JP2002537174A - Method and apparatus for sensing occupant weight - Google Patents

Abstract

(57) [Summary] An occupant weight measurement device is used to control the deployment of an airbag. This device is incorporated into a vehicle seat supported by the inner track assembly (26A) and the outer track assembly (26B). The inner and outer track assemblies are mounted to the vehicle structure such that the center is not supported. The first sensor assembly (38, 40) is attached to the inner track assembly (26A), and the second sensor assembly (58, 60) is attached to the outer track assembly (26). The first sensor assembly generates a first signal in response to measuring the deflection of the inner track assembly due to the occupant's weight. The second sensor assembly generates a second signal in response to measuring the deflection of the outer track assembly due to the occupant's weight. A central processor (66) determines a weight of the occupant based on the first and second signals. The central processor (66) communicates with the airbag device (70) and controls the deployment of the airbag according to the occupant's weight.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION

1. FIELD OF THE INVENTION The present invention relates to a method and apparatus for measuring the weight of an occupant. More specifically,
The sensor device is mounted in the vehicle's seat track to provide an accurate weight measurement of the occupant. 2. 2. Related Art Most vehicles are provided with airbags and seatbelt devices to protect drivers and passengers from being seriously injured in a high-speed collision. It is important to control the deployment force of the airbag and the force of the seatbelt pretensioner according to the size of the driver or passenger. One way to control these forces is to monitor the weight of the occupant. If there is a child, such as a child or infant, in the passenger seat, the weight on the seat is smaller than in an adult.

[0002] Current devices for measuring the weight of occupants are complex and expensive. One type of this device has a pressure sensitive foil mounted in a foam at the bottom of the seat. In some cases, sensors are arranged at a plurality of locations on the bottom of the seat. Combining the output from the mat or sensor gives the weight of the occupant. These sensors receive substantially vertical forces due to the occupant's weight, but also vertical and lateral forces caused by acceleration, deceleration or turning. The lateral and vertical forces sensed by the sensor introduce an error component into the weight measurement. Current occupant weight sensors use multiple strain gauges and complex bending elements to provide high measurement sensitivity in the vertical direction and low sensitivity to lateral and vertical forces, increasing accuracy. It is very elaborate.

[0003] Mounting these sensors in the seat bottom is not easy and time consuming. It is not easy to find the mounting position of each sensor, which not only gives accurate measurements, but also adapts to all the different postures of the occupant. Further, as the occupant moves on the seat, the sensors may leave or move out of position. Because these sensors are mounted in the seat bottom, it is difficult to change the position of the sensors after the seat is mounted on the vehicle.

[0004] It is therefore desirable to provide a simple occupant weight measurement device that is accurate and easy to install, and that overcomes the disadvantages of the prior art described above.

[0005]

Summary of the Invention

In the disclosed embodiment of the present invention, an occupant weight measurement device on a vehicle seat includes a truck assembly that uses the vehicle seat for support. This truck assembly
It comprises a first truck mounted on a vehicle structure and a second truck movably supported with respect to the first truck. These trucks can flex vertically due to the body gravity of the occupant sitting on the seat. These trucks are fitted with at least one sensor for generating a signal representative of the occupant's body gravity.

In a preferred embodiment, the track assembly comprises an inner track assembly and an outer track assembly spaced from the inner track assembly. The first sensor assembly is mounted on the inner truck assembly and generates a first signal in response to measuring the deflection of the inner truck assembly due to the occupant's weight. A second sensor assembly is mounted on the outer truck assembly and generates a second signal in response to measuring the deflection of the outer truck assembly due to the occupant's weight. This device comprises a first and a second
A central processor is used to determine the weight of the occupant based on this signal. The apparatus also preferably includes an airbag control module in communication with the processor. The deployment force of the airbag is controlled by the control module according to the weight of the occupant.

A method for measuring the weight of a seat occupant includes the following steps. The inner track assembly is mounted on the vehicle structure and the outer track assembly is mounted on the vehicle structure at a distance from the inner track assembly. The inner and outer track assemblies are defined by a predetermined cross-sectional area, each having at least one track portion having a cross-sectional area smaller than the predetermined cross-sectional area. The method includes attaching a first sensor assembly to a track portion of an inner truck assembly, attaching a second sensor assembly to a track portion of an outer truck assembly, and flexing the inner truck assembly due to the weight of the occupant. Generating a first signal from the first sensor assembly in response to the first sensor assembly; and generating a second signal from the second sensor assembly in response to the deflection of the outer track assembly due to the weight of the occupant; Combining the first and second signals to determine a weight of the occupant.

[0008] The method further includes providing a system controller for controlling the deployment force of the airbag and combining the first and second signals to generate a seat occupant weight signal. The weight signal of the occupant is transmitted to the controller, and the deployment force of the airbag is controlled according to the weight of the occupant. These and other features of the present invention will be best understood from the following description, which refers to the accompanying drawings.

[0009]

[Detailed description of embodiments]

The vehicle includes a vehicle seat assembly, generally indicated at 12 in FIG.
And The seat assembly 12 is a driver or passenger seat, and includes a seat back 16 and a seat bottom 18. When the occupant 20 sits on the seat 12, a vertical force Fv is applied to the seat bottom 18. The vertical force represents the weight of the occupant 20.

The airbag device 14 deploys the airbag 24 under a certain collision condition. The deployment force of the airbag 24 indicated by a chain line in FIG. The vehicle has a unique device for measuring the weight of the occupant 20. This unique device is mounted in a seat track assembly, indicated generally at 26 in FIG.

The seat truck assembly 26 has a first truck member 28 attached to a vehicle structure 30 such as, for example, a floor, frame or riser. The second track member 32 is movably supported along the longitudinal axis 34 with respect to the first track member 28. The first sensor 38 and the second sensor 40
, 32. The sensors 38, 40 are used to generate a signal representing the weight of the occupant. The first sensor 38 is the truck assembly 26
Preferably, the second sensor 40 is located at the front and the second sensor 40 is located at the front. First and second sensors 38, 40 are used to measure the deflection of the truck assembly 26 and generate that signal.

The first track member 28 has a front end 42 and a rear end 44 and has
A central portion 46 of the track extends between 2,4. Front end 42 and rear end 44
Is mounted on the vehicle structure 30 such that the central portion 46 is unsupported and a gap 48 is formed between the vehicle structure 30 and the central portion 46. The first track member 28 is mounted to a riser 50 having a support portion 52 extending upward at each end for mounting a front end 42 and a rear end 44 thereof.

Thus, the central portion 46 of the seat truck assembly 26 can flex under load. When the occupant sits on the seat 12, as shown in FIG. 3, a vertical force Fv is applied to the truck assembly 26, and a reaction force Fr acts in the opposite direction. These forces cause the central portion 46 to flex, as shown schematically at 54 in FIG. 3A, which reflects full bending beam behavior. The sensor is located at the center 4
Preferably, the strain gauges 38, 40 are arranged along 6, but other types of sensors known in the art may be used. For example, an optical fiber or a magnetoelastic sensor may be used.

The sensors 38, 40 are adapted to move the second track member 32 in a horizontal direction along the axis 34 so that the sensors 38, 40 are positioned on the unsupported track portion. 28 is preferred. As shown in FIG. 4, a plurality of ball bearings 56 are mounted between the track members 28 and 32 so that the second track member 32 can slide easily with respect to the first track member 28. Bearing 5
6 also transmits the force applied to the second track member 32 to a rigid track portion 46 between the two sensor locations.

As shown in FIG. 5, the seat 12 includes an inner track assembly 26 a of the vehicle structure 30 and an outer track assembly 26 separated from the inner track assembly 26 a by a predetermined distance.
b. The inner and outer track assemblies 26a, 26b are mounted with similar bending behavior. That is, both truck assemblies 26a, 26b can flex vertically due to the weight of the occupant. The inner and outer track assemblies 26a, 26b have first and second track members 28,32.

In one embodiment, first and second sensors 38, 40 are mounted on inner track assembly 26a, and third and fourth sensors 58, 60 are mounted on outer track assembly 26b. . The first and second sensors 38, 40 generate a first signal 62 indicative of the portion of the occupant's weight on the inner truck assembly 26a, and the third and fourth sensors 58, 60 provide an outer truck. A second signal 64 is generated that represents the weight portion of the occupant on assembly 26b. The signals 62, 64 are sent to an electronic control unit (ECU) 66, which combines these signals to determine the weight of the occupant 20. The ECU then sends a control signal 68 to the system controller 70. The system controller 70 is preferably an airbag control module that is in communication with the ECU 66 and controls the deployment force of the airbag 24 according to the weight of the occupant. The system controller 70 can also be used to control the force of the seat belt tensioning device according to the weight of the occupant.

The above arrangement is preferred, but is optionally attached to the inner track assembly 26a and generates a first signal 62 in response to measuring the deflection of the inner track assembly 26a due to the occupant's weight. Sensor assembly and outer track assembly 26
b and a second sensor that generates a second signal 64 in response to the measurement of deflection of the outer track assembly 26b due to the occupant's weight.

As shown in more detail in FIG. 6, the track assembly 26 has a predetermined cross-sectional area defined by the height H 1. The portion of each track assembly 26 indicated generally by reference numeral 70 has a cross-sectional area defined by H2 that is less than a predetermined cross-sectional area H1. Each track assembly 26a, 26b has two track portions 72 having this small cross-sectional area. One sensor assembly 38, 40, 58, 60 is attached to each track portion 72. FIG. 6 shows only the first sensor assembly 38. As the track assembly 26 flexes under load, the sensor assembly 38 measures the complete bending beam behavior 54, as shown in FIG. Thus, sensors 38 at four locations
, 40, 58, 60 act as a Wheatstone bridge to measure deflection. The operation of a Wheatstone bridge is well known in the art.

A track section 72 having a small cross-sectional area is provided by forming a square hole in the first track member 28. These holes constitute a double beam spring element. When such elements are placed on the inner and outer track assemblies 26a, 26b,
The vertical force Fv on the area between the two sets of track members 26a, 26b can be measured.

The method for measuring the weight of the occupant includes the following steps. Inner truck assembly 26a
Is mounted on the vehicle structure 30, and the outer track assembly 26b is mounted on the vehicle structure 30 at a distance from the inner track assembly 26a. The inner and outer track assemblies 26a, 26b are defined by an area H1 of a predetermined cross-sectional area, and each track assembly 26a, 26b has at least one track portion 72 having a cross-sectional area H2 smaller than the predetermined cross-sectional area H1. . The method includes attaching the first sensor assembly to the track portion 72 of the inner track assembly 26a,
Attaching the second sensor assembly to the track portion 72 of the vehicle. The first signal 62 is responsive to deflection of the inner track assembly 26a due to the weight of the occupant,
Generated by the first sensor assembly. The second signal 64 is generated by the second sensor assembly in response to the deflection of the outer track assembly 26b due to the occupant's weight. The first and second signals 62, 64 are used to determine the weight of the occupant.

As a further step, a system controller 70 for controlling deployment of the airbag 24 is provided and combines the first and second signals 62, 64 to generate a occupant weight signal 68. The weight signal of the occupant is sent to the controller, and the deployment force of the airbag is controlled according to the weight of the occupant.

As another step, a front end 42 and a rear end 44 are provided by inner and outer track assemblies 26 a, 26 b interconnected by a central portion 46, wherein the front end 42 and the rear end 44 are connected to each track. There is the step of securing the central portion 46 of the assemblies 26a, 26b to the vehicle structure 30 so that it is not supported. The track portion 72 is preferably located at the central portion 46.

As described above, the first sensor assembly is the first sensor assembly of the inner track assembly 26a.
Preferably, it comprises first and second sensors 38, 40 mounted on the track member 28. The second sensor assembly preferably comprises third and fourth sensors 58, 60 mounted on the first track member 28 of the outer track assembly 26b.

The seat truck assembly 26 with integrated weight sensors 38, 40, 58, 60 is provided for measuring the weight of the occupant 20 on the vehicle seat 12. Sensors 38, 40, 58, and 60 are preferably integrated into seat truck assembly 26 because they are a common part of most vehicle seats 12. The weighing system of the present invention can be easily integrated into any type of seat truck structure. Weight sensors 38, 40, 58, 60 are mounted in the smaller track portion 72 to measure the deflection of the track material due to the weight of the occupant 72. The measured weight is independent of the seat position and is accurately measured regardless of the various postures of the occupant on the seat 12.

Calculating the occupant's weight proportional to the sum of all sensors 38, 40, 58, 60 by measuring the deflection at all four locations of the inner and outer track assemblies 26a, 26b can do. The center of gravity of the upper part of the seat and the occupant can be calculated by subtracting the sum of the front sensor signals from the sum of the rear sensor signals and dividing the result by the sum of all four signals. .
The electronics for signal conditioning can be housed within the truck assemblies 26a, 26b, as is well known in the art.

Under a large overload, the truck assembly 26 is subjected to a large vertical force Fv and a horizontal force Fh. These forces exert an overloaded resultant force Fre on the truck, which tends to separate the truck 26 from the floor 30. In applications with large overloads, such as an integrated or all seated belt configuration, it is advantageous to incorporate active overload protection. In such a protection method, as shown in FIG.
An overload bolt 74 extending to zero is used. This bolt 74 prevents the truck assembly 26 from separating from the floor 30 under high vehicle impact. Therefore, the area 72 having a small cross-sectional area does not need to support the entire impact force.

While the preferred embodiment of the invention has been described, it will be apparent to those skilled in the art that many modifications and variations can be made within the scope of the invention. Therefore, in order to determine the true scope of the invention, it is necessary to review the appended claims.

[Brief description of the drawings]

FIG. 1 shows an airbag device and a vehicle in a state where a occupant is sitting in a seat with an airbag, and the airbag is in an operating state as shown by a dashed line.

FIG. 2 is a side view of a seat assembly incorporating the weight measurement system of the present invention.

FIG. 3 is a side view of the seat truck assembly of FIG. 2;

FIG. 3A is an enlarged view of a portion 3A shown in FIG. 3;

FIG. 4 is a cross-sectional view of the truck assembly taken along line 4-4 of FIG.

FIG. 5 is a schematic diagram showing a control device of the weight measuring device of the present invention.

FIG. 6 is a schematic diagram of a sensor mounted within the truck assembly of the present invention.

FIG. 7 is a schematic diagram illustrating a complete bending bridge.

FIG. 8 is a schematic diagram showing a sensor mounted in a truck assembly of the present invention with an overload mechanism.

[Procedural Amendment] Submission of translation of Article 34 Amendment

[Submission date] April 30, 2001 (2001.4.30)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Contents of correction]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Contents of correction]

[0004] DE-A-3809074 (Audi AG) provides a seat sensor that determines the position of a passenger based on the weight distribution of the passenger and controls the deployment of the airbag. Accordingly, it is desirable to provide a simple occupant weight measurement device that is highly accurate and easy to install, and that overcomes the disadvantages of the prior art described above.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Contents of correction]

According to a first aspect of the present invention, there is provided an apparatus for controlling deployment of an airbag of a vehicle according to a measured weight of a occupant, comprising: a first truck mounted on a vehicle structure; A second track deflectable vertically by the body gravity of the occupant and movably supported with respect to the first track; and measuring the deflection due to the weight of the occupant mounted on the first track. An airbag provided in cooperation with the vehicle structure, comprising at least one sensor for generating a weight signal according to claim 1, a processor for receiving the signal, and an airbag control module in communication with the processor, An airbag deployment control device that is operated and deployed with a deployment force according to a weight is provided. Therefore, when a child is sitting on the passenger seat, such as a child or an infant, the weight on the seat is taken into account.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Contents of correction]

In a preferred embodiment, the track assembly comprises an inner track assembly and an outer track assembly spaced from the inner track assembly. A first strain gauge assembly is mounted on the inner track assembly and generates a first signal in response to measuring the deflection of the inner track assembly due to the occupant's weight. A second strain gauge assembly is mounted on the outer track assembly and generates a second signal in response to measuring the deflection of the outer track assembly due to the occupant's weight. This device comprises a first and a second
A processor that determines the weight of the occupant based on the signal of the occupant is used. This device also
Preferably, an airbag control module is provided in communication with the processor.
The deployment force of the airbag is controlled by the control module according to the weight of the occupant.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Contents of correction]

In accordance with yet another aspect of the present invention, a first track attachable to a vehicle structure and a vertically deflectable body gravitational force of a occupant and movably supported with respect to the first track. A second truck supporting the seat, at least one strain gauge mounted on one of the trucks for generating a weight signal in response to deflection by the occupant's weight, a processor receiving the signal, and a processor. An airbag control module, which is in communication with the airbag device, is configured so that the airbag provided in cooperation with the vehicle structure operates and deploys with a deployment force according to the weight of the occupant. Controlling the deployment of an airbag in a vehicle, wherein when a occupant of a particular weight sits on the seat, the weight is output from the first strain gauge in response to the deflection of the truck due to the weight of the occupant. Generating a signal, transmitting a weight signal to the processor, and transmitting a control signal to the airbag in accordance with the determined occupant's weight. Is provided.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Demeyer, Joseph Bodenwald, Germany 92439 Waldstraße 9 F term (reference) 3B087 DE08 3D054 EE02 EE10 EE27 EE36

Claims (18)

[Claims] An apparatus for measuring the weight of a occupant on a seat of a vehicle, comprising: a first truck mounted on a vehicle structure; And a second track movably supported with respect to the first track, and at least one sensor mounted on one of the tracks for generating a signal representative of the body gravity of the occupant. 2. The apparatus of claim 1, further comprising a central processor for receiving said signal. 3. The apparatus of claim 2, further comprising an airbag control module in communication with the processor, wherein the deployment force of the airbag is controlled by the control module in response to the occupant's weight. 4. A first track having a front end, a rear end, and a central portion extending between these ends, wherein the front end and the rear end are centrally unsupported with the vehicle structure. 4. The device of claim 3, wherein the device is mounted to the vehicle structure such that a gap is formed between the parts. 5. The apparatus of claim 4, wherein the sensors are located along a center of the truck. 6. The at least one sensor comprises a first sensor located at the front of the center of the truck, and a second sensor located at the rear of the center of the truck, wherein the first and second sensors are located at the rear of the center. 6. The apparatus of claim 5, wherein the sensor measures the deflection of the second track to generate the signal. 7. A third truck mounted on the vehicle structure, and a fourth truck deflectable vertically by the body gravity of the occupant and movably supported with respect to the third truck. A third sensor mounted on the third or fourth track and cooperating with the first and second sensors to generate the signal, the first and second tracks including an inner track assembly. 7. The apparatus of claim 6, wherein the third and fourth tracks form an outer track assembly. 8. An apparatus for measuring the weight of a occupant on a vehicle seat, comprising: an inner truck assembly mounted on the vehicle structure; and an outer truck mounted on the vehicle structure spaced apart from the inner truck assembly. A truck assembly, a first sensor assembly attached to the inner truck assembly, the sensor assembly generating a first signal in response to a measurement of deflection of the inner truck assembly due to the weight of the occupant; and an outer truck assembly. A second sensor mounted on the second sensor for generating a second signal in response to a measurement of the deflection of the outer track assembly due to the weight of the occupant; and detecting a weight of the occupant based on the first and second signals. A weight measuring device comprising a central processor for determining. 9. The inner and outer track assemblies have a predetermined cross-sectional area, and each track assembly has at least one track portion having a cross-sectional area smaller than the predetermined cross-sectional area, and first and second track assemblies. 9. The apparatus of claim 8 wherein said sensor assembly is mounted on said track portion. 10. The inner and outer track assemblies each have a front end, a rear end, and a center portion extending between the ends, the ends being unsupported in the center of the vehicle structure. 10. The apparatus of claim 9, wherein the apparatus is mounted to a vehicle structure such that a gap is formed between the vehicle assembly and the truck assembly. 11. The apparatus of claim 10, wherein said track portion having a smaller cross-sectional area than said predetermined cross-sectional area is centrally located. 12. At least one track portion of each track assembly comprises a first track portion located at the front of the center and a second track portion located at the rear of the center. 11. The apparatus of claim 10, wherein each of the first and second sensor assemblies has a first sensor mounted on the first track portion and a second sensor mounted on the second track portion. 13. The apparatus of claim 10, further comprising an airbag control module in communication with the processor, wherein the deployment force of the airbag is controlled by the control module in response to the occupant's weight. 14. A method for measuring the weight of a seat occupant, comprising: an inner truck assembly mounted on a vehicle structure; and an outer truck assembly mounted on the vehicle structure at a distance from the inner truck assembly. Providing an inner and outer track assembly having at least one track portion each defined by a predetermined cross-sectional area, each having a cross-sectional area smaller than said predetermined cross-sectional area; Mounting the second sensor assembly on the track portion of the outer track assembly; and displacing the first sensor assembly from the first sensor assembly in response to deflection of the inner track assembly due to the occupant's weight. Generating a second signal from the second sensor assembly in response to deflection of the outer track assembly due to the weight of the occupant; And determining the weight of the occupant by combining the signals of the weights. 15. A system controller for controlling deployment of an airbag, comprising combining a first signal and a second signal to generate a occupant weight signal and transmitting the occupant weight signal to the controller. 15. The method of claim 14, including controlling the deployment force of the airbag in response to the occupant's weight. 16. An inner and outer track assembly having a front end and a rear end interconnected by a central portion, wherein the front end and the rear end are positioned such that the central portion of each track assembly is not supported. The method of claim 14 including the step of securing to the structure. 17. The method of claim 16 including the step of centering the track portion. 18. A first sensor assembly comprising: a first sensor mounted at a rear portion of the inner track assembly; and a second sensor mounted at a front portion of the inner track assembly. 15. The method of claim 14, wherein said sensor assembly comprises a third sensor mounted at a rear portion of the outer track assembly and a second sensor mounted at a front portion of the outer track assembly.