unit 9 may be used to manage the TDWS 1 by sending data 8 to and from the TDU 7 and the WAU 11. This data may be sent wirelessly (as shown in this embodiment) or via a wired connection. In embodiments, the TDWS 1 and / or the control unit 9, the TDU 7 and the WAU 11 may be considered to be mobile and / or portable (e.g. may be moved by a person or persons) and reusable in multiple locations. The control unit 9, the TDU 7 and the WAU 11 may each comprise a housing. In this embodiment, the control unit 9 is shown separately to the TDU 7 and the WAU 11. In embodiments, the control unit or at least part of the control unit may be considered to form part of or be within the WAU and / or the TDU. For example, some processing by the control unit may be carried out at the TDU and / or the WAU. The control unit, the TDU and the WAU may each be within a single housing.

[0094] In this embodiment, the TDWS 1 also includes an antenna 12 for sending wireless data 8. This antenna 12 is for receiving data / information from at least one external network (e.g. an external source 13). That is, data 8 can be received into the control unit 9 for use as part of establishing safe working. The antenna 12 is just an example of how train GPS may be received, or other system information that could be incorporated into the function of the TDWS 1. Although, in other embodiments, the TDWS 1 may not include the antenna 12, i.e. it will be appreciated that this is not necessary.

[0095] In this embodiment, the TDWS 1 is configured to receive (via antenna 12) additional or remote information from the external source 13. This information may be used in at least one external feedback loop (e.g. continuous feedback loop) for triggering an overall unsafe state in the TDWS 1. However, it will be appreciated that this is not essential for the TDWS 1 to function. The TDWS 1 may function without requiring any external information and / or any other safety or signalling system. The external source 13 may be considered to be external to the TDWS 1. The external source 13 may be considered to be an additional or remote information source.

[0096] Continuous feedback is important because the environment is potentially changing all the time, e.g. every second. For example, a train may be suddenly a hazard as it is approaching a person.

[0097] In some embodiments, the additional or remote information provided to the TDWS 1 is information provided from externally controlled systems to which the TDWS 1 and / or person 10 has no control. These may include Global Positioning System (GPS) location, Rail Traffic Management Systems (RTMS), European Train Control System (ETCS) or other information sources that may provide the necessary properties of trains 2 approaching the person 10 or persons, for example location, direction, routed path and speed of approach of the train 2. In this embodiment, whilst local elements operating together are used to create the fail safe TDWS 1 , it could also provide warnings based on the external systems providing hazards.

[0098] The TDWS 1 may be configured to default to use the local component or components (e.g. the TDU 7) to avoid a false-negative outcome, e.g. if the additional and / or remote information from the external sources 13 is inaccurate or erroneous. This element of redundancy enhances the safety of the system whilst providing various ways of detecting approaching trains 2 as hazards.

[0099] Figure 2 shows the TDWS 1 in more detail. A rail 5a of the train track 5 is shown and the TDU 7 is fixed or connected to the rail 5a. For example, the TDU 7 may be fixed or connected by magnet, glue, wax adhesive, being directly screwed on, and / or being clamped. The TDU 7 comprises an accelerometer 7.1 and a shaker 7.2. More generally, the accelerometer 7.1 is a vibration detecting sensor (an acoustic sensor being another example) and the shaker 7.2 is a vibration creating transducer. Even more generally, the accelerometer 7.1 may be considered to be a train detection transducer and the shaker 7.2 may be considered to be a train transducer. Furthermore, the accelerometer 7.1 may be considered to be a signal reception unit and the shaker 7.2 may be considered to be a signal transmission unit. The vibration detecting sensor and / or vibration creating transducer may comprise a piezoelectric element. The shaker 7.2 may be an electromagnetic device that may be used for vibration testing for excitation of the structure. The train detection transducer may be a sensor. This transducer may be referred to as a train sensing transducer. The train transducer may be referred to as a train actuator. The train transducer may be referred to as a train signal creating transducer or actuator. More generally, the train detection transducer may be a rail vehicle detector and the train transducer may be a rail vehicle generator. The rail vehicle generator may generate an (electrical) digital signal (the rail vehicle signal) which may be received (electrically) by the rail vehicle detector. The shaker 7.2 and the accelerometer 7.1 may be considered to be a transducer and sensor coupling. The TDWS 1 may comprise a plurality of transducer and sensor couplings. The TDWS 1 may comprise a plurality of train transducer and the train detection sensor couplings.

[0100] The TDU 7 has a battery or more than battery (not shown), i.e. the TDU 7 is battery powered. More generally, the TDU 7 is provided with power from a power source (which may be part of the TDU 7 or may be separate).

[0101] As mentioned above, vibrations 6 are propagated through the rail 5a from an approaching train 2 (i.e. in the direction shown by the arrow 2a). The accelerometer 7.1 is configured to sense the vibrations 6 (i.e. the train signal) of the approaching train 2.

[0102] In embodiments, the TDU 7 may comprise a signal processor arranged for receiving the train signal from the accelerometer 7.1 and determining if an approaching train 2 has been detected based on the train signal. The TDU 7 may be configured to send an indication to the control unit 9 that a train 2 has been detected and the control unit 9, in turn, may relay this to the WAU 11 so that the WAU 11 may provide a warning alert to the person 10.

[0103] In other embodiments, the signal processing of the train signal may be carried out at a signal processor of the control unit 9. In this case, the signal processor of the control unit 9 may be arranged for receiving train detection transducer output signals representing the train signal from the TDU 7. The control unit 9 may be configured to process the train detection transducer output signals and determine if an approaching train 2 has been detected. If it has been determined that a train 2 has been detected then the control unit 9 sends an indication to the WAU 11 that a train 2 has been detected so that the WAU 11 may provide a warning alert to the person 10.

[0104] In embodiments, when it has been determined that a train 2 has been detected by the TDU 7, the TDU 7 may be considered to be in an unsafe state. The unsafe state indicates that a train 2 has been detected. The unsafe state may be determined by the TDU 7 and the state of the TDU 7 may be sent to the control unit 9. In other embodiments, the control unit 9 may determine directly that the TDU 7 is in the unsafe state due to a train 2 being detected. It may be considered that, when the train (vibration) signal of a train 2 is detected, the state of the TDU 7 is set to unsafe, which triggers the overall state of the TDWS 1 to be unsafe.

[0105] Since the TDU 7 is considered to be in the unsafe state, the overall state of the TDWS 1 is also considered to be unsafe. The control unit 9 is configured to communicate the overall state of the TDWS 1 to the WAU 11 such that WAU 11 provides the warning alert when the TDU 7 is in the unsafe state. In embodiments, the overall state of the TDWS 1 may also be communicated to the TDU 7 from the control unit 9.

[0106] In embodiments, the vibration signal processing (i.e. determining if a vibration is a train or not) may take place at the TDU 7 only, and the state I reliability (safe or unsafe, reliable or unreliable) communicated to the control unit 9. However, in embodiments, the control unit 9 may be part of I within the TDU 7. For example, data acquisition signal processors allow software to be run on them. This may be a distinctly separate part of an evaluation cycle so as to enable fail safe loops. In general, the signal processing may be done at the TDU 7 (by at least part of the control unit) or separately (by the control unit 9, with the data being sent from the TDU 7 to the control unit 9).

[0107] The WAU 11 includes a speaker 11.1 for generating the warning alert and a microphone 11.2 for detecting the sound of the warning alert. More generally, the speaker 11.1. is an audible sound creating transducer and the microphone 11.2 is a sound detection transducer. The WAU 11 also includes a light emitting diode (LED) 11.3 for generating the warning alert and a light dependent resistor (LDR) 11.4 for detecting the light of the warning alert. More generally, the LED 11.3 is an electromagnetic radiation creating transducer or a light (e.g. visible light) creating transducer and the LDR 11.4 is an electromagnetic radiation detection transducer or a light (e.g. visible light) detection transducer.

[0108] Even more generally, the speaker 11.1 and the LED 11.3 may be considered to be alert transducers, and the microphone 11.2 and the LDR 11.4 may be considered to be alert detection transducers. Furthermore, the speaker 11.1 and the LED 11.3 may be considered to be signal transmission units, and the microphone 11.2 and the LDR 11.4 may be considered to be signal reception units. It will be understood that the warning alert may comprise, or be a combination of, one or more of audible, visual, and / or tactile alerts. It will be appreciated that, in some embodiments, the WAU 11 may only comprise a single alert transducer and a single alert detection transducer. The alert detection transducer(s) may be a sensor(s). This or these transducer(s) may be referred to as an alert sensing transducer(s). The alert transducer(s) may be referred to as an alert actuator(s). The alert transducer(s) may be referred to as an alert signal creating transducer(s) or actuator(s). More generally, the alert detection transducer(s) may be an alert detector(s) and the alert transducer(s) may be an alert generator(s). The alert generator may generate an (electrical) digital signal (the warning alert) which may be received (electrically) by the alert detector, e.g. of a robot or autonomous vehicle. That is, the warning alert may be considered to be an electric, electrical and / or digital alert. The warning alert may be considered to be an electromagnetic signal (e.g. an optical fibre signal or radio frequency signal).

[0109] The speaker 11.1 and the microphone 11.2 may be considered to be a transducer and sensor coupling. The LED 11.3 and the LDR 11.4 be considered to be a transducer and sensor coupling. The TDWS 1 may comprise a plurality of transducer and sensor couplings. The TDWS 1 may comprise a plurality of alert transducer and alert detection sensor couplings.

[0110] In response to receiving an indication (e.g. from the control unit 9) that a train 2 has been detected by the TDU 7, the WAU 11 provides the warning alert. More particularly, the speaker 11.1 emits the (sound) warning alert and the LED 11.3 emits the (light) warning alert. The warning alert warns the person 10 (or persons) that they are (or may be) unsafe, and they need to move to a safe position (e.g. a specific distance away from the railway track 5).

[0111] The TDU 7 (i.e. the accelerometer 7.1) may be configured to detect the train 2 at a distance sufficient to provide suitable warning for the person 10 to move to a safe location. This means that that a person 10 or persons 10 are not required to walk relatively large distances to set up the safe system of work. For example, a high speed train at 199mph may need 2.6km detection distance, a slow RRV at 20mph may need 270m detection, and a runaway trolley at 40mph may need 550m.

[0112] Figure 3 shows the WAU 11 in more detail. Since the warning alert may be the difference between a serious injury or even death of the person 10, it is important that the WAU 11 is working correctly and, if not, that the person 10 is informed of this. The WAU 11 may be tested to make sure it is functioning (i.e. functioning correctly).

[0113] A predetermined sound control signal alert 11.5 corresponding to the sound warning alert is generated from the speaker 11.1 and, similarly, a predetermined light control signal alert 11.6 corresponding to the light warning alert is generated from the LED 11.3. More generally, the predetermined sound control signal alert 11.5 and the predetermined light control signal alert 11.6 may be considered to be predetermined control signal alerts.

[0114] The predetermined control signal alerts corresponding to the warning alerts may be considered to be similar to the warning alerts, the same type of signal as the warning alerts, be representative of the warning alerts and / or be characteristic of the warning alerts.

[0115] The WAU 11 is considered to be working correctly if both of the predetermined sound control signal alert 11.5 and predetermined light control signal alert 11.6 are detected by the microphone 11.2 and the LDR 11.4 respectively. In this case, the WAU 11 may be considered to be in a safe state indicating that the WAU 11 is functioning (e.g. at least the speaker 11.1 and the LED 11.3 are working). If one or both of the predetermined sound control signal alert 11.5 and predetermined light control signal alert 11.6 are not detected by the microphone 11.2 and the LDR 11.4 respectively, then the WAU 11 is considered to be not working correctly (e.g. the speaker 11.1 and the LED 11.3 may be not working). In this case, the WAU 11 may be considered to be in an unsafe state indicating that the WAU 11 is not functioning. It will be appreciated that, in embodiments where there is only one alert transducer and only one alert detection transducer, then the WAU 11 may be considered to be working correctly (i.e. in the safe state indicating that the WAU is functioning) if the predetermined control signal alert from the single alert transducer is detected by the single alert detection transducer.

[0116] The safe or unsafe state may be determined by the WAU 11 and the state of the WAU 11 may be sent to the control unit 9. This may be considered to be a feedback loop (e.g. continuous feedback loop) or feedback circuit between the control unit 9 and the WAU 11. In other embodiments, the control unit 9 may determine directly that the WAU 11 is in the unsafe state due to one of the predetermined control signal alerts not being detected (or is in the safe state if both of the predetermined control signal alerts are detected). It may be considered that, when the state of the WAU 11 is set to unsafe, this triggers the overall state of the TDWS 1 to be unsafe.

[0117] Since the WAU 11 is considered to be in the unsafe state, the overall state of the TDWS 1 is also considered to be unsafe. In embodiments, the TDWS 1 may comprise a plurality of WAUs 11 (e.g. the WAU 11 that is in an unsafe state and one or more other WAUs 11). The control unit 9 is configured to communicate the overall state of the TDWS 1 to the other WAUs 11 such that the other WAUs 11 provide the warning alert when the WAU 11 is in the unsafe state. In embodiments, the overall state of the TDWS 1 may also be communicated to the TDU 7 from the control unit 9.

[0118] The state of the WAU 11 is evaluated in a continuous cycle driven by the control unit 9 that continues when the TDWS 1 is operating (e.g. during the whole time of operation). If during an evaluation cycle the predetermined control signal alerts are not detected, then the WAU 11 is considered to have failed and the overall state of the system is set to unsafe and this state is sent to the control unit 9. An alert trigger signal to the WAU 11 from the control unit 9 may form part of the evaluation cycle driven by the control unit 9. The alert trigger signal to the WAU 11 triggers the WAU 11 to output the predetermined control signal alerts. The alert trigger signal may be provided in a predetermined timescale (e.g. every 5 seconds).

[0119] If the WAU 11 does not receive the evaluation cycle trigger (i.e. the alert trigger signal) from the control unit 9 when expected (e.g. within the predetermined timescale), then the control unit 9 is considered to have failed (or at least the transmission part of the control unit 9 or the signal receiving part of the WAU 11 has failed) and the WAU 11 defaults to an unsafe state which is sent to the control unit 9. In other words, through at least one control feedback loop (e.g. continuous feedback loop) between the control unit 9 and the WAU 11 , the TDWS 1 is configured to determine if the WAU 11 (and / or control unit 9) is in a safe state indicating that the communication between the control unit 9 and the WAU 11 is functioning or an unsafe state indicating that the communication between the control unit 9 and the WAU 11 is not functioning. The communication failing may be due to either (or both) of the control unit 9 transmission and / or the WAU 11 reception specifically failing. If, at any point, an unsafe state occurs at the WAU 11 and / or an overall unsafe state occurs in the TDWS 1, the warning alert is triggered to inform the person 10 that the overall state of the TDWS 1 is unsafe and they must move to a position of safety. The warning alert may be provided when the control unit 9 is determined to be in the unsafe state (e.g. it is not functioning).

[0120] The unsafe state at the WAU 11 means that the WAU 11 is alerting the person that there is a problem so they can move to safety. The individual WAU 11 still communicates its state (e.g. to the control unit 9). It shouldn’t be assumed that all WAUs 11 have failed to receive the alert trigger signal, so other WAUs 11 might be correctly functioning until told it is unsafe.

[0121] It may be the receiving part on the WAU 11 that failed. So for completeness, the unsafe state of the WAU 11 is sent to the control unit 9. Furthermore, if the control unit 9 somehow receives the unsafe state from one WAU 11 then the control unit 9 is configured to alert all other WAUs 11 that there is an unsafe state. Alternatively, if no message is received from the WAU 11 (because of the first failure) then the overall state of the TDWS 1 would default to unsafe (e.g. the control unit 9 defaults to unsafe which leads to an overall state of the system being unsafe).

[0122] The WAU 11 performs its own evaluation (feedback) loop to ask, ‘have I received an evaluation cycle trigger and what is the system state that came with it (i.e. is it unsafe or safe)’. If the WAU 11 hasn’t received such a request, then it would report to the control unit 9 that something is wrong (unsafe), and emit the warning alert so that the person is alerted.

[0123] When the predetermined control signal alerts are able to be detected by the person 10 (e.g. the sounds are audible and the lights are visible), they can also be used by the person 10 to confirm for themselves that the WAU 11 is functioning.

[0124] In this embodiment, the WAU 11 is or forms part of a helmet. More generally, the WAU 11 forms part of personal protective equipment or wearable equipment. In other embodiments, the WAU may be or form part of a smart device (e.g. a mobile phone) that may be held by the person 10. In other embodiments, the WAU may be a loudspeaker. In embodiments, the WAU may form part of a device, equipment, tools, machinery, and / or a robotic / autonomous vehicle.

[0125] In this embodiment, the WAU 11 is located a distance away from the control unit 9 and the TDU 7. In other embodiments, the WAU 11 may be located with the control unit 9 and / or the TDU 7. The WAU 11 , the control unit 9 and / or the TDU 7 may be integrated into the same unit or may be separate components.

[0126] The WAU 11 has a battery or more than battery (not shown), i.e. the WAU 11 is battery powered. More generally, the WAU 11 is provided with power from a power source (which may be part of the WAU 11 or may be separate). If the WAU 11 is in an unsafe state, the WAU 11 has enough power from the battery to produce the warning alert. This means that, if the WAU 11 stops functioning (i.e. goes into an unsafe state), the WAU 11 will be able to provide the warning alert to the person 10 whilst, in embodiments where the TDWS 1 has more than one WAUs 11 , the rest of the TDWS 1 defaults to an overall unsafe state and triggers the other WAU 11 or WAUs 11 to produce respective warning alerts.

[0127] In embodiments, the TDWS 1 may comprise or may be connected to equipment, such as tools, machinery and robotic or autonomous devices (not shown), e.g. in use by the person 10 or persons. The TDWS 1 is configured to communicate with the equipment such that, if the overall state of the TDWS 1 is unsafe and / or the warning alert has been provided, the equipment stops working or moves to a position of safety. The WAU 11 may be linked with the equipment such that, when the warning alert is provided, a kill-switch is activated for the equipment. This may provide further notification (e.g. an additional warning device) to the person 10 that there is an overall unsafe state or a train 2 is approaching.

[0128] In embodiments, the TDWS 1 may be configured such the WAU 11 is removable from operating in the TDWS 1 without the TDWS 1 being considered to be in an overall unsafe state due to this removal. For example, if there were 5 people working and one person needed to leave, the control unit 9 may identify the specific WAU 11 of the person leaving and discount it from the evaluation cycle loops. E.g. select WAU #5 to remove from system, a button on WAU #5 flashes and then the button on the WAU may be pressed such that the WAU 11 disconnects itself and powers down. The control unit 9 then continues to perform evaluation on WAlls #1-4. This allows a person 10 or persons to leave an area where they are working (i.e. disconnecting their WAU 11) whilst maintaining the integrity of the TDWS 1. This may be most useful and / or evident where the TDWS 1 includes a plurality of WAlls 11.

[0129] In embodiments, the WAU 11 may comprise an accelerometer (not shown). Through the use of the accelerometer, the WAU 11 may be configured to provide data / information to the TDWS 1 (e.g. the control unit 9) on whether the worker is moving (i.e. whether the WAU 11 is moving). Thus, the control unit 9 and / or other WAUs 11 may be made aware if an individual is not moving (e.g. may be unwell) and may need assistance. More generally, the WAU 11 may comprise a (wearable) health monitor, such as a smart watch. The health monitor may comprise a thermometer, a oximeter, a heart rate monitor etc. This may be used to provide information on the health of the worker, e.g. heart rate, oxygen levels etc., as well as, or alternatively to, determining if the worker is moving through use of the accelerometer. It will be appreciated that, in embodiments, the accelerometer may be included in the wearable health monitor. The health monitor and / or accelerometer may be considered to be a worker status monitor.

[0130] Figure 4 shows the TDU 7 in more detail. Similarly as with the WAU 11, the TDU 7 may be tested to check if it is functioning. Again, it is important for the person 10 to know that the TDU 7 is functioning and thus an approaching train 2 will be detected.

[0131] A predetermined control train signal 7.3 corresponding to the train signal 6 is generated from the shaker 7.2. The predetermined control train signal 7.3 may be considered to be test vibrations in the rail 5a, e.g. used to confirm that the accelerometer 7.1 is working. The signal from the shaker 7.2 or 'signal transmission unit' is input to the rail, allowing a known signature to be detected by the accelerometer 7.1 or 'signal reception unit'. In embodiments, this allows the transfer function to be determined and changes to the signal to be measured which e.g. characterises the particular section of rail in use. This enables calibration of the system and improves performance of hazard detection as well as confirms the continued operation of the alert detection transducer (or sensor) that forms part of the fail safe continuous evaluation. The TDU 7 is considered to be working correctly if the predetermined control train signal 7.3 is detected by the accelerometer 7.1. In this case, the TDU 7 may be considered to be in a safe state indicating that the TDU 7 is functioning (e.g. at least the accelerometer 7.1 is working). If the predetermined control train signal 7.3 is not detected by the accelerometer 7.1, then the TDU 7 is considered to be not working correctly (e.g. the accelerometer 7.1 may be networking). In this case, the TDU 7 may be considered to be in an unsafe state indicating that the TDU 7 is not functioning.

[0132] The safe or unsafe state may be determined by the TDU 7 and the state of the TDU 7 may be sent to the control unit 9. This may be considered to be an additional feedback loop (e.g. continuous feedback loop) or feedback circuit between the control unit 9 and the TDU 7. In other embodiments, the control unit 9 may determine directly that the TDU 7 is in the unsafe state due to predetermined control train signal 7.3 not being detected (or is in the safe state if the predetermined control train signal 7.3 is detected). It may be considered that, when the state of the TDU 7 is set to unsafe, this triggers the overall state of the TDWS 1 to be unsafe.

[0133] Since the TDU 7 is considered to be in the unsafe state, the overall state of the TDWS 1 is also considered to be unsafe. In embodiments, the TDWS 1 may comprise a plurality of TDUs 7 (e.g. the TDU 7 that is in an unsafe state and other TDUs 7) - see e.g. Figure 5. The control unit 9 is configured to communicate the overall state of the TDWS 1 to the WAU 11 or WAUs 11 such that the WAU(s) 11 provides the warning alert when the TDU 7 is in the unsafe state. In embodiments, the overall state of the TDWS 1 may also be communicated to the other TDUs 7 from the control unit 9.

[0134] The state of the TDU 7 is evaluated in a continuous cycle driven by the control unit 9 that continues when the TDWS 1 is operating. If during an evaluation cycle the predetermined control train signal 7.3 is not detected, then the TDU 7 is considered to have failed and the overall state of the system is set to unsafe and this state is sent to the control unit 9. A train trigger signal to the TDU 7 from the control unit 9 may form part of the evaluation cycle driven by the control unit 9. The train trigger signal to the TDU 7 triggers the TDU 7 to output the predetermined control signal alert. The train trigger signal may be provided in a predetermined timescale (e.g. every 5 seconds). Similar to as with the WAU 11, if the TDU 7 does not receive the evaluation cycle trigger (i.e. the train trigger signal) from the control unit 9 when expected (e.g. within the predetermined timescale), then the control unit 9 is considered to have failed (or at least the transmission part of the control unit 9 or the signal receiving part of the TDU 7 has failed) and the TDU 7 defaults to an unsafe state which is sent to the control unit 9. In other words, through at least one control feedback loop (e.g. continuous feedback loop) between the control unit 9 and the TDU 7, the TDWS 1 is configured to determine if the TDU 7 (and / or control unit 9) is in a safe state indicating that the communication between the control unit 9 and the TDU 7 is functioning or an unsafe state indicating that the communication between the control unit 9 and the TDU 7 is not functioning. The warning alert may be provided when the TDU 7 (and / or the control unit 9) is determined to be in the unsafe state (e.g. it is not functioning). The communication failing may be due to either (or both) of the control unit 9 transmission and / or the TDU 7 reception specifically failing.

[0135] The error message (unsafe state of the TDU 7) should be sent to the to the control unit 9 so that, if it was the receiving part of the TDU 7 that failed, then the control unit 9 may not be aware of this unless it is informed of this.

[0136] When data 8 is sent and received from the control unit 9 (and / or where the control unit 9 is processing data), the overall state of the TDWS 1 may be evaluated as safe or unsafe. The TDWS 1 may be considered to be in an overall safe state when no train 2 has been detected and the control unit 9, the WAU 11 and the TDU 7 are in the safe state. The TDWS 1 may be considered to be in an overall unsafe state when an approaching train 2 has been detected and / or at least one of the control unit 9, the WAU 11 and the TDU 7 are in the unsafe state. It will be appreciated that the unsafe state of the TDU 7 may comprise either or both of the unsafe state indicating that the TDU 7 is not functioning and / or the unsafe state indicating that the TDU 7 has detected a train 2.

[0137] When the overall state of the TDWS 1 is safe, normal continuous operation continues and the control unit 9 triggers evaluation cycles to start. The control unit 9 sends the overall state of the TDWS 1 and a trigger to evaluate operation to the TDU(s) 7 and the WAU(s) 11. During an evaluation cycle, should no information be received back from a WAU 11 or a TDU 7, that evaluation cycle is considered to have failed and the overall state of the TDWS 1 will be set to unsafe. During an evaluation cycle, should a WAU 11 or a TDU 7 declare an unsafe state due to it being determined that the WAU 11 or TDU 7 is not functioning (i.e. that it is unreliable for safety), then the evaluation cycle is considered to have been successful but the overall state of the TDWS 1 will be set to unsafe. In practical terms, each outcome will have its own unique error code and success code so that fault finding is easy to do during manufacture testing and operation.

[0138] At any point that an unsafe state occurs, the state is immediately sent to the WAU 11 or all WAUs 11 and warning alerts are produced by the WAU 11 or all WAUs 11. In embodiments, the state may also be sent to the TDU 7 or all TDUs 7.

[0139] In embodiments, the control unit 9, the WAU 11 and the TDU 7 may be considered to be three separate things each asking the questions: 1. “Have I evaluated myself as functioning?” and 2. “Have I been informed that everything else is functioning?”. The control unit 9 starts an evaluation cycle, and expects some responses back from the WAU 11 and TDU 7 within a predetermined timescale, e.g. 5 seconds. The TDU 7 will either be functioning reliably and either be in a safe state or have triggered a train detected, so a unsafe state, or it will be unreliable having not detected the control signal and set the state to unsafe. The WAU 11 will either be functioning reliably and have detected the control signal (safe state) or will be emitting a warning alert signal, e.g. because it has been told to do so. Alternatively, the WAU 11 will be not reliable and have failed to detect the control signal and therefore set the state to unsafe, and thus will be emitting a warning alert signal.

[0140] It will be appreciated that the TDWS 1, through the provision of the control unit 9, the TDU 7 and the WAU 11 as described, has an advantage of providing a fail-safe system for detecting trains and providing warning alerts, e.g. to workers on a railway track. A fail-safe system may be considered to be a system that, even if it fails (e.g. even if one or more of the (key) components of the system fails (i.e. stops working), is still safe. For example, safe for the workers using the system as they are informed of the failure of the component or components and can thus take steps accordingly to keep themselves safe from harm. A fail-safe environment is established in which workers are continuously informed that they can either safely operate or need to evacuate the area. The TDWS 1 is a complete safety system that is mobile, portable and quick to set up for use. The TDWS 1 will identify approaching trains 2 as hazards to workers (persons 10) local to the work area. Through the series of feedback loops (e.g. continuous feedback loops), the TDWS 1 identifies any failures in the key elements (e.g. TDU 7 and WAU 11) of the TDWS 1 as a hazard and triggers an unsafe (and / or overall unsafe) state. On identification of the unsafe (and / or overall unsafe) state, the TDWS 1 provides warning to the workers enabling them to vacate the hazardous area to a place of safety. When there is no longer a safety concern or hazard, the TDWS 1 returns to an overall safe state, and the TDWS 1 allows the workers to resume activity until another hazard or safety concern is identified.

[0141] For a track worker warning system to be effective and fully fail-safe, there are two important processes that should be fully operational at all times. These are, firstly knowing that the train sensing elements (i.e. the TDlls 7) are working, and, secondly, knowing that the warning alerts (i.e. from the WAlls 11) are working. Due to workers being on a live railway, should either of these processes fail, the workers will be unaware of when a train 2 is approaching them and therefore, be in a potentially unsafe position.

[0142] The whole process of detecting a train 2, processing the data / information and warning workers has been taken into consideration with the result being a single TDWS 1 of combined elements that is entirely fail-safe, i.e. the operation of each part of the TDWS 1 (e.g. the control unit 9, the TDU 7 and the WAU 11) is continually assessed to confirm safe or unsafe operation. The TDWS 1 addresses at least some or all failure modes associated with existing train warning systems and methodologies causing a safety risk for track workers.

[0143] Advantages of the TDWS 1 include improving worker safety when working on the railway (e.g. improving reliability of the safety system), reducing the time required to establish the protection methods as part of the declared safe system of work on the railway (e.g. improving the ratio of ‘set up time’ to ‘time on tools’), enhancing the capacity to operate the railway and run trains, and improving reliability and efficiency in a railway network though implementation of this technology. The TDWS 1 allows the safe passage of trains and a safe working environment for track side workers on the railway.

[0144] When passively waiting to detect hazardous vibration signals from trains 2, it is important that functionality of the sensor or sensors in use are confirmed regularly by using a known control vibration for the sensor to detect. When passively waiting for the system to generate warning alerts, it is important that functionality of the warning alert transducer is confirmed regularly by a sensor detecting a known control alert. In embodiments, confirmation of functionality and successful operation of the TDWS 1 is achieved by using transducer - sensor couplings in each of the TDU 7 and the WAU 11, which are linked through the control unit 9.

[0145] For safety reasons, it is important to test all the key parts of the system in order to make the full system fail-safe. For example, only testing the train detection vibration sensors for proper operation using a known sound pattern input into the track rail does not consider the entire system and therefore again falls short of full system fail-safe operation. However, it will be appreciated that having only part of the system functioning (e.g. having only the WAU 11 transducer - sensor couplings testing the functionality of the WAU 11 may provide some benefits and advantages, albeit they may not be to as much of an extent as having the full system functioning (e.g. with the TDU 7 transducer - sensor couplings testing the functionality of the TDU 7). It may be considered that the TDWS 1 comprises individual systems (e.g. safety systems) that are combined together and may, e.g. improve safety compared to those individual safety systems functioning separately. That is, individual safety systems (e.g. safety system that that allows confirmation to be made that the train detection system is functioning or safety system that allows confirmation to be made that a warning alert system is functioning) may be connected together to form a larger system. Furthermore, individual systems (that may be combined) may include the train detection system that detects the trains and the warning alert system that warns the workers.

[0146] Previously, methods to protect track workers on live railway (‘red zone’) may include automatic train warning systems (ATWS) in which sensors detect an approaching train and a warning alert is provided to workers. However, this ATWS had limitations that any element of the system could fail and the rest of the warning system would be unaware of the failure. This method is therefore not fail-safe.

[0147] Previous technology exists in disparate forms and have a number of failure modes limiting the safety of the workers. There are methods available to detect the presence of an approaching train as a hazard. There are methods to alert workers of approaching trains. However none of these previous methods have eliminated all failure modes to provide a complete system of protection for the workers.

[0148] When workers arrive at a railway work area, safe systems of work (SSOW) are required to be established to protect the workers present. Establishing SSOW quickly is important to support completion of the required work under time sensitive circumstances. Previously, methods typically involved walking large distances in the order of hundreds of metres to establish protection for the workers to create the SSOW.

[0149] Furthermore, previously, methods typically required either closure of the railway or the signaller to stop their normal duties and grant the access. This can cause delays to trains.

[0150] Figure 5 shows a TDWS 1 according to a second embodiment of the invention. In this embodiment, there are three separate sections of track 5. The TDWS 1 includes three TDlls 7, with each TDU 7 being placed on a separate section of the track 5. For example, this may allow the person 10 working on the central section of the track 5 to be provided with a warning alert when the train 2 is on or approaching that section of the track 5. Furthermore, this may provide some level of redundancy in case one of the TDlls 7 is not working. A single WAU 11 is shown for a single person 10, but it will be appreciated that there may be a plurality of WAlls 11 e.g. for a plurality of persons 10. The WAlls 11 may be linked to only one of the TDlls 7 or may be linked to a plurality or all of the TDUS 7. The TDWS 1 may be set up so that, if one of the TDUs 7 detect a train 2, then only some (e.g. only those linked to the TDU 7 that detected the train 2) or all of the WAUs 11 of the TDWS 1 may provide a warning alert. Thus, a plurality of parts of TDWS 1 (in this case a plurality of TDUs and a plurality of WAUs 11) may be combined together to form an even larger system. Furthermore, although a single control unit 9 is shown, it will be appreciated that, in embodiments, there may be a plurality of control units 9, e.g. which may work separately or in combination.

[0151] Figure 6 shows a logic diagram of the TDWS 1 according to a third embodiment of the invention. The diagram shows example logic of how the TDU 7, the control unit 9 (CU) and WAU 11 may interact with each other to determine if they are functioning or not and therefore safe or unsafe. Furthermore, the diagram shows example logic to determine whether a train has been detected or not and therefore whether it is safe or unsafe to be working. It will be appreciated that this diagram is just illustrative and in other embodiments, there may be different set ups. This diagram shows data or information being communicated between the control unit 9 (CU), the TDU 7, the WAU 11 and the additional or remote information source 13. For example, it is determined if the TDU 7 and / or the WAU 11 is in safe or unsafe state and this is communicated to the control unit 9. Furthermore, the determination by the control unit 9 on whether the state (or overall state of the TDWS 1) is safe or unsafe and the communication of this state to the TDU 7 and WAU 11 is shown. In addition, evaluation cycle and control signal processes for both the TDU 7 and the WAU 11 are illustrated.

[0152] In this embodiment, if the additional or remote information source 13, such as European Train Communication System (ETCS), Rail Traffic Management Systems (RTMS) or Global Positioning System (GPS) information provides a notification of a hazard (e.g. an approaching train 2), then the TDWS 1 could use that as a trigger for an unsafe state (or unsafe overall state) at the control unit 9, which subsequently alerts the person 10 or persons of the unsafe state.

[0153] It will be appreciated by persons skilled in the art that various modifications may be made to the above embodiments without departing from the scope of the present invention as defined by the claims. Similarly, features from different embodiments, examples or aspects may be combined with those of other embodiments, examples or aspects.

[0154] It will be appreciated that, although the above description is generally related to the railway, and detecting trains that may cause a hazard, in other embodiments, the system may be for or adapted to detect and warn of other hazards. For example, hazards that occur in different environments and circumstances. Hazards for rail related example may be Road Rail Vehicles performing construction duties, Slow moving Rolling Stock Train movements in stabling yards, ‘Run away’ rail mounted trolleys that have lost control and are travelling downhill in an otherwise ‘closed’ section of railway where workers would not expect trolleys to hit them. Other examples may be a harbour or port authority detecting waterborne vibration and continuously assessing for approaching boats, preparing them for an arrival or alerting them to unwanted arrivals. Further examples may be highways I road maintenance using a motion detection trigger or light detection trigger to alert road workers to approaching vehicles on roads. Thus, more generally, the TDWS 1 may be considered to be a hazard detection and warning system for providing a warning alert, the system comprising at least one hazard detection unit comprising at least one hazard detection transducer for detecting a hazard based on a hazard signal. The system also comprising at least one warning alert unit, and at least one control unit. The TDU may be considered to be a hazard detection unit (HDU).

[0155] Embodiments, or features of such, can be implemented as a computer program product for use with a computer system, the computer program product being, for example, a series of computer instructions stored on a data recording medium, such as a disk, CD-ROM, ROM, or embodied in a computer data signal, the signal being transmitted over a tangible medium or a wireless medium, for example, microwave or infrared. The series of computer instructions can constitute all or part of the functionality described above, and can also be stored in any memory device, volatile or non-volatile, such as semiconductor, magnetic, optical or other memory device.

[0156] It will also be well understood by persons of ordinary skill in the art that whilst embodiments implement certain functionality by means of software, that functionality could be implemented solely in hardware or by a mix of hardware and software. As such, embodiments are not limited only to being implemented in software.

Claims

CLAIMS:

1. A rail vehicle detection and warning system for providing a warning alert, the system comprising: at least one rail vehicle detection unit comprising at least one rail vehicle detector for detecting an approaching rail vehicle based on a rail vehicle signal; at least one warning alert unit, and at least one control unit, wherein the warning alert unit is configured to provide the warning alert in response to the rail vehicle detector sensing the rail vehicle signal, wherein, through a feedback loop between the control unit and the warning alert unit, the system is configured to determine if the warning alert unit is in a safe state indicating that the warning alert unit is functioning or an unsafe state indicating that the warning alert unit is not functioning.

2. The system according to claim 1, wherein the warning alert unit comprises at least one alert generator for generating the warning alert and at least one alert detector for detecting the warning alert, wherein the warning alert unit is configured to output, from the at least one alert generator, a predetermined control signal alert corresponding to the warning alert, wherein, the system is configured to determine, dependent on the predetermined control signal alert being detected by the at least one alert detector, that the warning alert unit is in the safe state.

3. The system according to either of claims 1 or 2, wherein, through an additional feedback loop between the control unit and the rail vehicle detection unit, the system is configured to determine if the rail vehicle detection unit is in a safe state indicating that the rail vehicle detection unit is functioning or an unsafe state indicating that the rail vehicle detection unit is not functioning.

4. The system according to claim 3, wherein the rail vehicle detection unit comprises at least one rail vehicle generator for generating a predetermined control rail vehicle signal,wherein the rail vehicle detection unit is configured to output, from the at least one rail vehicle generator, a predetermined control rail vehicle signal corresponding to the rail vehicle signal, wherein, the system is configured to determine, dependent on the predetermined control rail vehicle signal being detected by the at least one rail vehicle detector, that the rail vehicle detection unit is in the safe state.

5. The system according to any of claims 2 to 4, wherein the control unit is configured to output an alert trigger signal to the warning alert unit to trigger the warning alert unit to output the predetermined control signal alert.

6. The system according to claim 4 and claim 5 when dependent on claim 4, wherein the control unit is configured to output a rail vehicle trigger signal to the rail vehicle detection unit to trigger the rail vehicle detection unit to output the predetermined control rail vehicle signal.

7. The system according to either of claims 5 or 6, wherein, through at least one control feedback loop between the control unit and the warning alert unit and / or the control unit and the rail vehicle detection unit, the system is configured to determine if the respective warning alert unit and / or rail vehicle detection unit is in a safe state indicating that communication between the control unit and the respective warning alert unit and / or rail vehicle detection unit is functioning or an unsafe state indicating that communication between the control unit and the respective warning alert unit and / or rail vehicle detection unit is not functioning.

8. The system according to claim 7, wherein the system is configured to determine, dependent on the alert trigger signal and / or the rail vehicle trigger signal from the control unit being received by the warning alert unit and / or the rail vehicle detection unit respectively within a predetermined timescale, that the respective warning alert unit and / or rail vehicle detection unit is in the safe state.

9. The system according to any preceding claim, wherein the system is configured to determine that the system is in an overall safe state when no rail vehicle has been detected and the warning alert unit and the rail vehicle detection unit are in the safe state, or an overall unsafe state when an approaching rail vehicle has been detectedand / or at least one of the warning alert unit and the rail vehicle detection unit are in the unsafe state.

10. The system according to claim 9, wherein the system is configured to communicate the overall state of the system to the warning alert unit such that the warning alert unit provides the warning alert when the rail vehicle detection unit and / or another warning alert unit is in an unsafe state.

11. The system according to either of claims 9 or 10, the system is configured such that the at least one warning alert unit is removable from operating in the system without the system being considered to be in an overall unsafe state.

12. The system according to any of claims 9-11, wherein the system is configured to communicate with equipment such that, if the overall state of the system is unsafe and / or the warning alert has been provided, the equipment stops working or moves autonomously to a position of safety.

13. The system according to any of claims 9-12, wherein the system is configured to receive additional and / or remote information from external sources in at least one external feedback loop for triggering an overall unsafe state in the system.

14. The system according to any of claims 1-13, wherein the system is configured to function without requiring any external information and / or any other safety or signalling system.

15. The system according to any preceding claim, wherein the system is configured to be installed or is installable in an area where work is being carried out.

16. The system according to any preceding claim, wherein the at least one rail vehicle detector is configured to detect the rail vehicle at a distance sufficient to provide suitable warning time.

17. The system according to any preceding claim, wherein the feedback loop, the additional feedback loop, the at least one control feedback loop, and / or the at least one external feedback loop is continuous.

18. The system according to any preceding claim, wherein the warning alert comprises at least one of audible, visual, electric, electromagnetic, electronic, digital and / or tactile alerts.

19. The system according to any preceding claim, wherein the at least one warning alert unit has a power source and the system is configured such that, if the warning alert unit is in an unsafe state, the warning alert unit has enough power from the power source to produce the warning alert.

20. A method of detecting a rail vehicle and providing a warning alert, the method comprising: detecting an approaching rail vehicle based on a rail vehicle signal sensed by at least one rail vehicle detector of at least one rail vehicle detection unit; providing a warning alert from at least one warning alert unit in response to the rail vehicle detector sensing the rail vehicle signal, and determining if the warning alert unit is in a safe state indicating that the warning alert unit is functioning or an unsafe state indicating that the warning alert unit is not functioning based on a feedback loop between a control unit and the warning alert unit.

21. The method according to claim 20, further comprising determining if the rail vehicle detection unit is in a safe state indicating that the rail vehicle detection unit is functioning or an unsafe state indicating that the rail vehicle detection unit is not functioning based on an additional feedback loop between the control unit and the rail vehicle detection unit.

22. The method of either claims 20 or 21, further comprising determining that the system is in an overall safe state when no rail vehicle has been detected and the control unit, the warning alert unit and the rail vehicle detection unit are in safe state or an overall unsafe state when an approaching rail vehicle has been detected and / or at least one of the control unit, the warning alert unit and the rail vehicle detection unit are in an unsafe state.

23. A computer program comprising computer readable instructions configured to cause a processor to carry out a method according to any one of claims 20-22.

24. A computer readable medium carrying a computer program according to claim 23.

25. A computer apparatus comprising: a memory storing processor readable instructions; and a processor arranged to read and execute instructions stored in said memory; wherein said processor readable instructions comprise instructions arranged to control the computer to carry out a method according to any one of claims 20-22.

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