EP0038268A1 - Intersection controller with command-phase signal groups and its method - Google Patents

Abstract

1. A crossroads controller of the type comprising : on the one hand a series of power change-over switching members (30) for selectively feeding power to the lamps of the traffic control lights such as the three-colour green-amber-red lights for vehicles, in dependence on control orders referred to as phase orders each corresponding to a light or a group of lights, and on the other hand a central logic means for generating said phase orders and comprising a processing unit (12), a clock (10) defining a working rate for said processing unit, and memories comprising at least a read only memory (21) and a random access memory (23) serving as a working memory for the processing unit, the central logic means further comprising a frequency displacing circuit (11) which is separate from the processing unit and which is capable of supplying same with pulses with a base rate which is lower than the working rate of the processing unit, said base rate serving as a time standard for counting digitally defined operating durations, the memories comprising a first fixed memory unit (23) capable of co-operating with the processing unit for causing it to carry out a predetermined cycle of operations, and a second fixed memory unit (22) containing : information defining light plans, and a set of conditions for safety between the different phase orders, characterised in that : A) said second fixed memory unit also comprises : data in respect of groups of type sequences, comprising a group indication, a sequence indication and at least one duration for each sequence, data establishing a correspondence between each phase order and a group of type sequences, with the designation of certain of the type sequences of said group, wherein the phase order in question can go to green only for the whole of each type sequence designated, and data establishing a correspondence between some at least of the phase orders and reference phase orders, which is matched on each occasion with an associated difference period, B) each safety condition is defined by a period to be observed between the end of a state such as amber of one of the phase orders and the beginning of a state such as green of another phase order, C) in the repetitive cycle that it performs in response to the first fixed memory unit (12), the processing unit authorises the transition of a phase order to green only when all the safety period conditions provided with all the phase orders which have just left green are satisfied, D) in each group the processing unit starts off the following type sequence when all the associated phase orders are in the corresponding state, whereafter the duration of the type sequence is counted down, and the processing unit establishes the departure from green of a phase order on the double condition that the corresponding type sequence is completed and that the difference period with regard to the end of green of its reference phase order is observed.

Description

The invention relates to the control of traffic control lights, and more particularly the electronic control devices provided for this purpose, commonly called "intersection controllers".

In general, the crossroad controllers known to date comprise a series of power switching elements, making it possible to selectively supply the lamps of the lights (green-yellow-red for vehicles) and, on the other hand, logic central which generates green orders to be executed respectively by the power switches. The duration of the yellow which occurs automatically after the green is fixed in advance. And, when it is neither green nor yellow, a light is set to red (possibly red + yellow).

Each intersection in principle has antagonistic traffic flows, to which the green light should not be given at the same time. To take this imperative into account, safety conditions are provided, taking into account the state of the lights, and reflecting the exclusions required between green lights. As soon as the safety conditions are no longer satisfied, the lights are generally flashing yellow.

The crossroads controllers are made in the form of wired or, for some, programmed logic. The logic can be broken down into a clock, a processing unit, as well as read-only and / or random access memories. Up to now, and as a general rule, the green orders are produced by the control logic in continuous connection with the time base defined by the clock. In addition, security checks are carried out a posteriori on the execution of orders from the control unit.

It results from this situation first of all a lack of flexibility, because the modifications of all or part of the orders of lights can be done only within the rigid time frame defined by the time base. On the other hand, important precautions must be taken to avoid that all of the situations or states of fire provided for in the intersection controller contain no incompatibility with the safety conditions. This would translate into a general change to flashing yellow, when no material anomaly justifies it.

The present invention brings a substantial improvement to the control of traffic lights.

The invention proposes a crossroads controller of the type comprising on the one hand a series of power switching elements, making it possible to selectively supply the lamps of traffic control lights, such as green-yellow-red three-color lights for vehicles , and this as a function of control orders called phase orders each corresponding to a light or a group of lights, and on the other hand a central logic generating these orders- phases, and preferably comprising a clock, a processing unit, as well as memories including at least one read only memory and a random access memory, serving as working memory for the processing unit.

• - des groupes de séquences-types, définies par une indication de groupe, une indication de séquence, et une durée au moins pour chaque séquence,
• - une correspondance entre chaque ordre-phase et un groupe de séquences-types, avec désignation de certaines des séquences-types de ce groupe, l'ordre-phase en question ne muvant passer au vert que pour l'intégralité de chaque séquence-type désignée, ainsi qu'une correspondance de certains au moins des ordres-phases avec des ordres-phases de référence, assortie, à chaque fois d'un délai de décalage associé, et
• - un jeu de conditions de sécurité entre les différents ordres-phases, chaque condition de sécurité définissant un délai à resnecter entre la fin d'un état, tel que jaune, de l'un des ordres-phases, et le début d'un état, tel que vert, d'un autre ordre-phase.

According to the invention, the central logic comprises a frequency scaling circuit, capable of producing pulses with a basic rate lower than the working rate of the processing unit, and distinct from the latter; the fixed memory comprises a first fixed memory unit capable of cooperating with the processing unit to make it carry out a predetermined cycle of operations, and a second fixed memory unit, defining information of fire plans; this second fixed memory unit includes:

• - groups of standard sequences, defined by a group indication, a sequence indication, and at least one duration for each sequence,
• - a correspondence between each phase order and a group of type sequences, with designation of some of the type sequences of this group, the phase order in question only changing to green for the entirety of each type sequence designated, as well as a correspondence of at least some of the phase orders with reference phase orders, accompanied, in each case by an associated delay time, and
• - a set of security conditions between the different phase orders, each security condition defining a delay to be resected between the end of a state, such as yellow, of one of the phase orders, and the start of a state, such as green, of another phase order.

Finally, in the repetitive cycle which it performs in response to the first fixed memory unit, the processing unit authorizes the transition from a phase order to green only when all the safety delay conditions provided with all the phase orders which have just left the green are satisfied and that, in each group, the processing unit starts the following standard sequence when all the associated phase orders are in the corresponding state, after which one counts the duration of the standard sequence, and the processing unit establishes the output of the green from a phase order on the double condition that the corresponding standard sequence is completed, and that the possible delay time with regard to of the green end of its reference phase order is respected.

Very advantageously, the second fixed memory unit further comprises indications of correlation between the standard sequences of the different groups, the correlated sequences having to be in a pre-established time relationship (such as simultaneous end), and the processing unit. extends the standard sequences thus correlated so that they end all together, substantially with the normal end of the last of them, or that they satisfy in some other way the pre-established temporal relation.

• - définir des groupes de séquences-types, chaque groupe comprenant des séquences-types rangées, associées chacune à au moins une durée,
• - associer chaque ordre-phase à l'un des groupes de séquences-types en y désignant certaines des séquences-types, à un délai de décalage, ainsi qu'à un ordre-phase de référence par rapport auquel est défini ce délai de décalage, et
• - établir entre les différents ordres-phases de conditions de sécurité, chaque condition de sécurité comp- portant un délai entre la fin d'un état, tel que jaune, de l'un des ordres-phases, et le début d'un état antagoniste, tel que vert, d'un autre ordre-phase.

The invention also provides a method for controlling traffic lights, of the type in which a series of phase-order signals is produced, each intended to be executed by a light or a group of lights, and comprising a sequential sequence and repetitive of different orders, green, yellow, red, and yellow-red if applicable. The method of the invention comprises the following preliminary operations:

• - define groups of standard sequences, each group comprising rows of standard sequences, each associated with at least one duration,
• - associate each phase order with one of the groups of standard sequences by designating some of the standard sequences, with an offset delay, as well as with a reference phase order relative to which this offset delay is defined , and
• - establish between the different phase orders of security conditions, each security condition comprising a delay between the end of a state, such as yellow, of one of the phase orders, and the start of a state antagonist, such as green, of another order-phase.

• - n'autoriser la transition d'un ordre-phase vers le vert que lorsque toutes les conditions de délai de sécurité prévues avec tous les autres ordres-phases venant de quitter le vert sont satisfaisantes, et
• - dans chaque groupe, faire démarrer la séquence-type suivante lorsque tous les ordres-phases associés sont dans l'état correspondant, après quoi l'on décompte la durée de la séquence-type, et chaque ordre-phase sort du vert à la double condition que la séquence type correspondante soit achevée, et que le délai de décalage à l'égard de la fin de vertæ son ordre-phase de référence soit respecté.

The process then includes the following common and repetitive operations:

• - authorize the transition from a phase order to green only when all the safety delay conditions provided for with all the other phase orders which have just left green are satisfactory, and
• - in each group, start the next standard sequence when all associated phase orders are in the corresponding state, after which the duration of the standard sequence is counted, and each phase order comes out from green to double condition that the corresponding standard sequence is completed, and that the delay delay with regard to the end of the vertæ its reference phase order is respected.

The invention allows independent evolution over time of phase orders belonging to different groups, while respecting the safety conditions.

Very advantageously, we also define as preliminary correlations between standard sequences of the different groups, to signify that these must respect a predefined time relationship; and, in repetitive current operations, all intercorrelated standard sequences are extended in the event of correlation in order to respect this temporal relation. Advantageously, the temporal relation consists in the simultaneous end of the correlated standard sequences.

• - la figure 1 illustre le schéma électrique général d'un contrôleur de carrefour selon la présente invention ;
• - la figure 2 illustre le diagramme fonctionnel général suivi par le contrôleur de carrefour de la figure 1 ;
• - la figure 3 illustre le diagramme fonctionnel simplifié appliqué par le contrôleur de la figure 1, et illustrant le procédé de l'invention ;
• - la figure 4 illustre phase par phase l'opération de détermination de l'état des feux, résumée en 56 sur la figure 3 ; et
• - la figure 5 est un diagramme temporel simple illustrant une commande de feux obtenue selon l'invention.

Other characteristics and advantages of the invention will appear on reading the detailed description which follows, given with reference to the appended drawings, given by way of nonlimiting example, and in which:

• - Figure 1 illustrates the general electrical diagram of a crossroad controller according to the present invention;
• - Figure 2 illustrates the general functional diagram followed by the intersection controller of Figure 1;
• - Figure 3 illustrates the simplified functional diagram applied by the controller of Figure 1, and illustrating the method of the invention;
• - Figure 4 illustrates phase by phase the operation of determining the state of the lights, summarized at 56 in Figure 3; and
• - Figure 5 is a simple time diagram illustrating a light control obtained according to the invention.

Figure 1 illustrates the block diagram of the crossroads controller according to the invention. Its control logic includes a clock 10, a frequency division circuit 11 (or frequency scaling in another way, with synthesizer for example), a processing unit 12, preferably with a microprocessor such as the MOTOROLA model 6800. , memories 21 to 23, connected by a bus line 13 to the processing unit 12, and finally an electronic security circuit 14 (watchdog notably connected to the processing unit 12, to the bus 13, as well to the light switches 30. There is an interface or input-output junction 28, connected to the bus 13, and ensuring the connection between the central unit 12 and the light power switches 30 (go- back), as well as an agent control unit, signals from sensors or other detectors of vehicles, pedestrians or other external events, a control unit for police officers, as well as synchronization or coordination lines which can be connected to another crossroad controller, ag issuing as a master (co-ordination on a single top per cycle) or even to a computer centrally managing traffic on a large number of crossroads (synchronization by time points, in particular).

The clock 10 provides the nominal working rate of the processing unit 12. The divided clock 11, which can also be independent of the clock 10, provides one or more lower rates - every 0.1 seconds and / or every second for example - suitably arranged to be perceptible by the processing unit 12 as a basic rate (s) for controlling the lights. This basic rate is received by the microprocessor 12 on interruptions, while it performs the processing operations defined by the first memory 21, or memory of program; which is advantageously of the RepROM (reprogrammable read only memory) type. In doing so, the processing unit 12 cooperates with one or more working memories 23 with direct access (RAM).

Also provided are fire plan memories 22, which are advantageously of the electrically programmable stored memories type (EAROM). These are therefore in principle fixed memories, but the processing unit 12 of which can modify the content under certain conditions (in particular to assist the operator in the initial definition of the fire plans).

We will now see how the fire plans are recorded. In the memory, the recording contains alphanumeric symbols allowing to recognize each of the recorded elements. To facilitate understanding, the recorded elements are designated by names, defined each time, and which do not necessarily coincide with the usual meaning of the word used.

In practice, it is common for several lights to be controlled in exactly the same way (all lights relating to the same channel, for example). The sequence of control signals jointly developed for a light or a group of lights of this kind is called here phase-order. Each phase order is generally associated with a "type", which determines its execution: red-yellow-green for vehicles; pedestrian crossing; or a flashing arrow for a turn allowed on an adjacent lane. The execution of a phase order taking into account the type of associated fire is known.

• - plage stable vert théorique (VT)
• - plage de transition jaune théorique (JT)
• - plage stable rouge théorique (RT)
• - plage de transition rouge-jaune théorique (RJT).

Taking into account all the types of existing lights, and in particular a "red and yellow" state used for vehicles in certain countries, each phase order is broken down into a continuous series of theoretical phase ranges whose motive is:

• - theoretical green stable range (VT)
• - theoretical yellow transition range (JT)
• - theoretical red stable range (RT)
• - theoretical red-yellow transition range (RJT).

The word "theoretical" is used here to simply recall that the execution of the phase order may differ from the basic pattern, depending on the type of fire concerned.

• - mode tricolore variable MTV ; c'est le mode ordinaire.
• - mode tricolore clignotant MTC ; à côté d'ordre-phases travaillant en mode ordinaire, d'autres vont rester au jaune clignotant.
• - mode tricolore éteint MTE; à côté d'ordres-phases travaillant en mode ordinaire, d'autres vont rester éteints.
• - mode global clignotant MGC : tous les ordres-phases sont au jaune clignotant.
• - mode global rouge MGR : tous les feux sont au rouge (pour laisser le passage à un véhicule prioritaire par exemple).

We also define modes which will influence globally or individually the phase orders:

• - MTV variable tricolor mode; it is the ordinary mode.
• - three-color MTC flashing mode; next to order-phases working in ordinary mode, others will remain flashing yellow.
• - tricolor mode off MTE; next to phase commands working in ordinary mode, others will remain off.
• - MGC flashing global mode: all phase orders are flashing yellow.
• - global red MGR mode: all lights are red (to allow passage to a priority vehicle for example).

These modes can themselves be differentiated according to their raison d'être, and this for each crossroads, a crossroads being therefore defined as a set of phase-orders which obey the same mode, which can be dictated by external events (detection vehicles on certain traffic currents, in particular).

At each crossroads, and to the corresponding set of phase orders, the memory of fire plans, which will now be called EAROM memory, therefore corresponds to a mode, which is one of the following in normal operation:

Added to this is the fact that each crossroads can be controlled in purely autonomous mode, or under the control of an agent, or even in coordination from the central station or another crossroads controller acting as master.

Finally, for normal tricolor mode, several light plans, each identified by a number, can be saved in the EAROM memory.

Without going fully into the detail of the recorded information, we will now focus on a single light plan, it being observed that the global modes offer no difficulty in controlling the central logic. It is for this reason that the EAROM memory was named higher memory of fire plans, although it can contain more extensive information (mode in particular).

• - des groupes d'informations de séquences-types, contenant un numéro de groupe, un numéro de séquence-type, et une information numérique de durée au moins est affectée à chaque séquence-type de préférence, on affecte deux durées différentes à chaque séquence-type, l'une minimale, l'autre maximale. La valeur numérique de durée est rapportée à la cadence de base définie par le circuit 11 (figure 1) ;
• - pour chaque ordre-phase, défini lui aussi par un numéro, une correspondance avec un et un seul des numéros de groupes, avec une ou plusieurs des séquences-types contenues dans ce groupe, désignées par leur numéro elles aussi, et, une information numérique de délai de décalage, elle aussi rapportée à la cadence de base, et à un autre ordre-phase pris comme référence ;
• - un jeu de conditions de sécurité à respecter entre différents ordres-phases. Chaque conditon de sécurité fait correspondre numériquement deux ordres-phases (au moins). Mais on ne se contente pas d'une interdiction logique du fait que les deux ordres-phases désignés ne puissent passer au vert théorique en même temps. Chaque condition de sécurité spécifie en outre un intervalle de temps à respecter entre la fin du jaune théorique (ou du vert théorique) dans l'un des ordres-phases, et le début du vert théorique dans le ou les autres. On assure ainsi que pendant un temps minimum, le rouge est mis sur les deux ordres-phases (ou plus), qui correspondent à des courants de circulation antagonistes.

According to the invention, for each fire plan, the EAROM memory contains:

• - groups of information of standard sequences, containing a group number, a number of standard sequence, and a numerical information of duration at least is assigned to each standard sequence preferably, two different durations are assigned to each sequence -type, one minimum, the other maximum. The numerical value of duration is related to the basic rate defined by the circuit 11 (Figure 1);
• - for each phase order, also defined by a number, a correspondence with one and only one of the group numbers, with one or more of the standard sequences contained in this group, also designated by their number, and, information digital offset delay, also related to the base rate, and to another phase order taken as a reference;
• - a set of safety conditions to be respected between different phase orders. Each safety condition digitally matches two phase orders (at least). But we are not satisfied with a logical prohibition on the fact that the two designated phase orders cannot go theoretical green at the same time. Each safety condition further specifies a time interval to be observed between the end of the theoretical yellow (or theoretical green) in one of the phase orders, and the start of the theoretical green in the other. It is thus ensured that for a minimum time, the red is put on the two phase orders (or more), which correspond to antagonistic circulation currents.

Advantageously, each phase order is associated with a safety time interval of recorded value. And the other phase orders which will have to respect the safety time interval therefore only have to designate the phase order on which they depend (by its number, in memory).

Under the action of the first fixed memory, now called REPROM, the processing unit will as a general rule define for each phase order theoretical ranges of green, each of which comprises at least the designated standard sequence. So we see that the orders- phases united in the same group will present substantial similarities: during each type sequence of this group the phase orders will remain within a stable range. This is a significant advantage: the crossroads controller of the invention brings together orders-phases which are similar.

• - fin de la séquence ; et
• - le cas échéant, fin du délai de décalage entre l'ordre-phase concerné et son ordre-phase de référence.

The end of the green range, and the change to yellow, is defined by meeting the following conditions:

• - end of the sequence; and
• - where applicable, end of the delay period between the phase order concerned and its reference phase order.

Of course, in addition to the durations of stable ranges (theoretical green and red), defined from the standard sequences, the memory set also contains durations of transition ranges (theoretical yellow, -and theoretical red-yellow, the case where applicable) which are defined either for the whole or for each phase order, possibly by number choice in a series of pre-established durations.

The prior art systematically uses a time base to define each of the phase orders. They therefore all remain more or less linked to this time base (jumps are possible). The invention proceeds otherwise.

The transition from a phase order to theoretical green is only authorized by the central logic processing unit if all the safety time interval conditions provided, if any, between this phase order and all orders- phases coming out of the theoretical green are satisfied (regardless of the group to which the phase orders coming out of the green belong).

Then, and this time in each group, the processing unit examines whether all the phase orders associated with the same standard sequence have gone to theoretical green for some and to theoretical red for others. As soon as this is done, it counts down the duration assigned to this standard sequence, then the delays respectively assigned to each of the phase orders, and puts an end to the theoretical green ranges of the different phase orders at the end of the delays which are respectively associates, counted from the end of their reference phase order.

This allows independent or asynchronous evolution over time of phase orders belonging to different groups, while respecting the safety conditions. In other words, the invention uses the clock_to define a base cadence which serves as a time standard for counting the durations defined numerically, but this clock plays absolutely no role as a time base which would serve rigid frame at all phase orders.

The difference will be better seen by remembering that the duration of each type sequence can have two different values, the choice of which depends, for example, on vehicle detection. The two digital duration values are written into memory, and the same is true for the duration variation threshold, the digital value of which naturally depends on the particular vehicle sensor that is used.

It can for example be assumed that the normal duration of the standard sequence is the minimum duration, but as long as the flow of vehicles exceeds the threshold, the standard sequence is extended, at most up to the maximum duration.

A variant consists in providing standard sequences which are entirely retractable, as a function of an external event such as a detection of vehicles.

On the other hand, some phase-orders may have, in the EAROM memory, alongside the designation of one or more of their associated standard sequences, a binary indication that the range of theoretical green represented by this sequence-type is retractable or not, for this order-phase. Better still, the designation of a retractable standard sequence for a phase order is advantageously accompanied by the numerical designation of the other phase order (s) on which the duration of green released by the retraction can be carried over.

According to a non-essential, but highly preferential aspect of the invention, the EAROM memory also includes indications of correlation between the standard sequences of different groups. For each correlation, there is a list of the numbers of the standard sequences to be correlated, the word meaning here that they must end together. Of course, more complex temporal relationships can be defined between the correlated sequences, for example defining their order, and other correlation points than the end of the sequence can be provided, for example ends of parts of sequences. In particular, for sequences likely to have two durations, a binary indication may specify whether it is the maximum or minimum duration.

The processing unit will then determine the correlations currently relevant (do the standard sequences concerned enter into correlations?), And above all extend some of the standard sequences entering into the same correlation so that they all end substantially in. at the same time as the later, or in a prescribed order.

These correlations make it possible to ensure long-term consistency between the different groups of phase-orders, while these groups retain a great deal of freedom in relative time shifts.

Very advantageously, at least one of the correlations concerns a standard sequence of each phase order, which makes it possible to have a reference time point common to all the phase orders (of a crossroads or of several crossroads). This reference point is useful for moving from one traffic light plan to another in the crossroad controller. Often, several intersection controllers are interconnected, and one of them, acting as a master, provides a so-called "unitop" coordination impulse, at a chosen point in the cycle or pattern of its light plan (the reference point here) the other intersection controllers will set their own reference point with respect to the coordination pulse (possibly with a predetermined offset and stored in memory). Several reference points may be provided in the case of coordination by central station (computer for example).

It will now be understood that if a standard sequence is to be retracted, the transfer will be made upstream, or downstream, depending on whether this standard sequence is correlated with others or not. It is also important to note that the correlations are systematically made on all the standard sequences, whether they are executed or retracted, shortened or not.

Without the correlations, the phase orders belonging to a group have a state independent of those of the phase orders of the other groups, outside the transition instants. The correlations described above make it possible to weight this independence to allow an overall synchronization as to the evolution of the different groups.

Finally, of course, the correlation points can be made conditional, by recording one or more digits designating the existence of a condition and its nature: number of vehicles detected by a sensor, for example.

Another condition can apply to all the correlation points (except, possibly, the aforementioned reference point): the controller can process several crossroads, each of which contains several groups of phase orders; and these crossroads can operate in the same mode or in different modes. Of course, when switching from a mode common to all the intersections to different modes, correlation points may disappear automatically. In other words, a block of groups of phase orders is assigned to each intersection. The different blocks will decorrelate, but the correlations will remain effective between the groups of phase orders of the same block, therefore of the same crossroads.

We can now describe with reference to Figure 2 the overall operating cycle of the intersection controller; to simplify the diagrams of the drawings, the words "order-phase" and "sequence-type" have been abbreviated as "phase" and "sequence", respectively.

• - l'activation d'une entrée, télécommande, coordination, boîtier agent, capteurs de véhicules, etc.
• - le mode actuel ou antérieur : après un plan de feu spécial, on passe par un plan de transition
• - l'état de la machine : jaune clignotant de sécurité en cas de défaut
• - la variable temps : un temps donné de rouge barrage doit être respecté après le jaune clignotant.

The first step 41 of the cycle consists in determining the mode changes, 'for each intersection, in particular from the inputs (coordination, agent unit, vehicle detectors, in particular), and if necessary from internal processing operations making intervene the state of certain phase orders, in particular. We have already indicated many modes by way of example. The first step 41 consists in a review of the various conditions likely to involve a change of mode, which can involve the following factors, separately or in combination:

• - activation of an input, remote control, coordination, agent unit, vehicle sensors, etc.
• - the current or previous mode: after a special fire plan, we go through a transition plan
• - machine status: yellow safety flashing light in the event of a fault
• - the time variable: a given dam red time must be observed after the flashing yellow.

The second step 42, consists, for each group of phase orders belonging to a crossroads in tricolor mode (non-global), to examine the progress of the standard sequence in progress, which essentially depends on the duration assigned to this sequence: there is a minimum duration. In addition, the presence or absence of a given event, such as a threshold in the number of vehicles detected, and this during a given time interval (in memory) can extend the standard sequence up to its maximum duration. It is the same for the presence of synchronization information in coordinated mode, or for the presence of an advance order coming from a police officer in control mode by the agent unit. After examining these conditions, we note the presence of an end-of-type sequence condition. It then remains, before the end of the standard sequence is made effective, to verify that the correlation conditions imposed on the group for this standard sequence do not oppose it.

Steps 43 to 46 will precisely check these correlations.

Step 43 will search the EAROM memory for the correlation conditions existing on the standard sequences whose end conditions are fulfilled. For each standard sequence, if no correlation condition is met, the end is immediately made effective. Otherwise we examine for each crossroads the respect of the conditions relating to the standard sequences of the groups which compose it, between them. As previously indicated, when a set of standard sequences are correlated (their numbers being in the same correlation list), they are extended so that all end at the time of the normal end scheduled for the later of them, or in a prescribed order.

In some modes, each intersection is controlled independently of the others. In other modes, the intersections will be more or less linked.

Step 44 therefore performs the correlation check on - all the crossroads, if the current mode requires it. If necessary, the processing unit acts as before so that all the correlated standard sequences end together, or, alternatively, in the prescribed order.

Step 45 then finally confirms the end of standard sequences after the correlation processes, and designates the following standard sequences, insofar as they are effective, that is to say not retracted.

In practice, it may be necessary to examine the correlations multiple times. Indeed, as previously indicated, each type sequence can. have two correlation conditions, one on its maximum duration, and the other on its minimum duration. Each standard sequence can also be hidden. Even if it is retracted, account should be taken of the correlation conditions which would have occurred in its course to authorize the course of the sequences which follow it. These conditions are then added to the conditions actually carried on the current sequence. The end of a sequence in progress can therefore involve several sets of conditions which must be considered successively, repeating each time operations 43 to 45, as indicated by the symbol "n times" of operation 46. The number of repetitions n depends in practice on the number of conditions normally assigned to each standard sequence, as well as on the number retractable standard sequences.

At the end of these n repetitions of operations 43 to 45, the final -type sequences are obtained. Operation 46 therefore establishes the desired phase orders in the form of theoretical ranges, taking into account the end of standard sequences and any mode transitions which may have been decided.

In operation 47, the logic determines whether the phase orders evolve or not (maintenance of the previous state and mode or change of the state or mode).

• - le délai affecté à cet ordre-phase par rapport à son ordre-phase de référence est-il atteint ? Cette condition permet d'assurer des décalages choisis entre les plages théoriques semblables (vert théorique par exem-- ple) d'ordres-phases donnés.
• - les intervalles de sécurité prévus entre l'ordre-phase en cours et d'autres ordres-phases sont-ils tous respectés ? Une telle condition, que l'on a décrite plus haut, fera que la plage de rouge-jaune théorique (ou de vert,avec un décalage) d'un ordre-phase ne peut commencer tant que les plages de vert théorique des ordres-phases donnés comme étant en sécurité avec elle ne sont pas terminées depuis une durée minimum, donnée pour chaque phase, et dite durée de Rouge de sécurité.

If an evolution is requested, each phase order is checked against the basic conditions of the invention

• - has the delay allocated to this phase order compared to its reference phase order been reached? This condition ensures shifts chosen between similar theoretical ranges (theoretical green for example) of given phase orders.
• - are the safety intervals between the current phase order and other phase orders all observed? Such a condition, which was described above, will cause the theoretical red-yellow range (or green, with an offset) of a phase-order cannot begin until the theoretical green ranges of the orders- phases given as being safe with it have not been completed for a minimum duration, given for each phase, and known as the safety red duration.

Finally, after having established the final phase orders, the central logic establishes the color orders, which depend directly on them, taking into account the type of fire concerned each time.

Step 49 controls, using the "report" lines coming back from the traffic lights, the execution of the phase orders. Logic concludes at the end of each transition phase when the desired state is acquired. When the transition is due to a change in standard sequence (sought), this examination is first carried out at the level of the group concerned; and, if all the states of fires sought after the transition from sequence-type are reached, the central unit "pronounces" or confirms the entry into the sequence towards which was effected. the transition.

A similar process is carried out at the crossroads, to examine whether a decided mode change has been made, either by switching to a global mode, or for a change of light plan.

In particular, certain shortcomings in the execution of phase orders may cause a crossroads or all of the controlled crossroads to turn yellow flashing of safety.

- The cycle of figure 2 repeats itself indefinitely. In general, the durations of the standard sequences can be modified as a result of external events (sensors of all kinds, intervention by agents, coordination, etc.) or internal events (state of a phase order, presence of certain standard sequences, of certain groups of standard sequences (depending on the mode, etc.). Logic can consider combinations of these internal or external events, or the result of processing by counting, integration or delay, in particular, such events.

We will now describe, with reference to FIGS. 3 and 4, the method applied according to the invention, in the simple example of a single plan of lights (there are therefore no different "modes").

In FIG. 3, the first step 51 is the determination of the sequences in progress which should end, according to the counting of the duration which is associated with them.

In step 52, the central unit will look for the various correlation lists from the EAROM memory, and regroup the standard sequences which should end in sets sorted according to the lists stored in memory.

Step 53 examines whether each set corresponds exactly to the associated list. If this is not the case, step 54 extends all the sequences of this set, until the next passage in the cycle of operations of the control logic. In any case, step 55 examines whether all the correlation lists stored have been reviewed. After that, the end of the type-sequences envisaged are therefore confirmed or else suspended (therefore inoperative).

Step 56 determines the situation of each phase order with respect to the end of confirmed standard sequences. It is illustrated in detail in Figure 4 described below. At the end of this step, the desired state of each phase order is established.

Step 57 controls the execution of the phases, by comparing the desired state and the actual state indicated in return by the power switches (voltage control of the lamps, and, in addition, current, for the red lamps, for example).

Step 58 groups together the phase orders associated with completed standard sequences, sequence by sequence.

Step 59 checks, for each completed sequence, whether all the associated phases have indeed reached the state corresponding to the following sequence. If yes, in step 60, the central logic in each case declares that the following sequence has started (the counting of its duration will therefore also start).

The same cycle is repeated indefinitely. Note that the more complex cycle in Figure 2 performs the same operations, in addition being interested in the mode for example, we have seen that step 49 of FIG. 2 additionally checks whether the desired mode has been reached.

Figure 4. illustrates the determination of the state for each of the phase orders, starting from the one with the number zero (0). Step 61 in fact initially sets the phase number to zero. Step 62 examines whether the requested phase state coincides with the existing state, or on the contrary if it must change. If for example, there is no end of sequence requested, it is that a sequence is in progress, and the light is either red or green, depending on what is established for this phase order in this standard sequence. No modification is required as soon as the requested state coincides with the existing state; in this case, as long as we have not reached the last phase (test 63, yes and end 65), we start again for the following phase order, after having incremented the phase number at 64.

If the requested state is not the existing state (62, yes), the rest depends on the existing state.

If green is in progress (66), (and the requested state is other), it means that an end of the standard sequence has occurred. To comply with the offset conditions, step 67 examines whether the delay time between the current phase order and the end of the green on the reference phase order is reached. If yes, step 68 changes the current phase order to yellow, and the rest is at 69. If not, we go to the next phase order (63, 64 or 65).

If yellow is in progress (69), we simply test at 70 if the duration of yellow provided (possibly zero, for certain pedestrian lights) is reached. If yes, we go to red (71). In both cases, the sequence is 63, 64 or 65

If red is in progress (72), step 73 look in memory for the antagonistic phase order (s) (safe with the one we are considering). It will be recalled that, in the example described, each phase order is associated with a safety interval, and that the phase orders of which a subsequent change of state will depend on safety purely and simply designate the phase order earlier (and thereby the associated delay).

We will therefore, in step 74, review all the phase orders designated as safe with the order. phase considered, and examine, for each designated phase order, if the time of red, since the end of yellow (or green) is at least equal to the safety interval provided. If this condition is not verified, we pass to the following phase-order.

If the condition is verified, we go to red + yellow (at least in the machine, because the duration of red + yellow is zero in France). Test 77 examines whether the duration of red + yellow (zero or not) is reached. If yes, we go green at 78, and in all cases, the sequence is for the following phase order (63, 64 or 65). Finally, we go to step 57 of FIG. 4.

FIGS. 3 and 4 clearly show that the combined functions according to the present invention are easily achievable using wired and / or programmed logic. In this regard, the functional diagrams (FIGS. 2 to 4 in particular) are to be incorporated into the present description, as illustrating without ambiguity combinations of functions which are difficult to define completely by the text.

FIG. 5 illustrates in the form of a time diagram a simplified example of implementation of the invention. We see above the type sequences SI and S2 of the group Gl, and below the type sequences S1 and S2 of the group G2. The phase orders are numbered from OP1 to OP7. Finally, the two SI sequences are correlated.

A previous state started the two SI sequences, but the top one, which should end on the dashed line, is extended to end at the same time as the bottom one, because of the correlation.

The phase order OP1 serves as a reference, and ends with S1. It turns yellow for 3 seconds, then red. OP2 turns yellow with an offset of 8 s. with regard to OP1. OP3, OP4 and OP7 are in Red (it is assumed here that the time of Red + Yellow is zero, according to usage in France) OP5 and OP6 turn yellow with an offset of 5 s. with regard to OP1.

OP3 and OP4 are safe for 2 seconds, respectively with OP1 and OP2. So OP3 goes green (or red-yellow if necessary) 2 seconds after the end of the Yellow of OP1, and similarly OP4 with regard to OP2.

As soon as OP3 and OP4 are green, the second S2 type sequence of group Gl starts, and its duration is defined by the value stored in memory (except the correlation set).

In the second group G2, the second sequence S2 starts with OP7 in green, which occurs 2 seconds after the yellow ends of OP5 and OP6.

The process then continues with the second sequences, then the third, etc. until returning to the first sequences, and so on.

In practice, a crossroads controller has been produced which makes it possible to process 32 phase orders which can be divided into eight different groups over six sequences, which makes it possible to process up to four crossroads.

The fire plan parameters saved in the EAROM memory can be modified after installation, with the help of the microprocessor, and via an adjustment box 25 (FIG. 1), which can be permanently installed, or be in the form of a case, with keyboard and digital display and / or on cathode ray tube.

Of course, the present invention is not limited by the embodiments described, and extends to any variant in accordance with its spirit.

Claims (10)

1. A crossroads controller of the type comprising on the one hand a series of power switching elements (30), making it possible to selectively supply the lamps of the traffic control lights, such as the green-yellow-red three-color lights for vehicles , and this as a function of control orders called phase orders each corresponding to a light or a group of lights, and on the other hand a central logic generating these phase orders, and comprising a clock (10), a processing unit (12), as well as memories including at least one read only memory (21) and a random access memory (23), serving as working memory for the processing unit, characterized in that the central logic comprises a frequency scaling circuit (11) capable of producing pulses of base rate lower than the working rate of the processing unit, and separate from it, that the fixed memory comprises a first fixed memory unit (23) able to cooperate with the processing unit to make it carry out a predetermined cycle of operations, and a second fixed memory unit (22) defining information of fire plans, that this second fixed memory unit comprises: - groups of standard sequences, defined by a group indication, a sequence indication, and at least one duration for each sequence, - a correspondence between each phase order and a group of type sequences, with designation of some of the type sequences of this group, the phase order in question can only turn green for the entirety of each designated type sequence , as well as a correspondence of at least some of the phase orders with reference phase orders, accompanied, each time by an associated delay time, - a set of security conditions between the different phase orders, each security condition defining a delay to. respect between the end of a state, such as yellow, of one of the phase orders, and the start of a state, such as green, of another phase order, and by the fact that in the cycle repetitive that it performs in response to the first fixed memory unit (23), the processing unit authorizes the transition from a phase order to green only when all the safety delay conditions provided with all the orders -phases from leaving the green are satisfied and that, in each group, the processing unit starts the following standard sequence when all the associated phase orders are in the corresponding state, after which the duration is counted of the standard sequence, and the processing unit establishes the output of the green from a phase order on the double condition that the corresponding standard sequence is completed, and that the delay time with regard to the end of green of its reference phase order is respected, which allows independent evolution over time of the phase orders apart by attending to different groups, while respecting safety conditions. 2. Controller according to claim 1, characterized in that the second fixed memory unit (22) further comprises indications of correlation between the standard sequences of the different groups, the correlated sequences having to end simultaneously, and that l the processing unit (13) extends the standard sequences thus correlated so that they end all together, substantially with the normal end of the last of them. 3. Controller according to claim 2, characterized in that at least one of the correlations concerns a standard sequence of each phase order, which establishes a reference time point for the coordination between several intersection controllers, or alternatively for switching from one light plan to another in the same intersection controller, the second memory unit of which contains several light plans. 4. Controller according to one of claims 1 to 3, characterized in that in the second fixed memory unit (22), there is provided in the designation of type sequence associated with at least some of the phase orders, a indication showing that the green duration associated with this standard sequence for this phase order is retractable or not. 5. Controller according to claim 4, characterized in that the retraction for a phase order is accompanied by a designation of the other phase order (s) on which the duration of the retracted green can be carried over. 6. Controller according to one of claims 1 to 4, characterized in that in the second fixed memory unit (22) at least some of the standard sequences are associated with at least two durations, and that the processing unit (12) is sensitive to factual data in order to decide whether the duration of a standard sequence is at the minimum or indeed the maximum, or whether this standard sequence is retracted. 7. Controller according to one of claims 1 to 6, characterized in that, in the second fixed memory unit (22), at least some of the standard sequences are designated as retractable, the correlation being effected independently of the retraction, and the postponement taking place upstream or downstream, depending on whether or not the sequence is correlated. 8. A traffic light control method, according to which a series of phase command signals is produced, each intended to be executed by a light or a group of lights, and comprising a sequential sequence and repetitive of different orders, green, yellow, red, and yellow-red if necessary, characterized by the following preliminary operations: , - define groups of standard sequences, each group comprising rows of standard sequences, each associated with at least one duration, - associate each phase order with one of the groups of standard sequences by designating some of the standard sequences, with an offset delay, as well as with a reference phase order with respect to which this offset delay is defined , and - establish between the different phase orders security conditions, each security condition comprising a delay between the end of a state, such as yellow, of one of the phase orders, and the start of an antagonistic state, such as green, of another phase order, and by the following common and repetitive operations: - authorize the transition from a phase order to green - only when all the safety delay conditions provided for with all the other phase orders which have just left green are satisfied, and - in each group, start the following standard sequence when all the associated phase orders are in the corresponding state, after which the duration of the standard sequence is counted, and each phase order comes out from green to double condition that the corresponding standard sequence is completed, and that the delay delay with respect to the green end of its reference phase order is respected, which allows an independent evolution in time of the phase orders belonging to different groups, while respecting the security conditions. 9. Method according to claim 8, characterized in that one defines correlations between standard sequences of the different groups, to signify that these ci must respect a predefined temporal relation, and by the fact that one prolongs in the event of correlation all the sequence sequences intercorrelated in order to respect this temporal relation. 10. Method according to claim 9, characterized in that the temporal relation consists in the simultaneous end of the correlated standard sequences.

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