Time Display System

Abstract

To display an exact time until switching of lighting even at a crossing where seconds of holding lighting are varied.SOLUTION: A time display system consists of a time display unit for performing count-down display of a remaining time of blue lighting and a signal control unit connected with a signal lamp L, a vehicle sensor and the time display unit. First steps K1 and K7 and second steps K2 and K8 which are the same in a lighting state where a vehicle signal lamp L12 or a vehicle signal lamp L22 is blue lighting are provided in an aspect table T stored in the signal control unit. Holding seconds of the first steps K1 and K7 are set as variable seconds and holding seconds of the second steps K2 and K8 are set as stationary seconds, such that even at a crossing where lighting control is performed in such a manner that holding seconds of blue lighting are varied, an exact remaining time from shifting the lighting control from the first steps K1 and K7 to the second steps K2 and K8 to switching to yellow lighting of the vehicle signal lamp L12 or the vehicle signal lamp L22 can be presented to traveling vehicles which travel in accordance with the blue lighting.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a time display system that displays to a traveling vehicle the time remaining until a signal lamp is changed. [Background technology]

[0002] Patent Document 1 discloses a traffic light display device that counts down the remaining time until the light changes from green to yellow by displaying segments.

[0003] The signal lights that light up in green, yellow, and red are controlled by a signal control device installed at the intersection, and the signal lights are controlled according to the indication table T0 shown in Figure 4, which is stored in the signal control device.

[0004] The aspect table T0 is composed of a number of stages K. At stage K1, for example, lighting control is set so that the pedestrian signal lamp L11 and the vehicle signal lamp L12 on the main road are lit green, and the pedestrian signal lamp L21 and the vehicle signal lamp L22 on the secondary road intersecting the main road are lit red.

[0005] At the staircase K2, the lighting control is set so that the pedestrian signal lamp L11 flashes green, the vehicle signal lamp L12 lights green, and the pedestrian signal lamp L21 and the vehicle signal lamp L22 light red. At the final staircase K, staircase K10, the lighting control is set so that all the signal lamps L light red.

[0006] Each of the steps K1 to K10 is set with a retention time for which each lighting state is maintained, and the total number of seconds for which each lighting state is maintained up to the steps K1 to K10 is counted as the number of seconds in one cycle, and the lighting control of each signal lamp L is performed by repeating a cycle consisting of the steps K1 to K10.

[0007] When controlling the lighting of stairs K1 and K6 in the indication table T0 shown in Figure 4, the signal display device of Patent Document 1 displays a countdown of the remaining time until the switch to stairs K2 and K7 is made to vehicles traveling with green lights on. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Utility Model Application Publication No. 4-87000 Summary of the Invention [Problem to be solved by the invention]

[0009] However, at intersections where lighting control is performed in such a way that the number of seconds to hold the lights on varies from time to time based on the traffic volume collected at the intersection, it may not be possible to determine the remaining time until switching to stairs K2 and K7 during lighting control of stairs K1 and K6.

[0010] When performing such lighting control, if the signal display device of Patent Document 1 is displayed, for example, while displaying a countdown with 10 seconds remaining, the light may switch to 15 seconds later, or the countdown may be terminated midway and the light may switch to yellow. Similar things can also occur when the signal display device is made to display the waiting time until the light switches from red to green for a waiting vehicle stopped with its light on red.

[0011] In this way, the countdown of the remaining time until the signal display device changes from green to yellow, or the waiting time until it changes from red to green, is not performed accurately, creating a very dangerous situation for vehicles traveling while checking the remaining time for the green light.

[0012] An object of the present invention is to solve the above-mentioned problems and provide a time display system which displays the accurate remaining time for the green light or the waiting time until the green light is turned on for a traveling vehicle with its green light on or a waiting vehicle stopped with its red light on, even at an intersection where lighting control is performed in which the number of seconds the green light is maintained fluctuates. [Means for solving the problem]

[0013] In order to achieve the above object, the time display system according to the present invention comprises a time display unit that is installed near a vehicle signal lamp at an intersection or disposed on a housing of the vehicle signal lamp and displays the time until the vehicle signal lamp is switched on, and a signal control unit that is connected to the time display unit and the signal lamps including the vehicle signal lamp and performs display processing for the time display unit, and the signal control unit is a time display system that repeatedly controls the lighting of the signal lamps according to an aspect table consisting of a plurality of stages in which the lighting states of the signal lamps are set, and the aspect table includes The time display system includes a set of identical stages in which one vehicle signal light is lit in green and the other vehicle signal light is lit in red, a first stage which is the previous stage of the set has a variable number of seconds to be held, and a second stage which is the next stage of the set has a fixed number of seconds to be held, and when the lighting control transitions from the first stage to the second stage, the time display unit displays the remaining time until the green light of one of the vehicle signal lights is switched to yellow, and displays the remaining time while subtracting it from the remaining time until the light is switched to yellow.

[0014] The time display system according to the present invention is a time display system that is installed near a vehicle signal lamp at an intersection or arranged on a housing of the vehicle signal lamp and displays the time until the vehicle signal lamp is switched on, and a signal control unit that is connected to the time display unit and the signal lamps including the vehicle signal lamp and performs display processing for the time display unit, and the signal control unit is a time display system that repeatedly controls the lighting of the signal lamps according to an aspect table consisting of a plurality of stages in which the lighting states of the signal lamps are set, and the aspect table includes, The vehicle signal light includes a set of identical stages in which the vehicle signal light of one vehicle is lit green and the other vehicle signal light is lit red, a first stage which is the previous stage of the set has a variable number of seconds to be held, and a second stage which is the next stage of the set has a fixed number of seconds to be held, and when the lighting control shifts from the first stage to the second stage, the time display unit displays a waiting time until the other vehicle signal light is switched from red to green, and the waiting time is displayed while being subtracted until the other vehicle signal light is switched to green. Effect of the Invention

[0015] According to the time display system of the present invention, the same first and second stages are provided in the display table when the vehicle signal lamp is green, and the holding time for the first stage is set to a variable number of seconds, and the holding time for the second stage is set to a fixed number of seconds, so that even at an intersection where the holding time for green is variable, after the lighting control is shifted from the first stage to the second stage, it is possible to provide a running vehicle running with the green light on with the accurate remaining time until the vehicle signal lamp switches to yellow. Also, it is possible to provide a waiting vehicle waiting with the red light on with the accurate waiting time until the vehicle signal lamp switches to green. [Brief description of the drawings]

[0016] [Figure 1] This is a block diagram of the time display system. [Diagram 2] FIG. 1 is a diagram showing the layout of a time display system at an intersection. [Diagram 3] 1 is an example of a current display table stored in the time display system. [Figure 4] 1 is an example of an indication table stored in a conventional signal control device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] The time display system of the present invention will be described in detail based on the embodiment shown in Figs.

[0018] FIG. 1 is a block diagram of a time display system, and FIG. 2 is a layout diagram of the time display system at an intersection C where a main road S10 and a minor road S20 that intersects with the main road S10 intersect.

[0019] The time display system is composed of signal lights L and vehicle detectors D installed on a road S, time display units 10, 20 that display the remaining time for the green light to be turned on or the waiting time until the green light is turned on, and a signal control unit 30 connected to the signal lights L, vehicle detectors D, and time display units 10, 20. It is sufficient for the time display system to have a time display unit 10 and signal control unit 30 for at least one road.

[0020] The traffic lights L installed at the intersection consist of pedestrian traffic lights L11 and vehicle traffic lights L12 installed on the main road S10, and pedestrian traffic lights L21 and vehicle traffic lights L22 installed on the secondary road S20.

[0021] Time display units 10, 20 are installed near the vehicle signal lights L12, L22, respectively, and these time display units 10, 20 display, in numerical segments, the remaining time until the vehicle signal lights L12, L22 change from green to yellow and the waiting time until the light changes from red to green.

[0022] As shown in FIG. 1, the time display units 10, 20 are installed on the lower side near the vehicle signal lights L12, L22, but the segments may be displayed in the green light areas when the vehicle signal lights L12, L22 are lit red. In other words, the time display units 10, 20 may be located on the housings of the vehicle signal lights L12, L22.

[0023] The display form of the time display units 10, 20 which display the time remaining until switching while subtracting it can be an hourglass display form or the like in addition to a numerical segment display. In this hourglass display form, multiple lighted windows are arranged vertically or horizontally, and after all of these lighted windows are lit, they are turned off in equal time intervals starting from the lighted window at one end as time passes.

[0024] For example, an ultrasonic vehicle detector is used for the vehicle detector D, which emits ultrasonic waves from a predetermined height above the road toward the road surface and measures the reflection time to measure the passage of vehicles and their speeds. The vehicle detectors D installed at the intersection C are composed of a vehicle detector D11 for detecting vehicles in one lane and a vehicle detector D12 for detecting vehicles in the opposite lane, which are installed on the main road S10, and a vehicle detector D21 for detecting vehicles in one lane and a vehicle detector D22 for detecting vehicles in the opposite lane, which are installed on the secondary road S20.

[0025] A signal control unit 30 installed on a pillar or the like near the intersection C is composed of a control processing unit 31 and a memory unit 32 connected to the control processing unit 31, which stores an indication table T for the signal lights L and traffic volume and the like based on measurements by the vehicle detector D. All of the signal lights L, time display units 10, 20, and vehicle detectors D installed at the intersection C are connected to the control processing unit 31, and it performs various control processes such as display processing and measurement processing for these.

[0026] Further, the control of the display processing of the time display units 10, 20 may be performed by a first signal control unit (not shown) provided in each housing of the vehicle signal lamps L12, L22, other than by the signal control unit 30 as described above. In such a case, the signal control unit 30, which serves as a second signal control unit, performs control processing for devices other than the time display units 10, 20.

[0027] FIG. 3 shows an example of an aspect table T stored in the memory unit 32. In accordance with the aspect table T consisting of stairs K1 to K12, lighting control of each signal lamp L arranged on the main road S10 and the secondary road S20 is repeatedly performed.

[0028] The control processing unit 31 can switch between a variable control mode in which the retention seconds for stairs K1, K7 are variable as variable seconds a, b, and a fixed control mode in which the retention seconds for all stairs K are fixed, based on the traffic volume collected from the vehicle detector D. Furthermore, it is also possible to set the control mode and the fixed value of the retention seconds of the indication table T appropriately according to the time period, day of the week, etc.

[0029] In addition, lighting control can be performed by switching between an online mode in which the light source is connected to a traffic control center (not shown) via a communication network, and an offline mode in which the light source is operated independently.

[0030] Compared with the conventional aspect table T0, which is operated in fixed control mode and has 10 steps in one cycle, the aspect table T shown in FIG. 3 divides the step K1 of the aspect table T0 into steps K1 and K2, and divides the step K6 of the conventional aspect table T0 into steps K7 and K8.

[0031] The stairs K1, K2 where one vehicle signal lamp L12 is green and the other vehicle signal lamp L22 is red, and the stairs K7, K8 where one vehicle signal lamp L22 is green and the other vehicle signal lamp L12 is red are stairs with the same lighting state, and the hold time of the first stairs K1, K7, which are the stairs ahead of the pair, is variable seconds a, b, while the hold time of the second stairs K2, K8, which are the stairs after the pair, is fixed. Note that the hold time of each stairs K other than stairs K1, K7 is also fixed as shown in Figure 3.

[0032] The variable seconds a and b maintain the lighting time between 1 second and the maximum settable number of seconds, and are set based on the measurement data from the previous cycle or the past few cycles measured by vehicle detector D after the lighting control shifts from stairs K12 and K6, which are the stairs just before stairs K1 and K7, to stairs K1 and K7.

[0033] The variable seconds a and b are calculated based on the traffic volume and average vehicle speed on the main road S10 measured by vehicle detectors D11 and D12, and the traffic volume and average vehicle speed on the secondary road S20 measured by vehicle detectors D21 and D22. For example, if the traffic volume on the main road S10 is greater than the traffic volume on the secondary road S20 and the average vehicle speed on the main road S10 is slower, the variable seconds a is set longer than the variable seconds b.

[0034] In addition, when the main road S10 is congested and there are almost no vehicles traveling on the secondary road S20, the variable number of seconds a is set to the maximum settable number of seconds, and the variable number of seconds b is set to 1 second. By repeating this type of current display table T, the congestion on the main road S10 is relieved, and as the congestion is relieved, the variable numbers of seconds a and b also change.

[0035] 1, the settings of these variable seconds a and b are calculated based on the traffic volume and the like of vehicle detectors D11, D12, D21, and D22 connected to signal control unit 30 of intersection C, but it is also possible to use variable seconds a and b calculated by adjacent signal control unit 30n of adjacent intersection Cn connected to vehicle detectors D11, D12, D21, and D22 of the adjacent intersection Cn in the connected signal control unit 30. In such a case, it is not necessarily necessary to install vehicle detectors D11, D12, D21, and D22 at intersection C.

[0036] The maximum number of seconds that can be set for one cycle is predetermined, and the variable seconds a and b are calculated within the number of seconds obtained by subtracting the fixed number of seconds for each step K from this maximum number of seconds that can be set.

[0037] The fixed number of seconds for the hold times of stairs K2 and K8 are set to be at least as long as the number of seconds required for a pedestrian to safely cross road S at intersection K. This number of seconds is set according to the width of road S at intersection K. For example, if the main road S10 at intersection C has a 10m wide crosswalk, the hold time of stairs K2 is set to 10 seconds.

[0038] The hold seconds for these stairs K2 and K8 are set to ensure that pedestrians can cross safely even when the variable seconds a and b are set to 1 second as described above, and any appropriate number of seconds can be set as long as it is equal to or greater than the crossing seconds.

[0039] Since the number of seconds that the vehicle signal lamp L12 maintains for staircase K1 while the signal lamp is green, i.e., the variable number of seconds a, is variable, when staircase K1 is in the lit state, the remaining time for the green light is not displayed to vehicles traveling on the main road S10 via the time display unit 10. Then, when the lighting control shifts from staircase K1 to staircase K2, the remaining time for the green light until it switches to yellow light, i.e., the total number of seconds for staircases K2 to K4, is displayed on the time display unit 10, and a countdown is displayed every second until it reaches 0 seconds.

[0040] Similarly, because the number of seconds a is also variable for the staircase K1 where the vehicle signal lamp L22 is lit red, when the staircase K1 is lit, vehicles waiting on the subsidiary road S20 are not prompted to wait until the light turns green via the time display unit 20. Then, when the lighting control shifts from staircase K1 to staircase K2, the waiting time until the light turns green, that is, the total number of seconds for staircases K2 to K6, is displayed on the time display unit 20, and a countdown is displayed every second until the number of seconds reaches 0.

[0041] In the lighting control based on the indication table T shown in Figure 3, when moving to stage K2, the time display unit 10 starts displaying a countdown from 16 seconds, and after a 16-second countdown until the vehicle signal lamp L12 switches to a yellow light, the lighting control moves to stage K5, the vehicle signal lamp L12 switches to a yellow light, and the display processing of the time display unit 10 ends.

[0042] Similarly, when moving to stage K2, the time display unit 20 begins to display a countdown from 20 seconds, and after a 20-second countdown until the vehicle signal light L12 switches to green, the lighting control moves to stage K7, the vehicle signal light L22 switches to green, and the display processing of the time display unit 20 ends.

[0043] Such display processing is also performed for the remaining time for the secondary road S20 to be lit green on the time display unit 20 for the stairs K8 to K12, and for the waiting time until the main road S10 is lit green on the time display unit 10. When the lighting control shifts from stairs K7 to stairs K8, the time display unit 20 displays the number of seconds for the total value of stairs K8 to K10, and displays a countdown until the vehicle signal lamp L22 switches to a yellow light, and when the lighting control shifts from stairs K7 to stairs K8, the time display unit 10 displays the number of seconds for the total value of stairs K8 to K12, and displays a countdown until the vehicle signal lamp L12 switches to a green light.

[0044] In the lighting control based on the display table T shown in FIG. 3, the display control has been described in which the time display units 10 and 20 alternately display the remaining time for green lighting and the waiting time until green lighting. However, the display control may be such that the time display units 10 and 20 display only the remaining time for green lighting or only the waiting time until green lighting.

[0045] In this way, according to the time display system of the present invention, the display table T is provided with the first staircases K1, K7 in which the vehicle signal lamp L12 is lit green and the vehicle signal lamp L22 is lit red and are identical in the lit state, and the second staircases K2, K8 in which the vehicle signal lamp L12 is lit red and the vehicle signal lamp L22 is lit green and are identical in the lit state, and the retention seconds of the first staircases K1, K7 are set to variable seconds and the retention seconds of the second staircases K2, K8 are set to fixed seconds.By this, even at an intersection C where lighting control is performed with a variable retention second number, after the lighting control has shifted from the first staircases K1, K7 to the second staircases K2, K8, it is possible to provide vehicles traveling with the green light on with the exact remaining time until the vehicle signal lamp L12 or the vehicle signal lamp L22 switches to yellow. Drivers of moving vehicles will be able to decelerate in advance of an intersection in accordance with the remaining time of the green light, preventing traffic accidents such as rear-end collisions caused by sudden braking.

[0046] Similarly, after the lighting control transitions from the first stage K1, K7 to the second stage K2, K8, it is possible to provide waiting vehicles waiting with the red light on with the exact waiting time until the vehicle signal lamp L22 or the vehicle signal lamp L12 switches to green. [Explanation of symbols]

[0047] 10, 20 hour display 30 Signal control section a, b variable number of seconds C intersection D, D11, D12, D21, D22 Vehicle detector K1 First Step K2 Second Staircase L Signal lamp L11, L21 Pedestrian signal lights L12, L22 Vehicle signal lamps S10 Main road S20 Secondary road T Current Display Table

Claims

1. A time display system comprising: a time display unit that is installed near a vehicle signal lamp at an intersection or disposed on a housing of the vehicle signal lamp and displays the time until the vehicle signal lamp is switched on; and a signal control unit that is connected to the time display unit and signal lamps including the vehicle signal lamp and performs display processing for the time display unit, the signal control unit repeatedly controls the lighting of the signal lamps according to an indication table consisting of a plurality of stages in which the lighting states of the signal lamps are set, The indication table includes a pair of identical stairs in which one of the vehicle signal lamps is green and the other of the vehicle signal lamps is red, A first step in the set has a variable number of retention seconds, and a second step in the set has a fixed number of retention seconds; a time display unit that displays, when the lighting control transitions from the first stage to the second stage, a remaining time for which the green light of one of the vehicle signal lamps is to be switched from green to yellow, and that subtracts from the remaining time while displaying the time, until the green light is switched to yellow.

2. A time display system comprising: a time display unit that is installed near a vehicle signal lamp at an intersection or disposed on a housing of the vehicle signal lamp and displays the time until the vehicle signal lamp is switched on; and a signal control unit that is connected to the time display unit and signal lamps including the vehicle signal lamp and performs display processing for the time display unit, the signal control unit repeatedly controls the lighting of the signal lamps according to an indication table consisting of a plurality of stages in which the lighting states of the signal lamps are set, The indication table includes a pair of identical stairs in which one of the vehicle signal lamps is green and the other of the vehicle signal lamps is red, A first step in the set has a variable number of retention seconds, and a second step in the set has a fixed number of retention seconds; When the lighting control transitions from the first stage to the second stage, the time display unit displays the waiting time until the other vehicle signal lamp changes from red to green, and the waiting time is subtracted from the waiting time until the other vehicle signal lamp changes to green.

3. 3. The time display system according to claim 1, wherein the time display unit displays the number of seconds remaining until the light is switched on as a number in segments.

4. The signal control unit is connected to a vehicle detector installed at the intersection, A time display system as described in any one of claims 1 to 3, characterized in that the variable number of seconds is set based on past measurement data measured by the vehicle detector after lighting control transitions from the stage immediately preceding the first stage to the first stage.

5. The vehicle detector comprises a first vehicle detector installed on a main road and a second vehicle detector installed on a secondary road intersecting the main road, 5. The time display system according to claim 4, wherein the variable number of seconds is calculated based on the traffic volume and average vehicle speed of the main road measured by the first vehicle detector and the traffic volume and average vehicle speed of the secondary road measured by the second vehicle detector.

6. 6. The time display system according to claim 4, wherein the variable number of seconds is set within a range from 1 second to a settable maximum number of seconds.

7. A time display system as described in any one of claims 1 to 6, characterized in that the number of seconds for which the second step is held is set to a number of seconds that is at least equal to or greater than the number of seconds required for a pedestrian to safely cross the road at the intersection.

8. 8. The time display system according to claim 7, wherein the number of seconds required for crossing is set in accordance with the width of the road at the intersection.

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