GB2355330A - Warning system - Google Patents

Abstract

A warning system for providing a warning of the presence of a danger, such as adverse environmental conditions, is disclosed. The warning system comprises a plurality of components including a warning sign (44) for providing a visual warning, and signal communications apparatus. The signal communications apparatus sends a signal to the warning sign to switch on, when it receives a warning signal indicating the presence of a danger. In a preferred embodiment, the warning sign (44) includes a controller (40) which receives communications from the signal communications apparatus through an aerial (46). The warning sign (44) further includes a power supply, and a power control circuit which continually monitors the state of charge of the power supply and controls the consumption of power. The power supply is preferably constantly recharged using a renewable energy source such as a wind generator or solar panels. The system is particularly suitable for use in detecting high wind conditions at remote locations on a railway network. When used for this purpose, the system additionally includes a wind monitor , circuitry for monitoring the output of the wind monitor and determining the wind speed, and for sending a warning signal to the signal communications apparatus when the determined wind speed exceeds a threshold.

Description

2355330 WARNING SYSTEM The present invention is concerned with a warning

system, and in particular a system for the detection of adverse environmental conditions and for providing a warning when such conditions are detected The present invention will be described primarily in relation to a system for detecting high wind at a location on a railway network, but it will be appreciated that the system is more generally applicable. For example, the system could be used to detect other adverse environmental conditions on a railway network or on other networks such as road networks.

High wind conditions pose a threat to railway systems, which use overhead cables. In particular, the electrical cable tends to sway in high winds, and the fast moving train tends to rock from side to side. This combined effect can lead to the electrical pick up pan mounted on the train, which normally moves beneath the electrical cables, sliding over the electrical cable, thus ripping down the overhead cable. The resulting damage can be expensive to repair and can lead to sections of the railway network being out of action for considerable periods of time. For remote locations, it may be difficult even to gain access to the section of the railway network for repair.

Previously, this problem has been addressed by introducing a blanket speed limit for trains running on sections of the railway network when high wind is forecast in the area. The reduction in speed of the trains ensures that the pick-up pan remains in physical and electrical contact beneath the overhead cable and cannot rip the cable down.

However blanket speed restrictions based on a weather forecast can lead to the unnecessary operation of trains at reduced speeds with consequential delays in the train timetable. In particular, delays can be caused by speed reduction in areas of the network, which are not affected by high wind. In addition, speed restrictions may be 2 in place both before and after high winds are present in the relevant areas of the network.

Furthermore, when a blanket speed restriction is imposed, train drivers are typically' informed by a railway signal operator using trackside telephones. This method of communication involves the signal operator providing a red signal ahead of the train to stop the train and the train driver dismounting the train to gain access to the trackside telephone. This is a time consuming method, which causes delays and poses a risk to the safety of train drivers from passing trains, on adjacent track.

A first aspect of the present invention aims to address these problems by providing a high wind detection system, which detects wind speed in localised areas of the railway network. The system further provides a warning signal to instruct train drivers to reduce speed in areas where high winds are present, when high winds are detected in those areas, Another aspect of the present invention aims to provide a safe and convenient method for communication between signal operators and train drivers on a railway network.

Embodiments of the present invention will now be described, with reference to the accompanying drawings, in which: Figure I is a front view of a wind monitoring station in accordance with an embodiment of the present invention; 25 Figure 2 is a front view of a trackside warning sign station in accordance with an embodiment of the present invention, and Figure 3 is a flow diagram illustrating the operation of the communication system of 30 an embodiment of the present invention.

A high wind detection system forming an embodiment of the present invention comprises three main parts, a wind monitoring station; trackside warning signs, and a signal box communications console, which are described in detail below. These parts are linked in a secure communications network, and each part includes a processor for controlling the functions of the part, and the necessary apparatus for communicating with every other part in a manner which maintains the integrity of communications, as described below.

The system of the embodiment further includes a central control and monitoring station, or "Engineer Station" for monitoring of the system by engineers. The central control and monitoring station not only enables the monitoring of system operation, but also enables engineers to remotely communicate with, and control, the various parts of the network.

The system includes power management systems, which ensure that the systen-4 and its individual parts, consumes minimal power. This is particularly important at remote locations without mains power.

An important aspect of the system include the mechanisms for ensuring secure communication and verifying the detection of adverse wind speeds, thus preventing the occurrence of false alarms. In addition, optional mechanisms are provided to protect the system from tampering.

The three main parts of the high wind detection system forming an embodiment of the present invention will now be described.

Wind Monitorin%x Statio Figure 1 illustrates the wind monitoring station 10, which comprises a mounting 12 having a concrete base 14, a vertically extending post 16 with a control box 20, for housing control and communications apparatus, and a solar panel 22 mounted 4 thereon. An anemometer 24 of conventional type and a communications aerial 26 are mounted on a platform 25 located on the top of the post 16.

The wind monitoring station 10 is adapted for use in remote locations. In particular the station has a self-contained power generating and management system including an integral rechargeable electric power cell (not shown), located within the control box 20, and high performance solar panels 22 for recharging the cell during daylight hours.

Furthermore, since the wind monitoring station 10 is principally for use at exposed sites, which are susceptible to high winds, the mounting post and mountings are designed to endure extreme weather conditions.

The anemometer 24 provides an output signal indicative of the Wind speed to the apparatus within the control box 20, which includes an electronics control board having a processor for inter alia analysing the output of the anemometer 24 as well as controlling the functions of the station 10. In particular, the processor is adapted to continuously monitor the output from the anemometer 24 to determine, in the manner described below, whether high winds are present. If high winds are found to be present, then the processor outputs a signal to the communications control board, also in the control box which, will cause a high wind warning signal to be sent through the aerial to the central control and monitoring station, the local railway signal box and/or the warning sign stations, as described below.

The continuous output signal of the anemometer 24 is processed using a specially designed method, implemented in the form of a computer program, to determine the presence of high winds. The method ensures that false alarms do not arise in response to short term gusts of wind.

The method assumes a predetermined wind speed, which is considered to be high, that is, which is considered to pose a threat to the railway network in the local area. This predetermined wind speed corresponds to the wind speed conventionally used by forecasters to determine whether a blanket speed restriction should be imposed, and is herein referred to as the "threshold wind speed".

The method works on the principle that if the wind level is at or above the threshold wind speed for a continuous period of time, for example 2 minutes, then a high wind speed condition exists which poses a threat to the railway system.

It has been found that the presence of high winds can be successfully determined over time periods within the range 30 seconds to 5 minutes and preferably over a time period of 2 minutes. It has further been found that the threshold wind speed is in the range 20 to 30 mph, and preferably 22mph, in order to avoid the risk of damage to overhead cable.

By way of example, assume a threshold wind speed of 22mph and a time period of 2 minutes. The wind speed detected by the anemometer 24 is continuously monitored.

If the wind speed reaches 22mph a timer is started, which continues to count time whilst the wind speed is greater than or equal to 22mph. If the wind speed falls below 22mph the timer is stopped and run in reverse, that is it'deducts time from the count.

Only when the timer reaches a count of 2 minutes is a high wind condition detected.

Warning Sign Station Figure 2 illustrates a warning sign station 3)0 of which two are typically employed at each site. The warning sign station 30 comprises a sign 44 comprising an array of LEDs mounted on a panel to display an appropriate warning indication to train drivers. In the illustrated embodiment the sign displays the words "FUGH WIND 80 WIT' indicating to the driver that the speed limit is 80 mph.

The sign 44 is secured to a mounting 32 having a concrete base 34, a vertically extending post 36 with a control box 40 mounted thereon for housing the 6 communications and control apparatus for the station 3) 0. A wind-powered generator 42 is mounted on to'p of the post and generates electricity for charging an electric power cell (not shown) provided within the control box 40 of the station 30. A communications aerial 46 is mounted on the panel.

When the warning sign station 30 receives a high wind warning signal originating from the associated wind monitoring station 10, as described below, through the aerial 46, the processor within control box 40 illuminates the LEDs in a controlled manner.

In particular, the illumination is pulsed so that the LEDs are simultaneously illuminated at a frequency in the range of 60 to 100 times a minute, and preferably 80 times per minute. It has been found that the flashing sign is eye- catching and draws the attention of train drivers more quickly than a constantly illuminated sign. In addition, the use of a flashing sign provides power saving advantages.

Furthermore, a light intensity sensor (not shown) is located on the sign and constantly measures ambient light and adjusts the brightness of the LEDs according to the level of ambient light to achieve maximum visibility to train drivers. This is particularly advantageous for operation of the system during dark mornings and evenings in the winter as well as daytime and nighttime operation. In particular, if the LEDs were operated at their standard maximum luminosity, as required in bright sunshine, the light output of the sign at darker times would be too intense for the sign to be read at a distance, and there would also be a danger of dazzling the approaching driver.

Furthermore, unnecessary power would be consumed.

The adjustment of the brightness of the LEDs is controlled by programming the processor with a computer program which processes the output signal received from the light intensity sensor and calculates the level of brightness necessary for maximum visibility of the LEDs. The program ensures that the LEDs are dimmed to an appropriate level in relation to the ambient light to ensure optimal visibility.

7 The warning sign station 30, like all other parts of the system, includes communications apparatus within control box 40 to allow it to receive signals from the other parts of the system and to send signals concerning its status to other parts of the system, as described in more detail below.

SigLial box communications console The communications console includes communications apparatus to receive signals from the other parts of the system and concerning their status. The communications console is principally designed to allow the signal operator to be informed when the wind monitoring station detects high winds and when the warning signs are activated.

The console preferably includes a panel, which includes a plurality of lights, each assigned to a separate part of the system. When the relevant part of the system is activated, for example when a particular wind monitoring station detects high winds and sends a signal to the communications console, the corresponding light on the console panel is automatically illuminated, as described below, thus providing a visual signal to the signal operator. An audible signal may also be provided simultaneously with the visual signal. In addition, the console processor may, as well as controlling the functions of the console, collate data received from the other parts of the system. For example, the data may include information such as battery status; wind speed status and system alert condition.

The high wind detection system of the present invention employs a special, fully automatic, commur&ations method and protocol in accordance with the present invention, which ensures that commands are verified before being executed. This ensures integrity of the communications within the system. It will be appreciated that this aspect of the present invention is widely applicable to communications systems, which require secure communication between components.

The communications method and protocol will now be described, in the context of the high wind detection system according to the embodiment of the present invention.

8 Communications method and protocol The communications system is a wireless system based on cellular telephone communications. The system provides a closed network with its own communications protocol for the transmission of signals across the network. Each part of the network includes, within its communications apparatus, a communications processor and a communications modem, e.g. Vodaphone Packnet, Siemens SM20, GSM and ISDN, which together permit and control the flow of cellular telephone communications between the parts of the system. Each modem, or corresponding part of the network, e.g. wind monitoring station, warning sign station or communications console, is assigned a unique identification code, which in the preferred embodiment is a six character ID, which is securely embedded within the controlling processor.

To ensure integrity, communications are only permissible between two modems, which are recognised by each other. Thus, two communicating modems first initiate contact by receiving and recognising their respective identification codes. If one modem receives a signal, which does not carry its relevant identification code, or which does not indicate a source identification code that the modem recognises, communication will be terminated.

This is achieved by pre programming all modems with a look up table comprising the identification codes of the modems with which they will need to communicate. When a call between two modems is being established, the modem being called will compare the identification code of the calling modem with the identification codes present in its look up table. Only if the identification code is present in the look up table, will the receiving modem respond, thus allowing the call to be established and communications to take place.

This system of identification of communicating modems is intended to eliminate "hacking" of the system, since it requires two six character modem IN to be discovered, and for the hacker to simulate one of the modems, in order for 9 communication to be possible. Furthermore, this system avoids the accidental activation of the system by unrelated modems and recognises mechanical or electronic failure.

Referring to Figure 3, the communications system operates principally in response to an event, which in the embodiment of the present invention described above is the detection of an adverse envirorimental condition, namely a high wind condition. It will be appreciated that the system can operate in response to any event, which may be detected automatically or manually. For example, if a train driver experiences 10 poor adhesion then this event may be communicated using the communications methodology of the present invention. The occurrence of an event, such as high wind speed, is determined at step 101. If the high wind condition is present then control apparatus in the wind monitoring station 15 automatically attempts a first call at step 102, transmission TX#l STS to the Engineer Station and a second call at step 103, transmission TX#2 STS to the communications console located within the local railway signal box. Both calls are "statue' calls to inform the Engineer Station and Signal Box, respectively, of the High Wind condition. 20 In the system, calls are preferably automatically attempted a predetermined number of times, for example, three times until the call is successfully established. Once the call to the signal box is established, by verification of the identification 25 codes by the modem in the signal box communications console, as described previously, the signal box communications console automatically calls each of the warning signs associated with the wind monitor. These calls, at steps 106 and 107, transmissions TX#1 CNM and TX#2 CMD are "Command" calls, which command the control apparatus in the warning sign stations to switch the signs on.

Alternatively, if after three attempts, the call from the wind monitoring station to the signal box, transmission TX#2 STS is unsuccessful, the wind monitoring station then automatically calls the associated warning sign stations directly, by calls at steps 104 and 105, transmissions TX#3 STS and TX44 STS which once established, directly command the warning sign stations to switch the signs on. In particular, the waming sign stations are adapted to respond to ffigh Wind status alarm signals originating directly from the wind monitoring station by switching on, in the same way as responding to command calls from the signal box console.

Once the warning signs have been switched on, each warning sign station automatically calls the communications console in the associated signal box, transmissions TX#2 ACK, which are "Acknowledge" calls, to acknowledge that the sign has been switched on, as shown in steps 108 and 109. In addition each waming sign station calls the Engineer Station, transmissions TX#1 STS to confirm the status of the warning sign, as shown in steps I 10 and I 11.

The communications console within the signal box receives the acknowledgement call from the warning signs and automatically illuminates the appropriate light on the console to show the signal operator that the warning signs are on.

In accordance with the present embodiment, the warning signs each include a timer which is activated when the sign is switched on. The warning signs remain illuminated for a predetermined period of time, for example I hour, before they are automatically switched off in response to a signal from the timer. The warning sign will be switched off only if no further high wind status signal has been received from the wind monitoring station. If during the initial part of the 1-hour time period, for example the first 10 minutes, a further high wind status call is received by the warning stations from the wind monitoring station, the timer will add an additional short period of time e.g. 10 minutes for which the warning sign will remain illuminated.

Thereafter, if a further high wind status call is received during the I hour period, it will be treated in the same way as a first call, and a command will be sent to the I I warning sign stations which resets the respective timers so that the signs will remain illuminated for a further I hour ftom the time they receive the further command.

If no further high wind status call is received from the wind monitoring station during the initial I hour period, the warning signs will switch themselves off. In addition, a manual mechanism may optionally be employed, whereby the signal operator can switch off the warning signs by calling the warning sign stations at steps 206 and 207, by transmissions TX#l CMD and TX#2 CMD. The control apparatus in the respective warning sign stations verify that the predetermined time period for illumination of the sign has expired in steps 214 and 215 before switching the signs off and acknowledging the status by respective acknowledgement and status calls to the signal box console at steps 208 and 209 and to the Engineer station at steps 210 and 211.

The communications console in the signal box receives the acknowledgement call from the warning signs and automatically turns off the appropriate light on the console to show the signal operator that the warning signs are no longer on.

The high wind detection system in accordance with an embodiment of the present invention includes further optional features, which enhance the operation and management of the system. These features include power management features, security features, which obviate security problems arising from tampering or vandalism of the system parts, and a central control and monitoring station for management and control of communications within a plurality of remote high wind detection systems across an entire railway or other network.

Power Management System The system is designed to minimise power consumption. Each part of the system, i.e.

each wind monitoring station and each warning sign station includes an electronic power control circuit which continually monitors the charging and discharging rates 12 of the battery-, the power consumption, and battery charge state. The circuit additionally monitors the charge delivered by the wind generator or solar panel. The control system, and in particular the processor, responds to the battery status to ensure maximum power efficiency. Thus, if the battery charge is critically low, the processor will terminate all unnecessary power consuming functions until the battery has sufficient charge to support the operation of these functions. The communications function should however remain active at all times.

Security System The control box of each part of the system includes a protective cover, which is removable by authorised personnel to gain access to the control electronics and processor for repair and maintenance. The cover is fitted with two separate relays, which are activated when the cover is removed or manipulated, as would occur during tampering or vandalism. When the relays are activated, they each send a signal to the processor within the control box, which responds by automatically erasing its associated memory, thereby deleting all associated systems software including the aforementioned identification codes. In addition, the activation of the relays causes the control system to send a signal to the communications console and/or central control and monitoring station to alert the operator that a problem has occurred and that the relevant control box is inactive.

Central Control and Monitoring Station A central control and monitoring station (Engineer Station) is provided for monitoring of the system by engineers, who not only can monitor the efficiency of system operation, but also cornmunicate with and control the various parts of the network. This enables engineers to remotely maintain, adjust and reprogram parts of the network, and if necessary override the operation thereof 30 The central control and monitoring station comprises the necessary communications apparatus, including a suitable modem and aerial, to receive signals from, and transmit signals to, the parts of the system in accordance with the communications protocol. A computer system is used to process the data contained within the signals for monitoring and control of the system.

As the skilled person will appreciate, many variations and modifications may be made to the described embodiment. For example, whilst the warning signs have been described as LED signs, any type of sign or signal which will be visible and which can be electronically activated using the described communications system could be employed. Accordingly, it is intended to include all such variations and modifications, which fall within the scope of the present invention.

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Claims (31)

CLAIMS:

1. A warning system comprising a plurality of components, including:

a warning sign for providing a warning indication when switched on, and.

providing no warning indication when switched off, and signal communications apparatus for sending signals to, and receiving signals from, remote locations using cellular or other wireless telecommunications; wherein the signal communications apparatus sends a signal to the warning sign to switch on, in response to receiving a warning signal indicating the presence of a danger.

2. A warning system as claimed in claim 1, wherein each component includes circuitry comprising a controller and associated memory.

3. A warning system as claimed in claim 2, wherein the circuitry of each component further includes telecommunications apparatus having a unique identification code used in sending and/or receiving communication signals.

4. A warning system as claimed in claim 2 or claim 3, wherein the circuitry 20 further comprises a look-up table, the look-up table storing the identification code of each of the components from which it is permitted to receive signals.

5. A warning system as claimed in claim 4, wherein, when a component receives a signal, the controller compares the identification code of the source of the signal 25 specified in the signal with the identification codes in the look-up table, and if there is a match responds to the signal.

6. A warning system as claimed in claim 3, 4 or 5, wherein the telecommunications apparatus of each component includes a modem and the 30 identification code is associated with the modem.

7. A warning system as claimed in any one of claims 2 to 6, wherein the circuitry of one or more components further comprises power supply, and power control circuit, the power control circuit for continually monitoring the state of charge of the power supply, and providing status signals to the telecommunications apparatus, for communication to other components in the system.

8. A warning system as claimed in claim 7, wherein the power control circuit provides a signal to the controller when the power supply charge falls below a predetermined threshold, and the controller terminates consumption of power within the component for at least some functions.

9. A warning system as claimed in claim 7 or claim 8, further comprising apparatus for recharging the power supply using a renewable energy source.

10. A warning system as claimed in any one of claims 2 to 8, wherein each component includes a housing for the circuitry, the housing comprising a removable cover.

11. A warning system as claimed in claim 10, wherein said removable cover is fitted with mechanism for detecting tampering therewith.

12. A warning system as claimed in claim 11, wherein, if tampering if detected, the mechanism sends a signal to the controller, which erases the associated memory.

13. A warning system as claimed in any preceding claim, wherein the warning sign circuitry further includes a timer.

14. A warning system as claimed in claim 13, wherein the timer is activated when the warning sign is switched on.

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15. A warning system as claimed in claim 14, wherein the warning sign is switched off only after the timer has run for a predetermined period of time.

16. A warning system as claimed in any preceding claim, wherein the plurality of components further include:

a wind monitor comprising an anemometer, and circuitry for monitoring the output of the anemometer and determining the wind speed.

17. A warning system as claimed in claim 16, the wind monitoring circuitry further including telecornmunications apparatus, the wind monitor sending a warning signal to the signal communications apparatus when the determined wind speed exceeds a predetermined threshold.

18. A warning system as claimed in claim 16 or claim 17, wherein the wind monitoring circuitry further includes a processor for continuously receiving an output signal from the anemometer and determining if the wind speed exceeds a predetermined threshold for a predefined period of time.

19. A warning system as claimed in claim 16, 17 or 18, wherein the wind monitoring circuitry further includes a timer, wherein the timer is started when the wind speed reaches a predetermined threshold, and continues to run forward whilst the wind speed is greater than or equal to the predetermined threshold until it reaches a predefined time, and if the wind speed falls below the predetermined threshold before the timer reaches the predefined time, the timer is run in reverse whilst the wind speed is less than the predetermined threshold.

20. A warning system as claimed in any preceding claim, wherein the warning sign comprises an LED display sign, and further including a fight intensity sensor for detecting the level of ambient light, the brightness of the LEDs being adjusted in response to the detected ambient light to provide maximum visibility.

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21. A method for operating a warning system comprising a plurality of components, the components including a warning sign, for providing a warning indication when switched on, and providing no warning indication when switched off, and a signal communications apparatus for sending signals to, and receiving signals.

from, remote locations using cellular or other wireless telecommunications; the method comprising the steps of receiving at the signal communications apparatus a signal indicating the presence of a danger, and sending from the signal communications apparatus a telecommunications signal to the warning sign to switch on.

22. A method as claimed in claim 2 1, further comprising the steps of receiving at the warning sign the signal from the signal communications apparatus, and switching the warning sign on in response thereto.

23 A method as claimed in claim 22, wherein each component includes circuitry comprising telecommunications apparatus having a unique identification code, and the step of sending includes sending the identification codes of the both the source and destination components.

24. A method as claimed in claim 23, wherein the circuitry of each component further comprises a look-up table, the look-up table storing the identification code of each of the components from which it is permitted to receive signals, the method ftirther comprising the step of after receiving at the warning sign, and prior to the switching, the warning sign comparing the source identification code in the received signal with the identification codes stored in the look up table thereof, wherein the step of switching is carried out only if the comparison finds a match.

18 25, A method as claimed in claim 23 or claim 24, wherein the circuitry of one or more components further comprises a power supply, and a power control circuit, the method further comprising the steps of the or each power control circuit periodically monitoring the state of charge of the power supply, and providing status signals indicative of the monitored state of charge to the telecommunications apparatus, for communication to other components in the system.

26. A method as claimed in claim 25, further comprising the step of comparing the monitored state of charge with predetermined threshold, and if the monitored state of charge is below the predetermined threshold terminating consumption of power within the component for at least some functions.

27. A method as claimed in any one of claim 23 to 26, wherein the warning sign circuitry further includes a timer, and the method further comprises the steps of starting the timer when the warning sign is switched on, and.

Switching of the warning sign only when the timer has run for a predetermined period of time.

28. A method as claimed in any one of claims 23 to 27, wherein the plurality of components further include a wind monitor comprising an anemometer, and circuitry for receiving the output of the anemometer and determining if the wind speed exceeds a predetermined threshold, the method finther comprising the step of the wind monitor circuitry sending said signal indicating the presence of a danger to the signal communications apparatus if it determines that the wind speed exceeds the predetermined threshold.

29. A method as claimed in claim 28, wherein the wind monitoring circuitry further includes a processor, the method further comprising the step of the processor continuously receiving an output signal from the anemometer and 19 the processor determining if the wind speed exceeds a predetermined threshold for a predefined period of time.

30. A method as claimed claim 29, wherein the wind monitoring circuitry further includes a timer, the method further comprising the steps of the processor starting the timer when the wind speed reaches a predetermined threshold, running the timer forward whilst the wind speed is greater than or equal to the predetermined threshold, if the wind speed falls below the predetermined threshold before the timer reaches the predefined time, running the timer in reverse whilst the wind speed is less than the predetermined threshold, the timer notifying the processor when it reaches the predefined time, and in response thereto, the processor sending said signal indicating the presence of a danger to the signal communications apparatus.

31. A method as claimed in any one of claim 22 to 30, wherein the warning sip comprises an LED display sign, and a light intensity sensor for detecting the level of ambient light, the method further comprising the steps of adjusting the brightness of the LEDs in response to the detected ambient fight to provide maximum visibility.