FR2655173A1 - Signalling device for road traffic - Google Patents

Abstract

The present invention relates to a signalling device for road traffic, of the type comprising lights for allowing/prohibiting passage, characterised in that it further comprises: at least one viewing unit (200) and a control unit (100) able to control the viewing unit (200) in such a way that the latter delivers changing information representing the passage of a time with respect to a reference event which corresponds to an alteration in the status of the lights for allowing/prohibiting passage.

Description

 The present invention relates to the field of signaling devices for road traffic.

 The signaling devices for road traffic hitherto proposed are of the all or nothing type. In other words, they are content to prohibit or authorize the movement of vehicles and pedestrians.

 This is the case, for example, with so-called tricolor lights intended for vehicle drivers. The green light authorizes the passage of vehicles. The red light prohibits the passage of vehicles.

 This is also the case with figurines placed at the level of pedestrian crossings. The 'still, more often, a figurine of green color authorizes the passage of pedestrians, while a figurine of red color prohibits the passage of pedestrians.

 These signaling devices have of course been of great service. The Applicant nevertheless intends to perfect these.

 To this end, the present invention provides a signaling device comprising authorization / prohibition of passage lights, characterized in that it further comprises - at least one display unit and - a control unit capable of controlling the display unit so that it delivers evolving information representative of the passage of time relative to a reference event which corresponds to a change in the state of the lights for authorization / prohibition of passage .

 The display of evolving information makes it possible to assure the vehicle driver of the correct functioning of the signaling system and in particular makes it possible to calm drivers who are generally in a hurry. The device according to the present invention also makes it possible to reassure pedestrians on the proper functioning of the system, and makes it possible, for example, to assure pedestrians that a manual call for crossing the roadway has been taken into account.

 According to a very important characteristic of the present invention, the control unit controls the display unit so that the latter delivers evolving information representative of the waiting time before a reference event which corresponds to a modification of the state of lights for authorization / prohibition of passage.

 The display unit can be intended either for the vehicle driver or for the pedestrian.

 The display unit preferably comprises a symbol having the general shape of an hourglass which gradually decreases over the course of time with respect to the reference event, that is to say that in the case of visualization of the waiting time before a reference event, the hourglass is gradually reduced to symbolize an empty hourglass.

 According to a preferred embodiment of the present invention, the device is designed to visualize the reduction in the waiting time before the greening of a pedestrian signal, for example the time that a pedestrian must wait after a call to cross the roadway .

 According to another characteristic of the present invention, the control unit comprises - a central unit comprising dividing means and - a main counter, mounted as a down-counter, the main counter being recharged to the value of cycle length when it reaches a zero count, and the central unit calculating from the appearance of an event of initialization of the display on the display unit, the time difference to be applied between each step of evolution of the information on the display unit, by dividing the instantaneous value of the main counter by the number of steps remaining active on the display unit.

 According to another advantageous characteristic of the invention, the central unit ensures readjustment of the main counter, each time the system cycle passes through a recognized instant.

 According to another advantageous characteristic of the invention, designed for operation in coordinated mode, the control unit comprises an auxiliary counter initialized to counting upon detection of a readjustment pulse used for coordination, a memory capable of memorizing a theoretical delay value which represents the theoretical time between the resetting pulse and the appearance of the reference event, and means for comparing the content of the auxiliary counter with the content of the memory, so that when the content of the auxiliary counter is greater than the content of the memory, the central unit loads the main counter with the sum formed on the one hand by the theoretical delay, and on the other hand by the value of the complement of the position of the auxiliary counter relative to the length of the cycle.

 Other characteristics, objects and advantages of the present invention will appear on reading the detailed description which follows, and with reference to the appended drawings given by way of nonlimiting examples and in which - FIG. 1 represents a schematic view of the general structure of a signaling device according to the present invention, - Figure 2 schematically represents a preferred hourglass-shaped symbol capable of being displayed by each display unit, - Figure 3 schematically represents a printed circuit board equipped with a set of light emitting diodes capable of displaying the hourglass symbol according to the present invention, - Figure 4 shows in a schematic view in vertical section a display unit housing according to the present invention, - the FIG. 5 represents a variant of implantation of light-emitting diodes on a plate printed circuit board for displaying a symbol according to the present invention, - Figure 6 schematically shows the structure of a control unit according to the present invention, - Figure 7 shows schematically the sequence of the device in the in the case of autonomous operation, - Figure 8 shows schematically the sequencing of the device in the case of coordinated operation, - Figure 9 shows all of Figures 7 and 8, and - Figure 10 shows schematically, in the form flowchart, the control process of the display unit according to the present invention.

GENERAL STRUCTURE OF THE SIGNALING DEVICE
As shown diagrammatically in FIG. 1, essentially the signaling device according to the present invention comprises a control unit 100 which controls at least one display unit 200, preferably several display units 200.

 In Figure 1 there is shown schematically a control unit 100 driving four display units 200. Of course this number should not be considered as limiting.

 The control unit 100 is positioned for example inside the conventional traffic light control cabinets.

 The display units 200 are placed in a manner known per se on suitable gantries.

STRUCTURE OF THE DISPLAY UNIT 200
The display unit 200 can be the subject of numerous variant embodiments.

 It can be any device giving digital information, or any indicating device, for example with a needle, delivering evolving information representative of the passage of time.

 However, the Applicant has determined that it is largely preferable to use a light signal whose illuminated surface decreases progressively as a function of the passage of time to be viewed, that is to say that it gradually decreases according to the waiting time before the relevant reference event.

 Even more specifically, the Applicant has determined that, as shown schematically in FIG. 2 appended, it was preferable for the display unit to represent an symbol 202 in the form of an hourglass. Such an hourglass-shaped symbol 202 can be schematized by two inverted and nested isosceles triangles referenced 204 and 206 respectively in FIG. 2. I1 can also be two nested or superimposed circles.

 Such a symbol can be formed by different horizontal rows of light-emitting diodes 208 carried by a printed circuit board 210.

 The symbol displayed on the display unit 200 can of course be obtained by any equivalent means.

 More specifically, there is shown schematically in Figure 3, 23 lines of light emitting diodes 208 carried by a printed circuit board 210. The number of light emitting diodes in each row decreases from one row to another, from the top to '' halfway up the symbols, then symmetrically increases again to the bottom of the symbol. Thus, as shown in Figure 3, the light emitting diodes symbolize an hourglass.

 Preferably, at the origin of the display, that is to say upon the detection of an initialization event, for example a manual request for a road crossing by a pedestrian, all the light-emitting diodes 208 are supplied . We thus symbolize a full hourglass. When the reference event occurs, for example, when the pedestrian is authorized to cross the road, all the diodes 208 are on the other hand extinguished. This symbolizes an empty hourglass.

 Between these two moments, that is to say between the initialization instant (for example, the pedestrian call) and the reference event (for example the authorization to cross the carriageway) the control unit 100 controls the display unit 200 in order to gradually extinguish row by row the diodes 208, starting from the top, to symbolize an hourglass which is gradually emptying.

 It will now be noted that preferably, the progression of the extinction of the symbol represented by the light-emitting diodes 208 takes place with optimal regularity, whatever the intermediate random events that can modify the cycle time.

 Is shown in Figure 4 attached, schematically and in vertical section, a housing 212 of the display unit. The vertical front face 214 of this box is preferably formed of a black screen provided with a transparent window 216 of the same geometry as the symbol to be displayed defined by the light-emitting diodes 208 carried by the wafer 210.

 In FIG. 4, this plate 210 can be seen carried vertically inside the housing 212 behind the front face 214.

We also see in Figure 4 a housing 218 carried on the rear face of the printed circuit 210 and serving as an interface between the control unit 100 and the light emitting diodes 208. The structure of the circuit 218 can be the subject of many variants well known to those skilled in the art and will therefore not be described in more detail below.

 Preferably, the outline of the transparent window 216 has the shape of an hourglass.

 It will be noted that in the case where the display device must be placed high enough on a gantry, to perfectly respect the geometry of the symbol to be displayed, preferably provision is made for an offset H between the upper and lower edges of the window 216 and the apex and the base of the symbol represented by the light-emitting diodes 208.

More specifically, the symbol represented by the light-emitting diodes 208 is shifted upwards by a value H relative to the base of the transparent window 216. The value of the shift H depends of course on the height of the display unit 200 .

 The display unit is not limited to the embodiments previously described.

 As shown in FIG. 5, it is possible, for example, to visualize a simple vertical strip, of constant width, formed by different horizontal rows of light-emitting diodes 208. Here again, all of the diodes 208 must be supplied at the origin of the visualization coinciding with the initialization event, for example a pedestrian call. All the diodes 208 must be extinguished at the end of the display, that is to say when the reference event occurs, for example the authorization to cross the road. Between these two instants, the different rows of diodes 208 are gradually extinguished, starting at the top of the symbol.

GENERAL STRUCTURE OF THE CONTROL UNIT 100.

 Essentially, as shown in FIG. 6 appended, the control unit comprises a central unit 102, a main counter 104, an auxiliary counter 106 and tables 108. The central unit 102 controls the main counter 104, the auxiliary counter 106 and the reading of tables 108. It receives on its inputs, via the bus referenced schematically 110 information which can come, for example, from a general coordination controller, and / or from external sensors such as traffic, pedestrian crossing call sensors. The central unit 102 also receives via the bus 110 other signals well known to those skilled in the art, coming from the controller controlling the known signaling lights, namely for example so-called green report information, so-called sequence report information, information determining one of several light plans potential plans. Of course, the nature of the information applied to the central unit 102 via the bus 110, previously indicated, should not be considered as limiting.

OPERATING CYCLE
As shown diagrammatically in FIG. 7, in general, the various operating cycles of automobile traffic lights can be divided into different ranges separated by interplages.

 FIG. 7 thus represents diagrammatically, by way of nonlimiting example, a sequence comprising five ranges respectively referred to as BEACH PO, BEACH P1, BEACH P2, BEACH P3, and BEACH P4, separated in pairs respectively by interages referenced IPO, IP1, IP2, IP3 and IP4.

 Each of these ranges and inter-ranges can have a fixed and predetermined duration.

 However, most often, at least some of these ranges and inter-ranges have variable durations defined as a function of external events, for example as a function of traffic and / or calls for crossing the road by pedestrians.

 Furthermore, most often, at least some of the ranges and / or inter-ranges are only optional, that is to say again conditioned by the appearance of external events, such as a momentary absence of traffic detected by a loop placed in the roadway or any equivalent means, reaching a traffic threshold, or a call for crossing the roadway by pedestrians.

 In FIG. 7, these external calls are represented diagrammatically under the names APPEL 0, APPEL 1, APPEL 2, APPEL 3, and APPEL 4. If these external events are detected in good time, the associated range is implemented. Otherwise, the corresponding area is retracted.

So for example, if CALL 0 is detected during the range
P4, the PO range is implemented after the IP4 interleaving. On the other hand, if CALL 0 is not detected in the P4 range, the PO range is retracted.

 Each of the instants of transition between a range and the following range or an interage and the following range, correspond to an identifiable instant called generally recognized instant is referenced IRO to IR9 in FIG. 7.

 As previously indicated, the control unit 100 in accordance with the present invention is designed to ensure progression of the extinction of the hourglass symbol on the display unit 200, with optimal regularity, regardless of the actual progress of the sequence, that is to say whatever the actual duration of variable tracks or inter-ranges, regardless of the number and duration of retracted tracks or inter-ranges, including in the case of a command of coordination by pulses coming from a central controller.

 Tables 108 contain theoretical values of the maximum durations of the length of the total cycle LCY, and of each range and inter-range PO to P4, IPO to IP4.

OPERATION IN AUTONOMOUS MODE.

 In the context of operation in autonomous mode, the main counter 104, mounted as a down-counter, is gradually decremented, for example at the rate of the second. It runs continuously.

When it reaches a zero count, it is automatically recharged by the central unit 102 to the value of cycle length denoted LCY.

Preferably, this LCY cycle length value is contained in tables 108 as indicated above.
Each time that the central unit 102 detects the passage through an instant recognized IR, that is to say detects a phase of transition between a range and a consecutive interplage or an interplage and a consecutive range, the central unit readjusts the main counter 104, that is to say that it reloads in the main counter a predetermined value stored in tables 108 and defined as a function of the current fire plan. Reloading the main counter 104 thus operated makes it possible, for example, to take account of the actual duration of variable ranges or inter-ranges, and / or to take account of the retraction of certain ranges and / or inter-ranges.

Each time the central unit 102 detects the appearance of an initialization event, the control unit 100 controls the lighting of all the diodes 208 symbolizing the hourglass, and calculates the difference to be applied between the extinctions of each horizontal row of lines. For this, the central unit 102 links the instantaneous value of the countdown, denoted
DI, contained in the main counter 104, and checks the number of rows of lit rows, marked NL, on the display unit 200, and calculates the difference to be applied between the extinctions of each row by dividing the instantaneous value of the D1 countdown by the number of lit lines
NL, either: DI / NL.

 The aforementioned initialization event, which initializes the lighting of the symbol on the display unit 200 and the calculation of the difference to be applied between the extinctions of each row of light-emitting diodes 208, can correspond for example to the request d '' a button worn on a gantry, by a pedestrian wishing to cross the road.

The initialization event can also coincide with the detection of a pedestrian by a loop placed on the ground, or even the detection of a pedestrian by an infrared system. The initialization event can correspond to the automatic emission of a cycle start pulse by a controller. Of course, the initialization event is not limited to the above examples.

 The operations of reading the instantaneous countdown value DI in the main counter 104, of checking the number of lit lines NL on the display unit 200 and of calculating the difference to be applied between the extinctions of each row of light-emitting diodes 208 (DI / NL) are repeated upon each detection of an IR recognized instant. Thus, the control unit 100 adapts the aforementioned deviation as the cycle progresses, in order to achieve complete extinction of the symbol on the display unit 200, at the time of the reference event. , that is to say for example in the context of the preferred embodiment of the present invention, the lighting of the pedestrian green. In order for this condition to be respected, including in the case of multiple retraction of ranges and / or inter-range, the central unit 102 performs at the end of each range a reading of the sum of the calls that may still be made during the cycle in question. If the sum of these calls is positive, the main counter 104 mounted as a down-counter is loaded at the value memorized in the table 108 coinciding with the recognized instant encountered.

 On the other hand, if the sum of the calls is zero, the main counter 104 is loaded with the value of the current interage. The amounts of calls taken into account are of course different for each interplage. These sums are shown diagrammatically in FIG. 7.

By way of example, for the IPO interlinking the sum of calls considered is equal to Al + A2 + A3 + A4. For the last IP3 interplotting, the sum of the calls corresponds only to A4.

 When operating in autonomous mode, the auxiliary counter 106 is inhibited.

 According to a preferred embodiment of the present invention, the display unit 200 generating an hourglass symbol is intended to display the time that a pedestrian must wait after a call to cross the road. The display unit 200 represents a luminous hourglass fully lit at the time of the call and which empties more or less quickly depending on the time remaining until the moment when the pedestrian is authorized to cross. As indicated previously, the control unit continuously examines these inputs identifying the various ranges and inter-ranges and determines at the time of each transition, recognized instant, on the basis of the predetermined time data stored in the tables 108, the time it stay until the pedestrian green. Thus, it adapts the speed of evolution of the hourglass to the presence of the ranges and to variations. It should be remembered that, as indicated above, each transition represents a recognized instant which leads to a reloading of the main counter 104.

This loading, based on information contained in tables 108, is a function of the presence of the following range conditioned by the corresponding call. The control unit 100 only takes the next range into account if it has received a corresponding call. If no call is present, the value of the range determines the time remaining to have pedestrian green.

COORDINATED OPERATION.

 Coordinated operation corresponds to the case of signaling lights of several consecutive intersections by a central controller. In this case, the central controller cyclically generates so-called coordination pulses well known to those skilled in the art.

 When a control unit 100 is placed in coordinated operation, the auxiliary counter 106 is launched upon detection of the reset pulse from the general controller (it is generally a green wave reset pulse ).

 Furthermore, in the case of coordinated operation, the table 108 receives a theoretical delay value denoted DT programmed for each cycle. This theoretical delay value DT represents the theoretical time between the reset pulse from the general controller and the appearance of the reference event, for example the appearance of pedestrian green.

 As long as the auxiliary counter 106 remains below the theoretical delay value DT, the loading of the main counter 104 is carried out as indicated previously in the context of operation in autonomous mode.

On the other hand, when the auxiliary counter 106 reaches a value greater than the theoretical delay value DT, the loading of the main counter 104, upon detection of the initialization event, for example a pedestrian call, is carried out at the sum theoretical delay
DT and the complement of position C of the auxiliary counter 106 with respect to the length of the LCY cycle.

 These arrangements are shown diagrammatically in FIG. 8.

 Furthermore, we find schematically in FIG. 9 the whole of an operating cycle of the display device according to the invention.

 It will be noted that preferably when a crossroads is placed in flashing operation or in manual piloting, the signaling device according to the invention is inhibited.

 The entire ordering process according to the present invention is shown schematically in Figure 10 attached.

 As shown in FIG. 10 appended, after an initial step 250 symbolizing the start of the process, the central unit 102 scans for the appearance of an initialization event. As indicated above, it may be in the context of the preferred embodiment of the invention a call to cross the road by a pedestrian requesting a button. However, the initialization event can also correspond to the detection of a pedestrian by a loop on the ground, by an infrared system, or even to the detection of a vehicle by a loop or an infrared system or still the generation of an automatic pulse by a general controller.

 When an initialization event is detected in step 252, the central unit 102 goes to step 254 for examining its inputs represented by the bus 110.

 The central processing unit 102 scans at step 256 the appearance of an instant recognized IR, that is to say a transition between a range and a range or a range and a range. If a recognized instant IR is detected in step 256, the central processing unit 102 links in the table 108 the corresponding time value, in step 258, and performs a corresponding registration of the main counter 104 in step 260. When the central unit 102 does not detect an instant recognized in step 256, it goes to step 262. The same is true after step 260 of readjusting the main counter 104.

 During step 262 the central unit 102 examines the appearance of a coordination pulse. When such a coordination pulse is detected in step 262, the central unit 102 links in the table 108 the cycle time value LCY, in step 264, and ensures the corresponding setting of the auxiliary counter 106 at l 'step 266.

 In the case where the central unit 102 does not detect a coordination pulse in step 262, it proceeds to step 268. The same applies after the step of setting the auxiliary counter 106.

 During step 268, the central unit 102 calculates the decrementing speed of the display unit 200. For this, as indicated previously, the central unit 102 calculates the ratio between the instantaneous value of the countdown contained in the main counter 104 and the number of lit lines NL on the display unit 200.

 After step 268, the central unit searches in step 270 if an instant of decrementation is detected. If this is not the case, step 270 is followed by step 254 of examining the inputs, on the other hand if an instant of decrementation is detected in step 270, the central unit 102 searches for the step 272 if the line to be reached corresponds to the last line.

 If so, the process is determined.

 On the other hand, if in step 272 the central unit 102 detects that the line to be reached is not the last line, it controls the decrementation of a line or row of light-emitting diodes 208 at the level of the display unit 200, at the step referenced 274. This is again followed by the aforementioned step of examining the entries 254.

VARIANTS
The foregoing description refers very particularly to the embodiments considered to be preferred in the context of the present invention for viewing the time that a pedestrian must wait after a call to cross the roadway.

 The signaling device according to the present invention is however not limited to this particular application.

 It can for example be used to visualize the time remaining available to the pedestrian to cross the road.

 Furthermore, the signaling device according to the present invention can be addressed not to pedestrians but to drivers of motor vehicles. By way of examples, the signaling device according to the present invention can, for example, display a waiting time before a three-color light turns green. It can also find application in the visualization of the time remaining to elapse before switching from a three-color light to red.

 Of course, the present invention is not limited to these applications.

 Furthermore, the present invention is not limited to the particular embodiments described above, but extends to all variants in accordance with its spirit.

Claims (21)

 1. Signaling device for road traffic of the type comprising authorization / prohibition of passage lights characterized in that it further comprises - at least one display unit (200), and - a control unit (100) able to control the display unit (200) so that it delivers evolving information representative of the passage of time with respect to a reference event which corresponds to a change in the state of the traffic lights passage authorization / prohibition.  2. Signaling device according to claim 1, characterized in that the control unit (100) controls the display unit (200) so that the latter delivers evolving information representative of the waiting time before a reference event which corresponds to a modification of the state of authorization / prohibition traffic light.  3. Signaling device according to one of claims 1 or 2, characterized in that the reference event corresponds to the start of the authorization period for a pedestrian crossing a roadway.  4. Signaling device according to one of claims 1 to 3, characterized in that the display unit (200) is intended for pedestrians.  5. Signaling device according to one of claims 1 or 2, characterized in that the display unit (200) is intended for drivers of motor vehicles.  6. Signaling device according to one of claims I to 5, characterized in that the display unit comprises a symbol (202) whose active surface is progressively reduced during the passage of time relative to l reference event.  7. Signaling device according to one of claims 1 to 6, characterized in that the display unit (200) comprises a symbol (202) whose lit area gradually reduces during the passage of time by report to the reference event.  8. Signaling device according to one of claims 1 to 7, characterized in that the display unit (200) comprises a symbol (202) having the general shape of an hourglass which gradually decreases during the 'passage of time in relation to the reference event.  9. Signaling device according to one of claims 1 to 8, characterized in that the display unit (200) comprises a set of light sources arranged in the form of a plurality of horizontal rows progressively extinguished row by row to start from the top during the passage of time in relation to the reference event.  10. Signaling device according to claim 9, characterized in that the light sources are arranged in the general shape of an hourglass.  11. Signaling device according to one of claims 9 or 10, characterized in that the light sources (208) are formed by light emitting diodes.  12. Signaling device according to one of claims 1 to 11, characterized in that the display unit comprises a light symbol (202) placed behind a screen (214) provided with a transparent window (216 ) and characterized in that the symbol (202) is shifted upwards relative to the transparent window (216).  13. Signaling device according to one of claims 1 to 12, characterized in that the display unit (200) is designed to visualize the reduction in the waiting time before going green for a pedestrian crossing.  14. Signaling device according to one of claims 1 to 7, characterized in that the display unit comprises a set of light sources (208) distributed in the form of a plurality of horizontal rows controlled by the unit control (100) to be gradually extinguished row by row from the top.  15. Signaling device according to one of claims 1 to 14, characterized in that the control unit (100) comprises a central management unit (102), a main counter (104), an auxiliary counter (106 ) and at least one table (108) capable of defining counter loading values.  16. Signaling device according to one of claims 1 to 15, characterized in that the control unit (100) comprises - a central unit (102) comprising dividing means, - a main counter (104) mounted down-counter, the counter (104) being reloaded to the cycle length value (LCY) when it reaches a zero count, and the central unit (102) calculating from the appearance of an initialization event of the display on the display unit (200), the time difference to be applied between each step of evolution of the information on the display unit (200), by dividing the instantaneous value of the counter (DI) by the number of steps (NL) remaining active on the display unit (200).  17. Signaling device according to one of claims 15 and 16, characterized in that the central unit (102) ensures readjustment of the main counter (104) each time the system cycle passes through a recognized instant (IR ).  18. Signaling device according to claim 17, characterized in that the readjustment of the main counter (104) is operated on the basis of values contained in a table (108) of the control unit (100).  19. Signaling device according to one of claims 16 to 18, characterized in that the initialization event corresponds to the call induced by a pedestrian to cross a roadway.  20. Signaling device according to one of claims 15 to 19, characterized in that for operation in coordinated mode the control unit further comprises an auxiliary counter (106) initialized at the counting when a detection is detected. registration pulse used for coordination, a memory (108) capable of memorizing a theoretical delay value (DT) which represents the theoretical time between the registration pulse and the appearance of the reference event, and means for comparing the content of the auxiliary counter (106) with the content of the memory (108) so that when the content of the auxiliary counter (106) exceeds the content of the memory (108), the central unit (102) loads the main counter (104) to the sum formed, on the one hand by the value of the theoretical delay (DT), and on the other hand by the complement of the position (C) of the auxiliary counter (106) with respect to the length of the cycle ( LCY).  21. Signaling device according to claim 16, characterized in that each operating cycle being divided into ranges separated by inter-ranges, brought into play only at the appearance of a call signal, at the end of each range the central unit (102) examines the sum of the potential future calls and readjust the main counter (104) to a predetermined value as a function of the recognized instant considered if the sum of the call signals is positive, and on the other hand if the sum of calls is zero, ensures that the main counter (104) is readjusted to a predetermined value for the current interage.