KR20020035286A - Vehicle occupant sensing system - Google Patents

Abstract

PURPOSE: A passenger sensing system of a vehicle is provided to facilitate installation and use, to exactly sense a passenger's position, and to control inflation of an air bag optimally by continuously measuring the sensed passenger's position. CONSTITUTION: A passenger sensing system of a vehicle comprises a laser array, a first sensor assembly, a second sensor assembly, a third sensor assembly and a CPU(Central Processing Unit). The laser array generate first beams(24) oriented toward a first passenger zone(30), second beams(26) oriented toward a second passenger zone(32), and third beams(28) toward a passenger zone(34). The first sensor assembly receives the reflection beams generated from the first beams lighting a first part of the passenger of the first zone and makes a first signal of indicating the first part proportionately. The second sensor assembly receives the reflection beams generated from the second beams lighting a second part of the passenger of the second zone and makes a second signal of indicating the second part proportionately. The third sensor assembly receives the reflection beams generated from the third beams lighting a third part of the passenger of the third zone and makes a third signal of indicating the third part. The CPU receives the first, second, third signal, combines the signals, and decides the passenger's position in the vehicle.

Description

Vehicle occupant detection system {VEHICLE OCCUPANT SENSING SYSTEM}

The present invention relates to a unique method and system for sensing the position of an occupant in a vehicle, wherein the laser and sensor assembly continuously monitor the occupant position in three different zones.

Many vehicles have airbag systems used to keep occupants in the vehicle under certain deceleration requirements. If the vehicle suddenly slows down, such as when a collision occurs, the occupant will tend to move forward due to inertial effects. Under these circumstances, the airbag is inflated to slow down the rider's crash speed before the rider contacts the vehicle structure, such as the steering wheel or instrument panel. Inflation of the airbags reduces the likelihood of fatal injury to the occupant.

If the vehicle occupant is located in close contact with the airbag, it may be desirable to reduce the inflation force of the airbag or prevent the airbag from inflating to prevent the occupant from injuring the airbag. The occupant detection system is used to provide information that optimizes or reduces the inflation of the airbag if the occupant is placed too close to the airbag. Some systems use sensors to determine when the seat belt is retracted from the retraction reel beyond the normal operating requirements. Other systems use visual or audio signals transmitted laterally across a vehicle extending parallel to the instrument panel to determine occupant access to the instrument panel. Another system uses an outgoing / receiving sensor directed towards the vehicle dashboard to determine when the occupant is approaching or touching the dashboard.

Such a system is complex and expensive. Often these complex systems are difficult to use, time consuming to install and provide inaccurate positioning. Accordingly, it is desirable to provide a simple method and system for detecting the position of a passenger in a vehicle that is easily installed and maintained. This simple system must be compact and provide continuous and accurate data on the occupant position used to optimize or reduce the inflation of the airbag if it is determined to be close enough to the airbag.

It is an object of the present invention to overcome the above-mentioned problems in the prior art, to be easy to install and use, to more accurately sense the position of the occupant in the vehicle, and to continuously measure the position of the detected occupant to inflate the inflation of the airbag. It is to provide a passenger detection system that allows optimal control.

1 is a side schematic view of one embodiment of an occupant detection system mounted in a vehicle;

2 is a schematic diagram of an occupant detection system;

3 is an enlarged schematic view of a sensor array used in the occupant detection system;

4 is an enlarged view of a sensor unit;

5 is a side schematic view of a vehicle with the airbag in an inflated position;

6 is a schematic diagram of an airbeck and occupant detection control system;

7 is a side schematic view of the orientation of the laser beam and a corresponding body zone;

8 is a front schematic view of the orientation of the reflective beam and the corresponding body zone;

9 is a top schematic view of sensor unit orientation with respect to body zones; And

10 is a graph showing triangulation methods used to determine occupant position.

In the disclosed embodiment of the present invention, the vehicle occupant detection system includes a laser array and three sensor assemblies. The laser array generates a first beam mounted to the vehicle structure and oriented towards the first occupant zone, a second beam oriented towards the second occupant zone and a third beam oriented towards the third occupant zone. The first sensor assembly accepts a reflected beam resulting from the first beam that illuminates a first portion of the occupant located in the first zone. The first sensor assembly generates a first signal that appears in proportion to the body weight of the occupant in the first zone. The second sensor assembly accepts a reflected beam originating from a second beam that illuminates a second portion of the occupant located in the second zone. The second sensor assembly generates a second signal that appears in proportion to the body weight of the occupant in the second zone. The third sensor assembly accepts a reflected beam originating from a third beam that illuminates a third portion of the occupant located in the third zone. The third sensor assembly generates a third signal that is proportional to the body weight of the occupant in the third zone. The central processing unit is used to accept and merge the first, second and third signals to determine the occupant's position in the vehicle.

In a preferred embodiment, the laser array and sensor assembly are both enclosed in a common housing that is mounted to the vehicle structure. The lens is installed in the housing to control the size, shape and direction of the laser beam. Preferably, the first zone is defined as the area typically occupied by the upper part of the occupant, the second zone is defined as the area typically occupied by the middle part of the occupant, and the third zone is the lower part of the occupant It is defined as the area normally occupied by the site. The lens directs the first beam to the first zone, the second beam to the second zone, and the third beam to the third zone.

In another preferred embodiment, each beam is spaced apart from each other by at least 10 degrees to form a light curtain that is at least 40 degrees wide and at least 3 degrees thick. The position of the occupant is continuously monitored as the sensor assembly receives the reflected beam from the light curtain illuminating the occupant seated on the vehicle.

The method of sensing the position of an occupant in a vehicle includes generating a first laser beam directed toward a first zone, and receiving a reflected beam from the first laser beam when the first laser beam shines on a part of the occupant in the first zone. Entering, and generating a first signal indicative of the first body weight of the occupant of the first zone. The next step is to generate a second laser beam towards the second zone, to accept the reflected beam from the second laser beam when the second laser beam shines on the occupant's part of the second zone, and Generating a second signal indicative of a second body weight of the occupant of the second zone. Additional steps include generating a third laser beam towards the third zone, accepting a reflected beam from the third laser beam when the third laser beam shines on the occupant's portion of the third zone, and Generating a third signal indicative of a third body weight of the occupant of the three zones. The first, second and third signals are merged to determine the occupant location in the vehicle. The first, second and third signals may be used to generate control signals for controlling the inflation of the airbag based on occupant position in the vehicle.

The above and other features of the present invention can be better understood from the following detailed description, drawings, and brief description of the drawings.

(Example)

The vehicle is shown generally by reference numeral 10 of FIG. 10. The vehicle 10 includes an occupant sensing system that continuously monitors the position of the occupant 12 therein and provides occupant position information to control the airbag system based on the position of the occupant 12 in the vehicle 10. . When a person is sitting in the vehicle seat 14 in the vehicle 10, the sensing system typically monitors the position of the occupant 12. However, the system may also monitor the position of the occupant 12 between the seat 14 and the vehicle dashboard 16, ie, the eye between the dashboard 16 and the seat 14.

The occupant detection system includes a sensor unit 18 mounted to the vehicle structure. Preferably, the sensor unit 18 is mounted in a vehicle at a relatively high vehicle position by means of a rear view mirror, for example as shown in FIG. Instead of being mounted at the center, the unit 18 may optionally be mounted near the side of the vehicle 10, for example in an A-shaped filler.

The sensor unit 18 produces at least three laser beams 24, 26, 28 which are oriented towards the area within the vehicle in which the occupant 12 sits. As shown entirely in FIG. 1, the first beam 24 is oriented towards the first occupant zone 30 and the second beam 26 is oriented towards the second occupant zone 32 and the third beam 28 is shown. ) Is oriented towards the third occupant zone 34. Preferably, the first zone 30 is formed as a zone filled with the upper portion of the occupant 12 and the second zone 32 is formed as a zone filled with the middle portion of the occupant 12 and the third zone 34 ) Is formed as an area filled with the lower part of the occupant 12.

The sensor unit 18 comprises a laser array, shown entirely by reference numeral 36 in FIG. 2, consisting of at least three laser elements 36a, 36b, 36c. The first laser element 36a forms the first beam 24, the second laser element 36b forms the second beam 26, and the third laser element 36c forms the third beam 28. do. The laser 36 can be any laser type known in the art, but is preferably a diode laser that includes a light emitting diode for the infrared band. An example of such a laser is the PGA series laser manufactured by EG & G Canade. The laser 36 is mounted in the housing 40 mounted to the A-shaped filler or the rear view mirror 20.

The first lens 42 is mounted in the housing 40 and positioned in front of the laser array 36 to control the shape and size of the first, second and third beams 24, 26, 28. The lens 42 is oriented with the first beam 24 in the first zone 30, the second beam 26 in the second zone 32, and the third beam 28 in the third zone 34. Also used.

When the beams 24, 26, 28 hit the target, ie the occupant sitting in the seat 14, the beams 24, 26, 28 are reflected back towards the sensor unit 1. The sensor array, indicated generally by reference numeral 44 in FIG. 2, is mounted in the housing 40 to receive the reflected beam. The second lens 46 is mounted adjacent to the sensor array 44 to control the focus and direction of the reflected beam. Both lenses are preferably plastic and may or may not include a coating for filtering light from the sun. The first lens 42 is preferably a cylindrical lens and the second lens is preferably a circular lens made by EG & G Canada. The use of cylindrical lenses reduces slow divergence while leaving unaffected rapid divergence. The circular lens is finely curved to reflect the distortion in the reflected beam as the reflected beam returns to the unit 18.

Sensor array 44 is shown in more detail in FIG. 3. The sensor array 44 includes a first sensor assembly 48 to receive a reflected beam resulting from the first beam 24 hitting the first position of the occupant 12 located in the first area 30. do. The second sensor assembly 50 receives a reflected beam resulting from the second beam 26 hitting the second position of the occupant 12 located in the second area 32. The third sensor assembly 52 receives a reflected beam resulting from the third beam 28 that hits the third position of the occupant 12 located in the third region 34.

The first sensor assembly 48 proportionally generates a first signal S _z1 , which represents the first portion of the occupant 12 in the first zone 30. The second sensor assembly 50 proportionally generates a second signal S _z2 , which represents the second portion of the occupant 12 in the second zone 32. The third sensor assembly 52 proportionally generates a third signal S _z3 , which represents the third portion of the occupant 12 in the third zone 34. These signals are combined to determine the occupant location in the vehicle.

The first sensor assembly 48 includes at least one sensor unit 54 that receives the reflected beam from the first zone 30. The second sensor assembly 50 includes at least three sensor units 54 that receive the reflected beam from the second zone 32. The third sensor assembly 52 includes at least five sensor units 54 that receive the reflected beam from the third zone 34.

Each sensor unit 54 consists of two triangular sensors 56 mounted adjacent to each other to form a parallelogram as shown in FIG. Each sensor 56 is connected to the anode 58 and operates to merge with the sensor 56 for each sensor assembly 48, 50, 52 to produce a control signal swatch of the occupant's position in the vehicle. If the occupant is determined to be too close to the airbag, as shown in FIG. 6, control signals are used to optimize or suppress the placement of the airbag 60 to provide accurate and continuous readings for the occupant's position.

As is well known in the art, the airbag 60 is connected to the system controller 62 (see FIG. 5). As discussed above, the sensor assemblies 48, 50, 52 generate signals S _z1 , S _z2 , S _z3 representing the portion of the occupant 12 in each zone 30, 32, 34. . The signals S _z1 , S _z2 and S _z3 are sent to a central processing unit (CPU) 64 which generates a control signal and then to the system controller 62 (see FIG. 6). The controller 62 controls the inflation and / or suppression of the airbag 60 based on the occupant 12 position in the vehicle 10.

The sensor unit 18 is a very compact assembly that requires very little space in the vehicle 10 because both the laser array 36 and the sensor assemblies 48, 50, 52 are mounted in the same housing 40. As is known in the art, this housing 4 is easily installed within the vehicle 10 and easily connected to a central processing unit (CPU) 64.

The sensor unit 18 is preferably oriented to monitor the passenger seat of the vehicle in the vehicle, but the unit 18 can be redirected to monitor the driver's seat in the vehicle 10. Each laser beam 24, 26, 28 generates a light curtain oriented in the appropriate zones 30, 32, 34. For a suitable monitoring range for the driver's seat, the light curtain preferably has an angular width of at least 40 °, ie extends across the driver's seat at least 3 ° in the transverse direction (from left to right) at 40 °. In addition, the first beam 24, the second beam 26 and the third beam 28 are spaced apart from each other by at least 10 ° as indicated by arrows 66 (see FIG. 7). Optimally, the laser beam curtain should cover an area of 1m x 65cm.

As discussed above, the occupant sensing assembly 18 includes a different number of sensor units 54 for each zone 30, 32, 34. As shown in FIGS. 8 and 9, the sensor array 44 has a single sensor unit 54 _z1 in the upper body region 30, with all sensors 54 deformed in a single chip. The body zone 32 includes three sensor units 54 _z2a-c and the lower body zone 34 includes five sensor units 54 _z3a-e . Preferably, the sensor 54 in each zone 30, 32, 34 emits a 40 ° fan shaped beam α _1-3 shown in FIG. 8. Preferably, as shown in FIG. 9, the beams are also 3 ° thick (β _1-3 ) and 10 ° (Δ _1-2 ) spaced from each other. Although this is the preferred shape, it should be understood that other shapes may be used.

Only one sensor unit 54 _z1 is preferred for the upper region 30 because this region is the longest distance in the longitudinal direction from the instrument panel 16. Lower zone 34 requires more sensors 54 _{z3a-e since} this zone 34 is closest to instrument panel 16 and requires proximity monitoring.

A method for detecting occupant position in a vehicle includes generating a first laser beam 24 toward a first zone 30, whereby the first laser beam 24 is occupant 12 in the first zone 30. Receiving a reflected beam from the first beam 24 when illuminating a body part of the body, and receiving a first signal S _z1 indicative of a first body weight of the occupant 12 in the first zone 30. Generating a step. The next step is to generate a second laser beam 26 towards the second zone 32, the second laser beam 26 when the second laser beam 26 shines on the body part of the occupant 12 in the second zone 32. Receiving a reflected beam from the two laser beams 26 and generating a second signal S _z2 indicative of a second body weight of the occupant 12 in the second zone 32; . The next step is to generate a third laser beam 28 towards the third zone 34, the first when the third laser beam 28 shines on the body part of the occupant 12 in the third zone 34. Receiving the reflected beam from the three laser beams 28 and generating a third signal S _z3 representing a third body weight of the occupant 12 in the third zone 34; . The first, second and third signals S _z1 , S _z2 and S _z3 are merged to determine the occupant position in the vehicle. The first, second and third signals S _z1 , S _z2 and S _z3 may be used to generate a control signal for controlling the inflation of the airbag 60 according to the occupant position in the vehicle 10.

The next step is to space the first laser beam, the second laser beam, and the third laser beams 24, 26, 28 at least 10 degrees apart from each other, each laser beam having an angular width of at least 40 degrees and a thickness of 3 degrees. Generating a curtain. The generation of the laser beam and the reception of the reflected beam through the sensor assemblies 48, 50, 52 provide continuous monitoring of the occupant 12 position in the vehicle 10.

The laser array 36 is powered to transmit a laser beam towards the target. The beam is reflected to the sensor array 44. The power Pr received from the reflection can be calculated based on the initial transmitted power Pt. The received power Pr can be calculated by the following equation.

Pr = Pt (Atc / Ab) (Aa / πr ² ) (ρT) where Pt is the transmitted power, Atc is the area of the captured target, Ab is the area of the beam, Aa is the area of the hole, R is from the source The distance to the target, ρ is the reflection efficiency, and T is the filter efficiency. The ratio (Atc / Ab) of the area Atc of the captured target to the area Ab of the beam is equal to the efficiency of the beam striking the target, which is approximately 10%. The reflection efficiency ρ is 90% for white and 3% for black. The filter efficiency T is approximately 50%. The ratio (Aa / πr ² ) of the area Aa of the hole to π times the square of the distance R from the source to the target is approximately 10 ⁻⁴ for 1 meter, which is equal to the efficiency of the reflected beam. Thus, for black, Pr = Pt (.1) (. 03) (. 5) (10 ⁻⁴ ), that is, Pr = Pt (1.56e- ⁶ ).

The occupant position is determined using known standard triangulation calculations. 10, D is the distance between the optical axis of the receiver and the transmitter, Dxt is the distance between the optical axis of the transmitter and the target, Dxr is the distance between the optical axis of the receiver and the target, Ft is the transmitter focal length, Fr is The receiver focal length, Ym is the distance between the system and the target, Xt is the transmitter distance from the optical axis, and Xr is the receiver distance from the optical axis (change is detected). The receiver distance Xr from the optical axis is determined from the equation:

Xr = ((D / Ym)-(Xt / Ft)) * Fr

This equation is derived from the following relationship:

Dxt = ((Xt * Ym) / Ft) and

Dxr = ((Xr * Ym) / Fr).

To determine the distance D between the optical axis of the receiver and the transmitter, the distance Dxt between the optical axis of the transmitter and the target is added to the distance Dxr between the optical axis of the receiver and the target: D = Dxr + Dxt = Ym * ((Xr / Fr) + (Xt / Ft)). Thus, the receiver distance Xr from the optical axis is easily solved: Xr = ((D / Ym)-(Xt / Ft)) * Fr.

The unique method and system of the present invention for detecting the occupant's position in a vehicle provides a simple system that is easily installed and maintained. The system of the present invention also requires relatively few components and is compact. This simplified system provides a continuous and accurate reading of the occupant's position so that it can be used to optimize or suppress the inflation of the airbag if the occupant is too close to the airbag.

Although preferred embodiments of the invention have been described, those skilled in the art will recognize that many changes can be made within the scope of the invention. For that reason, the claims are intended to determine the true scope and content of this invention.

The unique method and system of the present invention for detecting the position of a passenger in a vehicle provides a simple system that is easily installed and maintained. The system of the present invention also requires relatively few components and is compact. This simplified system provides continuous and accurate position reading of the occupant's position, making it possible to optimize or suppress the inflation of the airbag if the occupant is determined to be too close to the airbag.

Claims (20)

A laser array mounted to the vehicle structure to generate a first beam oriented towards the first occupant zone, a second beam oriented towards the second occupant zone and a third beam oriented towards the third occupant zone; Accepts a reflected beam resulting from a first beam that illuminates a first portion of the occupant located within the first zone, and generates a first signal proportionally representing the first portion of the occupant present within the first zone; A first sensor assembly; Accepts a reflected beam resulting from a second beam that illuminates a second portion of the occupant located within the second zone, and generates a second signal proportionally representing the second portion of the occupant present within the second zone; A second sensor assembly; Accepts a reflected beam resulting from a third beam that illuminates a third portion of the occupant located within the third zone, and generates a third signal proportionally representing the third portion of the occupant present within the third zone; A third sensor assembly; And And a central processing unit that receives the first signal, the second signal, and the third signal and merges the signals to determine the position of the occupant in the vehicle. The system of claim 1, wherein the first zone is formed as an area generally occupied by an upper portion of the occupant, and the second zone is formed as an area generally occupied by an intermediate portion of the occupant, the third zone Is formed as an area generally occupied by the lower portion of the occupant. The vehicle occupant detection system of claim 1, wherein the laser array, the first sensor assembly, the second sensor assembly, and the third sensor assembly are mounted in a common housing. 4. The vehicle occupant detection system according to claim 3, wherein the housing is mounted to a vehicle side member. 4. The vehicle occupant detection system according to claim 3, wherein the housing is mounted at the center of the vehicle interior. 4. The laser array of claim 3, wherein the laser array comprises a first laser element for generating the first beam, a second laser element for generating the second beam, and a third laser element for generating the third beam, And a first laser element, a second laser element and a third laser element each mounted in the common housing. The method of claim 6, wherein the size and shape of the first beam, the second beam, and the third beam are controlled, wherein the first beam is the first zone, the second beam is the second zone, and the second beam is controlled. And a lens mounted inside the housing for directing the three beams to the third zone. 8. The apparatus of claim 7, wherein the first sensor assembly includes at least one sensor unit for receiving the reflected beam from the first zone, and the second sensor assembly includes the reflection from the second zone. A vehicle comprising at least three sensor units for receiving beams, said third sensor assembly comprising at least five sensor units for receiving said reflected beams from said third zone Occupant detection system. 9. The vehicle occupant detection system according to claim 8, wherein each of the sensor units consists of two triangular sensors mounted adjacent to each other to form a parallelogram. The vehicle occupant detection system according to claim 1, wherein the processing device includes an airbag system for generating a control signal for controlling the inflation of the airbag according to the position of the occupant in the vehicle. 2. The vehicle occupant detection system of claim 1, wherein each of the first, second, and third beams is at least 40 degrees wide and at least 3 degrees thick. The vehicle occupant detection system of claim 1, wherein each of the first, second, and third beams is spaced apart from each other by at least 10 degrees. A housing mounted to the vehicle structure; A laser array mounted inside the housing to generate a first beam oriented towards the upper region, a second beam oriented towards the middle region and a third beam oriented towards the lower region; A first sensor assembly that receives a reflected beam from the upper zone and generates a first signal proportionally representing a first portion of an occupant present in the upper zone; A second sensor assembly that receives a reflected beam from the intermediate zone and generates a second signal proportionally representing a second portion of the occupant present in the intermediate zone; Accepts a reflected beam from the lower zone and generates a third signal proportionally representing a third portion of the occupant present in the lower zone, the housing together with the first sensor assembly and the second sensor assembly; A third sensor assembly mounted therein; A central processing unit for receiving the first signal, the second signal, and the third signal to generate a control signal indicating a position of a passenger in the vehicle; And And an airbag system configured to receive the control signal so that the inflation of the airbag changes according to the position of the occupant within the vehicle. 14. The vehicle occupant detection system of claim 13, wherein each of the first, second, and third beams is at least 40 degrees wide and at least 3 degrees thick. The vehicle occupant detection system of claim 14, wherein each of the first, second, and third beams is spaced apart from each other by at least 10 degrees. The method of claim 15, wherein the size and shape of the first beam, the second beam, and the third beam are controlled, wherein the first beam is the upper region, the second beam is the middle region, and the third beam. And a lens mounted inside the housing to orient the light into the lower zone. Generating a first laser beam directed towards the first zone; Generating a second laser beam directed towards the second zone; Generating a third laser beam directed towards the third zone; Accepting a reflected beam resulting from the first laser beam when the first laser beam hits the part of the occupant in the first zone; Generating a first signal indicative of a first proportional body weight of the occupant in the first zone; Accepting a reflected beam resulting from the second laser beam when the second laser beam hits the part of the occupant in the second zone; Generating a second signal indicative of a second proportional body weight of the occupant in the second zone; Accepting a reflected beam resulting from the third laser beam when the third laser beam shines on the part of the occupant in the third zone; Generating a third signal indicative of a third proportional body weight of the occupant in the third zone; And And determining the occupant position in the vehicle by merging the first signal, the second signal, and the third signal. 18. The method of claim 17, comprising generating a control signal indicative of the occupant position in the vehicle and controlling the inflation of the airbag according to the control signal. 19. The method of claim 18, comprising the step of separating the first laser beam, the second laser beam, and the third laser beam from each other by at least 10 degrees. 20. The method of claim 19, wherein each laser beam comprises generating a light curtain having a width of at least 40 degrees and a thickness of 3 degrees.