JP2013154667A - Device for determining object placed on vehicle seat - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for determining an object placed on a vehicle seat, configured to discriminate an occupant seated on the seat from an article placed thereon with a simple constitution.SOLUTION: A device 1 for determining an object placed on a vehicle seat determines an occupant or an article on the vehicle seat 100, and includes an electrode 2 provided on the vehicle seat, an acquisition means for acquiring a value on electrostatic capacity based on an output of the electrode, and a determination means which determines that an occupant is seated on the vehicle seat, and that any article is placed on the vehicle seat on the basis of a valued on the electrostatic capacity when the occupant or the article exists on the vehicle seat. The determination means determines that the occupant is seated when a variation range of the value on the electrostatic capacity is equal to or larger than a predetermined value, and determines that the article is placed when the variation range of the value on the electrostatic capacity is below the predetermined value.

Description

  The present invention relates to a vehicle seated object discriminating apparatus. More particularly, the present invention relates to a vehicle seated object discriminating device that can discriminate between the seating of an occupant on a seat and the placement of an article with a simple configuration.

It is known to detect whether a passenger is seated on a seat in a vehicle such as a passenger car. In the vehicle airbag device, there is a case where the airbag is controlled to be in a state where the airbag can be deployed or a state where the airbag cannot be deployed, based on detection information on the presence or absence of seating.
A state in which the airbag is required to be undeployable includes a state in which an article such as a child seat is installed on the seat. For this reason, an apparatus for discriminating between the seating of an occupant and the installation of a child seat as an article has been proposed (see, for example, Patent Document 1).

JP 2000-16233 A

In the above-mentioned Patent Document 1, the seating of the occupant and the installation of the child seat are the result of the vibration detection means for detecting the vibration of the seat, and the result of the distance detection means for detecting the distance from the predetermined position in the passenger compartment to the object on the seat. To determine.
However, when detecting vibration, there is a possibility that the detection result may be affected by vibration due to road noise and erroneous detection may occur. In addition, since the vibration detecting unit and the distance detecting unit are used in combination, there is a problem that the configuration is complicated and the cost of the apparatus itself is high.

  In view of the above circumstances, an object of the present invention is to provide a vehicle seated object discriminating device that can discriminate between the seating of an occupant on a seat and the placement of an article with a simple configuration.

In order to solve the above-mentioned problems, the invention according to claim 1 is a vehicle seat placement object discrimination device for discriminating an occupant or an article on a vehicle seat, comprising: an electrode provided on the vehicle seat; An acquisition means for acquiring a value related to capacitance based on the output of the electrode; and when the occupant or the article is present on the vehicle seat, based on the value related to the capacitance, A discriminating unit for discriminating whether an occupant is seated on the seat and an article is placed on the vehicle seat, wherein the discriminating unit has a predetermined fluctuation range of the capacitance value; When the value is equal to or greater than the value, it is determined that an occupant is seated on the vehicle seat, and when the fluctuation range of the value related to the capacitance is less than a predetermined value, an article is placed on the vehicle seat. It is determined that it is placed The the gist.
The invention according to claim 2 is summarized in that, in claim 1, the electrode is provided in a seat portion of the vehicle seat.
A third aspect of the present invention is summarized in that, in the first or second aspect, the electrode is a conductive yarn woven into a fabric constituting a skin of the vehicle seat.

According to the vehicle seat mounted object discriminating device of the present invention, the value related to the capacitance based on the output of the electrode provided on the vehicle seat is acquired, and based on the fluctuation range of the value related to the capacitance, It is determined whether an occupant is seated on the seat and whether an article is placed on the vehicle seat.
In the present invention, in order to discriminate between the seating of an occupant and the installation of an article, attention is paid to the fluctuation range of values related to capacitance. There is little difference in the capacitance generated in the electrode between when an occupant is seated on the vehicle seat provided with the electrode and when an article such as a child seat is installed, and the value related to the acquired capacitance is large. In some cases, it may be an approximation. In particular, in the case of a small woman (for example, the occupant model AF05), the value may be very close to that when a child seat is installed. However, when the occupant is seated, the capacitance varies relatively greatly due to the variation of the contact area caused by the movement of the occupant directly touching the vehicle seat, and the variation of the value related to the capacitance also increases. . On the other hand, when an article such as a child seat is installed, the contact area between the article and the vehicle seat hardly changes, so that the fluctuation range of the value related to the capacitance is relatively small. In particular, when the article is a child seat, the passenger (infant) on the child seat does not touch the vehicle seat directly, and even if the passenger on the child seat moves, the contact area between the child seat and the vehicle seat is Since it hardly changes, the fluctuation range of the value related to the capacitance is relatively small.
Therefore, in the vehicle seat placement object discriminating apparatus of the present invention, it is possible to easily discriminate between the seating of an occupant and the installation of an article on the vehicle seat with a simple configuration. Further, as compared with the case where two of the vibration detection unit and the distance detection unit are used, the configuration can be simplified and the device can be manufactured at low cost.

  In addition, when the electrode is provided on the seat of the vehicle seat, since both the occupant and the article are in contact with the seat on the vehicle seat, the seating of the occupant and the installation of the article are more reliably performed. Can be determined.

  Furthermore, when the electrode is a conductive yarn woven into the fabric constituting the skin of the vehicle seat, the seated occupant will not be uncomfortable, and the texture and breathability of the seat will not be impaired. In addition, since the electrode is formed integrally with the skin of the vehicle seat, the electrode assembly process is not necessary, as compared with the case where the electrode of the member separate from the vehicle seat member is provided. Workability can be improved.

The present invention is further illustrated by the following detailed description with reference to a number of referenced drawings, given non-limiting examples of exemplary embodiments according to the present invention, wherein like reference numerals denote Similar parts are shown throughout the figure.
It is a figure which shows typically schematic structure of the vehicle seat mounted article discrimination | determination apparatus which concerns on an Example. It is a circuit diagram which shows the structure of the acquisition means and discrimination | determination means concerning an Example. It is a flowchart which shows the control method of the vehicle seat mounted article discrimination | determination apparatus which concerns on an Example. It is a graph which shows the time change of a phase difference, (a) shows the case where a passenger | crew is seated in the vehicle seat, (b) shows the case where the child seat is installed in the vehicle seat, respectively.

  The items shown here are for illustrative purposes and exemplary embodiments of the present invention, and are the most effective and easy-to-understand explanations of the principles and conceptual features of the present invention. It is stated for the purpose of providing what seems to be. In this respect, it is not intended to illustrate the structural details of the present invention beyond what is necessary for a fundamental understanding of the present invention. It will be clear to those skilled in the art how it is actually implemented.

  The vehicle seat placement object discrimination device (1) of the present invention is a device for discriminating an occupant or an article on a vehicle seat (100). The vehicle seated object discriminating device includes an electrode (2) provided on the vehicle seat, an acquisition means for acquiring a value related to the capacitance based on the output of the electrode, and an occupant or an article on the vehicle seat. In this case, a determination unit that determines whether an occupant is seated on the vehicle seat and whether an article is placed on the vehicle seat based on a value related to the capacitance is provided. The determining means determines that the passenger is seated on the vehicle seat when the variation range of the value related to the capacitance is equal to or greater than the predetermined value, and the variation range of the value related to the capacitance is less than the predetermined value. If it is, it is determined that the article is placed on the vehicle seat.

Examples of the “vehicle seat” include general vehicle seats such as a passenger seat and a rear seat of a passenger car.
Examples of the “article” include child seats and luggage such as bags.
The configuration, shape, size and the like of the “electrode” are not particularly limited. Examples of the form of the electrode include a form that is a conductive yarn woven into a cloth constituting a skin of a vehicle seat, a form that is a flat plate formed of a conductive material, and the like. Moreover, as a site | part of the vehicle seat provided with this electrode, the seat cushion (101) used as a seat part, the seat back (102) used as a backrest, etc. can be mentioned, for example.
Examples of the “conductive yarn” include metal wires and conductive fibers whose surfaces are coated with metal.

  The configurations of the “acquisition unit” and the “discrimination unit” are not particularly limited. These can be constituted, for example, by an electronic control unit (ECU) (3). The “value relating to the capacitance” may be a value of the capacitance itself generated between the electrode and the occupant or the article, or generated between the electrode and the occupant or the article. Other values that vary depending on the capacitance value may be used.

  The acquisition means includes, for example, an oscillation circuit (31) that supplies an AC voltage having a predetermined frequency to the electrodes via the resistance element (32), and a comparison circuit (33) that compares the phases of the AC voltage applied to both ends of the resistance element. ) And a central processing unit (CPU) (34) that controls these and inputs the comparison result of the comparison circuit (for example, FIG. 2 and the like). reference). In the acquisition means having such a configuration, the difference between the phase of the supply voltage (V0) from the oscillation circuit and the phase of the voltage (V1) affected by the capacitance generated in the electrode is acquired. The voltage on the electrode side of the resistance element is delayed with respect to the phase of the supply voltage serving as a reference in accordance with the magnitude of the capacitance generated in the electrode. Thereby, this phase difference (PD) can be set to a “value relating to capacitance”.

  Hereinafter, the present invention will be specifically described with reference to the drawings. In the present embodiment, a vehicle seat placement object discrimination device provided in a passenger seat as a vehicle seat is illustrated. In this embodiment, a child seat is illustrated as an article according to the present invention.

(1) Configuration of Vehicle Seat Placed Object Discriminating Device The vehicle seat placed object discriminating device 1 according to this embodiment is a device that discriminates an occupant or a child seat on the vehicle seat 100. As shown in FIG. 1, the vehicle seated object discrimination device 1 includes an electrode 2 provided on the vehicle seat 100 and an electronic control unit (ECU) 3 electrically connected to the electrode 2. ing.
As shown in FIG. 1, the vehicle seat 100 includes a seat cushion 101 serving as a seat portion and a seat back 102 serving as a backrest portion, and is fixed to a vehicle floor by a seat frame (not shown). Each of the seat cushion 101 and the seat back 102 is formed by disposing a foamed urethane cushion material on a seat frame and covering the fabric with a skin.
In the present embodiment, the electrode 2 is provided on the seating surface side of the seat cushion 101 and is a conductive yarn woven into the fabric constituting the skin of the seat cushion 101.

The ECU 3 functions as an acquisition unit and a determination unit according to the present invention. As shown in FIG. 2, these means are realized by the ECU 3 being configured to include an oscillation circuit 31, a resistance element 32, a comparison circuit 33, and a central processing unit (CPU) 34. Is done.
The oscillation circuit 31 supplies an AC voltage V 0 having a predetermined frequency to the electrode 2 through the resistance element 32. The comparison circuit 33 detects and compares the phases of the voltage V0 on the oscillation circuit 31 side of the resistance element 32 and the voltage V1 on the electrode 2 side. The CPU 34 obtains the phase difference PD between the voltage V0 and the voltage V1 output from the comparison circuit 33, and confirms that an occupant or a child seat exists on the vehicle seat 100. In the present embodiment, the phase difference PD is a value related to the capacitance.

  When there is an occupant or a child seat on the vehicle seat 100, the CPU 34 confirms that the occupant is seated on the vehicle seat 100 based on the acquired phase difference PD and that the child seat is placed on the vehicle seat 100. It is determined that it has been placed. This determination is made based on the fluctuation range FR of the phase difference PD. Specifically, when the fluctuation range FR of the phase difference PD is greater than or equal to a predetermined value, it is determined that an occupant is seated on the vehicle seat 100, and the fluctuation range FR of the phase difference PD is less than the predetermined value. In this case, it is determined that the child seat is placed on the vehicle seat 100.

  In addition, the vehicle seat mounted item discrimination device 1 according to the present embodiment is connected to an airbag ECU 4 as shown in FIG. The airbag ECU 4 receives the determination result from the ECU 3, and based on the determination result, the airbag can be deployed when the occupant is seated, and the airbag is deployed when the child seat is installed. Control to disable.

(2) Control Method of Vehicle Seat Placed Object Discrimination Device Next, a control method of the vehicle seat placement object discrimination device 1 having the above-described configuration will be described with reference to the flowchart of FIG.
First, in step S100, it is confirmed whether or not the phase difference PD is greater than or equal to a predetermined value. When there is an object such as an occupant or a child seat on the vehicle seat 100, the value of the phase difference PD is larger than that in the case of a vacant seat. Therefore, if it can be confirmed that the phase difference PD is greater than or equal to a predetermined value, the vehicle It can be determined that there is an occupant or child seat on the safety seat 100. If the phase difference PD is greater than or equal to the predetermined value, it is determined that there is an object on the vehicle seat 100, and the process proceeds to step S110.

In step S110, it is confirmed whether or not the fluctuation range FR of the phase difference PD is greater than or equal to a predetermined value. As shown in FIGS. 4A and 4B, when the child seat is installed, the value of the phase difference PDc acquired is close to the value of the phase difference PDp acquired when the occupant is seated. Sometimes. For this reason, it is difficult to discriminate between the seating of the passenger and the installation of the child seat based on the value of the phase difference PD. However, when the occupant is seated, the occupant directly touches the vehicle seat 100 and moves on the vehicle seat 100. Therefore, as shown in FIG. 4A, the phase difference PDp has a relatively large width FRp. Fluctuates in time. On the other hand, when the child seat is installed, since the infant (occupant) on the child seat does not directly touch the vehicle seat 100, the temporal variation width FRc of the phase difference PDc as shown in FIG. 4B. Is relatively small. Thus, the seating of the occupant and the installation of the child seat can be discriminated based on the magnitude of the temporal fluctuation width FR of the phase difference PD.
Therefore, when the fluctuation range FR of the phase difference PD is greater than or equal to a predetermined value in step S110, it is determined that the passenger is seated (step S120), and the fluctuation range FR of the phase difference PD is not greater than or equal to the predetermined value. It is determined that the child seat is installed (step S130).
Finally, in step S140, the determination result is output to the airbag ECU.

(3) Effects of Example As described above, according to the vehicle seat mounted object discriminating apparatus 1 of the present example, the electrode 2 is provided on the vehicle seat 100, and the value relating to the capacitance based on the output of the electrode 2 is The phase difference PD is acquired, and it is determined based on the fluctuation range FR of the phase difference PD that an occupant is seated on the vehicle seat 100 and a child seat is placed on the vehicle seat 100. I am doing so. As a result, it is possible to determine whether the occupant is seated on the vehicle seat 100 and the child seat is installed with a simple configuration. Further, as compared with the case of using the vibration detection unit and the distance detection unit, the configuration can be simplified and the device can be manufactured at low cost.

  Further, in the above embodiment, since the electrode 2 is provided on the seat cushion 101 serving as the seat portion of the vehicle seat 100, both the passenger and the child seat are in contact with the seat cushion 101 on the vehicle seat 100. Thus, it is possible to more reliably determine the seating of the occupant and the installation of the child seat.

  Furthermore, in the above embodiment, since the electrode 2 is a conductive thread woven into the fabric constituting the skin of the vehicle seat 100, the seated passenger is not given a sense of incongruity, and the texture and ventilation of the seat There is no loss of sex. In addition, since the electrode 2 is formed integrally with the skin of the vehicle seat 100, an electrode assembly process is not required as compared with the case where the electrode of a member separate from the vehicle seat member is provided. Workability at the time can be improved.

  In the present invention, the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention depending on the purpose and application. That is, in the above-described embodiment, the electrode 2 is provided on the seat cushion 101. However, the present invention is not limited to this. For example, the electrode 2 may be provided on the seat back 102, or the seat cushion 101 and the seat back 102 may be provided. Alternatively, the electrodes 2 may be provided on both.

  The foregoing examples are for illustrative purposes only and are not to be construed as limiting the invention. Although the invention has been described with reference to exemplary embodiments, it is to be understood that the language used in the description and illustration of the invention is illustrative and exemplary rather than limiting. As detailed herein, changes may be made in its form within the scope of the appended claims without departing from the scope or spirit of the invention. Although specific structures, materials and examples have been referred to in the detailed description of the invention herein, it is not intended to limit the invention to the disclosure herein, but rather, the invention is claimed. It covers all functionally equivalent structures, methods and uses within the scope.

  The present invention is not limited to the embodiments described in detail above, and various modifications or changes can be made within the scope of the claims of the present invention.

  This is suitably used as a technique for determining whether an occupant is seated on a vehicle seat such as an automobile or an article is installed.

  DESCRIPTION OF SYMBOLS 1; Vehicle seat mounted object discrimination apparatus, 100; Vehicle seat, 101; Seat cushion, 102; Seat back, 2; Electrode, 3: Electronic control unit (ECU), 31; Oscillation circuit, 32; Resistance element, 33 Comparison circuit, 4: airbag ECU, FR: fluctuation range of phase difference PD, FRc; fluctuation range of phase difference when child seat is installed, FRp; fluctuation range of phase difference when passenger is seated, PD; Phase difference between voltages V0 and V1, PDc; phase difference when a child seat is installed, PDp; phase difference when a passenger is seated.

Claims (3)

A vehicle seat mounted item discrimination device for discriminating an occupant or an article on a vehicle seat,
An electrode provided on the vehicle seat;
Obtaining means for obtaining a value relating to capacitance based on the output of the electrode;
When the occupant or the article is present on the vehicle seat, the occupant is seated on the vehicle seat and the article is placed on the vehicle seat based on the value related to the capacitance. And determining means for determining
The determining means determines that an occupant is seated on the vehicle seat when the fluctuation range of the value related to the capacitance is equal to or larger than a predetermined value;
The vehicle seat placement object discriminating device, wherein when the fluctuation range of the value related to the capacitance is less than a predetermined value, it is discriminated that an article is placed on the vehicle seat.   The vehicle seat placement object discriminating device according to claim 1, wherein the electrode is provided on a seat portion of the vehicle seat.   3. The vehicle seat placement object discriminating device according to claim 1, wherein the electrode is a conductive yarn woven into a fabric constituting a skin of the vehicle seat.

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