JP2004161087A - Seat belt alarm device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a seat belt alarm device to inform an occupant of a wearing state of a seat belt by detecting it. <P>SOLUTION: This seat belt alarm device has an infrared ray camera 1 to photograph an indoor seat and make it a heat image, a seat belt sensor 3 to detect whether the seat belt of each of the seats is worn or not and a wheel speed sensor 4 to detect travelling speed which are connected to a microcomputer 2. The microcomputer 2 determines the seat on which the occupant is seated by processing a heat image data and detects the wearing state of the seat belt by using discontinuity of surface temperature distribution of an upper half body of the occupant's especially of a face and a scruff. Displays 5a, 5b and a speaker 6 are connected to the microcomputer 2 and inform mainly a driver of the wearing state of the seat belt by the display 5b in the case when the vehicle is in a stopping state and mainly a fellow occupant of it by the display 5a in the case when the vehicle is in the middle of travelling. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an alarm device for wearing a seat belt.
[0002]
[Prior art]
[Patent Document 1] Japanese Patent Application Laid-Open No. 10-226314 As a seat belt wearing promotion device, when a driver detects that a driver is not wearing a seat belt by a seat belt wearing detecting mechanism, the driver generates a sound by a voice generating mechanism. There is known a device that informs the user to wear a seatbelt to encourage the user to wear a seatbelt (see Japanese Patent Application Laid-Open No. 10-226314).
[0003]
[Problems to be solved by the invention]
However, it was not sufficient to simply judge whether or not a seat belt was worn.
SUMMARY OF THE INVENTION It is an object of the present invention to provide a seat belt alarm device that can determine a wearing state of a seat belt in order to solve the above problems.
[0004]
[Means for Solving the Problems]
For this reason, the present invention provides imaging means for photographing a seat in a passenger compartment to obtain a thermal image, occupant detecting means for determining whether or not an occupant is present in each seat from the thermal image, and at least a seat for the occupant seat. Seat belt wearing determining means for determining whether the belt is in a worn state, and wearing using the thermal image to determine the wearing state of the seat belt for each occupant sitting on the seat and wearing the seat belt. State determining means, based on a determination result of the wearing state determining means, a notification determining means for determining whether or not to notify an alarm, and a notifying means for notifying an alarm, the wearing state determining means, face or It is determined that the seat belt is applied to the face or the neck from the distribution of the surface temperature of the neck and the seat belt.
[0005]
【The invention's effect】
According to the present invention, it is possible to extract a face or a neck from a thermal image and detect and warn that the seat belt is applied to the face or the neck from a difference between the surface temperature of the face or the neck and the seat belt.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described.
FIG. 1 is a block diagram of the seat belt alarm device.
The seatbelt alarm device is an infrared camera 1 for taking a thermal image of an upper body of an occupant sitting in a seat in a vehicle and detecting whether or not a seatbelt tongue of each seat is connected to a seatbelt buckle. A sensor 3 and a wheel speed sensor 4 for detecting a traveling speed are connected to the microcomputer 2.
[0007]
The microcomputer 2 processes the thermal image data acquired by the infrared camera 1 to determine the seat where the occupant is, and utilizes the discontinuity of the surface temperature distribution of the upper body of the occupant, particularly the face and neck. Detects the wearing state of the seat belt.
The microcomputer 2 determines whether the seat belt of each seat is worn based on a signal from the seat belt sensor 3 and detects whether the vehicle is stopped or running based on a speed signal from the wheel speed sensor 4. I do.
[0008]
A display 5 and a speaker 6 are further connected to the microcomputer 2. The microcomputer 2 uses information or signals of the infrared camera 1, the seat belt sensor 3 and the wheel speed sensor 4 to give an occupant to wear a seat belt. When it is determined that the notification is necessary, the content of the warning is displayed on the display 5 and the speaker 6 gives a sound or voice notification.
The display 5 includes a display 5a provided on a center console at the front of the vehicle, in which an occupant other than the driver can check the display, and a display 5b provided in a position where the driver can check.
[0009]
Hereinafter, each configuration will be described in more detail.
The infrared camera 1 is installed in front of the front seat of the vehicle, substantially in the center in the left-right direction, slightly obliquely downward, facing the rear of the vehicle, and photographs the upper body of all the occupants sitting in the front seat and the rear seat. Set as possible.
The infrared sensor of the infrared camera 1 is made of, for example, uncooled amorphous silicon, and its detection wavelength is, for example, 10 μm band in order to avoid the influence of the infrared wavelength radiated from a seat or clothes heated by sunlight. Far infrared rays.
[0010]
The microcomputer 2 includes an image temporary storage unit 21, an occupant detection unit 22, a seat belt wearing state determining unit 23, a seat belt wearing determining unit 24, a running state detecting unit 25, and a notification determining unit 26.
The image temporary storage unit 21 temporarily stores data of a thermal image of the vehicle interior taken by the infrared camera 1.
The occupant detection unit 22 reads the image data from the image temporary storage unit 21 and determines in advance the position and the photographing direction of the infrared camera 1 and the seat arrangement of the vehicle. The thermal image is divided into sections, and it is determined whether or not a region having an image density higher than a predetermined value in each section has a predetermined area or more. As a result, it is determined whether an occupant is present for each seat.
[0011]
The seatbelt wearing state determination unit 23 determines whether the intensity of the far infrared rays radiated from the exposed face and neck is different for the section of the thermal image corresponding to the seat determined to be occupied by the occupant detection unit 22. Using the fact that it is stronger than the part covered by the clothing, the extraction of the head close to the ellipse and the constriction below it are extracted from the thermal image.
When a seatbelt is applied to the face or neck, it is determined whether a jump portion with a density equal to or higher than a predetermined value is detected in the face or neck using discontinuity in the image density distribution of the face or neck. I do.
[0012]
The seatbelt wearing determination unit 24 detects a signal indicating whether or not the seatbelt tongue of the seatbelt 33 installed in each seat as shown in FIG. 4 is connected to the seatbelt buckle. Judge whether or not to wear.
[0013]
The traveling state detection unit 25 acquires a signal from the wheel speed sensor 4 and detects whether the vehicle is in a traveling state.
The notification determination unit 26 determines whether the notification is required and which of the displays 5a and 5b and the speaker 6 is used for the notification, and outputs an alarm for the non-wearing of the seat belt and the wearing state of the seat belt.
[0014]
The operation of the present embodiment will be described below.
FIG. 2 is a flowchart showing a flow of outputting a seat belt alarm. In this flowchart, description will be given focusing on the notification regarding the wearing state of the seat belt.
In step 101, the driver makes an initial setting of the microcomputer 2 such as set values for determination by image processing.
[0015]
In other words, the image processing section corresponding to each seat in the thermal image of the passenger compartment taken by the infrared camera 1 is set in image processing, and the density of the thermal image for determining whether or not the occupant is present in the corresponding seat. The threshold, the area threshold of the area showing the density threshold or more, the size of the occupant's face for each seat position for extracting the occupant's face, the jump amount of the surface temperature distribution for detecting the wearing state of the seat belt, the wheel speed The settings for the occupant detection unit 22, the seat belt wearing state determination unit 23, and the traveling state detection unit 25, such as the traveling state determination value, are performed.
After step 101, the process proceeds to step 102.
[0016]
In step 102, the infrared camera 1 acquires a thermal image of the vehicle interior, and the microcomputer 2 stores the thermal image in the image temporary storage unit 21.
FIG. 3 schematically shows an example of a thermal image of the upper body from the chest of one occupant. The image density is high in the part where the surface temperature is high in the face part and the exposed part of the neck muscle, and the density is low in the clothes and the part of the seat belt obliquely worn from the left shoulder.
[0017]
In step 103, the occupant detection unit 22 detects the presence or absence of an occupant for each seat from the thermal image data in the temporary image storage unit 21. The entire area of the thermal image is divided in advance into image sections divided corresponding to each seat, and the area corresponding to the case where the area area indicating the temperature distribution of a person exhibiting a predetermined pixel density or higher is included in a predetermined value or more is included. It is determined that the occupant is in the image section, that is, the corresponding seat.
[0018]
In step 104, the seat belt wearing determination unit 24 reads a signal from the seat belt sensor 3 of each seat, determines whether or not the seat belt of each seat is worn, and stores it.
In step 105, the seat belt wearing state determination unit 23 stores the seat in which the occupant is determined to be present in the seat and detects the seat belt wearing signal in the image temporary storage unit 21 using the results of steps 103 and 104. The data of the thermal image of the corresponding section of the seat is read out from the data of the thermal image thus obtained, and it is determined by image processing whether or not the cross section of the seat belt 33 is on the face or the neck, that is, the state of wearing the seat belt.
[0019]
FIG. 4 shows an example of a wearing state of the seat belt.
FIG. 4A is a schematic diagram in which an adult sits on a front seat 31, here, a passenger seat and wears a seat belt 33, and a cross section of the seat belt 33 extends from shoulder to chest and waist. The wearing state of the seatbelt hanging diagonally below is shown.
On the other hand, FIG. 4B shows an example in which a child is seated in the passenger seat, and the seat belt 33 is worn diagonally downward from a part of the face and the neck to the chest. Indicates the status.
[0020]
Similarly, FIG. 4C shows an example of the case of the rear seat 32. The left side of the figure is a state in which the child is seated, and the seatbelt of the seatbelt 33 is worn obliquely downward from a part of the face and the neck to the chest. The right side shows a state in which an adult wears a seat belt without leaning on the face and neck.
[0021]
In step 106, the result of the determination in step 105 is checked. If the seat belt is not worn on the face or neck (NO), this process ends, and the process returns to step 102. If the seat belt is worn on the face or neck (YES), the process proceeds to step 107.
In step 107, the traveling state detection unit 25 receives the vehicle speed signal, that is, a signal indicating the traveling state of the vehicle, from the wheel speed sensor 4, determines whether the vehicle is traveling or stopped, and outputs the result to the notification determination unit 26. .
In step 108, the notification determination unit 26 checks the determination in step 107 whether the vehicle is in the traveling state or the stopped state. If the vehicle is running, the process proceeds to step 109;
[0022]
In step 109, the notification determination unit 26 selects the speaker 6 as a notification unit, and issues an alarm for the wearing state of the seat belt by voice. In addition, the corresponding seat position is displayed on the display 5a for the fellow passenger.
This notification method mainly alerts passengers.
In step 109, a series of operations ends, and the process returns to step 102.
[0023]
In step 110, the notification determination unit 26 selects the display 5b as the notification means, and indicates to the driver an alarm display for the wearing state of the seat belt and the corresponding seat position.
This notification method is mainly for notifying the driver of the wearing state of the seat belt.
In step 110, a series of operations ends, and the process returns to step 102.
[0024]
The infrared camera 1 of the present embodiment is the imaging means of the present invention, step 103 is an occupant detection means, step 104 is a seat belt wearing determination means, step 105 is a wearing state determination means, and steps 107 and 108 are information determination. The means, the display 5 and the speaker 6 constitute a notifying means. In particular, step 107 constitutes a traveling state detecting means, and step 108 constitutes a notifying selecting means.
[0025]
As described above, according to the present embodiment, when a part of the area indicating the surface temperature of the human body such as the face and neck extracted from the thermal image is covered by the seatbell, the image density of the seatbelt portion is Since it is thin, the wearing state of the seat belt with the seat belt resting on the face or neck can be easily detected and determined from the magnitude of the change in the density distribution of the image in that portion.
[0026]
Further, the method of notifying an alarm is automatically changed according to the running state of the vehicle, so that the method is appropriate for stopping or running.
In particular, when the vehicle is stopped, the seat belt warning by voice does not continue to be issued, so that it is not bothersome, and only the display warning is mainly given to the driver. Further, in the running state, the driver is alerted by voice so that the driver can concentrate his attention on driving.
[0027]
Since the infrared rays detected by the infrared camera are infrared rays emitted from the human body in a wavelength band of 10 μm, the image of the target human body is emphasized from other image areas inside and outside the vehicle, and a binary value for determining whether or not there is an occupant in the seat. An infrared image that can be easily converted is obtained regardless of daytime or nighttime.
Since the glass hardly transmits infrared rays in the 10 μm wavelength band, even if the scene of the window is reflected on the infrared camera, it is not reflected on the thermal image, and image processing is easy.
In particular, even when the seat is heated by the sun rays, an area such as the exposed face or neck can be easily extracted from the body area covered with other clothes by the density of the image.
[0028]
Next, a modified example of the present embodiment will be described.
In the present modified example, the seat belt sensor 3 of FIG. 1 is unnecessary, and the occupant wears the seat belt by image processing in the seat belt wearing determination unit using the thermal image stored in the image temporary storage unit. To determine if it is.
In the case of this modification, in step 104 of the flowchart of FIG. 2, instead of acquiring the signal from the seat belt sensor 3, it is determined from the thermal image whether or not each seat occupant wears the seat belt.
[0029]
The seat belt is made of thick and durable fiber, and the cross section of the seat belt worn over clothes has an effect of further blocking far-infrared rays from the human body. Therefore, it is possible to determine whether or not the user wears the seat belt by recognizing the low-density band-like pattern of the pixel corresponding to the cross section of the seat belt from the density distribution of the thermal image of the upper body in the thermal image.
According to this modification, the seat belt sensor 3 can be omitted.
[0030]
In addition, as shown in FIG. 5, zirconia, titania, which converts heat of sunlight or heat due to conduction of body temperature into far-infrared rays and effectively emits the infrared rays so as to easily identify the seat belt in image processing of the thermal image. The marker may be sewn with a fiber containing a ceramic material such as alumina or pasted with a film containing such a material. FIG. 5 shows an example in which such a seatbelt 33 'with a marker is worn.
[0031]
By attaching such a material that easily emits far-infrared rays to the seatbelt 33 ', when the seatbelt is worn, an area that strongly emits far-infrared rays is included in a band area where far-infrared rays are weak. Can easily be determined by image recognition.
[0032]
Conversely, using a material that absorbs or blocks relatively far infrared rays in the seat belt, for example, cotton or glass fiber as a marker, the thermal image density of the seat belt part is lower than that of the part wearing clothes. You may do so.
According to this modification, the presence / absence of wearing of the seat belt can be easily determined from the thermal image.
[0033]
In the above embodiment, one infrared camera 1 is installed at the upper front part of the front seat. However, a plurality of infrared cameras 1 may be provided so that the upper body of the occupant of each seat can be appropriately photographed. In addition, the display 5 has a configuration in which the display 5a is separately installed on the center console which is easy for the passenger to see, and the display 5b is separately installed at a position easy for the driver to see. It may be.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of an embodiment of the present invention.
FIG. 2 is a flowchart illustrating the operation of the present invention.
FIG. 3 is a diagram illustrating an example of a thermal image captured by an infrared camera.
FIG. 4 is a diagram illustrating a state in which a seat belt is worn.
FIG. 5 is a diagram showing a modification of the embodiment.
[Explanation of symbols]
Reference Signs List 1 infrared camera 2 microcomputer 3 seat belt sensor 4 wheel speed sensor 5, 5a, 5b display 6 speaker 21 image temporary storage unit 22 occupant detection unit 23 seat belt wearing state determining unit 24 seat belt wearing determining unit 25 running state detecting unit 26 Information determination unit 31 Front seat 32 Rear seat 33 Seat belt 33 'Seat belt 34 Passenger 35 Passenger 35

Claims (5)

Imaging means for photographing a seat in the passenger compartment and acquiring a thermal image,
Occupant detection means for determining whether an occupant is present in each seat from the thermal image,
Seat belt wearing determining means for determining whether at least the seat belt of the seat where the occupant is in the wearing state,
Using the thermal image, wearing state determination means for determining the wearing state of the seat belt for each occupant sitting on the seat and wearing a seat belt,
Based on the determination result of the wearing state determination means, notification determination means to determine whether to notify an alarm,
Equipped with a notification means for notifying an alarm,
The seat belt alarm device according to claim 1, wherein the wearing state determining means detects that the seat belt is applied to the face or the neck from the distribution of the surface temperature of the face or the neck and the seat belt. The occupant detection unit extracts a heat generation region indicating heat generation of a predetermined level or more from the thermal image corresponding to the position of each seat, and compares the area of the heat generation region with a predetermined value, thereby providing the seat with the heat generation region. 2. The seat belt alarm device according to claim 1, wherein it is determined whether an occupant is present. The notification determining means,
Traveling state detection means for detecting the traveling state of the vehicle,
3. The seat belt warning device according to claim 1, further comprising: a notification selecting unit that selects a method of notifying an occupant of a warning based on the running state of the vehicle detected by the running state detecting unit. The notification selection means,
The seat belt alarm device according to claim 3, wherein the display notification is selected when the vehicle is stopped, and the voice notification is selected when the vehicle is running. The seat belt wearing determination means,
The seatbelt alarm device according to any one of claims 1 to 4, wherein the seatbelt wearing determination is performed by detecting the seatbelt from the thermal image.

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