JP2021011126A - Occupant monitoring device - Google Patents

Abstract

To provide a vehicular occupant monitoring device that accurately detects biological information on an occupant, and does not impair chest protection performance of an occupant by a seat belt upon a vehicle collision.SOLUTION: An occupant monitoring device is provided on a vehicle having a shoulder belt portion 21 in a webbing 10 of a seat belt device 2, and monitors a state of an occupant M seated in a seat 1. The occupant monitoring device includes: a transmitting antenna 30 and a receiving antenna 31 provided on the shoulder belt portion 21 and configured by an electrode with flexibility; and a sensor ECU 32 detecting a heart rate of the occupant M on the basis of microwaves transmitted from the transmitting antenna 30 and reflection waves of the microwaves received by the receiving antenna 31. The plurality of receiving antennas 31 is arranged on the shoulder belt portion 21, and the sensor ECU 32 selects and uses the reflection wave with the highest single strength among the reflection waves output from the plurality of receiving antenna 31, thereby detecting the heart rate of the occupant M.SELECTED DRAWING: Figure 1

Description

The present invention relates to an occupant monitoring device that monitors the state of occupants of a vehicle.

Conventionally, various occupant monitoring devices for monitoring the condition of occupants of a vehicle have been proposed. As a device for monitoring the state of the occupant, for example, a device for photographing the facial expression of the occupant with a camera and monitoring the accelerator operation and the steering wheel operation by the driver have been proposed. The occupant monitoring device monitors the condition of the occupant, particularly the driver, and gives an alarm or the like when it is estimated that the driving is difficult, so that the driving can be suppressed.

As one of the occupant monitoring devices, a device for detecting the biological information of an occupant is known. For example, Patent Document 1 discloses that a heartbeat sensor is provided in a vehicle seat belt, and the heartbeat data detected by the heartbeat sensor is used to calculate the degree of fatigue of an occupant.
Further, Patent Document 2 discloses that a biosensor is provided on a seatbelt, and the biosensor detects the heartbeat and respiration of the occupant to detect the physical condition of the occupant.

Japanese Unexamined Patent Publication No. 2019-016273 Japanese Unexamined Patent Publication No. 2018-118671

However, even if a biosensor such as a heart rate sensor is provided on the seat belt as in Patent Document 1 or 2, the biosensor faces the occupant's chest, especially the heart, due to the difference in the physique of the occupant or the movement of the occupant. Therefore, it may not be possible to properly position the biometric information, and the biometric information may not be detected accurately.
Further, the seat belt is required to have flexibility so as not to impair the protection performance of the occupant in the event of a vehicle collision.

The present invention has been made to solve such a problem, and provides a vehicle occupant monitoring device that accurately detects occupant's biological information and does not impair the occupant's protection performance by a seatbelt in the event of a vehicle collision. To do.

In order to achieve the above object, the present invention is provided on a vehicle provided with a seat belt having a shoulder belt portion for restraining the upper body of the occupant seated on the seat, and the occupant who monitors the state of the occupant seated on the seat. A monitoring device, the transmitting antenna provided on the shoulder belt portion and composed of flexible electrodes and transmitting electromagnetic waves, and the transmitting antenna provided on the shoulder belt portion and composed of flexible electrodes. The biological information of the occupant is detected based on the receiving antenna that receives the reflected wave reflected by the occupant from the electromagnetic wave transmitted from the antenna, the electromagnetic wave transmitted from the transmitting antenna, and the reflected wave received by the receiving antenna. A plurality of the receiving antennas are arranged side by side on the shoulder belt portion, and the biometric information detecting unit is the most signal among the reflected waves received by the plurality of receiving antennas. It is characterized in that a high-intensity reflected wave is selected and used to detect the biological information of the occupant.

As a result, the biological information of the occupant is detected by using the transmitting antenna and the receiving antenna provided on the shoulder belt portion of the seat belt that is in close contact with the upper body of the occupant, so that the biological information of the occupant, especially in the chest, can be detected. .. Since the transmitting antenna and the receiving antenna are composed of flexible electrodes, it is possible to avoid causing harm to the occupant by the transmitting antenna or the receiving antenna when the occupant is restrained by the seat belt in the event of a vehicle collision. , It is possible not to impair the protection performance of the occupant by the seat belt.

In addition, a plurality of receiving antennas are arranged side by side on the shoulder belt portion, and among the reflected waves received by the plurality of receiving antennas, the reflected wave having the highest signal strength is used to detect the biological information of the occupant. , It becomes possible to accurately detect the biological information of the occupant.
Preferably, a plurality of the receiving antennas are arranged side by side in the extension direction of the shoulder belt portion.

This makes it possible to detect biological information in a wide range of ways for occupants of different physiques.
Preferably, the receiving antenna is arranged on the occupant-side surface of the shoulder belt portion.
This makes it possible to accurately detect the reflected wave of the electromagnetic wave reflected from the occupant by the receiving antenna.

Preferably, the biological information is the heartbeat of the occupant.
As a result, the heartbeat of the occupant can be accurately detected by using the transmitting antenna and the receiving antenna provided on the shoulder belt portion of the seat belt that is in close contact with the upper body of the occupant.
Preferably, the biometric information detection unit is arranged on the sheet.

As a result, the biological information detection unit can be arranged on the seat, and only the transmitting antenna and the receiving antenna can be arranged on the seat belt, and it is possible to prevent the seat belt from impairing the protection performance of the occupant in the event of a vehicle collision. ..

According to the occupant monitoring device of the present invention, the biological information of the occupant can be detected by using the transmitting antenna and the plurality of receiving antennas provided on the shoulder belt portion of the seat belt. In particular, among the reflected waves received by multiple receiving antennas, the reflected wave with the highest signal strength is used to detect the occupant's biological information, so the occupant's upper body can be seated while responding to differences in occupant's physique. Biological information can be detected accurately even if it moves on.

Further, since the transmitting antenna and the receiving antenna are composed of flexible electrodes, it is possible to prevent the seat belt from impairing the protection performance of the occupant.

It is a front view which shows the structure of the seat and the seat belt device provided with the occupant monitoring device of embodiment of this invention. It is a structural drawing which shows the pattern example of the receiving antenna in the shoulder belt part which concerns on this embodiment. It is a block diagram of the occupant monitoring device which concerns on this embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a front view showing the structure of the seat 1 and the seat belt device 2 provided with the occupant monitoring device according to the embodiment of the present invention. FIG. 2 is a structural diagram showing an example of arrangement of antennas in the shoulder belt portion 21 according to the present embodiment. FIG. 3 is a configuration diagram of the occupant monitoring device 3 according to the present embodiment.

The occupant monitoring device of the present invention is provided in the seat belt device 2 and the seat 1 having a shoulder belt portion 21 for restraining the upper body of the occupant seated on the seat 1, specifically the chest, such as a three-point seat belt device. ing.
As shown in FIG. 1, the seatbelt device 2 provided on the seat 1 which is the driver's seat of the vehicle is a webbing 10 (seatbelt) formed of a band-shaped cloth member, and a tongue slidably attached to the webbing 10. 11. A buckle 12 for fixing the tongue 11, a shoulder anchor 13 for slidably supporting the webbing 10, a retractor 14 for winding one end of the webbing 10, and a 15 for fixing the other end of the webbing 10 to the vehicle body or a seat frame. I have.

The buckle 12 is arranged inside the seat 1 in the vehicle width direction, and the tongue 11 is inserted to support the tongue 11 on the vehicle body side, specifically on the right side of the seat cushion 16 of the seat 1.
The shoulder anchor 13 is provided above the pillar 17 on the outer side of the seat 1 in the vehicle width direction, and is arranged behind and above the seat back 18.
The retractor 14 is arranged below the shoulder anchor 13, for example, below the pillar 17 on the outer side of the seat 1 in the vehicle width direction. The retractor 14 is provided with a pretensioner mechanism that pulls in the webbing 10 to apply tension when the vehicle collides.

The lap belt portion 20 which is a portion from the belt anchor 15 to the tongue 11 in the webbing 10 restrains the lower body of the occupant M seated on the seat 1, specifically the waist portion of the occupant M. On the other hand, the shoulder belt portion 21 which is a portion from the tongue 11 to the shoulder anchor 13 in the webbing 10 restrains the upper body of the occupant M seated on the seat 1.
The occupant monitoring device 3 of the present embodiment includes a transmitting antenna 30, a receiving antenna 31, and a sensor ECU 32 (biological information detection unit).

The sensor ECU 32 is provided on the side surface of the seat cushion 16 on the belt anchor 15 side.
The transmitting antenna 30 and the receiving antenna 31 are provided on the shoulder belt portion 21. The transmitting antenna 30 and the receiving antenna 31 are electrodes formed of a flexible conductor such as a thin copper plate.

As shown in FIG. 2, when a person of standard physique sits on the seat 1, the transmitting antenna 30 extends around the position closest to the position of the heart H of the person (occupant M) on the shoulder belt portion 21. It is formed to extend in the direction. The transmitting antenna 30 is set to cover a position close to the heart H for substantially all occupants who sit on the seat 1 and use the seatbelt device 2. Wiring 33 extends from the end of the transmitting antenna 30 on the belt anchor 15 side toward the belt anchor 15 in the shoulder belt portion 21 and the lap belt portion 20.

The receiving antennas 31 are arranged on the shoulder belt portion 21 along the transmitting antenna 30, and a plurality of receiving antennas 31 are arranged side by side in the extension direction of the shoulder belt portion 21. In FIG. 2, four receiving antennas 31 are provided. The receiving antenna 31 is bent into a complicated shape so that it can easily receive electromagnetic waves. Wiring 34 extends from each receiving antenna 31 toward the belt anchor 15 in the shoulder belt portion 21 and the lap belt portion 20 along the wiring 33.

The wirings 33 and 34 from the transmitting antenna 30 and the receiving antenna 31 pass through the shoulder belt portion 21 and the lap belt portion 20 and are connected to the sensor ECU 32 in the vicinity of the belt anchor 15 of the lap belt portion 20, respectively.
The transmitting antenna 30 and the receiving antenna 31 are arranged on the surface of the shoulder belt portion 21 on the occupant M side.

As shown in FIG. 3, the sensor ECU 32 includes a microwave sensor 40, a filter circuit 41, an MPU 42 (microprocessor), a 3-axis acceleration sensor 43, a CAN driver 44, an input / output device (not shown), a control program, a control map, and the like. It is equipped with a storage device (ROM, RAM, etc.) timer counter and the like used for storage.
The microwave sensor 40 is an electromagnetic wave sensor that detects an object, and the wiring 33 from the transmitting antenna 30 and the wiring 34 from the receiving antenna 31 are connected to each other. The microwave sensor 40 has a function of outputting microwaves (electromagnetic waves) via the transmitting antenna 30 and receiving the reflected waves reflected by the human body (occupant M) by the output microwaves via the receiving antenna 31. Has. The microwave sensor 40 is connected to the MPU 42 by SPI communication to control its operation, and outputs the received signal as an IQ output from the microwave transmission signal and reception signal.

The filter circuit 41 has a function of removing noise from the received signal (IQ output) output from the microwave sensor 40. Biological information such as a heartbeat signal and a respiration signal is added to the received signal, and the filter circuit 41 may be set to remove signals other than the required biometric information.
The 3-axis acceleration sensor 43 is a sensor that detects acceleration in the 3-axis direction, and detects the acceleration of the vehicle. The 3-axis acceleration sensor 43 is connected to the MPU 42 by SPI communication.

The CAN driver 44 is a unit for connecting the control unit 45 of the vehicle and the MPU 42 by CAN communication. Various vehicle signals, such as vehicle power signals and webbing 10 mounting signals, that is, insertion signals of the tongue 11 into the buckle 12 are input to the MPU 42, and the biometric information of the occupant M is output from the MPU 42 to the vehicle control unit 45. Has a function.

When the vehicle power is turned on and the mounting signal of the webbing 10 is input, the MPU 42 operates and controls the microwave sensor 40 by SPI communication to output microwaves from the transmitting antenna 30. The microwave output from the transmitting antenna 30 is reflected by the occupant M, and the reflected wave is received by the receiving antenna 31. The microwave sensor 40 outputs the received signal as IQ output to the MPU 42 after removing noise via the filter circuit 41.

A plurality of receiving antennas 31 are provided, and the microwave sensor 40 inputs a received signal from each receiving antenna 31 and outputs the received signal to the MPU 42. The MPU 42 selects and uses the received signal from the receiving antenna 31 having the highest signal strength among the received signals from each receiving antenna 31.
The MPU 42 extracts biological signals such as the heartbeat and respiration of the occupant M from the received signal from the receiving antenna 31 having the highest signal strength. Then, the MPU 42 of the sensor ECU 32 outputs the extracted biological information to the control unit 45 of the vehicle, and makes it available for various controls such as warning, communication to the outside of the vehicle, and stoppage of the vehicle.

The acceleration of the vehicle may be input from the 3-axis acceleration sensor 43 together with the received signal and used for extracting the biological signal, or for controlling a warning or the like executed based on the biological signal. For example, when the vehicle vibrates significantly up and down due to bumps or the like, the movement of the vehicle may be detected by the 3-axis acceleration sensor 43 and controlled so as to exclude noise of the received signal due to the vibration of the vehicle.

As described above, the occupant monitoring device 3 of the present embodiment detects the heartbeat of the occupant M seated on the seat 1 of the vehicle and monitors the physical condition of the occupant M.
The occupant monitoring device 3 includes a transmitting antenna 30 and a receiving antenna 31 on the shoulder belt portion 21 of the webbing 10 in the seat belt device 2, and the microwave (electromagnetic wave) transmitted from the transmitting antenna 30 is reflected by the occupant M. The receiving antenna 31 receives the reflected wave, and detects the heartbeat of the occupant M based on the transmitted microwave and the received reflected wave. By providing the transmitting antenna 30 and the receiving antenna 31 on the shoulder belt portion 21 in this way, the transmitting antenna 30 and the receiving antenna 31 can be brought into close contact with each other at a position close to the heart H of the occupant, and the heartbeat can be detected accurately. It will be possible.

Further, since the transmitting antenna 30 and the receiving antenna 31 are composed of thin plate electrodes formed of a flexible conductor, the flexibility of the shoulder belt portion 21 by providing the transmitting antenna 30 and the receiving antenna 31 can be obtained. The decrease can be suppressed. Therefore, even if the occupant is strongly restrained by the webbing 10 at the time of a vehicle collision, it is possible to avoid causing harm to the occupant by the transmitting antenna 30 or the receiving antenna 31.

Further, in the present embodiment, a plurality of receiving antennas 31 are provided side by side on the shoulder belt portion 21, and among the reflected waves received by each receiving antenna 31, the reflected wave having the highest signal strength is used by the occupant M. Since the biological information is detected, even if the occupant M moves with respect to the shoulder belt portion 21, the microwave can be appropriately received.
In particular, since the receiving antennas 31 are arranged side by side in the extension direction of the shoulder belt portion 21, it is possible to detect biological information widely corresponding to occupants having different physiques.

Further, since the transmitting antenna 30 and the receiving antenna 31 are arranged on the surface of the shoulder belt portion 21 on the occupant M side, the biological information of the occupant M can be detected more accurately.
Further, among the occupant monitoring devices 3, the sensor ECU 32 having a configuration other than the transmitting antenna 30 and the receiving antenna 31 is arranged on the seat 1. As a result, it is possible to prevent the function of the webbing 10 from being hindered without arranging components other than the transmitting antenna 30 and the receiving antenna 31 on the webbing 10.

The present invention is not limited to the above embodiment.
For example, the antenna patterns of the transmitting antenna 30 and the receiving antenna 31 may be changed as appropriate.
Further, the sensor ECU 32 may be arranged on the side surface of the seat cushion 16 on the buckle 12 side. In this case, a part of the wirings 33 and 34 between the transmitting antenna 30 and the receiving antenna 31 provided on the shoulder belt portion 21 and the sensor ECU 32 may be connected by wireless communication. As a result, when the tongue 11 is removed from the buckle 12 and the occupant M gets on and off the seat 1, the wirings 33 and 34 between the transmitting antenna 30 and the receiving antenna 31 and the sensor ECU 32 can be prevented from getting in the way. it can.

As for the microwave sensor 40, an electromagnetic wave sensor other than the microwave may be used as long as the biological information of the occupant M can be detected.
Further, the transmitting antenna 30 and the receiving antenna 31 may be provided on a seat other than the driver's seat to detect and monitor the biological information of the occupants other than the driver.

1 Seat 2 Seat belt device 3 Crew monitoring device 10 Webbing (seat belt)
21 Shoulder belt part 30 Transmitting antenna 31 Receiving antenna 32 Sensor ECU (Biological information detection part)

Claims (5)

An occupant monitoring device provided on a vehicle equipped with a seatbelt having a shoulder belt portion for restraining the upper body of an occupant seated on the seat, and monitoring the state of the occupant seated on the seat.
A transmitting antenna provided on the shoulder belt portion, which is composed of flexible electrodes and emits electromagnetic waves,
A receiving antenna provided on the shoulder belt portion, which is composed of flexible electrodes, and receives an electromagnetic wave transmitted from the transmitting antenna and reflected by the occupant.
A biological information detection unit that detects the biological information of the occupant based on the electromagnetic wave transmitted from the transmitting antenna and the reflected wave received by the receiving antenna is provided.
A plurality of the receiving antennas are arranged side by side on the shoulder belt portion, and the receiving antennas are arranged side by side.
The biological information detection unit selects and uses the reflected wave having the highest signal strength from the reflected waves received by the plurality of receiving antennas, and detects the biological information of the occupant. Monitoring device. The occupant monitoring device according to claim 1, wherein a plurality of receiving antennas are arranged side by side in an extension direction of the shoulder belt portion. The occupant monitoring device according to claim 1 or 2, wherein the receiving antenna is arranged on a surface of the shoulder belt portion on the occupant side. The occupant monitoring device according to any one of claims 1 to 3, wherein the biological information is the heartbeat of the occupant. The occupant monitoring device according to any one of claims 1 to 4, wherein the biological information detection unit is arranged on the seat.

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