EP0422308A1 - Traffic aid by coded marking - Google Patents

Traffic aid by coded marking Download PDF

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Publication number
EP0422308A1
EP0422308A1 EP89402801A EP89402801A EP0422308A1 EP 0422308 A1 EP0422308 A1 EP 0422308A1 EP 89402801 A EP89402801 A EP 89402801A EP 89402801 A EP89402801 A EP 89402801A EP 0422308 A1 EP0422308 A1 EP 0422308A1
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EP
European Patent Office
Prior art keywords
circuit
receiver
detector
voltage
transmitter
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Application number
EP89402801A
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German (de)
French (fr)
Inventor
Yves Archambault
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
SECTRONIC SA
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SECTRONIC SA
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Publication of EP0422308A1 publication Critical patent/EP0422308A1/en
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    • G—PHYSICS
    • G08—SIGNALLING
    • G08G—TRAFFIC CONTROL SYSTEMS
    • G08G1/00—Traffic control systems for road vehicles
    • G08G1/09—Arrangements for giving variable traffic instructions
    • G08G1/0962—Arrangements for giving variable traffic instructions having an indicator mounted inside the vehicle, e.g. giving voice messages
    • G08G1/0967—Systems involving transmission of highway information, e.g. weather, speed limits
    • G08G1/096708—Systems involving transmission of highway information, e.g. weather, speed limits where the received information might be used to generate an automatic action on the vehicle control
    • G08G1/096716—Systems involving transmission of highway information, e.g. weather, speed limits where the received information might be used to generate an automatic action on the vehicle control where the received information does not generate an automatic action on the vehicle control
    • G—PHYSICS
    • G08—SIGNALLING
    • G08G—TRAFFIC CONTROL SYSTEMS
    • G08G1/00—Traffic control systems for road vehicles
    • G08G1/09—Arrangements for giving variable traffic instructions
    • G08G1/0962—Arrangements for giving variable traffic instructions having an indicator mounted inside the vehicle, e.g. giving voice messages
    • G08G1/0967—Systems involving transmission of highway information, e.g. weather, speed limits
    • G08G1/096766—Systems involving transmission of highway information, e.g. weather, speed limits where the system is characterised by the origin of the information transmission
    • G08G1/096783—Systems involving transmission of highway information, e.g. weather, speed limits where the system is characterised by the origin of the information transmission where the origin of the information is a roadside individual element

Definitions

  • the present invention relates to a traffic assistance device, intended in particular, but not exclusively, for road traffic.
  • DE-A- 2 136 070 describes a road signaling warning device comprising a field or radiation source included in the road and at least one detector deposited on the vehicle, the detector generating an electrical signal which generates a sound signal and / or visual.
  • the source is a source of magnetic field which is detected by the detector.
  • EP-A- 0 135 749 proposes to include passive resonator components in the route by means of prefabricated marking strips, the vehicle including a transceiver. In both cases, the devices involve the use of specific means incorporated in the roadway.
  • a first object of the present invention is a signaling device using the markings on the roadways as they exist and which constitute a significant code for all drivers. (white or yellow bands, continuous or discontinuous etc ).
  • a second object of the present invention is the adaptation of the principle of the bar code, so as to transform a vehicle into a system for reading a code written on a roadway using light colored bands.
  • the main difficulty consists in allowing reliable detection and insensitive to the different atmospheric constraints and irregularities of the information medium which is the roadway. Indeed, a roadway is never very regular, both in terms of appearance (holes, rails, bridge joints, puddles, etc.), as regards its color (bitumen, cement , concrete, sand, gravel, etc ). In addition, temperature, rain, solar radiation are variable elements likely to disturb a reading.
  • the circulation assistance device is characterized in that it comprises a transmitter emitting invisible modulated light waves and a receiver, oriented in the same direction, a circuit for processing the information received by the receiver and signaling and / or alarm control means, the receiver receiving the beam emitted by the transmitter, after reflection on a surface carrying a coded marking, an optical filter being arranged in front of the receiver.
  • the operation of the device is independent of the illumination, that is to say that it can read a code, both day and night.
  • the code that is detected and processed can constitute either guidance information or reminders of authorized speed, dangerous turn, etc.
  • the filter only lets light signals pass at a defined frequency, corresponding to the frequency d 'emission from the transmitter, which eliminates all parasitic light phenomena.
  • the present invention also relates to a trajectory drift detector using at least two traffic assistance devices working in parallel.
  • the problem which arises is that of the marking codes perpendicular to the direction d vehicle advance. Indeed, this signaling risks generating error signals when crossing pedestrian crossings, bridge joints, and more generally of any traces perpendicular or oblique to the direction of travel of the vehicle.
  • Another object of the present invention is to free the sconductor from monitoring these perpendicular or oblique marks.
  • the trajectory drift detector comprising at least two sensors each including a transmitter and a receiver fixed to the front of the vehicle, is characterized in that the output signals from the sensors are routed on a surveillance stage or discriminator stage.
  • This stage receives the output signals from the two sensors and, if it receives only one signal, it takes it into account, whereas if it receives two signals separated or not by a short interval and relating to the two sides of the vehicle , it will know that it is a transverse marking and will cancel the reception.
  • the sensors are connected to the same oscillator.
  • the detector is advantageously provided with self-diagnostic means making it possible to cancel the operation of the detector in the event of a fault in one of the components or of a track.
  • FIG. 1 there is a transmitter 1 emitting invisible light radiation, the transmitter 1 being connected to an oscillator 16, through a frequency divider 17, followed by a power amplifier 18.
  • a photosensitive receiver 2 oriented in the same direction as the emitter 1, after passing through an optical filter 3, receives pulses of light more or less reflected by the surface R "bombarded” or “illuminated” by the emitter 1, and transforms them into electrical pulses .
  • the frequency of emission of the modulated light is greater than 6000 Hertz.
  • the response speed of the detector is such that the speed of the mobile carrying the detector or the code does not intervene.
  • the output of receiver 2 is connected to an information processing circuit making it possible to use the information received.
  • This circuit includes a first high-pass filter 4, intended to eliminate unwanted parasitic low frequencies.
  • the pulses thus filtered are routed to the input of a variable gain amplifier 5, where they are amplified.
  • the output of the variable gain amplifier 5 is connected to the input of a very narrow band pass filter 6 with a very high quality coefficient, the tuning frequency of which is controlled by the transmission frequency of oscillator 16 or a multiple thereof.
  • the tuning frequency of filter 6 is thus locked on the basis of a signal taken from stage 17.
  • This enslavement of the tuning frequency overcomes the inevitable drifts for operation in a temperature range between -10 and + 65 °, since the temperature influences the sensitive elements of the oscillator 16 and the filter 6 Furthermore, this enslavement makes it possible to lower the production costs of the device, since the manufacture of this filter no longer requires precise components, nor tedious adjustments.
  • the output of the filter 6 is connected to a rectifier stage 7, intended to transform the envelope curve of the signal into average DC voltage, thanks to the time constants used.
  • An integrator 8 compares this signal with a reference voltage B, available on the supply stage 14, to act on the gain of the amplifier 5, with a long time constant with respect to the code reading time.
  • a comparator 9 on one of the inputs to which a reference voltage C is applied, receives on its other input the output signals from stage 7, and formats them.
  • the code printed on roadway R is decrypted and transformed into continuous electrical signals, of variable durations.
  • the output signals of the comparator 9 can supply, either directly or via a relay 12, equipment intended to allow the interpretation of the code read by the sensor 2 which is then connected at 23.
  • the output signals of the comparator 9 can also be routed directly, either to an audible alarm 11 and / or to an indicator light 10, to signal the proper functioning of the device.
  • the power supply 14 supplies the voltage 12 Volts necessary for the operation of the different stages, and has sockets A, B, C, on which are available the reference voltages necessary for the proper functioning of the code reader.
  • the operation of the latter can be interrupted by a switch 13, 15, if the driver so desires.
  • the reader has been designed for outdoor use and the reading of a code is not disturbed by day or night weather conditions. This is achieved by the use of filters, optics and electronic slaves.
  • the automatic gain control allows an adaptation of the sensitivity level according to the "color", in invisible light, of the background of the surface on which the codes are written. This color is responsible for the absorption coefficient of light radiation, and therefore for the average amount of signal picked up by the receiver, so that the decoding threshold is independent of the average value of the reception signal. It is only necessary that there is sufficient contrast between the background "color” and the marking codes for the device to function properly.
  • the duration of the output signal from comparator 9 is proportional to the width of the marking strips, and its amplitude is constant.
  • the elements 1, 2 and 3 are preferably included in a support 21. These elements are themselves mounted on a block 20.
  • the support 21 preferably has a configuration cylindrical or oblong completely hermetic at its upper part, the connecting wires (not shown) coming out downwards, in order to ensure greater immunity to humidity and runoff.
  • the support 21 is advantageously mounted in front of one of the front wheels, substantially at the level of the bumper, by a "V" of attachment 19 articulated at 22, to avoid splashing water .
  • the height at which the device is fixed is preferably of the order of 40 to 45 cm, but it can increase to 1 meter or more, with a parabolic reflector and / or a focusing optic in transmission and in reception.
  • the device which has just been described can be carried by a mobile (road or rail vehicle for example), this vehicle decoding fixed signals "printed" on the road or on the track, and recalling them by an audible or light signal at driver. It can also be mounted on post fixed, the code then being carried by the mobile, it being understood that there must always be a relative speed between the reading device and the coding.
  • the drift detector device shown in FIG. 4, comprises two sensors which each consist of a transmitter 1 and a receiver 2, the receiver 2 being arranged behind an optical filter 3, as before.
  • the emitter emits invisible light radiation, for example infrared, which allows the device to operate without being disturbed by visible light.
  • the two transmitters 1 are connected to a single oscillator 16, followed by a voltage divider 17 which, in the example shown, controls two amplifiers 18, the output of which is connected to a transmitter 1.
  • the divider stage 17 also allows to control filters 6 slaved in each of the sensors.
  • the output of each of the receivers is followed by a high-pass filter 4, by a variable gain amplifier 5, each amplifier 5 being followed by a band-pass filter 6 controlled by the transmission frequency, and by a rectifier stage 7.
  • the rectified signal is compared, in the integrator 8, to a reference voltage B to control the gain of the amplifier 5.
  • the output signal from the rectifier stages 7 is compared to a reference voltage C, in a comparator stage 9.
  • a logic signal "0" or "1” is obtained. of duration proportional to the width of marking detected, depending on whether there is detection or not.
  • the discriminator stage 24 detects a change in the output level on one of the two comparators 9, and stores it in memory. If no signal appears on the other comparator within a predetermined time interval, it authorizes the transmission of the signal to the corresponding timer.
  • the output of timer 25 is connected to a light indicator and / or to a circuit 26 ensuring the function of logical OR, which triggers an audible alarm 11, if one " OR " the other of the sensors signals a white line.
  • the discriminator 24 acts on switches 15 to cut the transmission in the event that two simultaneous or consecutive level changes (line perpendicular or oblique to the direction of the vehicle) are detected by the detector.
  • the detector In order to increase the operating reliability of the detector, it is equipped with a self-diagnostic circuit which tests the device each time it is powered up, in order to avoid triggering false alarms.
  • the average voltage at the output of each of the rectifier stages 7 (supplied with a DC voltage A) is equal to the reference voltage B, the voltage B being less than the reference voltage C. If a malfunction appears in the signal amplification chain from a sensor or in the sensor itself during system initialization, the voltage regulation at the output of rectifier 7 does not reach the reference level 8.
  • the corresponding differential amplifier 9 does not deliver any signal and the start-up indicator does not light up.
  • the voltage generator 14 imposes, only during initialization, a reference voltage C ′, which is less than B, so that the comparators 9 switch to the "alarm" position if the voltage at the output of the rectifier 7 reaches the voltage B, and the comparators 9 validate the correct operation of the device. If the test is conclusive for the sensors, the reference voltage generator 14 then imposes a reference voltage C, greater than C ′ and B, corresponding to the normal operation of the device. The test is indicated by an indicator light for each sensor.
  • the voltage generator 14 is supplied by a stage 27 which supplies the voltages A and B necessary for operation, a voltage C or C ′ being available at the output of the generator 14.
  • the sensitivity for detecting optical transitions is determined by the value of the reference voltage C, applied to one of the inputs of the comparators 9.

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  • Life Sciences & Earth Sciences (AREA)
  • Atmospheric Sciences (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Traffic Control Systems (AREA)

Abstract

Device to aid road traffic, comprising at least one transmitter and one receiver of infrared radiation which are pointed in the same direction, a circuit for processing the information received by the receiver, and means of control, signalling and/or alarm. The receiver (2) receives the beam emitted by the transmitter (1), after reflection on surfaces (R) bearing a coded marking on the ground or on panels and, after processing, possibly triggers an alarm. <IMAGE>

Description

La présente invention a pour objet un dispositif d'aide à la circulation, destiné en particulier, mais non exclusivement, à la circulation routière.The present invention relates to a traffic assistance device, intended in particular, but not exclusively, for road traffic.

Différents dispositifs d'aide à la circulation ont déjà été proposés. DE-A- 2 136 070 décrit un dispositif avertisseur de signalisation routière comprenant une source de champ ou de rayonnement incluse dans la route et au moins un détecteur déposé sur le véhicule, le détecteur générant un signal électrique qui génère un signal sonore et/ou visuel. La source est une source de champ magnétique qui est détecté par le détecteur. EP-A- 0 135 749 propose d'inclure dans la route des composants résonateurs passifs au moyen de bandes de marquage préfabriquées, le véhicule incluant un émetteur-récepteur.
Dans les deux cas, les dispositifs impliquent la mise en oeuvre de moyens particuliers incorporés dans la chaussée.Various traffic assistance devices have already been proposed. DE-A- 2 136 070 describes a road signaling warning device comprising a field or radiation source included in the road and at least one detector deposited on the vehicle, the detector generating an electrical signal which generates a sound signal and / or visual. The source is a source of magnetic field which is detected by the detector. EP-A- 0 135 749 proposes to include passive resonator components in the route by means of prefabricated marking strips, the vehicle including a transceiver.
In both cases, the devices involve the use of specific means incorporated in the roadway.

Un premier objet de la présente invention est un dispositif de signalisation utilisant les marquages sur les chaussées tels qu'ils existent et qui constituent un code significatif pour tous les conducteurs. (bandes blanches ou jaunes, continues ou discontinues etc...)A first object of the present invention is a signaling device using the markings on the roadways as they exist and which constitute a significant code for all drivers. (white or yellow bands, continuous or discontinuous etc ...)

Un second objet de la présente invention est l'adaptation du principe du code barre, de manière à transformer un véhicule en système de lecture dlun code inscrit sur une chaussée à l'aide de bandes de couleur claire. La principale difficulté consiste à permettre une détection fiable et insensible aux différentes contraintes atmosphériques et aux irrégularités du support de l'information qui est la chaussée. En effet, une chaussée n'est jamais très régulière, tant au point de vue aspect (trous, rails, joints de pont, flaques d'eau, etc...), qu'en ce qui concerne sa couleur (bitume, ciment, béton, sable, gravillons, etc...). De plus, la température, la pluie, le rayonnement solaire sont des éléments variables susceptibles de perturber une lecture.A second object of the present invention is the adaptation of the principle of the bar code, so as to transform a vehicle into a system for reading a code written on a roadway using light colored bands. The main difficulty consists in allowing reliable detection and insensitive to the different atmospheric constraints and irregularities of the information medium which is the roadway. Indeed, a roadway is never very regular, both in terms of appearance (holes, rails, bridge joints, puddles, etc.), as regards its color (bitumen, cement , concrete, sand, gravel, etc ...). In addition, temperature, rain, solar radiation are variable elements likely to disturb a reading.

Il existe, bien entendu, des lecteurs de code barre, mais ceux-ci opèrent toujours en milieu protégé, ce qui n'est pas le cas selon la présente invention.There are, of course, bar code readers, but these always operate in a protected environment, which is not the case according to the present invention.

Selon l'invention, le dispositif d'aide à la circulation est caractérisé en ce qu'il comprend un émetteur émettant des ondes lumineuses modulées invisibles et un récepteur, orienté dans la même direction, un circuit de traitement de l'information captée par le récepteur et des moyens de commande de signalisation et/ou d'alarme, le récepteur recevant le faisceau emis par l'émetteur, après réflexion sur une surface portant un marquage codé, un filtre optique étant disposé devant le récepteur.According to the invention, the circulation assistance device is characterized in that it comprises a transmitter emitting invisible modulated light waves and a receiver, oriented in the same direction, a circuit for processing the information received by the receiver and signaling and / or alarm control means, the receiver receiving the beam emitted by the transmitter, after reflection on a surface carrying a coded marking, an optical filter being arranged in front of the receiver.

Ainsi, par le choix d'une émission-réception de lumière modulée, dans un spectre de fréquences différent de celui de la lumière visible, le fonctionnement du dispositif est indépendant de l'éclairement, c'est-à-dire qu'il peut lire un code, tant de jour que de nuit.Thus, by the choice of a modulated light emission-reception, in a frequency spectrum different from that of visible light, the operation of the device is independent of the illumination, that is to say that it can read a code, both day and night.

Le code qui est détecté et traité peut constituer, soit des informations de guidage, soit des rappels de vitesse autorisée, de virage dangereux, etc...le filtre ne laisse passer que les signaux lumineux à une fréquence définie, correspondant à la fréquence d'émission de l'émetteur, ce qui élimine tous les phénomènes lumineux parasites.The code that is detected and processed can constitute either guidance information or reminders of authorized speed, dangerous turn, etc. The filter only lets light signals pass at a defined frequency, corresponding to the frequency d 'emission from the transmitter, which eliminates all parasitic light phenomena.

La présente invention vise également un détecteur de dérive de trajectoire utilisant au moins deux dispositifs d'aide à la circulation travaillant en parallèle.The present invention also relates to a trajectory drift detector using at least two traffic assistance devices working in parallel.

Dans le cas de l'application du dispositif selon l'invention à une dérive de trajectoire, telle que, par exemple, le franchissement d'une bande blanche continue, le problème qui se pose est celui des codes de marquage perpendiculaires à la direction d'avance du véhicule. En effet, cette signalisation risque de générer des signaux d'erreur lors du franchissement de passages pour piétons, de joints de ponts, et plus généralement de toutes traces perpendiculaires ou obliques à la direction de déplacement du véhicule.In the case of the application of the device according to the invention to a trajectory drift, such as, for example, the crossing of a continuous white strip, the problem which arises is that of the marking codes perpendicular to the direction d vehicle advance. Indeed, this signaling risks generating error signals when crossing pedestrian crossings, bridge joints, and more generally of any traces perpendicular or oblique to the direction of travel of the vehicle.

Un autre objet de la présente invention est de libérer le sconducteur de la surveillance de ces marques perpendiculaires ou obliques.Another object of the present invention is to free the sconductor from monitoring these perpendicular or oblique marks.

Selon une caractéristique de l'invention, le détecteur de dérive de trajectoire, comprenant au moins deux capteurs incluant chacun un émetteur et un récepteur fixés à l'avant du véhicule, est caractérisé en ce que les signaux de sortie des capteurs sont acheminés sur un étage de surveillance ou étage discriminateur.According to a characteristic of the invention, the trajectory drift detector, comprising at least two sensors each including a transmitter and a receiver fixed to the front of the vehicle, is characterized in that the output signals from the sensors are routed on a surveillance stage or discriminator stage.

Cet étage reçoit les signaux de sortie des deux capteurs et, s'il ne reçoit qu'un signal, il le prend en compte, alors que s'il reçoit deux signaux séparés ou non par un bref intervalle et relatifs aux deux côtés du véhicule, il saura qu'il s'agit d'un marquage transversal et annulera la réception. De préférence, les capteurs sont connectés à un même oscillateur.This stage receives the output signals from the two sensors and, if it receives only one signal, it takes it into account, whereas if it receives two signals separated or not by a short interval and relating to the two sides of the vehicle , it will know that it is a transverse marking and will cancel the reception. Preferably, the sensors are connected to the same oscillator.

Le détecteur est muni avantageusement de moyens d'autodiagnostic permettant d'annihiler le fonctionnement du détecteur en cas de défaut de l'un des composants ou d'une voie.The detector is advantageously provided with self-diagnostic means making it possible to cancel the operation of the detector in the event of a fault in one of the components or of a track.

D'autres caractéristiques et avantages de l'invention apparaitront au cours de la description qui va suivre d'un mode particulier de réalisation, donné uniquement à titre d'exemple non limitatif, en regard des dessins qui représentent :

  • - la figure 1, un schéma par blocs du dispositif selon l'invention
  • - la figure 2, une vue d'un ensemble émetteur-récepteur à l'intérieur de son support, en vue de face
  • - la figure 3, une vue du même support, en vue de côté.
  • - la figure 4 un schéma par blocs d'un détecteur de dérive de trajectoire équipé de deux capteurs.
Other characteristics and advantages of the invention will appear during the description which follows of a particular embodiment, given solely by way of nonlimiting example, with reference to the drawings which represent:
  • - Figure 1, a block diagram of the device according to the invention
  • - Figure 2, a view of a transmitter-receiver assembly inside its support, in front view
  • - Figure 3, a view of the same support, in side view.
  • - Figure 4 a block diagram of a trajectory drift detector equipped with two sensors.

Sur la figure 1, on distingue un émetteur 1 émettant une radiation lumineuse invisible, l'émetteur 1 étant connecté à un oscillateur 16, à travers un diviseur de fréquence 17, suivi par un amplificateur de puissance 18. Un récepteur 2 photosensible, orienté dans la même direction que l'émetteur 1, reçoit après passage à travers un filtre optique 3, des impulsions de lumière plus ou moins réfléchie par la surface R "bombardée" ou "éclairée" par l'émetteur 1, et les transforme en impulsions électriques. De préférence, pour une plus grande insensibilité aux réflexions parasites, la fréquence d'émission de la lumière modulée est supérieure à 6000 Hertz. La vitesse de réponse du détecteur est telle que la vitesse du mobile portant le détecteur ou le code n'intervient pas.In FIG. 1, there is a transmitter 1 emitting invisible light radiation, the transmitter 1 being connected to an oscillator 16, through a frequency divider 17, followed by a power amplifier 18. A photosensitive receiver 2, oriented in the same direction as the emitter 1, after passing through an optical filter 3, receives pulses of light more or less reflected by the surface R "bombarded" or "illuminated" by the emitter 1, and transforms them into electrical pulses . Preferably, for greater insensitivity to stray reflections, the frequency of emission of the modulated light is greater than 6000 Hertz. The response speed of the detector is such that the speed of the mobile carrying the detector or the code does not intervene.

La sortie du récepteur 2 est connectée à un circuit de traitement de l'information permettant d'exploiter les informations captées. Ce circuit comprend un premier filtre passe-haut 4, destiné à éliminer les fréquences basses parasites indésirables. Les impulsions ainsi filtrées sont acheminées sur l'entrée d'un amplificateur à gain variable 5, où elles sont amplifiées en amplitude. La sortie de l'amplificateur à gain variable 5 est connectée à l'entrée d'un filtre passe-bande 6, très étroit, à très fort coefficient de qualité, dont la fréquence d'accord est asservie à la fréquence d'émission de l'oscillateur 16 ou à un multiple de celle-ci. La fréquence d'accord du filtre 6 est ainsi verrouillée à partir d'un signal prélevé sur l'étage 17.The output of receiver 2 is connected to an information processing circuit making it possible to use the information received. This circuit includes a first high-pass filter 4, intended to eliminate unwanted parasitic low frequencies. The pulses thus filtered are routed to the input of a variable gain amplifier 5, where they are amplified. The output of the variable gain amplifier 5 is connected to the input of a very narrow band pass filter 6 with a very high quality coefficient, the tuning frequency of which is controlled by the transmission frequency of oscillator 16 or a multiple thereof. The tuning frequency of filter 6 is thus locked on the basis of a signal taken from stage 17.

Cet asservissement de la fréquence d'accord permet de pallier les dérives inévitables pour un fonctionnement dans une plage de températures comprise entre -10 et +65°, étant donné que la température influe sur les éléments sensibles de l'oscillateur 16 et du filtre 6. Par ailleurs, cet asservissement permet d'abaisser les coûts de production de l'appareil, puisque la fabrication de ce filtre ne nécessite plus de composants précis, ni de réglages fastidieux. La sortie du filtre 6 est reliée à un étage redresseur 7, destiné à transformer la courbe enveloppe du signal en tension continue moyenne, grâce aux constantes de temps utilisées.This enslavement of the tuning frequency overcomes the inevitable drifts for operation in a temperature range between -10 and + 65 °, since the temperature influences the sensitive elements of the oscillator 16 and the filter 6 Furthermore, this enslavement makes it possible to lower the production costs of the device, since the manufacture of this filter no longer requires precise components, nor tedious adjustments. The output of the filter 6 is connected to a rectifier stage 7, intended to transform the envelope curve of the signal into average DC voltage, thanks to the time constants used.

Un intégrateur 8 compare ce signal à une tension de référence B, disponible sur l'étage d'alimentation 14, pour agir sur le gain de l'amplificateur 5, avec une constante de temps longue par rapport au temps de lecture du code. Ainsi, il est possible d'éliminer le paramètre résultant de la diversité de couleurs des chaussées et d'obtenir une adaptation automatique du gain de l'ensemble des lecteurs en fonction d'une part, des couleurs de revêtement, et d'autre part, de la distance de lecture. Ce dispositif de contrôle automatique du gain apporte des avantages en fabrication, par l'absence de réglage et l'auto-adaptation à des capteurs plus ou moins sensibles.An integrator 8 compares this signal with a reference voltage B, available on the supply stage 14, to act on the gain of the amplifier 5, with a long time constant with respect to the code reading time. Thus, it is possible to eliminate the parameter resulting from the diversity of pavement colors and to obtain an automatic adaptation of the gain of all of the readers as a function, on the one hand, of the coating colors, and on the other hand , the reading distance. This automatic gain control device brings advantages in manufacturing, by the absence of adjustment and self-adaptation to more or less sensitive sensors.

Un comparateur 9, sur l'une des entrées duquel est appliquée une tension de référence C, reçoit sur son autre entrée les signaux de sortie de l'étage 7, et les met en forme. A ce niveau, le code imprimé sur la chaussée R est décrypté et transformé en signaux électriques continus, de durées variables. Les signaux de sortie du comparateur 9 peuvent alimenter, soit directement, soit par l'intermédiaire d'un relais 12, un équipement destiné à permettre l'interprétation du code lu par le capteur 2 qui est alors branché en 23. Les signaux de sortie du comparateur 9 peuvent également être acheminés directement, soit sur une alarme sonore 11 et/ou sur un témoin lumineux 10, pour signaler le bon fonctionnement de l'appareil. L'alimentation 14 fournit la tension 12 Volts nécessaire au fonctionnement des différents étages, et présente des prises A, B, C, sur lesquelles sont disponibles les tensions de référence nécessaires au bon fonctionnement du lecteur de code. Le fonctionnement de celui-ci peut être interrompu par un interrupteur 13, 15, si le conducteur le désire. Par ailleurs, il est possible de brancher directement sur les bornes 23 un circuit de commande pouvant agir sur certains organes essentiels du véhicule.A comparator 9, on one of the inputs to which a reference voltage C is applied, receives on its other input the output signals from stage 7, and formats them. At this level, the code printed on roadway R is decrypted and transformed into continuous electrical signals, of variable durations. The output signals of the comparator 9 can supply, either directly or via a relay 12, equipment intended to allow the interpretation of the code read by the sensor 2 which is then connected at 23. The output signals of the comparator 9 can also be routed directly, either to an audible alarm 11 and / or to an indicator light 10, to signal the proper functioning of the device. The power supply 14 supplies the voltage 12 Volts necessary for the operation of the different stages, and has sockets A, B, C, on which are available the reference voltages necessary for the proper functioning of the code reader. The operation of the latter can be interrupted by a switch 13, 15, if the driver so desires. Furthermore, it is possible to connect directly to the terminals 23 a control circuit which can act on certain essential components of the vehicle.

Le lecteur a été conçu pour une utilisation à l'extérieur et la lecture d'un code n'est pas perturbée par les conditions météorologiques diurnes ou noctures. Ce résultat est obtenu par l'emploi de filtres, optique et électronique asservi. Le contrôle automatique du gain permet une adaptation du niveau de sensibilité en fonction de la "couleur", en lumière invisible, de fond de la surface sur laquelle sont inscrits les codes. Cette couleur est responsable du coefficient d'absorption du rayonnement lumineux, et par suite, de 'la quantité moyenne de signal captée par le récepteur, de sorte que le seuil de décodage est indépendant de la valeur moyenne du signal de réception. Il est seulement nécessaire qu'il existe un contraste suffisant entre la "couleur" de fond et les codes de marquage pour que l'appareil fonctionne convenablement. La durée du signal de sortie du comparateur 9 est proportionnelle à la largeur des bandes de marquage, et son amplitude est constante.The reader has been designed for outdoor use and the reading of a code is not disturbed by day or night weather conditions. This is achieved by the use of filters, optics and electronic slaves. The automatic gain control allows an adaptation of the sensitivity level according to the "color", in invisible light, of the background of the surface on which the codes are written. This color is responsible for the absorption coefficient of light radiation, and therefore for the average amount of signal picked up by the receiver, so that the decoding threshold is independent of the average value of the reception signal. It is only necessary that there is sufficient contrast between the background "color" and the marking codes for the device to function properly. The duration of the output signal from comparator 9 is proportional to the width of the marking strips, and its amplitude is constant.

Dans le cas d'un véhicule automobile, les éléments 1, 2 et 3, sont, de préférence, inclus dans un support 21. Ces éléments sont eux-mêmes montés sur un bloc 20. Le support 21 a, de préférence, une configuration cylindrique ou oblongue totalement hermétique à sa partie supérieure, les fils de liaison (non représentés) sortant vers le bas, afin d'assurer une plus grande immunité à l'humidité et aux eaux de ruissellement. Dans le cas d'un véhicule automobile, le support 21 est avantageusement monté devant l'une des roues avant, sensiblement au niveau du pare-choc, par un "V" de fixation 19 articulé en 22, pour éviter les projections d'eau. La hauteur à laquelle est fixé le dispositif est, de préférence, de l'ordre de 40 à 45 cm, mais elle peut passer à 1 mètre ou davantage, avec un réflecteur parabolique et/ou une optique de focalisation en émission et en réception.In the case of a motor vehicle, the elements 1, 2 and 3 are preferably included in a support 21. These elements are themselves mounted on a block 20. The support 21 preferably has a configuration cylindrical or oblong completely hermetic at its upper part, the connecting wires (not shown) coming out downwards, in order to ensure greater immunity to humidity and runoff. In the case of a motor vehicle, the support 21 is advantageously mounted in front of one of the front wheels, substantially at the level of the bumper, by a "V" of attachment 19 articulated at 22, to avoid splashing water . The height at which the device is fixed is preferably of the order of 40 to 45 cm, but it can increase to 1 meter or more, with a parabolic reflector and / or a focusing optic in transmission and in reception.

Le dispositif qui vient d'être décrit peut être porté par un mobile (véhicule routier ou ferroviaire par exemple), ce véhicule décodant des signaux fixes "imprimés" sur la route ou sur la voie, et les rappelant par un signal sonore ou lumineux au conducteur. Il peut également être monté à poste fixe, le code étant alors porté par le mobile, étant entendu qu'il faut qu'il y ait toujours une vitesse relative entre le dispositif de lecture et le codage.The device which has just been described can be carried by a mobile (road or rail vehicle for example), this vehicle decoding fixed signals "printed" on the road or on the track, and recalling them by an audible or light signal at driver. It can also be mounted on post fixed, the code then being carried by the mobile, it being understood that there must always be a relative speed between the reading device and the coding.

La description qui vient d'être donnée se rapporte à l'utilisation d'un seul lecteur, mais il est bien entendu possible de monter sur un véhicule ou un aéronef deux ou plusieurs détecteurs, de manière à former un ensemble de guidage permettant de suivre, même sans visibilité, des lignes blanches délimitant une zone de roulage.The description which has just been given relates to the use of a single reader, but it is of course possible to mount on a vehicle or an aircraft two or more detectors, so as to form a guide assembly making it possible to follow , even without visibility, white lines delimiting a driving area.

Le dispositif de détecteur de dérive, représenté sur la figure 4 comprend deux capteurs qui se composent, chacun d'un émetteur 1 et d'un récepteur 2, le récepteur 2 étant disposé derrière un filtre optique 3, comme précédemment.The drift detector device, shown in FIG. 4, comprises two sensors which each consist of a transmitter 1 and a receiver 2, the receiver 2 being arranged behind an optical filter 3, as before.

L'émetteur émet une radiation lumineuse invisible, par exemple infrarouge, ce qui permet au dispositif de fonctionner sans être perturbé par la lumière visible. Les deux émetteurs 1 sont connectés à un oscillateur unique 16, suivi d'un diviseur de tension 17 qui, dans l'exemple représenté, pilote deux amplificateurs 18, dont la sortie est reliée à un émetteur 1. L'étage diviseur 17 permet également de piloter des filtres 6 asservis dans chacun des capteurs. La sortie de chacun des récepteurs est suivie d'un filtre passe-haut 4, d'un amplificateur à gain variable 5, chaque amplificateur 5 étant suivi d'un filtre passe-bande 6 asservi à la fréquence d'émission, et d'un étage redresseur 7. Le signal redressé est comparé, dans l'intégrateur 8, à une tension de référence B pour piloter le gain de l'amplificateur 5.The emitter emits invisible light radiation, for example infrared, which allows the device to operate without being disturbed by visible light. The two transmitters 1 are connected to a single oscillator 16, followed by a voltage divider 17 which, in the example shown, controls two amplifiers 18, the output of which is connected to a transmitter 1. The divider stage 17 also allows to control filters 6 slaved in each of the sensors. The output of each of the receivers is followed by a high-pass filter 4, by a variable gain amplifier 5, each amplifier 5 being followed by a band-pass filter 6 controlled by the transmission frequency, and by a rectifier stage 7. The rectified signal is compared, in the integrator 8, to a reference voltage B to control the gain of the amplifier 5.

Pour chacune des deux voies, le signal de sortie des étages redresseurs 7 est comparé à une tension de référence C, dans un étage comparateur 9. A la sortie de chacun des comparateurs 9, on obtient un signal logique "0" ou "1" de durée proportionnelle à la largeur de marquage détecté, selon qu'il y a détection ou non.For each of the two channels, the output signal from the rectifier stages 7 is compared to a reference voltage C, in a comparator stage 9. At the output of each of the comparators 9, a logic signal "0" or "1" is obtained. of duration proportional to the width of marking detected, depending on whether there is detection or not.

Jusqu'à ce point, il n'y a aucune interférence entre les signaux, les voies étant indépendantes l'une de l'autre, à l'exception de l'oscillateur 16 et du diviseur 17.Up to this point, there is no interference between the signals, the channels being independent of each other, with the exception of the oscillator 16 and the divider 17.

Mais, il convient maintenant de séparer les "bons" signaux et "mauvais" signaux. Cette fonction est assurée par l'étage discriminateur 24. L'étage discriminateur 24 détecte un changement du niveau de sortie sur l'un des deux comparateurs 9, et le garde en mémoire. Si aucun signal n'apparaît sur l'autre comparateur dans un intervalle de temps prédéterminé, il autorise la transmission du signal vers le temporisateur 25 correspondant. La sortie du temporisateur 25 est connectée à un indicateur lumineux et/ou à un circuit 26 assurant la fonction de OU logique, qui déclenche une alarme sonore 11, si l'un "OU" l'autre des capteurs signale une ligne blanche. Le discriminateur 24 agit sur des interrupteurs 15 pour couper la transmission dans le cas où deux changements de niveau simultanés ou consécutifs (ligne perpendiculaire ou oblique à la direction du véhicule) sont détectés par le détecteur.However, it is now necessary to separate the "good" signals and "bad" signals. This function is provided by the discriminator stage 24. The discriminator stage 24 detects a change in the output level on one of the two comparators 9, and stores it in memory. If no signal appears on the other comparator within a predetermined time interval, it authorizes the transmission of the signal to the corresponding timer. The output of timer 25 is connected to a light indicator and / or to a circuit 26 ensuring the function of logical OR, which triggers an audible alarm 11, if one " OR " the other of the sensors signals a white line. The discriminator 24 acts on switches 15 to cut the transmission in the event that two simultaneous or consecutive level changes (line perpendicular or oblique to the direction of the vehicle) are detected by the detector.

Afin d'accroître la fiabilité de fonctionnement du détecteur, celui-ci est muni d'un circuit d'auto-diagnostic qui teste l'appareil à chaque mise sous tension, afin d'éviter le déclenchement d'alarmes erronées. Lors du fonctionnement normal du détecteur, la tension moyenne à la sortie de chacun des étages redresseurs 7 (alimentés sous une tension continue A), est égale à la tension de référence B, la tension B étant inférieure à la tension de référence C. Si un défaut de fonctionnement apparaît dans la chaîne d'amplification du signal issu d'un capteur ou dans le capteur lui-même lors de l'initialisation du système, la régulation de tension en sortie du redresseur 7 n'atteint pas le niveau de référence 8. L'amplificateur différentiel 9 correspondant ne délivre aucun signal et le voyant de mise en fonctionnement ne s'allume pas.In order to increase the operating reliability of the detector, it is equipped with a self-diagnostic circuit which tests the device each time it is powered up, in order to avoid triggering false alarms. During normal operation of the detector, the average voltage at the output of each of the rectifier stages 7 (supplied with a DC voltage A) is equal to the reference voltage B, the voltage B being less than the reference voltage C. If a malfunction appears in the signal amplification chain from a sensor or in the sensor itself during system initialization, the voltage regulation at the output of rectifier 7 does not reach the reference level 8. The corresponding differential amplifier 9 does not deliver any signal and the start-up indicator does not light up.

Dans le cas habituel de fonctionnement normal, le générateur de tension 14 impose, uniquement lors de l'initialisation, une tension de référence C′, qui est inférieure à B, de sorte que les comparateurs 9 passent en position "alarme" si la tension à la sortie du redresseur 7 atteint la tension B, et les comparateurs 9 valident le bon fonctionnement de l'appareil. Si le test est concluant pour les capteurs, le générateur de tension de référence 14 impose alors une tension de référence C, supérieure à C′ et à B, correspondant au fonctionnement normal de l'appareil. Le test est signalé par un voyant lumineux pour chaque capteur. Le générateur de tension 14 est alimenté par un étage 27 qui fournit les tensions A et B nécessaires au fonctionnement, une tension C ou C′ étant disponible à la sortie du générateur 14. Ainsi, la sensibilité de détection des transitions optiques (passage de la route à une bande blanche) est déterminée par la valeur de la tension de référence C, appliquée sur l'une des entrées des comparateurs 9.In the normal case of normal operation, the voltage generator 14 imposes, only during initialization, a reference voltage C ′, which is less than B, so that the comparators 9 switch to the "alarm" position if the voltage at the output of the rectifier 7 reaches the voltage B, and the comparators 9 validate the correct operation of the device. If the test is conclusive for the sensors, the reference voltage generator 14 then imposes a reference voltage C, greater than C ′ and B, corresponding to the normal operation of the device. The test is indicated by an indicator light for each sensor. The voltage generator 14 is supplied by a stage 27 which supplies the voltages A and B necessary for operation, a voltage C or C ′ being available at the output of the generator 14. Thus, the sensitivity for detecting optical transitions (passage of the route to a white stripe) is determined by the value of the reference voltage C, applied to one of the inputs of the comparators 9.

Il est bien entendu possible de monter sur un même véhicule plus de deux détecteurs et de traiter les signaux détectés comme indiqué précédemment.It is of course possible to mount more than two detectors on the same vehicle and to process the detected signals as indicated above.

Claims (14)

1. Dispositif d'aide à la circulation, caractérisé en ce qu'il comprend au moins un émetteur (1), émettant des ondes lumineuses invisibles et un récepteur (2), orientés dans la même direction, un circuit de traitement de l'information reçue par le récepteur, et des moyens de commande, de signalisation et/ou d'alarme, le récepteur recevant le faisceau émis par l'émetteur, après réflexion sur des surfaces portant un marquage codé, un filtre optique (3) étant disposé devant le récepteur (2).1. A circulation aid device, characterized in that it comprises at least one transmitter (1), emitting invisible light waves and a receiver (2), oriented in the same direction, a circuit for processing the information received by the receiver, and control, signaling and / or alarm means, the receiver receiving the beam emitted by the transmitter, after reflection on surfaces carrying a coded marking, an optical filter (3) being arranged in front of the receiver (2). 2. Dispositif selon la revendication 2, caractérisé en ce que le circuit de traitement de l'information comprend un filtre passe-haut (4), un amplificateur à gain variable (5), un filtre passe-bande (6) et un étage redresseur (7).2. Device according to claim 2, characterized in that the information processing circuit comprises a high-pass filter (4), a variable gain amplifier (5), a band-pass filter (6) and a stage rectifier (7). 3. Dispositif selon les revendications 1 et 2, caractérisé en ce que le circuit de l'émetteur (1) inclut un oscillateur (16), un diviseur de fréquence (17) et un amplificateur (18), la fréquence du filtre passe-bande (6) étant assérvie à une fréquence du diviseur (17).3. Device according to claims 1 and 2, characterized in that the transmitter circuit (1) includes an oscillator (16), a frequency divider (17) and an amplifier (18), the frequency of the pass filter strip (6) being servo frequency at a frequency of the divider (17). 4. Dispositif selon la revendication 2, caractérisé en ce que l'amplificateur à gain variable (5) est commandé par le signal de sortie d'un circuit intégrateur (8), dont l'une des entrées reçoit une tension de référence (8), la seconde entrée du circuit (8) recevant un signal dérivé du signal de sortie de l'étage redresseur (7).4. Device according to claim 2, characterized in that the variable gain amplifier (5) is controlled by the output signal of an integrator circuit (8), one of the inputs of which receives a reference voltage (8 ), the second input of the circuit (8) receiving a signal derived from the output signal of the rectifier stage (7). 5. Dispositif selon la revendication 4, caractérisé en ce que la sortie de l'étage redresseur (7) est connectée à une entrée d'un comparateur (9) dont la seconde entrée reçoit une tension de référence (C).5. Device according to claim 4, characterized in that the output of the rectifier stage (7) is connected to an input of a comparator (9) whose second input receives a reference voltage (C). 6. Dispositif selon la revendication 5, caractérisé en ce que le comparateur (9) délivre un signal continu dont la durée est proportionnelle à la durée apparente du marquage codé, en fonction de la vitesse relative de la partie mobile par rapport à la partie fixe.6. Device according to claim 5, characterized in that the comparator (9) delivers a continuous signal whose duration is proportional to the apparent duration of the coded marking, as a function of the relative speed of the movable part with respect to the fixed part . 7. Dispositif selon la revendication 1, caractérisé en ce que l'émetteur (1), le récepteur (2) et le filtre optique (3) sont inclus dans un support (21) en forme de cloche.7. Device according to claim 1, characterized in that the transmitter (1), the receiver (2) and the optical filter (3) are included in a support (21) in the shape of a bell. 8. Dispositif selon la revendication 8, caractérisé en ce que le support (21) est articulé (22) sur une patte de fixation (19).8. Device according to claim 8, characterized in that the support (21) is articulated (22) on a fixing lug (19). 9. Détecteur de dérive de trajectoire matérialisée au sol, selon la revendication 1 comprenant deux capteurs incluant chacun un émetteur-récepteur (1, 2), un circuit de traitement et des moyens d'alarme (10, 11), caractérisé en ce que les deux capteurs sont disposés de part et d'autre d'un véhicule, les sorties desdits capteurs étant reliées à un circuit discriminateur (24) détectant un changement de niveau de sortie sur les comparateurs (9), et actionnant les circuits d'alarme (io, 11) correspondant lorsqu'une seule variation de niveau est constatée dans un temps donné.9. Track drift detector materialized on the ground, according to claim 1 comprising two sensors each including a transceiver (1, 2), a processing circuit and alarm means (10, 11), characterized in that the two sensors are arranged on either side of a vehicle, the outputs of said sensors being connected to a discriminator circuit (24) detecting a change in output level on the comparators (9), and actuating the alarm circuits (io, 11) corresponding when a single level change is noted in a given time. 10. Détecteur selon les revendications 1, 2, 3 caractérisé en ce que les émetteurs (1) sont connectés à un oscillateur commun (16) à travers un diviseur de tension (17) par l'intermédiaire d'un amplificateur (18).10. Detector according to claims 1, 2, 3 characterized in that the transmitters (1) are connected to a common oscillator (16) through a voltage divider (17) via an amplifier (18). 11. Détecteur selon la revendication 10, caractérisé en ce que un circuit de test automatique (14) délivre une tension de référence (C′), légèrement inférieure à la tension de consigne de régulation (8), à chaque mise en route de l'appareil pour détecter, par basculement des comparateurs (9), si le fonctionnement est correct, la tension (C′) étant portée à (C) lors du fonctionnement normal.11. Detector according to claim 10, characterized in that an automatic test circuit (14) delivers a reference voltage (C ′), slightly lower than the regulation setpoint voltage (8), each time the 'apparatus for detecting, by tilting the comparators (9), if the operation is correct, the voltage (C ′) being brought to (C) during normal operation. 12. Détecteur selon l'une des revendications 10 ou 11, caractérisé en ce que le circuit (24) maintient la séquence de test et interdit l'utilisation du détecteur en cas de défaillance.12. Detector according to one of claims 10 or 11, characterized in that the circuit (24) maintains the test sequence and prohibits the use of the detector in the event of failure. 13. Dispositif selon la revendication 3, caractérisé en ce que le circuit de test automatique (34) délivre une tension de référence (C) supérieure à la tension (B), lorsque les deux voies ont satisfait au test.13. Device according to claim 3, characterized in that the automatic test circuit (34) delivers a reference voltage (C) greater than the voltage (B), when the two channels have passed the test. 14. Dispositif selon la revendication 1, caractérisé en ce que la sensibilité du détecteur aux signaux de marquages sur route est déterminée par une variation de tension de référence (C).14. Device according to claim 1, characterized in that the sensitivity of the detector to road marking signals is determined by a variation in reference voltage (C).
EP89402801A 1988-07-28 1989-10-11 Traffic aid by coded marking Withdrawn EP0422308A1 (en)

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GB2336205B (en) * 1998-04-08 2000-08-23 Factorgraft Limited A vehicle telemetry system
CN105118319A (en) * 2015-09-02 2015-12-02 宁波摩米创新工场电子科技有限公司 Shaping-circuit-based mode identification prompting system for infrared positioning signal lamp

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FR2634929A1 (en) 1990-02-02

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