JP5003928B2 - Signal control apparatus, system and method - Google Patents

Description

  The present invention relates to a signal control device, system, and method for controlling a signal light at an intersection using a detection signal from a vehicle detector installed in any lane entering the intersection.

When a vehicle is traveling on a road toward an intersection with a signal, the vehicle may not enter the intersection by the end of the yellow signal at the intersection, and may not stop before the intersection.
FIG. 8 is a graph for explaining this risk. The vertical axis represents the vehicle travel speed (km / h), and the horizontal axis represents the distance (m) from the stop line at the intersection to the vehicle position.
In the figure, a curve L1 represents a relationship between a traveling speed and a distance (stop condition) that can be stopped at a stop line if the vehicle decelerates, and a curve L2 represents a yellow signal when the vehicle is traveling. It represents the relationship between the traveling speed and the distance (entrance condition) that the vehicle can reach the stop line of the intersection within the yellow traffic light time (before it becomes red).

The vehicle in the region A on the left side of the curves L1 and L2 cannot stop before the stop line at the current travel speed and distance, and can reach the stop line within the yellow traffic light time. Therefore, it is determined that the vehicle will cross the intersection when a yellow signal is generated during traveling.
The vehicle in the region B on the right side of the curves L1 and L2 can stop before the stop line at the current travel speed and distance, and when reaching the stop line, the yellow signal time has already ended ( It ’s red.) Therefore, when a yellow signal is generated during traveling, it is determined to decelerate and stop at the intersection.

A region C between the curve L1 and the curve L2 is called a dilemma zone, and is a region where the vehicle cannot stop smoothly (safely) at the stop line and cannot enter the intersection before the yellow signal ends. Since the vehicle in the region C has plunged in red, there is a possibility that the pedestrian on the crossing side that has turned blue will bounce or a side collision with the vehicle on the crossing side may occur.
A region D between the curve L1 and the curve L2 is called an option zone, and is a region where the stop can be safely stopped or the vehicle can enter the intersection before the yellow signal ends. If vehicles with different personalities continue because the vehicles are mixed, there is a risk of a rear-end collision with the following vehicle when the preceding vehicle stops.

Therefore, a sensor that measures the speed of the vehicle is installed in front of the intersection (for example, at a point of 150 m), and when a vehicle in such a dilemma zone or option zone is detected, the green light time is extended to prevent an accident. At the same time, when it is not detected, the control that cuts off the green light and smoothes the flow of traffic is called “dilemma sensitive control”.
JP-A-4-163700 JP-A-62-229398 JP 2003-317186 A JP 58-213399 A

The dilemma zone and the option zone are collectively referred to as a “danger avoidance area”.
In order to find a vehicle in this danger avoidance area, speed information of each vehicle is required.
However, in order to obtain speed information of individual vehicles, a speed detection type vehicle sensor is required. As such a speed detection type vehicle sensor, two vehicle detectors are embedded in the road along the running direction, and the distance between the two vehicle detectors is divided by the vehicle detection time difference to obtain the speed, or the road is monitored with a camera. It is necessary to obtain the vehicle speed from the movement of the vehicle image on the camera screen.

Such a speed detection type vehicle sensor is expensive and unsuitable for installation on a road. Therefore, a signal control device that can use an inexpensive vehicle detection type sensor that does not need to detect the speed is required.
In addition, since it is necessary to set the risk avoidance area larger in consideration of the speed measurement error, there is a problem that the accuracy of signal control is lowered.

  Therefore, according to the present invention, it is possible to perform the sensitive control of the traffic signal only by installing a sensor for detecting the passing of the vehicle or the presence of the vehicle without measuring the speed of the vehicle, thereby smoothly moving the traffic flow. An object of the present invention is to provide a signal control apparatus, system, and method that can be used.

Signal control apparatus of the present invention, the vehicle a receiver for receiving a vehicle sensing signal from the sensor for sensing the passage of a vehicle, the vehicle sensing signal a predetermined observation interval transit time from the time that senses the passage of the vehicle on the basis of If no passage of the next vehicle is detected before the time elapses, there is no traveling vehicle in the observation section set between the stop line provided in the lane at the intersection and the vehicle detector. And a signal control unit that terminates the green light under a predetermined condition.

FIG. 1 is a graph for explaining the principle of signal control of the present invention. The vertical axis represents the vehicle travel speed v, and the horizontal axis represents the distance x from the stop line of the intersection to the vehicle position.
Similarly to FIG. 8 described above, the curve L1 is a curve representing the limit of the traveling speed and distance that can be stopped at the stop line if the vehicle decelerates, and the curve L2 is a yellow signal when the vehicle is traveling. It is a straight line representing the travel speed and the limit of the distance that the vehicle can reach the stop line of the intersection within the yellow traffic light time (before it becomes red light).

A region C between the curve L2 and the curve L1 is a region where the vehicle cannot stop smoothly (safely) at the stop line and cannot enter the intersection before the yellow light ends. Since the vehicle in the region C has plunged in red, there is a possibility that the pedestrian on the crossing side that has turned blue will bounce or a side collision with the vehicle on the crossing side may occur.
A region D between the curve L2 and the curve L1 is a region where the vehicle can stop safely at the stop line or enter the intersection before the yellow signal ends, and vehicles with different judgments regarding stop or pass are mixed. Therefore, if drivers with different personalities continue, there is a risk of a rear-end collision with the following vehicle when the preceding vehicle stops.

The area C and the area D are “danger avoidance areas”.
The danger avoidance area is located closer to the intersection as the vehicle speed is lower.
When there is no traffic jam, the speed of the vehicle traveling on the road is distributed over a certain range as shown in FIG. A value close to the lower limit of the distribution is set as the first speed V1, and a value close to the upper limit of the distribution is set as the second speed V2.

In FIG. 1, a portion sandwiched between the first speed V <b> 1 and the second speed V <b> 2 larger than the first speed V <b> 1 in the danger avoidance region is indicated by hatching.
The end closest to the intersection of the danger avoidance area at the first speed V1 is indicated by a position D1 in FIG. The farthest end from the intersection of the danger avoidance area at the second speed V2 is shown by a position D2 in FIG. A section between the positions D1 and D2 is referred to as an “observation section”.

In the present invention, at a predetermined position in any lane that leads to the intersection, a vehicle detector that detects the passage of the vehicle detects a vehicle that attempts to enter the observation section, and the time during which the vehicle is considered to have exited the observation section is detected. When it has passed, the green light is cut off and control is performed to smooth the traffic at the intersection.
The second speed V2 can be a regulated speed of the road. The first speed V1 is a value obtained from experience, and is 50 to 60% of the second speed V2.

Some vehicles are slower than the first speed V1 and some are faster than the second speed V2, but most vehicles (eg, 95%) are within the range from the first speed V1 to the second speed V2. I think that it will run on.
Note that the speed distribution becomes slower during traffic jams, but traffic jams are not assumed in the present invention. This is because there is usually no dilemma sensitive control during traffic jams.

From the above, the boundary position where the vehicle entering at the lower limit speed V1 leaves the danger avoidance region is indicated by D1 in FIG. The boundary position where the vehicle that has entered at the upper limit speed V2 leaves the danger avoidance area is indicated by D2 in FIG.
There is a possibility that the vehicle existing in the observation section is in the danger avoidance area depending on the speed.

In the present invention, the next vehicle is detected until a predetermined time elapses from the time when the vehicle is sensed based on the vehicle sensing signal so that it is not necessary to measure the vehicle speed for the dilemma sensitive control. If not, it is assumed that no vehicle exists in the danger avoidance area set between the intersection and the vehicle detector.
That is, in the present invention, a vehicle detector is installed at the position D2 or upstream thereof to detect the presence or absence of a traveling vehicle. When a vehicle traveling at a certain time is detected, it is determined that the vehicle is in the danger avoidance region before a predetermined observation section passage time elapses until the vehicle finishes passing through the end D1 of the observation section. . If the observation section passage time has elapsed, it is determined that the vehicle has left the danger avoidance area.

The predetermined observation section passage time is assumed to be, for example, that the vehicle has traveled at a constant speed VN that is equal to or higher than the first speed V1 and equal to or lower than the second speed V2 from the position detected by the vehicle detector. In this case, the time until passing through the end closest to the intersection of the observation sections may be used.
As shown in FIG. 2, this speed VN may be the mode Vu of the speed distribution or the average value Vm of the speed distribution. However, it is desirable to set the first speed V1. When the speed VN is determined to be the first speed V1, most vehicles traveling faster than this have already left the danger avoidance area when the observation section passage time has elapsed, so there is a vehicle in the danger avoidance area. This is because the misjudgment that the green light is cut off by mistake is avoided.

In this way, when the vehicle travels from the position detected by the vehicle detector at the speed VN, the next vehicle detects even if the time passing through the end closest to the intersection of the observation section has elapsed. If not, it is considered that no vehicle is in the danger avoidance area, and the traffic light is smoothed by cutting off the green light.
However, it is desirable not to stop the green signal unconditionally, but to stop the green signal after the minimum green time has elapsed.

As long as there are vehicles in the danger avoidance area, it is preferable to prevent the accident by extending the green light time (however, the maximum green time is set to prevent the green light time from becoming too long) Good).
Also, the signal control device of the present invention uses a vehicle presence sensor that detects the presence of a vehicle installed at a predetermined position in any lane that leads to the intersection, and the vehicle presence sensor causes the stop line of the intersection to be detected. a receiver for receiving a presence sensing signal of the vehicle present in the observation interval that is set on the upstream side of, if not sense the presence of the vehicle on the basis of the presence sensing signal, the hazard avoidance region It is assumed that the vehicle does not exist, and includes a signal control unit that stops the green signal under a predetermined condition.

  If it is the structure of this invention, it is thought that the vehicle escaped the observation area by using the vehicle presence sensor which can detect the vehicle which exists in an observation area instead of the vehicle sensor which detects passage of a vehicle. There is no need to count time. If it is detected that there is no vehicle in the observation section, the green light can be cut off. Therefore, it is not necessary to keep track of time, and the configuration of the apparatus can be further simplified.

As in the case of the above-mentioned invention, it is preferable that the blue signal is terminated on condition that the minimum blue time has elapsed.
The signal control system and the signal control method of the present invention are substantially the same as the invention of the signal control device.

  According to the present invention, it is possible to install and use a vehicle sensor or a vehicle presence sensor that is less expensive than a speed sensor, so that the cost of the entire signal control system can be reduced. Since it is not necessary to keep away from the intersection like the installation position of the speed sensor, the degree of freedom of sensor installation is improved. Furthermore, since it is not necessary to track each vehicle and measure the speed, it is possible to reduce the signal control processing load and improve the accuracy of signal control.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 3 is a map of the intersection. In one lane entering the intersection, a point at a distance L1 from the position of the stop line at the intersection is D1, and a point at a distance L2 is D2. A section (shown by hatching) from the point D1 to the point D2 is set as an observation section.
If there are four lanes entering this intersection, four such observation sections are set.

A vehicle detector 2 is installed at a point D2, which is the upstream end of the observation section.
However, the vehicle detector 2 does not have to be strictly installed at the point D2, and may be installed at a point further away from the intersection. FIG. 3 illustrates a state in which the vehicle detector 2 is installed at a position further away from the point D2 by a distance L3.
If the vehicle detector 2 is of an ultrasonic type, for example, the distance to the object is measured by measuring the time from launching the ultrasonic wave onto the road directly below and receiving the reflected wave. Is counted.

However, the vehicle detection method is not limited to the ultrasonic method, and for example, a sensor of the type that detects the passage of the vehicle by embedding a coil in the road and detecting the change in the magnetic field lines due to the vehicle passing over it is adopted. May be.
Even if this vehicle sensor 2 does not have a function of measuring the traveling speed of the vehicle, it can be used in the present invention.

As shown in FIG. 3, the signal control device 4 is installed near the signal lamp 3 and is connected to the vehicle detector 2 and the signal lamp 3 through a communication line (not shown). The installation position of the signal control device 4 is not limited to this place, and may be installed in any place as long as it is connected to the vehicle detector 2 and the signal lamp 3 via a communication line.
Further, the communication medium, frequency band, communication method, encoding method, and the like of the communication line that the signal control device 4 is connected to the vehicle detector 2 and the signal light 3 are not limited. Wired communication may be used, wireless radio waves may be used, and optical communication may be used. Further, a communication method suitable for extremely short distances such as DSRC (Dedicated Short Range Communication) may be used. A wide range of communication systems such as FM multiplex communication, mobile phones, and the like may be used.

FIG. 4 is a block diagram for illustrating each function of the vehicle sensor 2 and the signal control device 4 connected to each other.
The vehicle detector 2 includes a vehicle detection unit 21 that detects a vehicle and outputs a vehicle detection signal, and a transmission unit 22 that transmits the vehicle detection signal through a communication line.
The signal control device 4 includes a receiving unit 41 that receives a vehicle detection signal from the vehicle detector 2, a time measuring unit 42 that measures various times, display information (for example, red, yellow, and blue time of each display) of the signal lamp 3 and the like. A storage unit 43 for storing the intersection stop line and the vehicle when the next vehicle is not detected before the passage of a predetermined observation section from the time when the vehicle is detected based on the vehicle detection signal. A determination control unit 44 that controls the signal lamp 3 by determining that the vehicle does not exist in the danger avoidance region set between the sensor 2 and the like is provided.

The signal control device 4 includes a computer and a program for operating the computer. The signal control procedure of the present invention is realized by a computer executing a program recorded on a predetermined medium such as a CD-ROM or a hard disk.
Hereinafter, the signal control procedure of the present invention will be described with reference to a flowchart (FIG. 5).
First, the determination control unit 44 sets the “blue elapsed time T”, which is a variable measured from the time when the signal is switched to blue, to 0, and is a variable measured on the condition that the vehicle is not sensed. The vehicle non-detection time t ”is set to 0 (step S1). Further, a minimum blue time T1 and a maximum blue time T2 are set. The minimum blue time T1 is a time during which the blue time should not be shortened any more, and the maximum blue time T2 is a time during which the blue cannot be continued any longer. Both are constants determined by transportation policy.

The determination control unit 44 determines whether or not the maximum blue time T2 has elapsed since the time when the signal was switched to blue (step S2), and if the maximum blue time T2 has elapsed, the blue signal is terminated (step S8). If the maximum blue time T2 has not elapsed, it is determined whether a vehicle detection signal has been received from the vehicle detector 2 (step S3).
When the vehicle detection signal is received, Δt is added to the blue elapsed time T to update the time, and the vehicle non-detection time t is reset to 0 (step S6). Here, Δt is a time corresponding to a period for receiving a vehicle detection signal from the vehicle detector 2. Δt is, for example, 0.2 seconds.

If no vehicle detection signal is received, the vehicle non-detection time t is compared with the observation section passage time UG (step S4). If the vehicle non-sensing time t does not exceed the observation section passage time UG, Δt is added to the blue elapsed time T, Δt is added to the vehicle non-sensing time t (step S7), and the process returns to step S2.
In this way, the vehicle non-sensing time t, which is the time when no vehicle sensing signal is received, is updated.

If the vehicle non-sensing time t is equal to or longer than the observation section passing time UG, it is determined whether or not the minimum blue time T1 has elapsed (step S5). If the minimum blue time T1 has not elapsed, Δt is added to the blue elapsed time T, Δt is added to the vehicle non-sensing time t (step S7), and the process returns to step S2.
When the minimum green time T1 has elapsed, it is considered that there is no vehicle in the danger avoidance area, and the blue signal is discontinued and switched to the yellow signal (step S8).

Then, the “blue elapsed time T” is reset to 0, Δt is added to the vehicle non-detection time t (step S9), and the process returns to step S2.
In this way, since a vehicle sensor that is less expensive than a speed sensor can be installed and used, the cost of the entire signal control system can be reduced. Since it is not necessary to keep away from the intersection like the installation position of the speed sensor, the degree of freedom of sensor installation is improved. Furthermore, since it is not necessary to track each vehicle and measure the speed, it is possible to reduce the signal control processing load and improve the accuracy of signal control.

As a numerical example, when the first speed V1 is 36 km / h and the second speed V is 60 km / h, which is equal to the regulation speed, the graph of FIG. The nearest end is 27 m from the stop line, and the end farthest from the intersection is 64 m from the stop line. Therefore, the section length of the observation section is 64-27 = 37 m.
The vehicle detector 2 was installed at a position L3 = 10 m, that is, a position 74 m from the stop line, further upstream from the end D2 of the observation section.

Therefore, the vehicle detector 2 is at a position 47 m from the end D1 closest to the intersection of the observation sections. This distance is expressed as L.
The speed VN of the vehicle passing through the observation section is set to 36 km / h which is equal to the first speed V1.
The time T passing at the speed VN from the position of the vehicle detector 2 to the end D1 closest to the intersection of the observation section is expressed by T = L / VN,
L = 47m, VN = 36km / h
Then, T = 4.7 seconds.

The observation section passage time UG is a time obtained by subtracting the detection delay time τ of the vehicle detector 2 from the time T.
UG = T−τ = 4.5 seconds τ is about 0.2 seconds and is a numerical value that can be ignored. If τ is ignored, UG is 4.7 seconds.

The signal control processing described above uses theoretical and deterministic formulas, but in order to provide a margin or to deal with measurement errors, the time is fine-tuned to allow margins in the curves or straight lines of each formula. It is preferable to have it.
Next, another embodiment of the present invention will be described.
In the embodiment so far, the determination control unit 44 measures the “vehicle non-sensing time t” on the condition that the vehicle is not sensed. Control is performed to stop the green light, assuming that no vehicle is present.

  However, instead of measuring the “vehicle non-detection time”, it may be determined directly using the vehicle presence detector 2a whether or not a vehicle is present in the observation section. Examples of the vehicle presence sensor 2a include image sensors such as a visible light camera, a near infrared camera, and a far infrared camera, a near infrared sensor, and a far infrared sensor. In the case of a far-infrared sensor, for example, a far-infrared ray emitted from a road or vehicle in the sensing area is received by a thermopile element, and a voltage corresponding to the amount of far-infrared light received and the temperature of the thermopile body is detected and detected. The presence or absence of a vehicle in the area is detected.

FIG. 6 is a perspective view showing the vehicle presence detector 2a installed in one lane entering the intersection and the installed state. The vehicle presence detector 2a detects a vehicle existing in this observation section, and its detection area coincides with the observation section. In addition, as long as the vehicle which exists in an observation area can be detected, it does not need to correspond completely and may include an observation area.
The vehicle presence detector 2a transmits a presence detection signal indicating the presence / absence of a vehicle in the detection area to the signal control device 4 every predetermined time.

The determination control unit 44 of the signal control device 4 detects the presence or absence of a vehicle within the observation section.
The vehicle detection method will be described. For example, the detection signal of the thermopile element is compared with the background level stored in the memory, and it is determined that there is a vehicle when the difference between the background level is equal to or greater than a threshold value. If it is less than the threshold, it is determined that there is no vehicle. For details of this determination method, see JP-A-2003-317186.

FIG. 7 is a flowchart for explaining the signal control procedure of this embodiment.
The determination control unit 44 sets “blue elapsed time T” to 0, and sets a minimum blue time T1 and a maximum blue time T2 (step U1).
The determination control unit 44 determines whether or not the maximum blue time T2 has elapsed (step U2). If the maximum blue time T2 has elapsed, the determination signal is terminated. (Step U7) If the maximum green time T2 has not elapsed, it is determined whether a vehicle presence signal is received from the vehicle presence detector 2a (step U3).

If the vehicle presence detection signal is received, Δt is added to the blue elapsed time and the process returns to step U2 (step U5).
If the vehicle presence detection signal is not received, it is determined whether or not the counted blue elapsed time T is equal to or greater than the minimum blue time T1 (step U4). If the minimum blue time T1 has not elapsed, Δt is added to the blue elapsed time T and the process returns to step U2 (step U6).

If the minimum green time T1 has elapsed, the blue signal is discontinued (step U7).
Then, “blue elapsed time T” is reset to 0 (step U8), and the process returns to step U2.
Thus, the signal control of the present invention can be performed without measuring the vehicle non-detection time t using the vehicle presence detector 2a installed on the roadside. Therefore, the processing load is reduced and the processing speed can be improved as compared with the case where the vehicle detector is used. Further, the vehicle presence sensor 2a is less expensive than the speed sensor, and the overall cost of the signal control system can be reduced. Moreover, since it is not necessary to install it apart from the intersection like a speed sensor, the degree of freedom of the sensor installation location is improved.

  Although the embodiments of the present invention have been described above, the embodiments of the present invention are not limited to the above-described embodiments. For example, the present invention can also be applied when an inflow path at an intersection has a plurality of lanes. In this case, the logical sum determination is performed for all lanes. That is, when a vehicle is detected in any lane, the vehicle non-detection time may be reset.

It is a graph for demonstrating the principle of the signal control of this invention. It is a speed distribution map of a vehicle. It is a plane map of the intersection where signal control was installed. It is a block diagram which shows each function of a vehicle sensor and a signal control apparatus. It is a flowchart which shows a signal control procedure. It is a perspective view of the intersection concerning other embodiments. It is a flowchart which shows the signal control procedure concerning other embodiment. It is a graph for demonstrating the principle of general signal control.

Explanation of symbols

2 vehicle detector 2a vehicle presence detector 21 vehicle detection unit 22 transmission unit 3 signal lamp 4 signal control device 41 reception unit 42 timing unit 43 storage unit 44 determination control unit

Claims (10)

A signal control device for controlling a signal light at the intersection using a vehicle detection signal from a vehicle detector installed at a predetermined position in any lane connected to the intersection,
Depending on the speed of the vehicle and the distance to the stop line at the intersection, an area where the traveling vehicle can safely stop at the stop line or enter the intersection before the yellow signal ends, and the traveling vehicle Is a dangerous avoidance area that combines with the area where it can stop smoothly at the stop line, and the area where it can not enter the intersection by the end of the yellow light,
A receiving unit for receiving a vehicle detection signal for detecting passage of a vehicle from the vehicle sensor;
A stop line provided in the lane at the intersection when no passage of the next vehicle is detected from the time when the passage of the vehicle is sensed based on the vehicle sensing signal until a predetermined observation section passage time elapses. And the vehicle sensor, the vehicle is considered to have no traveling vehicle in the observation section that may enter the danger avoidance area depending on the speed, and a predetermined condition A signal control device comprising: a signal control unit that cuts off the blue light underneath. The observation section starts from the end closest to the intersection of the danger avoidance area set when the vehicle travels in the lane at the first speed V1. 2. The signal control device according to claim 1, wherein the signal control device is a section from an intersection of the danger avoidance area set when the vehicle travels at a speed of V2 to a farthest end. The predetermined observation section passing time is that the vehicle has traveled through the observation section at a speed VN that is not less than the first speed V1 and not more than the second speed V2 from the time when the vehicle is detected by the vehicle detector. The signal control device according to claim 2 , wherein the time is a time required to pass through an end closest to the intersection of the observation sections. 4. The signal control device according to claim 3 , wherein the speed VN is equal to the first speed V1. A signal control system for controlling signal lights at intersections,
Depending on the speed of the vehicle and the distance to the stop line at the intersection, an area where the traveling vehicle can safely stop at the stop line or enter the intersection before the yellow signal ends, and the traveling vehicle Is a dangerous avoidance area that combines with the area where it can stop smoothly at the stop line, and the area where it can not enter the intersection by the end of the yellow light,
A vehicle detector installed at a predetermined position in any lane leading to the intersection;
A vehicle detection signal for detecting the passage of a vehicle is received from the vehicle detector, and the next vehicle passes until a predetermined observation section passage time elapses from the time when the passage of the vehicle is detected based on the vehicle detection signal. If the vehicle is not detected, it is a section set between the stop line provided in the lane at the intersection and the vehicle detector, and the vehicle can enter the danger avoidance area depending on the speed. A signal control system provided with a signal control device that considers that no traveling vehicle is present in the observation section having a characteristic and terminates the green light under a predetermined condition. Depending on the speed of the vehicle and the distance to the stop line at the intersection, an area where the traveling vehicle can safely stop at the stop line or enter the intersection before the yellow signal ends, and the traveling vehicle Is a dangerous avoidance area that combines with the area where it can stop smoothly at the stop line, and the area where it can not enter the intersection by the end of the yellow light,
Receive a vehicle detection signal to detect the passage of the vehicle by a vehicle detector installed at a predetermined position in any lane leading to the intersection,
A stop line provided in the lane at the intersection when no passage of the next vehicle is detected from the time when the passage of the vehicle is sensed based on the vehicle sensing signal until a predetermined observation section passage time elapses. And the vehicle sensor, the vehicle is considered to have no traveling vehicle in the observation section that may enter the danger avoidance area depending on the speed, and a predetermined condition A signal control method that cuts off the green light below. A signal control device for controlling a signal light at an intersection using a presence detection signal from a vehicle presence sensor that detects the presence of a vehicle installed at a predetermined position in any lane connected to the intersection,
Depending on the speed of the vehicle and the distance to the stop line at the intersection, an area where the traveling vehicle can safely stop at the stop line or enter the intersection before the yellow signal ends, and the traveling vehicle Is a dangerous avoidance area that combines with the area where it can stop smoothly at the stop line, and the area where it can not enter the intersection by the end of the yellow light,
Observation from the vehicle presence detector that is set on the upstream side of a stop line provided in the lane at the intersection, and the vehicle may enter the danger avoidance region depending on speed. A receiving unit for receiving a vehicle presence detection signal in the section;
Wherein if not sense the presence of the vehicle on the basis of the presence sensing signals, the risk avoidance area is regarded that the vehicle is not present, the signal control unit and a signal controller to abort the green light under predetermined conditions. The observation section starts from the end closest to the intersection of the danger avoidance area set when the vehicle travels in the lane at the first speed V1. The signal control device according to claim 7, wherein the signal control device is a section from an intersection of the danger avoidance area set when traveling at a speed V2 of a maximum to the farthest end. A signal control system for controlling signal lights at intersections,
Depending on the speed of the vehicle and the distance to the stop line at the intersection, an area where the traveling vehicle can safely stop at the stop line or enter the intersection before the yellow signal ends, and the traveling vehicle Is a dangerous avoidance area that combines with the area where it can stop smoothly at the stop line, and the area where it can not enter the intersection by the end of the yellow light,
A vehicle presence detector installed at a predetermined position in any lane leading to the intersection and sensing the presence of the vehicle;
Observation from the vehicle presence detector that is set on the upstream side of a stop line provided in the lane at the intersection, and the vehicle may enter the danger avoidance region depending on speed. receiving a presence sensing signal of the vehicle present in the sections, if not sense the presence of the vehicle on the basis of the presence sensing signal, it is assumed that the vehicle is not present in the danger avoidance area, the predetermined conditions And a signal control system comprising a signal control device that cuts off the green light. Depending on the speed of the vehicle and the distance to the stop line at the intersection, an area where the traveling vehicle can safely stop at the stop line or enter the intersection before the yellow signal ends, and the traveling vehicle Is a dangerous avoidance area that combines with the area where it can stop smoothly at the stop line, and the area where it can not enter the intersection by the end of the yellow light,
A section set upstream of a stop line provided in the lane of the intersection by a vehicle presence sensor that is installed at a predetermined position of any lane connected to the intersection and senses the presence of the vehicle , the vehicle However, depending on the speed, it receives a vehicle presence detection signal that exists in the observation section that may enter the danger avoidance area ,
Wherein if not sense the presence of the vehicle on the basis of the presence sensing signals, it is assumed that the vehicle is not present in the danger avoidance area, the signal control method aborting green light under predetermined conditions.

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