EP0976640B1 - Anti-collision system for level crossing - Google Patents

Abstract

The level crossing, equipped with train approach warning devices (22, 24) and half-barriers (14, 16), also has video cameras (26, 28, 30, 32) mounted on poles to provide image information to a computer (34). Image analysis software, including stereoscopic processing, is used to determine the nature of any obstacle on the crossing and a controller (36) then sends speed control or braking commands as necessary to an approaching train via the usual track communication link (40). Preferably, pixels received from the video cameras are compared with at least one threshold value to determine obstacle contour.

Description

The present invention relates to an anti-collision system for switching to level.

Railway accidents occurring on a railway crossing are generally due to a collision between a railway convoy and a motor vehicle.

Such collisions are first caused by the presence of a vehicle car immobilized on the railway, due either to a breakdown of the vehicle or to a imprisonment of the latter between the gates of the crossing.

The broken down vehicles are most often immobilized well before the approach railway convoy, the imprisonment of vehicles being relatively rare because of the widespread use of polyester fiber barriers that can be easily broken.

Railway accidents can also be caused by a abnormal behavior of road users, resulting in non-compliance with the road regulations. An example of faulty behavior is the anti-incursion barriers at the level crossings.

Penetrations of barriers, due to voluntary behavior or unintentional road user can also cause collisions on level crossings.

Currently, the elimination of the risk of collision passes through the replacement of level crossings by bridges or tunnels, which represents a considerable investment effort.

It is known, in particular from document US-5,331,312, an anti-collision system for level crossing according to the preamble of claim 1.

The object of the invention is to provide an anti-collision system for passage to level capable of providing an alternative to the removal of crossings at levels while being efficient and cheap.

It therefore relates to an anti-collision system for level crossing, including roadside equipment in the vicinity of the roadway level to indicate the approach of a railway train and to stop the vehicles traveling on the roadway, characterized in that it comprises detection means obstacles on the railroad tracks of the crossing, located in the vicinity of the railway crossing and connected to control means for stopping railway convoys traveling in upstream of the crossing, in the presence of an obstacle on the latter.

• les moyens de détection comportent au moins un dispositif de prise de vues dirigé vers le passage à niveau et raccordé à une unité centrale de traitement comprenant des moyens de traitement d'images et de reconnaissance du type d'obstacle présent sur la voie ferrée ;
• le ou chaque dispositif de prise de vues délivrant des images du passage à niveau sous la forme d'un ensemble de pixels associés chacun à une valeur numérique de luminance, les moyens de traitement d'images comportent des moyens de filtrage desdits pixels par comparaison desdites valeurs numériques avec au moins une valeur de seuil de détection du contour dudit obstacle ;
• il comporte un ensemble de dispositifs de prise de vues disposés par paires de part et d'autre de la chaussée du passage à niveau, l'unité de traitement assurant un traitement stéréoscopique des images formées par les dispositifs de prise de vues ;
• les moyens de commande de l'arrêt du convoi ferroviaire comportent, relié à l'unité centrale de traitement et recevant en entrée un signal de détection d'obstacle délivré par cette dernière, un dispositif de contrôle de vitesse de convois ferroviaires, comprenant une unité d'élaboration de consignes de vitesse raccordée à un ensemble de balises disposées le long de la voie ferrée en amont du passage à niveau et destinées chacune à entrer en communication avec un dispositif de gestion de vitesse embarqué à bord de chaque convoi ferroviaire, lors du passage de ce dernier au voisinage de chaque balise;
• les moyens de commande de l'arrêt du convoi comportent des dispositifs optiques de signalisation ferroviaire implantés le long de la voie ferrée, en amont du passage à niveau et pilotés par les moyens de détection d'obstacles ;
• les moyens de commande de l'arrêt du convoi comportent des moyens d'émission de signaux d'alarmes en direction d'un récepteur correspondant embarqué à bord de chaque convoi ferroviaire ;
• il comporte un modulateur-démodulateur raccordé à l'unité centrale de traitement en vue de la mise en communication du système anti-collision avec un centre de télésurveillance, par l'intermédiaire d'un réseau téléphonique ;
• l'unité centrale de traitement comporte en outre des moyens de mémorisation périodique des images délivrées par les dispositifs de prise de vues ;
• les équipements routiers comportent des barrières automatiques anti-incursion disposées de part et d'autre du passage à niveau et pilotés par des moyens de détection de convoi disposés sur la voie ferrée en amont du passage à niveau ;
• les consignes de vitesse sont calculées en fonction du type d'obstacle détecté et de la distance du train par rapport au passage à niveau ;
• la chaussée routière comporte, de part et d'autre du passage à niveau, des moyens de ralentissement de véhicules circulant sur cette dernière ; et
• il comporte deux barrières anti-incursion disposées chacune sur l'une des voies de la chaussée, et est muni d'obstacles séparant lesdites voies pour empêcher le passage en chicane du passage à niveau.

The anti-collision system according to the invention may further comprise one or more of the following characteristics, taken separately or in any technically possible combination:

• the detection means comprise at least one shooting device directed towards the level crossing and connected to a central processing unit comprising image processing means and recognition of the type of obstacle present on the railway track;
• the or each recording device delivering images of the level crossing in the form of a set of pixels each associated with a digital luminance value, the image processing means comprise means for filtering said pixels by comparison of said numerical values with at least one contour detection threshold value of said obstacle;
• it comprises a set of cameras arranged in pairs on either side of the roadway of the level crossing, the processing unit providing stereoscopic processing of the images formed by the cameras;
• the means for controlling the stopping of the railway train comprise, connected to the central processing unit and receiving as input an obstacle detection signal delivered by the latter, a device for controlling the speed of railway convoys, comprising a unit of setting speed instructions connected to a set of beacons arranged along the railway track upstream of the level crossing and each intended to communicate with an on-board speed management device on board each railway train, during the passage of the latter in the vicinity of each beacon;
• the convoy stop control means comprise optical railway signaling devices located along the railway track, upstream of the level crossing and controlled by the obstacle detection means;
• the control means of stopping the convoy comprise means for transmitting alarm signals towards a corresponding receiver on board each rail train;
• it comprises a modulator-demodulator connected to the central processing unit in order to put the anti-collision system in communication with a central station by means of a telephone network;
• the central processing unit further comprises means for periodically storing the images delivered by the cameras;
• the roadside equipment comprises automatic anti-incursion barriers arranged on either side of the level crossing and controlled by convoy detection means arranged on the railway track upstream of the level crossing;
• the speed setpoints are calculated according to the type of obstacle detected and the distance of the train from the crossing;
• the road surface comprises, on either side of the level crossing, means for slowing down vehicles traveling on the latter; and
• it includes two anti-incursion barriers each disposed on one of the roadways of the roadway, and is provided with obstacles separating said lanes to prevent the crossing of the crossing in a baffle.

• la figure 1 est une vue schématique d'un passage à niveau équipé d'un système anti-collision selon l'invention ;
• la figure 2 est un schéma synoptique du système anti-collision de la figure 1;
• les figures 3 à 5 sont des courbes montrant la variation des consignes de vitesse imposées aux convois ferroviaires en fonction de la distance de ces derniers par rapport au passage à niveau et du type d'obstacle détecté, pour un passage à niveau équipé de barrières anti-incursion ; et
• les figures 6 et 7 montrent la variation des consignes des vitesses imposées aux convois ferroviaires en fonction de la distance de ces derniers par rapport au passage à niveau et du type d'obstacle détecté, pour un passage à niveau de type non gardé.

Other features and advantages will become apparent from the following description, given solely by way of example, and with reference to the appended drawings, in which:

• Figure 1 is a schematic view of a level crossing equipped with an anti-collision system according to the invention;
• Figure 2 is a block diagram of the anti-collision system of Figure 1;
• FIGS. 3 to 5 are curves showing the variation of the speed instructions imposed on the railway convoys as a function of the distance of the latter relative to the level crossing and the type of obstacle detected, for a level crossing equipped with anti-railing barriers. - incursion; and
• FIGS. 6 and 7 show the variation of the setpoints of the speeds imposed on the railway convoys as a function of the distance of the latter relative to the level crossing and the type of obstacle detected, for a non-guarded level crossing.

FIG. 1 shows a level crossing of the signaling type automatic light (SAL) with an anti-collision system according to the invention.

In this FIG. 1, the reference numeral 10 denotes the railroad of a network railway and the reference numeral 12 designates a roadway of a road network.

To eliminate the risk of collisions between a motor vehicle present on railroad 10 and, in general, between an obstacle present on that last and a rail convoy traveling on lane 10, and to reduce the consequences such a collision when the latter is unavoidable, the crossing is equipped with road equipment intended to indicate to road users the approach of a convoy and stop the vehicles on the road, and equipment intended to stop convoys traveling upstream of the level, in the presence of an obstacle.

As seen in this FIG. 1, and in the exemplary embodiment represented in this figure, the roadside equipment includes two half-barriers automatic anti-incursion respectively 14 and 16 arranged on both sides of the Railroad Crossing.

These barriers 14 and 16 are controlled at the opening and closing by convoy detection means (not shown in this figure) arranged on the track railway upstream of the level crossing, considering the direction of movement of the convoys rail.

These detection means are means of conventional type and suitable for the intended use. They will not be described in detail later. We will note however they are not example constituted by a detection device of the type "pedal "classically equipping the rail networks.

FIG. 1 also shows that the road surface is equipped with retarders 18 and 20 arranged on both sides of the crossing so as to avoid a crossing of the lane 10 at high speed.

Signs, respectively 22 and 24, driven by the convoy detection means are arranged on both sides of the crossing. indicate to road users the impending closure of barriers 14 and 16 and the coming arrival of a railway convoy.

For example, the traffic signs 22 and 24 are constituted by electroluminescent or liquid crystal display panels for displaying variable information sequences to warn road users of the status of the transition to level, that is to say the imminent closing of the barriers, their closure in progress, ...

Alternatively, in a complementary manner, the level crossing is provided with flashing optical devices, of the "flash" type or flash lamp, making it possible to dramatically materialize the closing of the barriers.

FIG. 1 also shows that in the example shown which has two half-gates each extending, in the closed position, on one of the roads, the roadside equipment also includes a set of obstacles, such as 25, separating the tracks from the roadway 12 so as to prevent the transition to a chicane crossing.

For example, these obstacles are constituted by terminals or implanted islands in the middle axis of the roadway.

Finally, roadside equipment can be supplemented by located upstream and downstream of the level crossing to regulate the flow of shifting the lines of waiting motor vehicles upstream of the level crossing, by example of retractable complementary barriers.

Referring also to FIG. 2, railway equipment enabling stopping railway convoys traveling upstream of the level crossing, in the presence of a obstacle on the latter, include means for detecting obstacles associated with control means for stopping railway convoys.

The obstacle detection means comprise a set of cameras of 26, 28, 30 and 32, located in the vicinity of the railway line of the railway crossing and directed towards the latter. They are connected to a central processing unit 34, constituted by a computer in which is stored an image processing algorithm and recognition of the type of obstacle present on the track.

Referring more particularly to FIG. 2, the control means of the railway train stop include, connected to the central processing unit 34 and receiving input an obstacle detection signal issued by the latter, a device 36 of speed control of railway convoys.

Such a device, also known as "KVB device" includes a speed setting unit 38 intended to be imposed on the trains, consisting of a digital coding device connected to a set of beacons, such as 40, arranged along the railway line 10 upstream of Railroad Crossing.

These tags 40, also known as "KVB tags" are each intended to communicate with a speed management device (no represented), of a conventional type, embarked on board railway convoys traveling on the track railway and adapted to enslave the speed of the latter on the value of the speed instructions which is transmitted to them by the beacons 40.

As seen in this FIG. 2, the control device 36 comprises, in input, a control relay 42 connected to the processing unit 34 and to which is delivered the obstacle detection signal, this relay controlling the commissioning of the coding device 38 for the purpose of developing speed regulations to be imposed on railway convoys.

Alternatively, in the case where the railway and the convoy are not equipped with a KVB speed control equipment, the anti-collision system is equipped with railway signaling optics (not shown) located along the railway line in upstream of the level crossing and controlled by the relay 42 so as to respond to an order of braking to the driver of the railway train.

The device 36 is completed by a conventional power supply unit 44 supplying the encoder device 38 and the central processing unit 34 with that the supply of lighting devices equipping the railway crossing so as to allow the detection of obstacles in low light conditions.

Moreover, the central processing unit 34 receives as input, in addition to the images provided by the cameras, signals delivered by the equipment of the crossing, such as signals indicating the state of the barriers, detection signals of a railway train, signals indicating the status of track circuits, with a view to providing a indication of the position of the railway train, ..., so as to adapt the value of speed instructions according to these parameters, as will be described later.

Optionally, the control device 36 may be provided with a transmitter radio wave driven by the actuator 42 so as to transmit alarm signals to a corresponding receiver boarded railway convoys traveling on the track railway.

It may also be provided with means for transmitting images delivered by the cameras shooting to transmit the latter to the convoy.

Advantageously, a modulator-demodulator (not shown) is connected to the central processing unit 34 for the transmission of all the information relating to the operation of the system to a central monitoring station, using a telephone network.

It is thus possible to remotely detect operating incidents like barrier breakages, breakdowns, ... and to identify the perpetrators of faulty behavior.

Finally, the central processing unit 34 is provided with memory means, type "black box", allowing the periodic storage of the images delivered by the cameras 26,28,30 and 32.

Referring again to Figure 1, we see that the cameras are arranged in pairs on either side of the roadway 12.

The processing unit 34 is also capable, by stereoscopic processing, to discriminate between a detected flat object, such as a shadow, a reflection, ... and an object in three dimensions (motor vehicle, pedestrian, ...).

Such stereoscopic processing is performed by comparing the images obtained by the cameras of each pair, the images coinciding for flat objects and being in offset for three-dimensional objects. Such treatment is also carried out comparing the dimensions of the non visible areas of the roadway due to the presence of a obstacle, which differs from one camera to another for three-dimensional objects.

As mentioned previously, the detection of obstacles located on the crossing is done by processing the images delivered by the cameras 26, 28, 30 and 32.

Although the obstacles likely to be present on track 10 at the approach of a railway convoy may be of different natures, it will be considered, in the following the description, that these obstacles are constituted either by motor vehicles stationary on track 10, for example because of a breakdown, or by vehicles cars crossing railway line 10 during the closing of gates 14 and 16 or when they are closed, despite the use of obstacles designed to crossing in a chicane of the crossing.

As will be described later, the behavior to be obtained from a convoy approach is adapted according to the distance to which the convoy of the type is obstacle detected and possibly the position of the anti-incursion barriers 14 and 16.

As is conventional, each camera delivers to the central processing unit 34 a set of images in the form of pixels each associated with a value luminance, that is to say, for monochrome cameras, values each corresponding to a gray level.

An image processing algorithm, stored in the processing unit 34, performs a filtering of the pixels delivered by the cameras, by comparison of the values of luminance with one or more threshold values for detecting the contour of an obstacle.

The rest of the treatment uses a classical technique of recognition of forms capable of determining the type of obstacle present on the crossing, by example by extracting characteristic parameters from detected objects and comparing of these parameters with predetermined parameters obtained by prior learning and each corresponding to a type of obstacle.

As mentioned previously, after detecting a vehicle on the level crossing, the central processing unit 34 operates the relay 42 so as to transmit a stop command signal to the railway train and then to provoke emergency braking or to ensure that the locomotive engineer braking necessary to stop the railway convoy.

In addition, for railways that do not have stopping equipment type KVB, relay 42 activates optical devices for railway signaling located along the railway line so as to warn the locomotive engineer of the risk of collision.

Speed setpoint signals and stop commands sent to beacons KVB are developed based on the distance to which the rail convoy is type of obstacle detected, namely a vehicle immobilized before closing the gates or vehicle attempting to cross the crossing during the closure of the crossing or after closing and, possibly, the position of the barriers.

Indeed, with reference to FIGS. 3 to 5, the positioning of the pedal electronics 46 for detecting railway convoy and controlling the closing of barriers 14 and 16 is the distance traveled by a railway train during the closing time of the barriers. This distance is usually called "distance Ad ".

The announcement distance is related to the maximum speed of movement of convoys but is independent of the stopping distance of the latter.

The stopping distance being generally greater than the advertisement distance, one distinguishes three distinct modes of detection and action on the convoy, corresponding respectively to the cases illustrated in Figures 3,4 and 5.

In the first case, shown in Figure 3, a railway train 47 travels next to a first group of KVB 48 beacons located at the stopping distance, that is to say a distance from the level crossing corresponding to the distance required for convoy 47 stops according to the deceleration curve C1 shown in this figure.

When a motor vehicle 50 immobilized on the crossing is detected while the convoy is at such a distance, the anti-collision system generates speed instructions so as to control the deceleration of the convoy 47 according to the curve C1, so as to avoid any collision.

In the second case shown in FIG. 4, the convoy 47 is located at the announcement distance and runs next to the electronic pedal 46 allowing the detection of the convoy and controlling the closing of the barriers 14 and 16.

In this situation, the detection of a vehicle immobilized or incursion in the crossing causes the emission of an emergency braking signal triggered by the KVB control device by transmission, at the level of a second group of KVB 52 beacons, with a zero speed reference value (curve C2), so as to slow convoy 47 as much as possible to limit the consequences of a collision in the where the vehicle does not have the possibility to disengage.

Thus, in this case, the detection of a vehicle immobilized or incursion causes the emergency braking of the convoy 47.

Finally, with reference to FIG. 5, the detection of any obstacle while the barriers 14 and 16 are in a closed position causes the emission, by a third group of beacons 54, a setpoint signal C3 identical to the signal of reference C2 mentioned above so as to minimize the consequences of a collision.

In the description just given, it was considered that the transition to level is equipped with anti-incursion barriers.

With reference to FIGS. 6 and 7, for a non-guarded level crossing, that is to say without such barriers, when a railway train 56 is located at a distance of the crossing, detection of a vehicle immobilized on the crossing causes a first group of beacons 58 to transmit setpoint signals of speed so as to obtain a stop of the train before the level crossing, according to the deceleration C4.

In the example shown in FIG. 7, in which the convoy 56 is located at a distance less than its stopping distance, the anti-collision system ensures, besides Detection of immobilized vehicles, detection of moving vehicles, that is to say in incursion.

In this case, we see in this figure that the system is equipped with a pedal 60 for the detection of the convoy 56, located at a distance close to the announcement distance mentioned with reference to FIGS.

According to this example, the detection of a vehicle immobile or incursion causes groups of beacons 62 and 64 to transmit setpoint signals C5 from emergency braking.

Claims (11)

1. Anti-collision system for level crossing, comprising road equipment (14, 16, 18, 20, 22, 24) which is arranged near the carriageway (12) of the level crossing to indicate the approach of a train and cause vehicles moving on the carriageway to be stopped, and means for detecting obstacles (26, 28, 30, 32, 34) on the track (10) of the level crossing, these means being arranged near the latter and connected to means (36) for commanding trains moving upstream from the level crossing to stop if an obstacle is present on it, the detection means including at least one device for taking pictures (26, 28, 30, 32) which is directed towards the level crossing, characterized in that the picture-taking device(s) is/are connected to a central processing unit (34), comprising means for processing images and recognising the type of obstacle which is present on the track.
2. Anti-collision system according to Claim 1, characterized in that whereas the or each picture-taking device (26, 28, 30, 32) delivers images of the level crossing in the form of a set of pixels each of which is associated with a numeric luminance value, the means for processing images includes means for filtering the said pixels by comparison of the said numeric values with at least one threshold value for detecting the contour of the said obstacle.
3. Anti-collision system according to one of Claims 1 and 2, characterized in that it includes a set of picture-taking devices (26, 28, 30, 32) which are arranged in pairs on either side of the carriageway of the level crossing, the processing unit providing stereoscopic processing (34) of the images which are formed by the picture-taking devices.
4. Anti-collision system according to any one of Claims 1 to 3, characterized in that the means (36) for commanding trains to stop include, connected to the central processing unit (34) and receiving as input an obstacle detection signal which is supplied by the latter, a device for controlling the speed of railway vehicles, comprising a unit (38) for developing speed instructions, which is connected to a set of beacons (40) which are arranged along the track (10) upstream from the level crossing and each intended to enter into communication with a speed management device on board the train, when the train passes near each beacon (40).
5. Anti-collision system according to any one of Claims 1 to 4, characterized in that the means (36) for commanding the train to stop include optical railway signalling devices which are located along the track (10), upstream from the level crossing and controlled by the means for detecting obstacles (26, 28, 30, 32).
6. Anti-collision system according to any one of Claims 1 to 5, characterized in that the means (36) for commanding the train to stop include means for emitting alarm signals in the direction of a corresponding receiver on board the train.
7. Anti-collision system according to any one of Claims 1 to 6, characterized in that it includes a modulator-demodulator which is connected to the central processing unit (34) to put the anti-collision system into communication with a remote monitoring centre via a telephone network.
8. Anti-collision system according to any one of Claims 1 to 7, characterized in that the road equipment includes automatic anti-incursion barriers (14, 16) which are arranged on either side of the level crossing and controlled by train detection means (46, 60) which are arranged on the track (10) upstream from the level crossing.
9. Anti-collision system according to any one of Claims 1 to 8, characterized in that the road carriageway includes, on either side of the level crossing, means (18, 20) for slowing down vehicles moving on the latter.
10. Anti-collision system according to one of Claims 8 and 9, characterized in that it includes two anti-incursion barriers (14, 16) which are each arranged on one of the lanes of the carriageway, and in that it is equipped with obstacles (25) separating the said lanes to prevent zigzag passage through the level crossing.
11. Anti-collision system according to any one of Claims 2 to 10, characterized in that the central processing unit (34) also includes means for periodic recording of the images which are supplied by the picture-taking devices.

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