VEHICLE DETECTOR UNIT, VEHICLE DETECTOR SYSTEM AND A METHOD FOR DETECTING PRESENCE OF A VEHICLE ON A RAIL

Abstract

A vehicle detector unit for detecting presence of a vehicle moving along a rail, including a distance sensor for sensing a body of the vehicle, a rail translation sensor for sensing translation of the rail, a rail torsion sensor for sensing torsion of the rail, and a processor adapted to process data received from the distance sensor, the rail translation sensor and the rail torsion sensor, whereby the processor applies an algorithm to said data to determine whether to output an alert signal.

Description

FIELD OF THE INVENTION

The invention relates to a vehicle detector unit, a vehicle detector system and a method for detecting presence of a vehicle on a rail. More particularly, but not exclusively, the invention relates to a vehicle detector unit for detecting presence of a train on a rail for providing an alert to a worksite.

BACKGROUND OF THE INVENTION

It is known to provide a railroad warning system for train operators. In particular, U.S. Pat. No. 8,109,474 discloses a dual ultrasonic train detector for giving train workers, railroad personnel and others warning of oncoming trains.

The applicant has identified that existing train detector systems are prone to unreliability, faulty detection of threat, and possible failure to identify threats in certain circumstances. Examples of the present invention seek to provide an improved train detection system which overcomes or at least alleviates disadvantages associated with existing systems.

SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided a vehicle detector unit for detecting presence of a vehicle moving along a rail, including a distance sensor for sensing a body of the vehicle, a rail translation sensor for sensing translation of the rail, a rail torsion sensor for sensing torsion of the rail, and a processor adapted to process data received from the distance sensor, the rail translation sensor and the rail torsion sensor, whereby the processor applies an algorithm to said data to determine whether to output an alert signal.

Preferably, the processor applies said algorithm to detect uncorrelated data received from the distance sensor, the rail translation sensor and the rail torsion, sensor to distinguish between a dangerous event, in which case the vehicle detector unit outputs an alert signal, and a non-dangerous event, whereby the processor identifies a non-dangerous event in response to detecting uncorrelated data and the processor identifies a dangerous event in response to detecting correlated data.

Preferably, the processor is arranged to detect possible degradation of operation of the vehicle detector unit when greater than a predetermined threshold of non-dangerous events are detected within a predetermined period and in the absence of detecting a dangerous event. More preferably, the vehicle detector unit outputs an error signal in response to detecting possible degradation of operation of the vehicle detector unit.

In a preferred form, the processor is arranged to detect correlated data when there is consistency between data received from the distance sensor, the rail translation sensor and the rail torsion sensor to indicate presence of a vehicle moving along the rail, based on threshold values for each of the sensors. More preferably, the processor is arranged to detect, correlated data for fast short vehicles and slow long vehicles on the rail, and to detect uncorrelated data for wind-blown debris, dust, rain and the like.

Preferably, the processor is arranged to distinguish presence of vehicles on adjacent tracks from presence of vehicles on said rail.

Preferably, the distance sensor is in the form of an ultrasonic sensor.

Preferably, the rail translation sensor is in the form of an accelerometer.

Preferably, the rail torsion sensor is in the form of a gyroscopic sensor.

In a preferred form, the vehicle detector unit includes base for passing beneath said rail a first clamp which is fixed relative to the base for clamping one side of the rail, and a second clamp which is selectively movable relative to the base for clamping an opposite side of the rail. More preferably, the second clamp is selectively held in place relative to the base by operation of a releasable fastener.

In accordance with another aspect of the present invention, there is provided a vehicle detector system for detecting presence of a vehicle moving along a rail relative to a work site, said system including a pair of vehicle detector units at spaced locations along the rail, a first one of the vehicle detector units being located in one direction from the work site and a second one of the vehicle detector units being located in an opposite direction from the work site, each of the vehicle detector units being a vehicle detector unit as claimed in claim 1, said system further including a site warning unit located at the work site, wherein the site warning unit is in communication with the vehicle detector units, and the site warning unit outputs audible and/or visual alerts in response to an alert signal received from either of the vehicle detector units.

Preferably, the site warning unit is in communication with the vehicle detector units by way of radio communication.

In accordance with another aspect of the present invention, there is provided a method for detecting presence of a vehicle on a rail, said method including the steps of:

• • using a distance sensor for sensing a body of the vehicle,
  • using a rail translation sensor for sensing translation of the rail.
  • using a rail torsion sensor for sensing torsion of the rail, and
  • processing data received from the distance sensor, the rail translation sensor and the rail torsion sensor, whereby an algorithm is applied to said data to determine whether to output an alert signal.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

FIG. 1a shows a side view of a vehicle detector unit in accordance with an example of the present invention;

FIG. 1a shows a bottom perspective view of the vehicle detector unit;

FIG. 2 shows a detailed transparent view of one end of the vehicle detector unit;

FIG. 3 is a diagrammatic representation of an algorithm used by a vehicle detector unit;

FIG. 4 is a diagrammatic view of a vehicle detector system in accordance with an example of the present invention;

FIG. 5 is a diagrammatic representation of hardware architecture of a repeater unit of the vehicle detector system;

FIG. 6 is a diagrammatic representation of a procedure followed by the vehicle detector system;

FIG. 7 is a diagrammatic representation of the vehicle detector system when installed to provide warning to worksite;

FIG. 8 shows a detailed side view of a vehicle detector unit in accordance with an example of the present invention, depicting clamps of the vehicle detector unit;

FIG. 9 shows a side view of a vehicle detector unit in accordance with the example shown in FIG. 8; and

FIG. 10 shows a partial sectional side view of one end of the vehicle detector unit shown in FIG. 9.

DETAILED DESCRIPTION

With reference to FIGS. 1a to 3 of the drawings, there is shown a vehicle detector system which is able to provide warning to a worksite of a train (or other vehicle) approaching the worksite along a rail. Advantageously, as the vehicle detector unit includes a distance sensor, a rail translation sensor, a rail torsion sensor and a processor, the vehicle detector unit is able to combine data received from the different sensors so as to achieve an improved level of reliability, particularly in detecting dangerous events and in avoiding being triggered by false triggers.

More specifically. FIGS. 1a to 3 depict a vehicle detector unit 10 for detecting presence of a vehicle moving along a rail 12, including a distance sensor 14 for sensing a body of the vehicle, a rail translation sensor 16 for sensing translation of the rail 12, and a rail torsion sensor 18 for sensing torsion of the rail 12. The vehicle detector unit 10 also includes a processor adapted to process data received from the distance sensor 14, the rail translation sensor 16 and the rail torsion sensor 18, whereby the processor applies an algorithm to the data to determine whether to output an alert signal. The alert signal can be transmitted to produce an audible and/or visual alert to a worksite which is remote to the vehicle detector unit 10, as depicted in the vehicle detector system shown in FIGS. 4 to 7.

The processor may be located within a housing 20 of the vehicle detector unit. The processor applies the algorithm to detect uncorrelated data received from the distance sensor 14, the rail translation sensor 16 and the rail torsion sensor 18 to distinguish between a dangerous event, in which case the vehicle detector unit 10 outputs an alert signal, and a non-dangerous event, in which case the vehicle detector unit 10 does not output an alert signal. The processor identifies a non-dangerous event in response to detecting, uncorrelated data, and the processor identifies a dangerous event in response to detecting correlated data. This processing of data is performed by combining data from the distance sensor 14. the translation sensor 16 and the rail torsion sensor 18 in a manner which is depicted by the flow chart in FIG. 3. Provided the processor recognises criteria according to the algorithm wherein data from the sensors is correlated to indicate presence of a vehicle moving along the rail 12. an alert signal is provided as an output of the vehicle detector unit 10.

The processor may be arranged to detect possible degradation of operation of the vehicle detector unit 10 when greater than a predetermined threshold of non-dangerous events are detected within a predetermined period and in the absence of detecting a dangerous event. In this case. the vehicle detector unit 10 may output an error signal in response to detecting possible degradation of operation of the vehicle detector unit. This may indicate that the system may be unable to operate correctly. The system may use an alternative signal to indicate, that the system may be unable to function. For example, the system may use an alert sound from repeater units and site warning units to warn operators that the system may be unable to function and that the system may be less reliable.

The processor may be arranged to detect correlated data when there is consistency between data received from the distance sensor 14, the rail translation sensor 16 and the rail torsion sensor 18 to indicate presence of a vehicle moving along rail, based on threshold values for each of the sensors 14, 16, 18. The processor may be arranged to collect correlated data for fast short vehicles and slow long vehicles on the rail 12. and to detect uncorrelated data for wind-blown, debris, dust, rain and the like. The processor may be arranged to distinguish presence of vehicles on adjacent tracks from presence of vehicles on the rail 12.

The distance sensor 14 may be in the form of an ultrasonic sensor, the rail translation sensor 16 may be in the form of an accelerometer, and the rail torsion sensor 18 may be in the form of a gyroscopic sensor.

Advantageously, the applicant has been able to apply a combination of microelectronic sensors and signal processing in a novel, fashion to reliably detect approaching trains. The vehicle detector unit 10 incorporates microelectronics, complex signal processing, and radio communications technology. Ultrasonic sensing technology combined with precision measurement of rail translation and rail torsion provides filtering that, when combined, provide a level of reliability that is superior to existing vehicle protection products. In particular, improved system reliability is achieved via combined monitoring of vehicular presence by way of combining a distance sensor with rail translation and rail torsion sensors. Although it has previously been proposed in an existing system to use only an ultrasonic sensor, the presence of a vehicle which is relatively small (for example, a 3 metre length vehicle as opposed to a 100 metre length train) may appear similar to an animal running past, at least to an ultrasonic sensor in isolation. Accordingly, if a mere ultrasonic sensor system is programmed to avoid false triggering based on a running animal, that system may also miss the threat provided by such a relatively small vehicle. Advantageously, by virtue of the sensor fusion of the present invention, such threats and false triggers are accommodated. Previously, false triggers of this kind may have been dealt with by simply removing short pulses, however this would effectively limit the maximum speed at which the existing system would detect vehicles (in particular relatively short vehicles or “high-rail” vehicles).

Advantageously, the present invention uses an algorithm which combines data collected on the ultrasonic sensor, accelerometer and gyroscope to manage scenarios including but not limited to fast short vehicles, long slow vehicles and vehicles on adjacent tracks.

In relation to the algorithm, digital signal filtering and temporal synchronisation are used for the Accelerometer, Gyroscope and Ultrasonic sensors. Ultrasonic sensor phenomena unrelated to vehicle detection, as defined by duration, distance thresholds and correlation with other sensors, is implemented such that these phenomena are removed to the reduce effect on digital signal filtering in following stages. If many phenomena are removed in a short time, a degraded system signal is triggered.

The ultrasonic sensor is used such that a threshold and minimum time period are required to trigger an alarm. The time period is shortened if a detection trigger is present from MEMS sensors.

A MEMS trigger is determined primarily by a threshold on the ratio of RMS power in short and long terms whereby the long term period follows the short term period. A MEMS trigger is continued while the long term RMS power remains above a threshold. The MEMS trigger is finally continued by way of a fixed period after the aforementioned triggers. Thresholds and timers vary between gyroscopic and accelerometric sensors.

Accordingly, examples of the present invention use a distance sensor in combination with torsion and translation sensors, using analogue distance, which is useful for defining thresholds and determining between rain and trains, rather than simple digital (on/off) “presence”. The present invention uses soundwaves from the ultrasonic sensor to determine distance to the train. No electric or physical connection is made to the train or components of the train. There is no electrical or mechanical interface interfering with the train or the rail. Sensor fusion as implemented in the present invention enables the vehicle detector unit 10 to differentiate trains, track equipment, environmental effects, debris, electrically and mechanically induced noise, the adjacent track, and other factors. This improvement in differentiation significantly improves the reliability of detection and incidences of false detection.

The vehicle detector unit 10 may include a base 22 for passing beneath the rail, a first clamp 24 which is fixed relative to the base 22 for clamping one side of the rail 12, and a second clamp 26 which is selectively movable relative to the base 22 for clamping an opposite side of the rail 12 (see FIG. 1A and FIG. 1B). The second clamp 26 may be selectively held in place relative to the base 22 by operation of a releasable fastener 28 which can be in the form of a threaded base and a wing nut. As the second clamp 26 is able to be slid on and locked to the base 22 by a single wing nut, this makes for very fast attachment and reduces the time spent by an operator on the track in the danger zone. The profile of the base 22 allows for easy installation with minimal disruption to ballast (rock) from under the foot of the rail 12 during installation. Accordingly, examples of the present invention may be quick to install and may support multiple rail standard sections. Accordingly, the vehicle detector unit 10 may be readily installed temporarily when work is to be undertaken at a worksite at or near a section of the rail 12.

With reference to FIGS. 4 to 7, one aspect of the present invention provides a vehicle detector system 30 for detecting presence of a vehicle moving along a rail 12 relative to a worksite 32. The system 30 includes a pair of vehicle detector units 10 at spaced locations along the rail 12, a first one of the vehicle detector units 10 being located in one direction from the worksite 32 and a second one of the vehicle detector units 10 being located in an opposite direction from the worksite 32. The first vehicle detector unit 10 is for detecting trains incoming to the worksite 32 while the second one of the vehicle detector units 10 is for detecting trains leaving the worksite such that they do not initiate an alarm. In an alternative example, there may be more than one vehicle detector unit 10 located at each side of the worksite 32 for detecting incoming velocity of trains. Each of the vehicle detector units 10 may he a vehicle detector unit 10 as shown in FIGS. 1a to 3 and as described above.

The system 30 further includes a site warning unit 34 located at the worksite 32. The site warning unit 34 is in communication with the vehicle detector units 10 and the site warning unit 34 outputs audible and/or visual alerts in response to an alert signal received from either of the vehicle detector units 10.

The site warning unit 34 may he in communication with the vehicle detector units 10 by way of radio communication. Alternatives includes satellite, cellular and wired communication. Satellite has ongoing costs and is unreliable. Cellular is not available in the normal areas of deployment. Although inherently more reliable than wireless, wired connections require long lengths of wires and need to be run under the tracks. This increases installation time and equipment weight significantly. In addition, long installation times prevent use of safety systems during short track occupations where the risk to workers may be very high. Radio communication certification is related to output power (effective isotropic radiated power). To achieve acceptable range through radiofrequency opaque objects in the Frenel zone, high sensitivity receivers are required. Range is related to elevation so as the train detectors are low on the track, and repeater units (used close to the train detectors) are on tripods.

More specifically, with reference to FIG. 4, the system 30 may include a plurality of repeater units 36 which have sirens and lights on a tripod with an additional long distance radio. Hardware architecture of the repeater units 36 is shown in FIG. 5.

The site warning units 34 may each include a siren and lights on a tripod. The vehicle detector system 30 may also include personal warning units 38 which may be clipped onto a belt by workers, and lookout units 40 which may be held by a lookout person.

FIG. 6 shows a series of steps in a flowchart which may be followed by examples of the vehicle detector system 30, and FIG. 7 shows a diagrammatic view where vehicle detector units 10 are installed at a distance of 1.5 km at either side of the worksite 37.

FIGS. 8 to 10 depict a vehicle detector unit 10 in accordance with a further example of the present invention. The vehicle detector unit 10 shown in FIGS. 8 to 10 is generally similar to the one shown in FIGS. 1a to 7, and like features are denoted with like reference numerals.

The vehicle detector unit 10 of FIGS. 8 to 10 differs in that it includes a cam 42 for operating the second clamp 26 in place of the nut (or wing nut) used in the example shown in FIG. 1a. The vehicle detector unit 10 of FIGS. 8 to 10 also differs in that it includes heat shielding 44 to protect the housing 20 and the processor within the housing 20.

More specifically, with reference to FIG. 8, the cam 42 is operated by way of a lever 46, and may be configured for quick operation such that the cam 42 is able to be operated to engage/disengage the clamp 26 against the rail 12 by less than a single full turn of the lever 46. As shown in FIG. 9, the first and second clamps 24, 26 are able to accommodate rails 12 of different profiles—rails of different profiles have been superimposed in FIG. 9 to illustrate this aspect.

Turning to FIG. 10, heat shielding 44 is provided below the housing 20 to protect from heat the housing 20 and the processor within the housing 20. The applicant has determined that at locations where the vehicle detector unit 10 is to be used there may be damaging heat not only from direct sunlight but also in the form of radiation from “ballast” rocks beneath or adjacent the rails, with the rocks acting in a similar manner to coals of a barbecue. The heat shielding 44 may be in the form of a sled mounted to an underside of the vehicle detector unit 10 with an air gap between the heat shielding 44 and the vehicle detector unit 10 along a substantial portion of a length of the sled as shown in FIG. 10 so as to insulate the vehicle detector unit 10.

While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not by way of limitation. It will be apparent to a person skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Thus, the present invention should not be limited by any of the above described exemplary embodiments.

The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word “comprise”, and variations such as “comprises” and “comprising”, will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

Claims

1. A vehicle detector unit for detecting presence of a vehicle moving along a rail, including a distance sensor for sensing a body of the vehicle, a rail translation sensor for sensing translation of the rail, a rail torsion sensor for sensing torsion of the rail, and a processor adapted to process data received from the distance sensor, the rail translation sensor and the rail torsion sensor, whereby the processor applies an algorithm to said data to determine whether to output an alert signal.

2. A vehicle detector unit as claimed in claim 1, wherein the processor applies said algorithm to detect uncorrelated data received from the distance sensor, the rail translation sensor and the rail torsion sensor to distinguish between a dangerous event, in which case the vehicle detector unit outputs an alert signal, and a non-dangerous event, whereby the processor identifies a non-dangerous event in response to detecting uncorrelated data, and the processor identifies a dangerous event in response to detecting correlated data.

3. A vehicle detector unit as claimed in claim 1 , wherein the processor is arranged to detect possible degradation of operation of the vehicle detector unit when greater than a predetermined threshold of non-dangerous events are detected within a predetermined period and the absence of detecting a dangerous event.

4. A vehicle detector unit as claimed in claim 3, wherein the vehicle detector unit outputs an error signal in response to detecting possible degradation of operation of the vehicle detector unit.

5. A vehicle detector unit as claimed in claim 2, wherein the processor is arranged to detect correlated data when there is consistency between data received from the distance sensor, the rail translation sensor and the rail torsion sensor to indicate presence of a vehicle moving along the rail, based on the threshold values for each of the sensors.

6. A vehicle detector unit as claim in claim 5, wherein the processor is arranged to detect correlated data for fast short vehicles and slow long vehicles on the rail, and to detect uncorrelated data for wind-blown debris, dust, rain and the like.

7. A vehicle detector unit as claimed in claim 1, wherein the processor is arranged to distinguish presence of vehicles on adjacent tracks from presence of vehicles on said rail.

8. A vehicle detector unit as claimed in claim 1, wherein the distance sensor is in the form of an ultrasonic sensor.

9. A vehicle detector unit as claimed in claim 1, wherein the rail translation sensor is in the form of an accelerometer.

10. A vehicle detector unit as claimed in claim 1, wherein the rail torsion sensor is in the form of a gyroscopic sensor.

11. A vehicle detector unit as claimed in claim 1, wherein the vehicle detector unit includes base for passing beneath said rail, a first clamp which is fixed relative to the base for clamping one side of the rail, and a second clamp which is selectively movable relative to the base for clamping an opposite side of the rail.

12. A vehicle detector unit as claimed in claim 11, wherein the second clamp is selectively held in place relative to the base by operation of a releasable fastener.

13. A vehicle detector system for detecting presence of a vehicle moving along a rail relative to a work site, said system including a pair of vehicle detector units at spaced locations along the rail, a first one of the vehicle detector units being located in one direction from the work site and a second one of the vehicle detector units being located in an opposite direction from the work site, each of the vehicle detector units being a vehicle detector unit as claimed in claim 1, said system further including a site warning unit located at the work site, wherein the site warning unit is in communication with the vehicle detector units, and the site warning unit outputs audible and/or visual alerts in response to an alert signal received from either of the vehicle detector units.

14. A vehicle detector system as claimed in claim 13, wherein the site warning unit is in communication with the vehicle detector units by way of radio communication.

15. A method for detecting presence of a vehicle on a rail, said method including the steps of: using a distance sensor for sensing a body of the vehicle,using a rail translation sensor for sensing translation of the rail,using a rail torsion sensor for sensing torsion of the rail, andprocessing data received from the distance sensor, the rail translation sensor and the rail torsion sensor, whereby an algorithm is applied to said data to determine whether to output an alert signal.

16-18. (canceled)