JP3171030B2 - Occupant detection device and auxiliary device control device using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an occupant detection device for detecting an occupant of a vehicle and an auxiliary device control device for controlling an auxiliary device based on the detection output.

[0002]

2. Description of the Related Art An occupant detection device for detecting an occupant such as a driver of a vehicle is conventionally known. As one type of such an occupant detection device, for example, Japanese Patent Application Laid-Open No. 4-287724 discloses that a photoelectric sensor is installed on the left and right sides of a headrest or a sun visor on the driver side and the driver's head blocks light from the photoelectric sensor. It describes a device that considers driving aside and issues an alarm.

[0003]

The conventional device can detect only that the driver's head moves left and right. In addition, even when the driver raises his hand, the photoelectric sensor performs detection, and there is a risk of erroneous detection. Furthermore, since the photoelectric sensor is used, sunlight may enter the photoelectric sensor depending on the traveling environment of the vehicle and may not be detected. In order to prevent this, it is conceivable to attach a light-shielding hood to the photoelectric sensor. However, there is a problem that it cannot be realized in practice due to restrictions on residents and interior design.

[0004] The present invention has been made in view of the above points,
By detecting the displacement speed of the seat pad with a Doppler sensor, the presence or absence of an occupant of the vehicle can be accurately detected, and based on this accurate occupant detection information, an occupant detection device and an occupant detection device capable of accurately controlling auxiliary equipment can be provided. An object of the present invention is to provide an accessory control device.

[0005]

The invention according to claim 1 is directed to a seat pad inside a vehicle seat cushion.
And emits an electromagnetic beam.
Doppler sensor that detects the displacement speed of the heat pad
And, varying the seat pad which is detected by the Doppler sensor
The presence or absence of an occupant is determined based on the position speed.

According to a second aspect of the present invention, there is provided a driving state detecting means for detecting a driving state of a vehicle, and a change of the seat pad.
2. The Doppler sensor according to claim 1, which detects a position speed, and a displacement speed of a seat pad determined by a driving state of the vehicle.
And the seat pad detected by the Doppler sensor .
Determining means for comparing with the displacement speed and determining that there is an occupant when they match.

[0007] The invention described in claim 3 is the first or second invention.
The auxiliary device is controlled according to the occupant of the vehicle detected by the occupant detection device described above.

[0008]

According to the first aspect of the present invention, the Doppler
Sensor to detect the displacement speed due to the load on the seat pad.
The occupant sitting on the seat from the displacement speed of the seat pad
Can be accurately detected separately from the placement of other objects.

According to the second aspect of the present invention, the driving condition
The Doppler sensor measures the displacement speed of the seat pad according to the condition.
Determine the presence or absence of an occupant by comparing the detected movement
Therefore, occupant detection can be performed extremely accurately.

According to the third aspect of the present invention, since the auxiliary device is controlled in accordance with the accurate detection output of the occupant detection device according to the first or second aspect , the auxiliary device can be accurately controlled.

[0011]

1A, 1B, and 1C show the configuration of a first embodiment of an occupant detection system according to the present invention. In FIG. 1A, a Doppler sensor 12 is provided inside a headrest 11 of a seat 10. The Doppler sensor 12 has a microwave or millimeter electromagnetic beam 13 in the direction of the occupant's head.
Is mounted on and fixed to a reinforcing member 16 in the headrest 11 as shown in the cross-sectional views of FIGS. The electromagnetic beam 13 penetrates through the cushion material 15 and the cover 14 with very little attenuation, and is emitted from the occupant's shoulder to the head. As a result, it is possible to reliably detect the movement of the head in the front-back or left-right direction from the shoulder of the occupant.

The occupant's torso is restrained by the seat belt and has relatively small movement, but the vicinity of the head is not restrained.
The vehicle easily moves according to the behavior of the vehicle such as roll and pitch, and this movement can be detected by the Doppler sensor 12. Since the occupants to be detected have differences in sitting height and sitting style as individual differences in body shape, the beam size is 120 ° in the vertical direction as shown in FIG. 1B, and the horizontal direction as shown in FIG. 1C. 90 °
(BB section), if the detection distance is about 20 to 30 cm, occupants in the next seat can be erroneously detected, or undetected such that large-sized adults can be detected but children cannot be detected can be prevented.

By mounting the Doppler sensor 12 using microwaves in the headrest 11 as described above, it is possible to reliably detect the movement near the head without being influenced by the occupant's body shape or riding posture. In addition, the microwave itself has good environmental resistance and has less malfunctions than a system using light. Further, since the electromagnetic beam can easily penetrate the cushion material or the like, it can be mounted in the headrest 11, which is highly effective in terms of interior design or securing a living space.

Next, a modified example of the mounting location of the Doppler sensor 12 for detecting the vicinity of the occupant's head will be described. First
In the modified example, as shown in FIG. 2A, the Doppler sensor 12 is mounted in a roof 19 hidden by a sun visor 18. The Doppler sensor 12 is arranged and fixed between the roof outer plate 20 and the roof interior material 21 as shown in the sectional view of FIG. Electromagnetic beam 13 emitted by Doppler sensor 12
Is transmitted through the roof interior material 21 and the sun visor 18 and is irradiated near the occupant's head.

In the second modification, as shown in FIG.
The Doppler sensor 12 is mounted inside each of the front pillar 23, the roof side rail 24, and the sensor pillar 25. For example, as shown in the sectional view of FIG. 3B, the Doppler sensor 12 of the center pillar 25 is attached and fixed to an outer pillar member 26, and the electromagnetic beam 13 emitted from the Doppler sensor 12 passes between the inner pillar members 27, and The light passes through 28 and is irradiated near the occupant's head. The front pillar 23 or the roof side rail 24 is similarly installed.

In a third modification, as shown in FIGS. 4A and 4B, the Doppler sensor 12 is connected to the steering wheel 3.
1 is mounted inside a steering pad 30 that supports the steering pad 1. In the fourth modification, as shown in FIG. 5, the Doppler sensor 12 is mounted near the headrest 11 in the seat back 33 of the seat 10. In the fifth modification, FIG.
As shown in (A), the Doppler sensor 12 is mounted inside the armrest 35 of the rear seats 34a, 34b. In this case, as shown in FIG.
a, 12b and two electromagnetic beams 13a, 13b, respectively.
b is emitted toward the vicinity of the head of the occupant of each of the rear seats 34a and 34b.

Also in the first to fifth modifications, the electromagnetic beam penetrates through the resin, cloth or the like with only a slight attenuation and is irradiated near the occupant's head, thereby minimizing the effect on the interior design of the vehicle. It can be mounted in a form. FIGS. 7A and 7B show the configuration of a second embodiment of the occupant detection device according to the present invention. FIG.
2A, Doppler sensors 42 and 43 are provided inside the seat cushion 40 of the seat 10. Each of the Doppler sensors 42 and 43 is attached and fixed to the seat cushion frame 45 as shown in the sectional view of FIG.
Fire. Doppler sensor 4 under seat pad 46
A reflection plate 48 is attached at a position facing each of the reference numerals 2 and 43. 49 is a spring and 50 is a seat cover.

In the seat pressure distribution, as shown in FIG. 8, the portion where the buttocks of the human body touches shows the peak value of the seat pressure. For this reason, the Doppler sensors 42 and 43 and the respective reflection plates 48 are arranged at positions corresponding to the seat pressure peak positions. The seat pad 46 is deformed due to a change in load when the occupant is seated or a change in load due to the vertical movement of the occupant during running, and
8, a displacement in the vertical direction occurs, and the displacement speed changes. The Doppler sensor 42 detects the change in the displacement speed to detect the occupant. The reflecting plate 48 is coated with a metal plate such as aluminum or a resin plate so that the electromagnetic beam 47 does not directly detect the movement of an object on the seat cushion 40 through the seat pad 46 and the seat cover 50. Alternatively, a metal foil may be bonded to the sheet pad 46 directly.

When the occupant is not sitting on the seat 40, there is no change in the relative distance between the Doppler sensor 42 and the reflection plate 48, so that no change appears in the output of the Doppler sensor 42. Next, when an object other than the detection target of the occupant detection system, such as a cardboard box, is placed on the seat, a uniform seat pressure distribution different from the human seat pressure distribution shown in FIG. .

FIG. 9 shows the amount of deformation of the seat pad 46 with respect to the seat pressure. When the seat pressure is less than a certain fixed value, the lower surface is not deformed due to the absorption of the load of the seat pad 46 itself. However, if the seat pressure exceeds that, the load cannot be completely absorbed by the seat pad 46 itself.
With the deformation of 9, the lower surface of the seat pad 46 is pushed downward and deformed. That is, the reflection plate 4
8 moves up and down at a certain speed.

As shown in FIG. 10, the maximum seat pressure with respect to the load applied to the seat has a maximum seat pressure value corresponding to the position of the seat in the case of a human, while a uniform load such as a corrugated cardboard box exists. In a working object, the maximum seat pressure with respect to the load has a linear relationship and the maximum seat pressure value itself has a uniform distribution of seat pressure, so that it shows a small value as compared with humans.

In addition, among the objects such as cardboard boxes which do not show an equal load and which cannot be detected by the occupant detection system, there are animals represented by pets. Even in the case of this pet, since the human seat pressure distribution shown in FIG. 8 is not shown, there is no erroneous detection by the Doppler sensor arranged in the portion showing the maximum seat pressure. As described above, in the above embodiment, the presence or absence of an occupant can be reliably detected by distinguishing a person from an object such as luggage and an animal. In addition, since there are few erroneous detections and non-detections, reliability is improved. Furthermore, since the seat is built in, it is advantageous for mounting and securing living space.

FIG. 11 is a block diagram of an occupant detection system using the Doppler sensor with a built-in headrest of FIG. In this system, in order to make the determination of the presence or absence of the occupant more reliable, the movement of the occupant's head predicted from the movement of the vehicle,
The determination is made by comparing the movement of the head of the occupant detected by the Doppler sensor. In FIG. 11, the vehicle stop determination unit 63
Determines whether or not the vehicle is stopped based on the brake switch signal 61 and the vehicle speed signal 62, and notifies the occupant detection determination unit 69. If the vehicle is stopped and the head speed signal calculation unit 66 receives a Doppler sensor input 64 and outputs a signal of a certain speed pattern, the occupant detection determination unit 69 determines that there is an occupant.

FIG. 12 shows a flowchart of the processing executed by the occupant detection judging section 69. In the figure, it is determined in step S10 whether or not the brake switch signal is ON, whether or not the vehicle speed is less than a threshold value _{Vref in} step S12, and in step S14, the vehicle body acceleration (differential value of the vehicle speed) is a negative threshold value. G
_It is determined whether the vehicle is decelerating at less than _ref1 . Further, in step S16, it is determined whether or not the head speed pattern is less than the negative threshold value V _head2 and then exceeds the positive threshold value V _head1 . If all of the above steps S10 to S16 are satisfied, it is determined in step S18 that there is an occupant, and step S1 is performed.
If any one of 0 to S16 is not satisfied, step S20
It is determined that there is no occupant.

When the vehicle starts at point a, passes points b and c, and stops at point d on the curved road shown in FIG. 13, the brake switch signal, the vehicle speed signal, the vehicle acceleration, the steering angle, the steering angular velocity, Fig. 1 shows the signal waveforms of the steering angular acceleration, the absolute value of the head speed, and the head speed.
4 (A) to 4 (H). Note that points a, b, c,
d denote the time at which the vehicle exists in each of ta, tb, tc, t
Shown as d.

At td immediately before the vehicle stops, FIG.
When the brake switch signal shown in FIG.
The vehicle speed signal shown in FIG. 12B decreases, and the vehicle acceleration shown in FIG. 12C shows a negative value. At this time, the occupant's head moves forward, and a negative speed is detected as shown in FIG. Further, if the brake pressure is not sufficiently released immediately before the stop, the head that has moved forward moves backward and generates a positive speed.

In FIG. 11, the occupant detection / judgment unit 70 is supplied with the vehicle acceleration from the vehicle speed signal processing unit 66, and when the vehicle shifts from a stopped state to a running state, or when the vehicle suddenly accelerates or decelerates during running. It detects the movement of the occupant's head, and executes the processing shown in FIG. In FIG. 15, in a step S30, it is determined whether or not the brake switch signal is off, and in a step S32, it is determined whether or not the vehicle speed is _lower than the threshold value _Vref . If steps S30 and S32 are satisfied, it is determined in step S34 whether or not the vehicle is accelerating, that is, whether or not the vehicle body acceleration exceeds a positive threshold _Gref2. It is determined whether or not V _head1 is _exceeded . If the vehicle is not accelerating, it is determined in step S38 whether or not the head speed is lower than the negative threshold value V _head2 .

[0028] When the head speed <V _{he ad2} the head velocity> V _head1, or step S38 in step S36 determines that there is an occupant in the step S40. Step S30, S3
2 is not satisfied, or in step S36, the head speed ≦ V _head1 , or in step S38, the head speed ≧ V
_In the case of _head2 , it is determined in step S42 that there is no occupant.

When the stopped vehicle starts running at a constant acceleration at point a in FIG. 13, the head speed of the occupant shown in FIG. 14H is a positive speed proportional to the vehicle body acceleration shown in FIG. Acts on the head of the occupant, so if this movement is detected by the Doppler sensor, the presence or absence of the occupant can be detected. For a higher detection accuracy, the vehicle acceleration is positive threshold G _{re f2}
The occupant detection judgment is performed only when the vehicle speed exceeds.

The occupant detection / judgment unit 71 detects that a lateral force acts on the head of the occupant due to the lateral acceleration generated when the steering is operated on a curved road or the like, and the head moves. Execute the processing shown. The steering angle signal processor 67 differentiates the steering angle signal twice to obtain a steering angular acceleration. In FIG. 16, at step S50, it is determined whether or not the vehicle speed exceeds a threshold value _Vref . At step S52, it is determined whether or not the steering angular acceleration has exceeded a threshold value _AST. It is determined whether or not the value exceeds a threshold (absolute value) _Vhead .

When all of steps S50, S52 and S54 are satisfied, it is determined in step S56 that there is an occupant. If any of steps S50 to S54 is not satisfied, it is determined in step S58 that there is no occupant. When the vehicle travels at a constant speed on the curved road shown in FIG. 13, in a straight running state (from point a to point b), the head speed shown in FIGS. At point b), when the steering is operated at a constant steering angular velocity, the steering angular velocity shows a positive value at the start of steering as shown in FIG. At the same time, a lateral acceleration is also generated in the vehicle body, and the occupant's head moves outward by applying a lateral force according to the lateral acceleration. Similarly, at the exit of the curve (point c), a lateral force is applied to the head in accordance with the lateral acceleration. The occupant detection determination is performed only when the steering angular acceleration exceeds the threshold value _AST in order to increase the detection accuracy.

The occupant detection determining section 69 corresponding to the determining means,
Each of the determination results 70 and 71 is ANDed by the AND circuit 72, and when all of the determination units 69 to 71 determine that there is an occupant, an occupant presence / absence determination signal 73 indicating that there is an occupant is output. The occupant presence / absence determination is performed by the occupant detection determination units 69 to 7.
Although described as a logical product of one output, it may be used alone or a logical sum of a plurality of combinations according to the detection accuracy and the like required by the application system. The same applies when a lateral acceleration sensor is used as a sensor input signal instead of a brake switch signal, instead of a brake pressure, a brake pedal stroke, or a vehicle speed signal, instead of a longitudinal acceleration sensor or a steering angle signal. Effects can be obtained.

FIG. 17 shows a configuration diagram of an occupant detection system using the Doppler sensor with a built-in seat shown in FIG. In FIG. 17, an occupant detection determination unit 86 corresponding to the determination unit includes a steering angular acceleration signal 85 obtained by differentiating the steering angle input 81 twice 84 and a region having the largest seat pressure distribution shown in FIG. The occupant detection is determined based on the two Doppler sensor inputs 82 and 83 installed in the occupant.

FIG. 18 shows a flowchart of the processing executed by the occupant detection judging section 86. In the figure, in a step S60, it is determined whether or not the vehicle speed exceeds a threshold value _Vref, and in a step S62, the absolute value of the steering angular velocity is set to the threshold value (absolute value) _Vst.
It is determined whether or not: If both steps S60 and S62 are satisfied, it is determined in step S64 whether the steering wheel is turned to the right. If the steering wheel is turned right, the Doppler sensor 43 on the right side of the seat detects at a negative speed in step S66, and in step S68. It is determined whether the Doppler sensor 42 on the left side of the sheet has detected a positive speed. If both steps S66 and S68 are satisfied, step S70
To set the occupant presence condition 1 flag in step S72.
It is determined whether or not the condition 2 flag has been set. Condition 2
If the flag has been set, it is determined in step S74 that there is an occupant, and the condition 1 flag and the condition 2 flag are reset in step S76. If it is determined in step S64 that the steering wheel is turned right, the Doppler sensor 43 on the right side of the seat detects a positive speed in step S78, and it is determined whether the Doppler sensor 42 on the left side of the seat detects a negative speed in step S80. . If both steps S78 and S80 are satisfied, a condition 2 flag indicating that there is an occupant is set in step S82, and it is determined in step S72 whether the condition 1 flag has been set. If the condition 1 flag has been set, it is determined in step S74 that there is an occupant, and the condition 1 flag and the condition 2 flag are reset in step S76.

On the other hand, steps S60, S62, S66,
If any of S68, S72, S78, S80, and S84 is unsatisfactory, the process ends without determining that there is an occupant. In time t ₁ smell running state steering angular velocity is not generated that shown in FIG. 19 (B) in the steering operation which the steering angle signal is obtained shown in FIG. 19 (A), a load change of the seat occupant is sitting Because there is little, no signal change is seen at the Doppler sensor inputs 82,83. In FIG. 20A, the radio waves transmitted from the Doppler sensor 42 and the Doppler sensor 43 provided on the floor are reflected by the reflectors 48a and 48b provided on the lower surface of the seat pad 46 with a gap d therebetween. At this time, the load M / 2 is substantially uniformly applied to the seat pad 46, and there is no change in the gap d, so that the Doppler signal does not show a change as shown in FIGS.

Next, at time t ₂ , when the steering wheel is rotated to the left at a constant angular velocity as shown in FIG.
As shown in (C), a positive steering angular acceleration signal is generated, and accordingly, a lateral acceleration is generated in the vehicle. Therefore, the lateral force proportional to the lateral acceleration acts on the occupant, and the seat pressure distribution changes. In FIG. 20B, the gap is reduced by Δd in the right Doppler sensor 42 and the gap is increased by Δd in the left Doppler sensor 43 due to the load change ΔM on the sheet. When these two types of distance change detection are performed by two Doppler sensors, the Doppler sensor input 82 becomes a positive polarity speed signal and the Doppler sensor input 83 becomes a negative speed signal as shown in FIGS. Then by rotating the steering to the right at time t _3, change in opposite directions as compared with the load change and the Doppler sensor applied to the seat and the distance change time t ₂ of the reflector when the operation of returning to the original position .
The Doppler sensor inputs 82 and 83 output reverse speed signals due to the influence of the inertia of the movement of the head.

As described above, the occupant detection / judgment section 86 is generated in accordance with the steering angular acceleration signal shown in FIG. 19C generated when the steering wheel is steered and the change in the seat pressure distribution of the occupant. Patterns of a plurality of Doppler signals [FIG.
(D), (E)], the presence or absence of an occupant is determined. With the crew,
For example, in a system that does not need to be distinguished from other objects such as luggage, animals, and the like, the Doppler sensor input in FIG. 19D or FIG. Because it is easy to determine the presence of an occupant,
The detection performance is not inferior.

In the first and second embodiments, a radar device such as a pulse radar or an FM-CW radar may be used instead of the Doppler sensors 12, 42, and 43.
It is not limited to the above embodiment. A control system for an auxiliary device to which the above-described occupant detection system is applied is shown below. 1) Deployment Switch for Passenger Seat Airbag System In the airbag system, when the occupant is not present in the passenger seat, that is, when the occupant detection system determines that there is no occupant in the passenger seat, the passenger seat airbag is not deployed. As a result, it can be activated only when there is an object to be protected by the airbag, for example, preventing the harmfulness of the airbag deployment to the child on the child seat, and reducing the vehicle repair cost after an accident Is done.

2) Alarm for Wearing Seat Belt The occupant detection system detects the presence of an occupant and issues an alarm for not wearing the seat belt when the seat belt is not worn. This is highly effective in a situation where there are many occupants, such as a highway bus, and the driver promptly wears the seatbelt in a situation where the driver cannot easily confirm the seatbelt wearing state or the occupant position of each passenger.

3) Speaker volume control of the audio system The car audio system has a manual volume control function of adjusting the front, rear, left and right speaker volumes according to the occupant layout to create an optimal sound field. By adding an occupant detection system to this car audio,
It is possible to automatically provide a sound with an optimal volume balance to all of the currently occupants.

4) Air Conditioner Control The air volume at the air conditioner outlet is adjusted by the occupants themselves by adjusting dampers and the like. By adding the occupant detection system to the air conditioner system, air can be automatically blown to the seat with the occupant, the convenience is improved, and the air conditioner itself can be operated efficiently.

[0042]

As described above, according to the first aspect of the present invention, the displacement caused by the load of the seat pad by the Doppler sensor.
To detect the speed, the seat pad displacement speed
The occupant sitting on the vehicle
I can know.

According to the second aspect of the present invention, the operating state
The Doppler sensor detects the displacement speed of the seat pad according to the
The presence or absence of an occupant was determined by comparing with the above-mentioned known movement.
Therefore, occupant detection can be performed extremely accurately.

According to the third aspect of the present invention, since the auxiliary device is controlled in accordance with the accurate detection output of the occupant detection device according to the first or second aspect , the auxiliary device can be accurately controlled. Controllable and very useful in practice.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a modified example of the present invention.

FIG. 3 is a configuration diagram of a modified example of the present invention.

FIG. 4 is a configuration diagram of a modified example of the present invention.

FIG. 5 is a configuration diagram of a modified example of the present invention.

FIG. 6 is a configuration diagram of a modified example of the present invention.

FIG. 7 is a configuration diagram of a second embodiment of the present invention.

FIG. 8 is a diagram showing a seat pressure distribution.

FIG. 9 is a diagram showing a relationship between a seat pressure and a seat pad deformation amount.

FIG. 10 is a diagram illustrating a relationship between a seat load and a maximum seat pressure.

FIG. 11 is a configuration diagram of an occupant detection system.

FIG. 12 is a flowchart of an occupant detection determination process.

FIG. 13 is a diagram for explaining vehicle running.

FIG. 14 is a signal timing chart of each unit in FIG. 11;

FIG. 15 is a flowchart of an occupant detection determination process.

FIG. 16 is a flowchart of an occupant detection determination process.

FIG. 17 is a configuration diagram of an occupant detection system.

FIG. 18 is a flowchart of an occupant detection determination process.

FIG. 19 is a signal timing chart of each unit in FIG. 17;

FIG. 20 is a diagram for explaining a detection state of Doppler sensors 42 and 43.

[Explanation of symbols]

 Reference Signs List 10 seat 11 headrest 12, 42, 43 Doppler sensor 40 seat cushion 46 seat pad 48 reflector 65 vehicle stop determination unit 66 vehicle speed signal processing unit 67 steering angle signal processing unit 68 head speed calculation unit 69, 70, 71, 80 occupant Detection judgment unit

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B60R 21/16-21/32 B60R 22/00-22/48 B60N 2/00 B60K 25/00 B60K 28/02 G01P 15 / 00 B60N 2/42

Claims (3)

(57) [Claims] (1)Inside the vehicle seat cushion, the seat
An electromagnetic beam is emitted toward the pad's reflector,
To detect the displacement speed of the seat pad
With a puller sensor, Seat pad displacement speed detected by the above Doppler sensor
Crew inspection characterized by determining the presence or absence of an occupant based on the degree
Knowledge device. (2)Driving state detection that detects the driving state of the vehicle
Means, 2. The method according to claim 1, wherein a displacement speed of the seat pad is detected.
A Doppler sensor, Seat pad displacement determined by the driving condition of the vehicle
Speed and seat pad detected by the Doppler sensor
Is compared with the displacement speed of
An occupant detection device comprising: 3. An occupant detection device according to claim 1 or 2,
Controlling auxiliary equipment according to the known vehicle occupants
Auxiliary equipment control device.