JP7240182B2 - intersection warning system - Google Patents

Description

The present invention relates to an intersection warning system that warns an operator operating a mobile terminal such as a smartphone at an intersection.

2. Description of the Related Art In recent years, smartphones equipped with applications such as map search have become more multi-functional and more convenient. Accidents often occur due to users who have such smart phones performing operations such as map search and e-mail while walking.

Pedestrians who are concentrating on operating their smartphones are walking without sufficiently checking what is ahead, so accidents such as colliding with oncoming pedestrians or missing a step are likely to occur. Especially at an intersection, a pedestrian operating a mobile terminal may come into contact with a running vehicle or the like, which may lead to a serious accident.

Japanese Patent Laid-Open No. 2005-100000 discloses a system in which a movement state of a user is determined based on position information, whether or not the user is in a walking state is determined according to the calculated moving speed, and if the user is in a walking state, the backlight of the liquid crystal display unit is turned off. Disclosed is a mobile terminal that allows

JP 2014-60481 A

However, the mobile terminal of Patent Document 1 must have a function of acquiring position information, and furthermore, software having walking state determination processing and liquid crystal display unit lighting control processing is installed in the mobile terminal in advance. There is a need.

There are various types of mobile terminals such as smart phones and folding mobile phones. Depending on the presence or absence of the GPS function and the difference in OS of the terminals, the mobile terminal software of Patent Document 1 may be used for various mobile terminals. The problem is that it is difficult to implement.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems, identify an operator of a mobile terminal based on the brightness of the screen of the mobile terminal, and issue a warning to the operator who is concentrating on the mobile terminal at an intersection. To provide an intersection warning system that performs

An intersection warning system according to the present invention for achieving the above object includes a photographing unit that is installed above a pedestrian crossing and photographs downward, a warning sound output unit that outputs a warning sound, the photographing unit, and and a control unit connected to the warning sound output unit , wherein the control unit detects the display screen of the mobile terminal based on the brightness of the display screen of the mobile terminal in the captured image captured by the imaging unit. Detecting the operator who is operating the terminal, judging whether the operator is stopped or walking from the amount of movement of the display screen, and based on the input lighting state of the pedestrian signal lights and the amount of movement of the display screen. The warning sound is output to the operator from the warning sound output unit according to the stop or walking state of the operator.

According to the intersection warning system according to the present invention, it is possible to warn operators who are operating various mobile terminals such as smartphones and folding mobile phones at intersections. People can stop operating their mobile devices and safely walk across pedestrian crossings.

1 is a system configuration diagram of an embodiment; FIG. It is a block circuit configuration diagram. FIG. 4 is an explanatory diagram of a shooting screen; It is explanatory drawing of the state which extracted the display screen. FIG. 10 is a flowchart of warning processing for an operator;

The present invention will be described in detail based on the illustrated embodiments.
FIG. 1 is a system configuration diagram of an intersection warning system, and FIG. 2 is a block circuit configuration diagram of the intersection warning system. a warning sound output unit 3 that outputs a warning sound such as a voice or a buzzer sound to the operator U who is operating the mobile terminal M near the pedestrian crossing W, the photographing unit 2, and A control unit 4 connected to the warning sound output unit 3 is provided.

In addition, the existing traffic signal system 5 includes a vehicle signal light 6 which is a light device for a traveling vehicle, a pedestrian signal light 7 which is a light device for a pedestrian H crossing the pedestrian crossing W, a vehicle signal light 6 and a walking signal light. It is composed of a signal control section 8 which is connected to the pedestrian signal light 7 and performs lighting control of the vehicle signal light 6 and the pedestrian signal light 7. The control section 4 and the signal control section 8 are connected.

Although the controller 4 and the signal controller 8 are shown separately, the function of the controller 4 may be added to the signal controller 8 in the signal controller.

The photographing unit 2 is a video camera or the like, and is installed, for example, 5±0.5 m above the crosswalk W near the pedestrian signal light 7 . The photographing unit 2 has a photographing range around the pedestrian H who is waiting for a signal at a depression angle of, for example, 15±2° obliquely downward, and photographs a moving image from behind the pedestrian H. The number of frames of this moving image is preferably about 30 fps.

In addition, in order to improve detection accuracy, the photographing unit 2 may be increased according to the scale of the intersection. For example, if the width of the pedestrian crossing is 3 m or more and less than 4 m, one car is suitable, and if the width is 4 m or more, two cars are suitable. This is because there is a large number of pedestrians H at a large-scale intersection, so blind spots are likely to occur, and the operator U may not be detected.

FIG. 3 is an example of an image captured by the image capturing unit 2, and the image capturing range is adjusted so that the pedestrian H who is waiting for the signal is captured entirely. When there is an operator U who is operating a mobile terminal M such as a smart phone among the pedestrians H, the bright display screen D of the mobile terminal M is reflected.

Also, in order to reliably recognize the operator U both during the day and at night, different detection modes may be prepared for each. At night, the operator U is detected based on the brightness of the screen of the mobile terminal M. On the other hand, during the daytime, the surrounding brightness is higher than at night. Extraction of the shape, operation, etc. of the portable terminal M can also be used together. By increasing the recognition rate of the operator U during the daytime, it becomes possible to reliably recognize the operator U both during the daytime and at night. Therefore, in the daytime, three stages of extraction and recognition are performed: extraction based on brightness, extraction based on the shape of the mobile terminal M, and extraction based on the operation of the mobile terminal M. FIG. The switching between the daytime mode and the nighttime mode in the detection mode may be performed based on time information or the like possessed by the signal control section 8 .

The warning sound output unit 3 is a speaker, and outputs a sound, which is a warning sound, from overhead to the operator U who is waiting for a signal or crossing the pedestrian crossing W, and responds to an output command from the connected control unit 4. output audio accordingly.

This warning sound output unit 3 may use a speaker for the visually impaired, which is an additional device provided in advance at the intersection. In this case, output processing of voice guidance for the visually impaired is performed. It operates as a speaker of the intersection warning system 1 except for the time.

The control unit 4 performs image processing on each image of the moving image captured by the imaging unit 2 to identify the operator U who is operating the mobile terminal M, and a warning sound output unit for the operator U. 3 and a function to output audio.

Further, the control unit 4 can obtain information on the lighting state of the pedestrian signal light 7 from the signal control unit 8 . The control unit 4 may be provided in a dedicated control box and arranged in the control box, or may be arranged in the control box in which the signal control unit 8 is arranged.

FIG. 4 shows an image after image processing has been performed on the example image shown in FIG. It is a thing. In this binarization process, a threshold luminance value is set in advance, and pixels with luminance values higher than the threshold value are displayed in black, and pixels with luminance values lower than the threshold value are displayed in white. It's about processing.

The method of determining the threshold value is relatively determined because the appropriate threshold value varies depending on the aging of the photographing unit 2, dirt on the camera lens, and installation conditions such as surrounding streetlights and neon signs. For this reason, the background image is constantly learned, and the brightness of the background image, which serves as a reference for the threshold value, is updated.

As a method of determining the brightness of the background image, which is the threshold value, a brightness value histogram created for the captured image is used before image processing is performed. This brightness value histogram is a graph of the distribution of brightness values of pixels in an image. Based on this luminance value histogram, a threshold value for clipping a part of the image is determined by binarization processing. For example, the brightness value is obtained for each pixel photographed in 8 bits consisting of 256 gradations, and the brightness value histogram is displayed with the brightness value (0-255) on the horizontal axis and the number of pixels with each brightness value on the vertical axis. Based on the distribution, a luminance value at the center of the histogram, a luminance value with a peak, a luminance value with the largest number of pixels, or the like can be set as a threshold.

The threshold may be set to a value slightly lower than the standard brightness of the display screen D of the mobile terminal M, that is, the brightness of the background image. can be extracted, and an image in which the display screen D is black can be obtained. In this case, black and white display may be reversed.

In addition, the pixel area and shape of the display screen D, for example, the size of a substantially rectangular screen from a small mobile phone to a tablet terminal, the aspect ratio of the screen, etc., are set in advance. Even if a high luminance area of an object other than the pixel area is detected, it is excluded from the detection of the display screen D of the mobile terminal M. Similarly, even if a high-brightness area of an object other than a substantially rectangular object is detected, it is excluded from the detection of the display screen D of the mobile terminal M.

By performing such exclusion processing, it is possible to prevent an LED light emitting element attached to a bicycle or the like from being erroneously detected as the display screen D of the mobile terminal M, for example.

FIG. 5 is a flow chart of warning processing by the controller 4 to the operator U who is operating the portable terminal M. As shown in FIG. When the process is started, in step S1, the image captured by the capturing unit 2 is binarized as needed, and the display screen D of the portable terminal M that is lit is detected. By detecting the display screen D, the presence or absence of the operator U operating the mobile terminal M is identified.

The process of step S1 is sequentially performed for each image constituting the moving image output from the photographing unit 2, and the operator U who is operating the portable terminal M is detected based on the above-described high luminance area detection process. When it is identified, the process proceeds to step S2. If the operator U is not identified, step S1 is repeated, and the interval between these repetitions is preferably the same as the interval of one frame of the moving image.

In step S2, the control unit 4 determines whether or not the pedestrian signal light 7 of the crosswalk W is lit in green from the information on the lighting state of the pedestrian signal light 7 of the signal control unit 8. FIG. In step S2, if the pedestrian signal light 7 is lighting a red signal indicating that crossing is prohibited or blinking a green signal, the process proceeds to step S3. Transition.

In step S3 when the pedestrian signal light 7 is lit in red or blinking in green, the amount of movement of the display screen D after the image of the operator U detected in step S1 on the display screen D. judge. When the display screen D has moved on the image by a predetermined number of pixels within a predetermined time, it is determined that the operator U is walking, and the process proceeds to step S5. As a walking determination criterion, an average human walking speed of 1.25 m/s per second is replaced with the amount of movement on the image of the display screen D of the operator U, and the image of the operator U is determined. It may be determined whether or not the user is walking based on the amount of movement.

Conversely, if the display screen D has not moved by a predetermined number of pixels on the image for a predetermined time, for example, one second, that is, if the distance is equivalent to 1.25 m, it is determined that the operator U has not moved (step S2). back to In this loop processing, it can be determined that the operator U is waiting for a traffic light, and when the process proceeds to step S5, the operator U ignores the blinking red or green signal of the pedestrian signal light 7. This means that the crossing of the pedestrian crossing W has started.

Then, in step S5, the control unit 4 issues a voice output command to the warning sound output unit 3, saying, "The signal is red. Please be careful." After outputting the sound in step S5, the process returns to step S1.

In step S2, if the pedestrian signal light 7 is lighting a green signal or has switched to a green signal, the process proceeds to step S4. Step S4 is the same process as step S3, and determines whether or not the operator U is walking.

In step S4, if the operator U is not walking, that is, if the operator U is in a stopped state, the process proceeds to step S6. In step S6, it is determined that the operator U is too focused on the operation of the portable terminal M and does not notice that the pedestrian signal light 7 is lit in green. Then, a voice output command is issued to prompt the crossing of the crosswalk W, saying, "It's now blue." Upon hearing this voice, the operator U realizes that the light is green and starts crossing. After outputting the sound in step S6, the process returns to step S1.

When it is determined in step S4 that the operator U is walking, the process proceeds to step S7. In step S7, it is determined that the operator U is walking on the pedestrian crossing W while operating the display screen D of the mobile terminal M, and the control unit 4 instructs the warning sound output unit 3 to perform the operation while walking. Let's stop." is issued as a voice output command for suppressing the operation of the mobile terminal M. After outputting the sound in step S7, the process returns to step S1.

After the warnings in steps S5, S6, and S7, if the operator U continues to operate the mobile terminal M, the warning sound is repeatedly output from the warning sound output unit 3 by the process from step S1. .

After detecting the display screen D in step S1, if the display screen D does not detect the display screen D continuously for a predetermined period of time, for example, two seconds, it is assumed that the operator U has stopped operating the portable terminal. Then, the process of each step S in the flow chart of FIG. 5 is stopped, and the process returns to step S1.

In this way, by identifying the operator U who is operating the mobile terminal M before crossing the pedestrian crossing W at the intersection, a person who enters the crosswalk W while operating the mobile terminal M or a mobile terminal M can be identified. It is possible to issue a voice warning to a person who concentrates too much on the operation of , and does not notice that the light has turned green. By giving the warning, the operator U can stop operating the portable terminal M and cross the pedestrian crossing W safely.

In the intersection warning system of this embodiment, there is no need to install dedicated software in the mobile terminal M used by the operator U. Therefore, not only a smartphone but also a mobile terminal M having a display screen D such as a foldable mobile terminal can be identified as the operator U who operates the mobile terminal M. FIG. By issuing a warning to the operator U, the operator can stop operating the portable terminal M and safely walk on the pedestrian crossing W, thereby avoiding a dangerous situation at the intersection.

1 intersection warning system 2 imaging unit 3 warning sound output unit 4 control unit 5 traffic signal system 6 vehicle signal light 7 pedestrian signal light 8 signal control unit H pedestrian U operator M mobile terminal D display screen W crosswalk

Claims (4)

An intersection comprising a photographing unit installed above a pedestrian crossing to photograph downward, a warning sound output unit outputting a warning sound, and a control unit connected to the photographing unit and the warning sound output unit. A warning system,
The control unit detects an operator operating the mobile terminal based on the brightness of the display screen of the mobile terminal in the captured image captured by the imaging unit, and detects the operator based on the amount of movement of the display screen. and the warning to the operator according to the input lighting state of the pedestrian signal lamp and the stop or walking state of the operator based on the amount of movement of the display screen. An intersection warning system, wherein the warning sound is output from a sound output unit. 2. The control unit detects a high luminance range based on lighting of the display screen in the captured image captured by the imaging unit, and identifies the operator from the detection of the high brightness range. The intersection warning system described in . Outputting a warning sound from the warning sound output unit to encourage crossing the pedestrian crossing when the pedestrian signal light is in a lighting state in which the operator can cross the pedestrian crossing and the operator is stopped. The intersection warning system according to claim 1 or 2, characterized by: When the pedestrian signal light is on so that the operator can cross the pedestrian crossing and the operator is walking, the warning sound output unit outputs a warning sound to suppress the operation of the portable terminal. The intersection warning system according to any one of claims 1 to 3, characterized in that:

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