JPS63159158A - Detection device for seat belt fitting - Google Patents

Abstract

PURPOSE:To detect fitting or no-fitting of a seat belt with high reliability by detecting the electrostatic capacity between the first electrode provided on at least one part of a seat belt and the second electrode disposed on a seat. CONSTITUTION:Non-electrolytic nickel plating is applied to the inner core of parts A, B of a seat belt 10 making contact with a human body to form the first electrode 10a. On the other hand, the second electrodes ELFR, ElFR made of electrically conductive cloth formed by making non-electrolytic mickel plating on cloth are incorporated in the portions touching human bodies staying on the seat cusion SCFR of a front seat STFR and seat back SBFR. And electrostatic capacity between the first electrode 10a and the second electrodes ELFR/ElFR is detected and either fitting or non-fitting of a seat belt is detected by a change in the electrostatic capacity since this capacity changes by existence of human body between the seat belt 10 and the front seat STFR. Thus, fitting or non- fitting of a seat belt can be detected with high reliability.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a device for detecting whether a seat belt is fastened or not.

(Prior Art) For example, a vehicle is equipped with a seat belt device that restrains an occupant on a vehicle seat to prevent the occupant from colliding with a steering wheel or the like in the event of a vehicle emergency. This type of seat belt device is an essential device for ensuring the safety of occupants, and when an occupant gets into the vehicle, the occupant fastens the seat belt by engaging the tongue plate and buckle provided on the seat belt device.

However, since the occupant must perform this type of operation to fasten/unfasten the seat belt every time the passenger gets on or off the vehicle, he or she may often forget to fasten the seat belt.

Therefore, as a solution to this kind of inconvenience, for example, a mounting detection switch is provided that turns on (or off; hereinafter omitted) when the tongue plate is engaged with the buckle of the seat belt device. ) has been proposed, and if the attachment detection switch is off, an alarm device such as a warning lamp or a buzzer is energized for a predetermined period of time to notify that the attachment has been forgotten.

(Problems to be Solved by the Invention) Generally, a vehicle has multiple seats such as a passenger seat in addition to the driver's seat, and each seat is equipped with a seat belt device. The system may also detect that the seatbelt of a seat that is not occupied is not being fastened. Therefore, in many of this type of forget-to-wear prevention devices, the warning device is deenergized when the wearing detection switch of any seat belt device is turned on after the ignition switch is turned on.

Therefore, for example, if the driver removes the seatbelt and gets out of the vehicle with the engine running, even if the driver forgets to put it on the next time they get in the vehicle, this will not be detected.

In addition, especially in the rear seats, seat belt devices are often set to the fastened state even when no one is seated in order to organize the seat belt system, but in this way, the seat belt is not actually worn by the seat belt. Sometimes, when the tongue plate is engaged with the buckle, the attachment detection switch is turned on, so forgetting to attach the device is not detected.Therefore, people may consider the alarm to be a nuisance and use this to their advantage to intentionally detect attachment. Some drivers keep the switch on.

As described above, conventionally, the seatbelt attachment is detected simply by the engagement between the buckle and the tongue plate, which is unreliable, and people still occasionally forget to attach the seatbelt.

SUMMARY OF THE INVENTION An object of the present invention is to provide a seat belt attachment detection device that can detect whether or not the seat belt is attached in a manner capable of protecting a seated person.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the seat belt attachment detection device of the present invention is capable of attaching/unattaching it freely, and in the attached state, at least part of the person seated on the seat a seat belt that restrains a person; a first electrode installed on at least a portion of the seat belt; and with the seat belt worn, at least a portion of the person seated on the seat is placed between the seat belt and the first electrode; , a second electrode insulated from the first electrode; capacitance detection means for detecting capacitance between the first electrode and the second electrode; detection capacitance of the capacitance detection means; Detects whether the seat belt is fastened when a predetermined change occurs.
Signal processing means;

(Function) According to this, when the seat belt is worn, the first electrode and the second electrode form a capacitor with at least a portion of the person seated on the seat placed between them. Since the human body has a high dielectric constant (approximately 80), the capacitance of the capacitor, that is, the electrostatic capacity between the first and second electrodes, depends on whether or not the person is wearing a seat belt correctly. Capacity changes. In other words, since this capacitance is monitored, it is possible to accurately detect whether the seat belt is being worn in a manner that can protect the seated person.

For example, even if the buckle of the on-vehicle seat belt device is engaged and the detection switch is turned on, according to the present invention, if the person is not actually wearing the seat belt at that time, the first W1 pole and Since the capacitance between the two electrodes does not change within a predetermined range, whether or not the device is attached is not detected. Therefore, the reliability of detecting whether a seat belt is worn or not is high.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

FIG. 1 shows an on-vehicle seat belt device according to an embodiment of the present invention. Figure 1 is a side view of the driver's seat (hereinafter referred to as FR seat, meaning the front right side; the subscripts have the same meaning) of the vehicle, as seen from inside the vehicle. The figure shows the state in which the seatbelt is worn, with the tongue plate 11 movably engaged with the seatbelt 10 engaged with the buckle 17.

The buckle 17 is fixed to the vehicle body via an extension rod 18.

The details of the tongue plate 11 and buckle 17 are shown in the 28th page.
As shown in the figure. Belt through hole 11a in tongue plate 11
and llb are provided, through which the seat belt 10 is passed as shown in FIG. 2b. When the tongue lla of the tongue plate 11 is inserted into the insertion opening 17a of the buckle 17, the latch mechanism inside the buckle 17
By biting a, the tongue plate 11 and buckle 17 are joined. Furthermore, when the pressure knob 17b is pressed down, the latch mechanism is released, so the tongue plate 11
The connection between the buckle 17 and the buckle 17 is released.

Referring again to FIG. 1, one end of the seat belt 10 is
Hanging ring 1 swingably engaged with the upper part of the center pillar of the vehicle
3 and enters the center pillar PLA through the opening 14 of the center pillar PLA, where it is wound around the belt winding mechanism 15. The belt winding mechanism 15 has a built-in inertia locking mechanism that locks when sudden tension is applied to the seat belt 10.

The other end of the seat belt 10 is fixed to an end plate 16 pivotally attached to the lower part of the center pillar PLA.

See Figures 3a and 3b. The seat belt 10 of this embodiment has a looped belt and has a belt core inside. Both of these are made of woven nylon fabric.

A first electrode 10a is formed on a portion A of the belt core that contacts the waist of the driver when the seat belt 10 is worn by electroless nickel plating. Even if the belt core is plated with nickel to form the first electrode, there is almost no change in its strength or flexibility, so it can be handled in the same way as a normal seat belt. Furthermore, since the nylon constituting the seat belt 10 is an insulator, the first electrode 10a is insulated from other parts of the vehicle (roof ROOF, floor F1, so-called body ground, etc.).

Also, referring to FIG. 4, the FR sheet STF.

The seat cushion 5CFR is equipped with a second electrode ELF.

The second electrode ELFR will be explained in more detail.

FIG. 6a is a partially fragmented sectional view of the FR sheet STp R. The FR seat S T F R consists of a seat cushion S C F R *seat back 5BF8 and a headrest 5HFR. Although there are differences in the support structure of each part, each is a full-form sheet that uses pads made of urethane molding.

■B-V of seat cushion 5CFR shown in Figure 6a
FIG. 6b shows a cross-sectional view taken along line IB, that is, a cross-section perpendicular to the vehicle traveling direction of the seating area of the occupant MAN.

Referring to this FIG. 6b, seat cushion 5CFR
covers the surface of the urethane seat cushion pad 60 supported on the resin pad support 70 with the trim cover assembly 50, retains both ends of the trim cover assembly 50 to the pad support 70, and Through hole 6 of seat cushion pad 60
1 and 62, etc., and is suspended on the back side of the seat cushion pad 60 by a tension rope. The second electrode ELFR is incorporated into the trim cover assembly 50, and the lead wire 53 of the second electrode ELFR is
It is guided to the back side of the seat cushion pad 60 using the through hole 62.

The structure of the trim cover assembly 50 of the second electrode ELPR incorporating portion is shown in more detail in FIG. 6C.

In FIG. 6c, 51 is a skin, 52 is a wadding made of a sponge sheet that creates a three-dimensional effect of the trim cover assembly, and 54 is a wadding cover. Second electrode E
The LFR is made of a conductive woven fabric that is electrolessly plated with nickel, and is sandwiched between the wadding 52 and the wadding cover 54 and sewn simultaneously when the trim cover assembly 50 is sewn. In this example, the size is approximately 30 cm.
The lead wire 53 is formed into a ribbon-shaped end.

In this way, the second electrode ELFPL can be incorporated without significantly increasing the manufacturing process of the trim cover assembly 50, and the material of the second electrode ELFR is similar to the materials of other components of the trim cover assembly. , second
Trim cover assembly 50 for electrode ELFR installation part
can be treated in exactly the same way as other parts. In other words, by incorporating the second electrode ELFR into the trim cover assembly 50, there is no effect on workability, appearance, seating feeling, etc.

Outer skin 51° wadding 52. that constitutes the trim cover assembly. Since the wadding cover 53, seat cushion pad 60, and pad support 70 are all insulators, the second electrode ELFR is connected to other parts of the vehicle.
That is, it is insulated from the metal constituting the seat, the roof ROOF, the floor floor, and other body ground.

That is, the above-mentioned first electrode 10a and this second electrode ELFR
and are insulated from each other, so that when the seat belt 10 is fastened, they form a capacitor with the waist of the driver MAN placed therebetween. The capacitance of this capacitor is
For example, when the driver MAN is wearing the seat belt 10 correctly as shown in FIG.
and the buckle 17 and the seat belt 10 is attached and the seat is seated from above, or the seat belt 10
After the FR sheet STF, turn the tongue plate 11
The result will be completely different if it is used incorrectly, such as when the and buckle 17 are combined.

Therefore, by monitoring the capacitance of the capacitor constituted by the first electrode 10a and the second electrode ELFR,
It is possible to reliably detect whether the seat belt 10 is correctly worn.

In this embodiment, the passenger seat (hereinafter referred to as the front left side)
The seats in the PL seats (hereinafter referred to as PL receipts) are also equipped with seat belt devices with the same configuration as above, and the seat belts have the same first electrode as above. Each has two electrodes.

Figure 7 shows the first electrode (
10a) for FR seats and the second electrode (ELFR for FR seats)
The configuration block diagram of a seat belt warning device that monitors the capacitance between the seat belt and the seat belt, detects whether the seat belt is fastened, and alerts you if the seat belt is not fastened is shown.

Referring to FIG. 7, this device is mainly composed of a microcomputer (hereinafter referred to as CPU) l.

CPUUI includes attachment detection unit 2 and 0.1 second timer 3.
．． Decoder 4. A lamp driver Drvl, a buzzer driver Drv2, and a relay driver Drv3 are connected.

The positive terminal of the on-board battery BT is connected to the input terminal V of the power supply unit 5, the lamp driver Drvl, the buzzer driver Drv2, and the relay driver Drv3 via the ignition switch SWig.

connected to the terminal.

The power supply unit 5 supplies a constant voltage Vc to each component such as the CPUI and the decoder 4. Also, the ground output is connected to equipment ground.

The lamp driver Drvl is connected to the output port P6 of the CPUI.
When output port P7 goes to H level, lamp LMr is turned on, when output port P7 goes to H level, lamp LMJ is turned on and when output port P6 goes to L level, lamp LMr is turned on.
When the output port P7 becomes L level, the lamp L
Deactivate MQ.

The buzzer driver Drv2 intermittently energizes the buzzer Bz when the output port P8 of the CPUI goes to the H level, and de-energizes the buzzer Bz when the output port P8 goes to the L level.

Relay driver Drv3 is output port P9 of CPUI.
When output port PIO becomes H level, energizes 2-pole relay RLI, when output port PIO becomes H level, energizes 2-pole relay RL2, and when output port P9 becomes L level, 2-pole relay RL is activated.
When output port P10 becomes L level, two-pole relay RL2 is deenergized.

The decoder 4 is connected to coupling detection switches SWr and SWQ that detect the coupling between the tongue plate (11) and the buckle (17) of the seat belt devices of the FR and FL seats, and the decoder 4 detects the states of these switches. is read and the information is given to the CPU.

The coupling detection switch SWr is installed inside the buckle 17 as shown in FIG. When they come into contact, the switch turns on. A coupling switch SWQ (not shown) is also installed in the same manner.

The output terminal of 0.1 second timer 3 is interrupt port I of CPUI.
nt, and issues an interrupt request to the CPUI every 0.1 seconds. The CPU uses the interrupt processing by the timer 3 to perform an F using the attachment detection unit 2, which will be explained below.
Detects the presence or absence of people in the R and FL seats, and detects whether seatbelts are being worn.

The attachment detection unit 2 includes an FR seat attachment detection unit h2a and an FL seat bag attachment detection unit 2b. With reference to FIG. 8, details of the FR seat bag attachment detection unit 2a will be explained.

Referring to FIG. 8, this unit 2a has an oscillation@OS
C, counter CTR and parallel-in serial-out shift register (hereinafter referred to as PS register) PSR
It consists of

The 1st terminal of the oscillator O8C is connected to the input terminal of the counter CTR, the 2nd terminal is connected to the constant voltage Vc, and the 3rd terminal is connected to the equipment ground.
The fourth terminal and the fifth terminal are connected to an external variable capacitor Cx. In Figure 8, the resistors that make up the oscillator O8C are shown as rectangles. By appropriately selecting the resistance value of each of these resistors, the reciprocal of the product of capacitor CX and resistor R can be proportional frequency,
That is, when the capacitance of the capacitor Cx is large, a low frequency signal is obtained, and when the capacitance of the capacitor Cx is small, a high frequency signal is obtained.

The counter CTR counts up at the rising edge of the oSC output signal. A 16-bit parallel output terminal of counter CTR is connected to a 16-bit parallel input terminal of PS register PSR. Further, the reset input terminal Rst of the counter CTR is connected to the output port P5 of the CPU1.

The clock input terminal of the PS register PSR is connected to the output port P2 of the CPU1, the clock inhibit input terminal CI is connected to the output port P3 of the CPUI, and the shift load input terminal S is connected to the output port P3 of the CPU1.
L are respectively connected to the output port P4 of the CPUI. PS register PSR has shift load input terminal SL
The 16-bit data applied to the parallel input terminal is preset to each bit at the rise of the shift load pulse from the CPU applied to the CPU, and the clock inhibit signal from the CPU applied to the clock inhibit input terminal CI becomes L (low). When it comes to level.

In synchronization with the clock pulse applied to the clock input terminal CLK, the preset data is serially output from the output terminal OUT to the serial input port R8 of the CPUI.

By the way, the first electrode 10 installed on the seat belt 10
a and FR receipt T 2nd electrode E equipped on FR
As described above, the attachment detection capacitor for detecting whether the seatbelt 10 is attached or not is configured by the LFR, and similarly, the second electrode ELFR and the body ground constitute the FR receipt T p A person detection capacitor is configured to detect the presence or absence of an occupant of R. In other words, as mentioned above, since the second electrode ELFR is insulated from the body ground, this second electrode ELFR
and the body ground (e.g. roof ROOF) form a capacitor (person detection capacitor) with the FR Receipt TFR occupant in between, and the capacitance of the capacitor is greater depending on whether there is an FR Receipt TFR occupant or not. Change. Therefore, by monitoring the capacitance of this passenger detection capacitor, it is possible to reliably detect whether or not there is an occupant in the FR receipt TFR.

That is, the external capacitor Cx of the oscillator oSC shown in FIG. 8 is the occupant detection capacitor Cx1 . Alternatively, it is a mounting detection capacitor Cx2 composed of the second electrode ELFR and the first electrode 10a, and the No. 4 terminal of the OSC is connected to the second electrode ELFR, and the No. 5 terminal is connected to the second electrode ELFR through the relay contact rQ1 of the two-pole relay RLI. Body ground or first electrode 10
connected to a. The two-pole relay RLI makes the relay contact rQ1 on the body ground side when deenergized, and makes it on the first electrode 10a side when energized.

FL seat bag attachment detection unit 2b, not shown.

The FR seat bag attachment detection unit 2a described above is configured in substantially the same manner. In this case, the 4th terminal of the oscillator is connected to the second electrode equipped with the FL receipt, and the 5th terminal is connected to the 2-pole relay R.
It is connected to body ground or a first electrode provided on the seat belt via the relay contact L2. 2 pole relay R
L2 connects the No. 5 terminal and the body ground when deenergized, and connects the No. 5 terminal and the first electrode when activated.

Further, the output of the FL seat bag attachment detection unit 2bPS register is given to the serial input port R9 of the CPU1.

The CPU de-energizes the two-pole relay RLI and monitors the capacitance of the passenger detection capacitor in the FR seat (capacitance associated with the oscillation frequency of the OSC: the same applies hereinafter) to detect the presence or absence of a passenger. ), energizes the two-pole relay RLI and F
The system monitors the capacitance of the passenger detection capacitor in the R seat to detect whether the seat belt 10 is fastened or not, and deenergizes the two-pole relay RL2 to monitor the capacitance of the passenger detection capacitor in the FL seat. Then, the FL seat occupant detection is performed, and the two-pole relay RL2 is energized to monitor the capacitance of the FL seat attachment detection capacitor to detect the FL seat attachment.

Next, with reference to FIG. 5, an outline of mounting detection and occupant detection in the device of this embodiment will be explained. Note that since the mounting detection and occupant detection are based on the same principle, the following description regarding occupant detection is shown in curly brackets.

In FIG. 5, the solid line indicates the oscillation frequency f of the oscillator OSC,
Each broken line shows an example of a change over time in the reference data Ref.

The CPUI is set at every 0.1 second timer 3 interrupt (that is, 0
．． (at 1 second intervals) counter CTR and PS register PS
The number of pulses output by the oscillator oSC (corresponding to the oscillation frequency f of the oSC) is sampled via R, and the frequency data corresponding to the number of pulses is set. (Frequency data at the time of timer interrupt) is used to set change amount data corresponding to time changes in the oscillation frequency f of the oSC. Here, if the change amount data indicates a change in the oSC's oscillation frequency f within a predetermined range (however, different values are used for attachment detection and occupant detection), "no attachment"["nooccupant"] is detected. Then, the frequency data is updated and set as reference data Ref; if the change amount data indicates a decrease exceeding a predetermined range of the frequency f (that is, the capacitance increases rapidly), it is determined as "attached". "Occupant present"] is detected, and the reference data Ref is set to be fixed. In other words, "with installation" (
When "occupant present" is detected, the reference data Ref is not updated from the next timer interrupt, and the value indicated by the reference data is compared with the value indicated by the frequency data at that time, and the frequency data is updated. If the indicated value exceeds the value indicated by the reference data Ref (decreased capacitance), "not attached"
Detects [“No Occupant”].

The CPU energizes the FR seat seat belt warning lamp LMr and buzzer Bz when the combination detection switch SWr is off and the FR seat is occupied, and when the combination detection switch SWr is on and the FR seat receipt belt is fastened. , when the combination detection switch SWQ is off and the FL seat is occupied, and when the combination detection switch SW2 is on and the FL seat receipt belt is fastened, the FL seat seat belt alarm lap LMI2 is activated.
and energizes buzzer Bz. In other words, when there is an occupant, the tongue plate (11) and buckle (17) of the seat belt device.
), and when the tongue plate (11) and buckle (17) of the seat belt device are connected but not attached, the correct seat belt (10
) is not installed, so an alarm will be issued to notify you.

The specific operation of the CPUI will be described below with reference to the flowcharts shown in FIGS. 9 and 10.

Referring to FIG. 9, the ignition switch SWig
When the CPU is turned on and a predetermined voltage is supplied to each component of the device, the CPUI initializes the input/output ports, internal registers, and each component.

When the combination detection switch SWr that detects the combination of the FR seat receipt belt device tongue plate 11 and the buckle 17 is off (no combination), the first threshold value C is set in the register C1.
omA is stored, and an L level is output from output port P9 to instruct relay driver Drv3 to de-energize relay RLI. Due to this.

The oscillator oSC of the FRR arrival detection unit 2a is a second electrode EL incorporated in the FR receipt TFR.

It oscillates at a frequency corresponding to the capacitance of the person detection capacitor in the FR seat, which is composed of the FR seat and the body ground. The first threshold value CmpA stored in the register C1 is used when determining whether the FR seats are occupied by monitoring the oscillation frequency change of the oscillator oSC of the FRR arrival detection unit 2a in a timer interrupt process to be described later.

Furthermore, when the coupling detection switch SWr is on (coupled), the second threshold value ComB is stored in the register C1, and the H level is output from the output port P9, and the relay driver D
Instructs rv3 to energize relay RLI. This results in
The oscillation aosc of the FRR attachment detection unit 2a is caused by the electrostatic charge of the attachment detection capacitor of the FR seat, which is composed of the second electrode EL incorporated in the FR receipt TF, and the first electrode 10a incorporated in the seat belt 10. Oscillates at a frequency depending on the capacitance. Second threshold value CmpB stored in register C1
is used to monitor the oscillation frequency change of the oscillator O8C of the FRR wearing detection unit 2a and to determine whether the FR seat seat belt 10 is fastened in the timer interrupt processing to be described later.

The CPU executes the timer interrupt process shown in FIG. 10 for each interrupt request from the timer 3, samples the oscillation frequency of the oscillator SC of the FR mounting detection unit 2a, and detects the occupant or mounting of the FR seat.

Similarly, when the combination detection switch SWQ that detects the combination between the FL seat receipt belt device tongue plate and the buckle is off (no combination), the first threshold value C is set in the register C2.
0IIA is stored, and an L level is output from output port P1'0 to instruct relay driver Drv3 to de-energize relay RL2. As a result, the oscillator O8C of the FLL arrival detection unit 2b oscillates at a frequency corresponding to the capacitance of the person detection capacitor in the FL seat, which is constituted by the second electrode incorporated in the FL receipt and the body ground. Register C
The first threshold value CmpA stored in 2 is used by the oscillator O8 of the FLL arrival detection unit 2b in the timer interrupt processing described later.
This is used when monitoring the change in the oscillation frequency of C and determining whether there is someone in the FL seat.

Further, when the coupling detection switch swn is on (coupled), the second threshold value ComB is stored in the register C2, and an H level is output from the output port P10 to instruct the relay driver Drv3 to energize the relay RL2. As a result, the oscillator O8C of the FLL arrival detection unit 2b generates a frequency corresponding to the capacitance of the attachment detection capacitor of the FL seat, which is composed of the second electrode incorporated in the FL receipt and the first electrode incorporated in the seat belt. oscillates. Register C2
The second threshold value CmpB stored in the oscillator O8C of the FLL arrival detection unit 2b is
This is used to monitor the change in oscillation frequency and determine whether the FL seat receipt belt is fastened.

The CPU executes the timer interrupt process shown in FIG. 10 for each interrupt request from the timer 3, samples the oscillation frequency of the oscillator oSC of the FLL arrival detection unit 2b, and detects the occupant or attachment of the FL seat.

Here, occupant detection and mounting detection will be explained with reference to FIG.

In timer interrupt processing, first the contents of register R1a are stored in register R1b, and the contents of register R2a are stored in register R2b.
, respectively. This register R1a and R2
The content of a will become clear from the following explanation, but 1
FR installation detection unit 2 in previous timer interrupt processing
Frequency data of a and FLL arrival detection unit 2b output (that is, frequency data from 0.1 seconds ago; old frequency data)
It is.

Next, the PS register P of each attachment detection unit 2a, 2b
When a shift load pulse (SL pulse) is output to the shift load input terminal of SR, each register PSR
The 16-bit data from each counter CTR applied to the parallel input terminal is preset to each bit.

Thereafter, a reset pulse is applied to the reset input terminal Rst of each counter CTR to reset the CTR. That is, each counter CTR counts the number of pulses generated by each oscillator O8C from the occurrence of a timer interrupt to the occurrence of the next timer interrupt.

By applying an L level (low level) to the clock input terminal CI of each PS register PSR, the PS
Since the register PSR serially outputs the preset data from the output terminal OUT in synchronization with the clock pulse, this output, that is, the input power of serial input port R8 and the input power of serial input port R9, is read and sent as frequency data to registers R1a and R2a, respectively. Store in.

The following routine consists of two parts: the FR seat detection routine and the FL seat detection routine. First, the FR seat detection routine will be explained. If register S1, which will be described later, is 0, register R1a is determined from the contents of register R1b. The value obtained by subtracting the contents is stored in register R1c as change amount data, and the contents of register R1a are stored in register R as reference data.
After storing to efl, the contents of register R1c (change amount data) are set to first threshold CmpA or second threshold Cn+p.
Compare with register C1 where B is stored.

At this time, if the contents of register R1c are less than the value of register C1, the FL seat detection routine is continued, but if the contents of Rlc exceed the value of register C1, register MAN1 and register SL are set to 1. After setting , the continuation<FL seat detection routine is executed (the contents of register Ref1 at this time are equal to the contents of register R1a).

When register S1 is set to 1, the contents of register Refl (reference data) will not be updated (fixed) in the next timer interrupt processing, and the contents of register Refl set previously (reference data) and the new contents of register R1a will be updated. (frequency data).

This comparison causes the contents of register R1a to be changed to register Re.
When the content of fl is exceeded, 0 is set in register MAN1 and register S1.

When the first threshold value C PA is stored in the register C1, the FR seat occupant detection is performed by the above timer interrupt process, and 1 is set in the register MAN1 when rFR seat occupant is detected.
When the register MAN1 is set to 0 and the second threshold value CmpB is stored in the register C1 in the case of "No occupant in the R seat", the FR seat receipt belt 10 attachment is detected by the above timer interrupt processing, and the rFR seat seat belt 10 attachment is detected. 1 is set in register MAN1 for "Yes", and O is set in register MAN1 for "FR seat bag installed".

In the FL seat detection routine, register S2 (described later)
is 0, register R2 is calculated from the contents of register R2b.
The value obtained by subtracting the contents of a is set as change amount data in register R2.
After storing the contents of register R2a as reference data in register Ref2, the contents of register R2c (change amount data) are set to the first threshold CmpA or the second threshold CmpA.
It is compared with the register C2 in which the threshold value CmpB is stored.

At this time, if the contents of register R2c are less than the value of register c2, the process returns to the main routine, but if the contents of register R2c exceed the value of register C2,
After setting register MAN2 and register S2 to 1, the process returns to the main routine (the contents of register Ref2 at this time are equal to the contents of register R2a).

When register S2 is set to 1, the contents of register Raf2 (reference data) will not be updated (fixed) in the next timer interrupt process, but the contents of register Ref2 (reference data) set previously will be updated and the new register R2a will be updated. (frequency data).

This comparison causes the contents of register R2a to be changed to register Re.
When the content of f2 is exceeded, 0 is set in register MAN2 and register S2.

When the first threshold value CIIPA is stored in the register C2, the FL seat occupant detection is performed by the above timer interrupt process, and 1 is set in the register MAN2 when rFL seat occupant is detected.
When the register MAN2 is set to 0 and the second threshold value CmpB is stored in the register c2 for "no FL seat occupant", the FL seat receipt belt attachment detection is performed by the above timer interrupt processing, and it is determined that the rFL seat is attached. ”, register MAN2 is 1, rFL seat is not installed”, register M is
0 is set in AN2.

In this way, in the timer interrupt process, the second electrode (FR
The presence of an occupant is detected when there is a sudden change in the capacitance between the body ground and the ELFR electrode on the seat ST, and the ELF AN electrode on the FL seat. 1st electrode (FR seat receipt belt 1
0 equipped with LEA and FL seat receipt belt equipped with 10
Since the presence of the seat belt is detected when there is a sudden change in the capacitance between the seat belt and the electrode (corresponding to electrode a), there is no possibility of false detection due to the effects of temperature, humidity, or changes over time. Also.

In particular, when detecting a single occupant, the change in capacitance when luggage is placed on the FR or FL seat is very different from that when a person is seated. There are no false positives like there would be with a switch).

Referring again to FIG. 9.

When the combination detection switch SWr is off, the timer interrupt process detects an occupant in the FR seat and indicates that there is an occupant (register M
A N 1 = 1), the flag FSr
Check the flag FS when it is reset (0).
Set r and FTr (1) and clear T timer &
Start. In other words, when there is an occupant in the FR seat and the ring plate 11 and buckle 17 of the seat belt device of the FR seat are not connected, the seat belt 1o is not properly fastened, so the flags FSr and FTr are set (1) and the Clear and start the timer.

After this, even if a similar state is detected successively, this step is not executed because the flag FSr is set (1).

When the combination detection switch SWr is off, a timer interrupt process is used to detect an occupant in the FR seat and register one occupant (register M).
When AN1=0) is detected, the flag FSr is checked, and if it is set (1), the flags FSr and FTr are set.
Reset (0).

In other words, when there is no occupant in the FR seat and the tongue plate 11 and buckle 17 of the seat belt device of the FR seat are separated, the flags FSr and FTr are reset (0).
do. This step is not executed when the flag FSr is reset (0).

When the combination detection switch SWr is on, the timer interrupt process detects the attachment of the FR seat receipt belt 1o, and if register MAN1=O) is detected without attachment, the flag F is set.
Sr is checked, and when it is reset (0), flags FSr and FTr are set (1) to clear and start the T timer.

In other words, the tongue plate 1 of the seat belt device for FR seats
F even though 1 and buckle 17 are connected
If the seatbelt fastening of the R seat is not detected, it means that the seatbelt 10 is not correctly fastened, so the flags FSr and FTr are set (1) to clear and start the T timer. After this, even if a similar state is detected successively, this step is not executed because the flag FSr is set (1).

When the combination detection switch SWr is on, the attachment of the FR seat seat belt '10 is detected in the timer interrupt process, and when it is detected that it is attached (register MAN1 = 1), the flag FSr is checked and this is set (1). When P
When the tongue plate 11 and buckle 17 of the seat belt device for the R seat are connected and the attachment is detected, the seat belt 10 is correctly attached, so the flags FSr and FTr are reset (0).

After the flag FSr is reset (to 0), this step is not executed even if a similar state is detected successively.

When the combination detection switch SWQ is off, the timer interrupt process detects an occupant in the FL seat and indicates that there is an occupant (register M
When AN2=1) is detected, the flag FSQ is checked, and if it is reset (0), the flags FSQ and FT are
Set Q (1) to clear and start the T timer. In other words, if there is an occupant in the FL seat and the tongue plate and buckle of the FL seat's seat belt device are not connected, the seat belt is not properly fastened, and the flags F S 'Q and FTQ are set (1). Clear and start the T timer. After this, even if a similar state is detected successively, this step is not executed because the flag FSQ is set to (CER)-(1).

When the combination detection switch SWQ is off, a timer interrupt process is used to detect an occupant in the FL seat, and register M is detected without an occupant.
When AN2=0) is detected, the flag FSQ is checked, and if it is set (1), the flags FSQ and FTf are
Reset (0) l.

In other words, when there is no occupant in the PL seat and the tongue plate and buckle of the seat belt device in the FL seat are separated, the flags FSn and FTQ are reset (0), and when the flag FSfi is reset (0), Steps are not executed.

When the combination detection switch SWQ is on, the FL seat receipt belt attachment is detected in the timer interrupt processing, and if no attachment is detected and register MAN2 = 0), the flag FSR is set.
Check the flag FS when it is reset (0).
Set fi and FTQ (1) to clear and start the T timer.

In other words, if the seatbelt fastening of the FL seat is not detected even though the tongue plate and buckle of the seatbelt device of the FL seat are connected, the seatbelt is not fastened correctly, so the flags FSQ and FTQ
is set (1) to clear and start the T timer.

After this, even if a similar state is detected successively, this step is not executed because the flag FSQ is set (1).

When the combination detection switch SWQ is on, the FL seat receipt belt attachment is detected in the timer interrupt processing, and if it is detected that the seat belt is attached (register MAN2 = 1), the flag FSQ is set.
Check the flag FSQ when it is set (1).
and FTfi is reset (to 0). In other words, when the tongue plate and buckle of the seat belt device of the FL seat are connected and the seat belt is detected to be fastened, the seat belt is correctly fastened, so the flags FSQ and FT are set.
Reset (0) Q. Reset flag FSQ (0
), this step will not be executed even if a similar condition is subsequently detected.

When the flag FSr is set (1), the CPU outputs an H level from the output port P6, instructs the lamp driver Drv2 to activate the FR seat seat belt alarm lap LMr, and sets the flag FSQ (1). ), the H level is output from output port P7 and the FL seat seat belt alarm lap LMf is sent to the lamp driver Drv2.
Instructs to energize i.

Set flag FSr and/or flag FSfi (
1), the flag FTr and/or the flag FTfl are set (1) at the same time, and the timer T is cleared and started, so in this case, the value of the timer T is monitored,
If it is within the predetermined time TH (5 seconds in this embodiment), output the H level from the output port P8 to instruct the buzzer driver Drv3 to energize the alarm buzzer Bz, and the predetermined time T
When H has passed, the flag FTr and the flag FTQ are reset (0), and the L level is output from the output port P8 to instruct the buzzer driver Drv3 to deactivate the alarm buzzer Bz.

When the flag FSr is reset (o), the output port P6 outputs L level to instruct the lamp driver Drv to de-energize the FR seat seat belt warning lamp LMr, and resets the flag FSffi (0). When the signal is on, the output port P7 outputs L level to send the FL seat seat belt warning alarm signal to the lamp driver Drv.
order the extinction of

Reset flag FSr and/or flag FsQ (
0), the flag FTr and/or the flag FTQ are simultaneously reset (to 0).

At this time, if the flag FTr and the flag FTffi have been reset (0), the output port P8 outputs a light level and instructs the buzzer driver D r v 3 to deactivate the alarm buzzer Bz.

By the way, in the above embodiment, as shown in FIG.
Although the first electrode 10a is incorporated in the seat belt, it may be incorporated, for example, in the region B corresponding to the chest of the personnel MAN, or in the entire seatbelt 1° without distinction between A and H. Also, the second
Regarding the electrode ELFR, depending on the installation position of the first electrode, for example, as shown in FIG.
Various modifications using an electrode EΩFR built into the body, a body ground, etc. are conceivable, but a detailed explanation will not be given here.

In addition to what is shown in the above embodiment, it is also possible to detect whether a seat belt is worn or not by detecting the change in capacitance between the first electrode and the second electrode using a capacitance comparison circuit such as a Wien bridge. good.

Further, in the embodiments described above, the present invention was applied to detect the attachment of an on-vehicle seat belt, but the present invention is not limited thereto. For example, a wide range of applications are possible, such as detecting whether a seat belt is fastened on an airplane.

〔Effect of the invention〕

As explained above, the seat belt attachment detection device of the present invention can be attached/unattached freely, and in the attached state, the first electrode installed on the seat belt restrains at least a portion of the person seated in the seat. , a second electrode insulated from the first electrode, which is installed with at least a part of the person seated on the seat placed between the first electrode and the seat belt when the seat belt is fastened;
The 8 poles form a capacitor for detecting seat belt attachment, and its capacitance is monitored. The capacitance of the capacitor varies greatly depending on whether or not the person seated in the seat is wearing the seat belt correctly, so it is important to check whether the seat belt is actually attached in a manner that can protect the person sitting in the seat. It is possible to correctly detect whether or not the

For example, even if the buckle of the on-vehicle seat belt device is engaged and the detection switch is turned on, according to the present invention, if the person is not actually wearing the seat belt at that time, the first electrode and Since the capacitance between the two electrodes does not change within a predetermined range, the presence or absence of the seatbelt is not detected.In other words, the reliability of detecting whether the seatbelt is fastened is high.

[Brief explanation of the drawing]

FIG. 1 is a side view of a driver's seat of a vehicle as viewed from inside the vehicle, and shows an on-vehicle seat belt device embodying the present invention as an example. 2a and 2b are perspective and side views showing in detail the tongue plate 11 and buckle 17 of the device shown in FIG. 1. FIG. Fig. 3a is a rear view of the driver's seat of the vehicle as seen from the rear, and the 11th! pole 10a
shows the arrangement. FIG. 3b is a partially exploded perspective view showing the structure of the seat belt 1o. FIG. 4 is a side view showing the arrangement of the second electrode ELFR mounted on the driver's seat 5TFR and the arrangement of the second electrode EJlpR of a modified example. FIG. 5 is a graph showing, by way of example, temporal changes in the oscillation frequency f of the oscillator osc shown in FIG. 8 and the reference data Ref. Fig. 6a is a partially exploded perspective view showing the configuration of the driver's seat S T tx rz, Fig. 6b is a VIB-VIB sectional view of the seat cushion 5cFR shown in Fig. 6a,
FIG. c is a perspective view showing the structure of the trim cover assembly 50 of the seat cushion SC shown in FIGS. 6arXI and 6b. FIG. 7 is a block diagram showing a detection system for detecting the seat belt 1° fastening state of the apparatus shown in FIG. 1. Figure 8 shows the driver seat installation detection unit 2 shown in Figure 7.
It is a block diagram showing the composition of a. 9 and 10 are flowcharts showing the general operation of the microcomputer 1 shown in FIG. 7. 1: Microcomputer (signal processing means, storage means,
Memory updating means, comparison processing means, reference value setting means) 2: Attachment detection unit 2a: Driver seat attachment detection unit 2b: Passenger seat attachment detection units 2a, 2b: (Capacitance detection means) 3: 0.1 second timer 4: Decoder 5: Power supply unit 10: Seat belt (seat belt) 10a: First electrode (first electrode) 11: Tongue plate 13: Hanging ring 14: Opening 15: Belt winding device 17: Buckle 18: Extension rod 50 ni Drim cover assembly 51: Skin 52: Wadding 53: Lead wire 54: Wadding force bar 60 = Seat cushion pad 61.62: Through hole 7o: Pad support 5T
FR: Vehicle seat (seat) SCF, : Seat cushion SO, Niji-dopack SHF, : Headrest PLA : Center vehicle MAN : Driver (personnel) ELF tqrEn FR: 2nd pole (2nd train 4
1) Floor: Floor ROOF: Roof S
vr, SVI: Binding detection switch Drvl, Drv2. Drv3: Driver LMr, L
MI: Alarm lamp Bz: Buzzer RLI, RL2: Relay BT = On-board battery OSC: Oscillator CTR: Counter PSR: Parallel in/serial out/shift register Method 1 Figure 38 ■ 3b Round 5 Figure 6a Figure 6b J6c Figure 7th B Procedural Amendment (Spontaneous) January 23, 1985 1, Case Indication 1985 Patent Application No. 30592
No. 6 No. 2, Title of the invention Seat belt attachment detection device 3, Relationship to the amended person's case Patent applicant address 2-1 Asahi-cho, Kariya City, Aichi Prefecture Name (001) Aisin Seiki Co., Ltd. Representative Italy Kiyoshi Fuji 4, Agent 103 Phone 03-86
4-6052 Address: 2-27-6 Higashi-Nihonbashi, Chuo-ku, Tokyo Drawing 6, Contents of Amendment Figure 8 of the drawing is corrected as shown in the attached appendix. 7. List of attached documents

Claims (10)

[Claims] (1) Seat; A seat belt that can be attached/unattached freely, and which restrains at least a portion of the person seated on the seat in the attached state; A first electrode installed on at least a portion of the seat belt; The seat belt in the attached state, between the first electrode and the
a first seat on which at least a portion of the person seated is placed;
a second electrode insulated from the electrode; the first electrode and the second electrode;
Capacitance detection means for detecting capacitance between the capacitance and the electrode; and signal processing means for detecting whether the seat belt is fastened when the detected capacitance of the capacitance detection means reaches a predetermined change. A seat belt attachment detection device is provided. (2) The signal processing means detects whether the seat belt is fastened when the detected capacitance of the capacitance detection means is larger than a set value, and detects that the seat belt is not fastened when the detected capacitance is less than the set value. A seat belt attachment detection device according to item (1). (3) The signal processing means includes a memory means; a memory updating means for updating and storing the detected capacitance of the capacitance detecting means in the memory means at a predetermined period; and a detected electrostatic capacitance of the capacitance detecting means. The seatbelt attachment detection device according to claim 1, further comprising: comparison processing means for detecting whether or not the seatbelt is attached according to the difference between the capacitance and the storage capacitance of the storage means. (4) The comparison processing means updates the reference value according to the detected capacitance when the difference between the detected capacitance of the capacitance detection means and the storage capacitance of the storage means is less than or equal to a predetermined value. The seat belt attachment detection device according to claim 3, further comprising reference value setting means for setting a reference value and canceling update setting of the reference value when the predetermined value is exceeded. (5) The comparison processing means detects whether the seat belt is fastened when the detected capacitance of the capacitance detection means is larger than the storage capacitance of the storage means and the difference therebetween exceeds a predetermined value. Then, when the detected capacitance of the capacitance detection means is equal to or less than the storage capacitance of the storage means, and the detected capacitance becomes equal to or less than the reference value, it is detected that the seat belt is not fastened. A seat belt attachment detection device according to claim (4). (6) The seat belt attachment detection device according to claim (5), wherein the comparison processing means includes a holding means for holding information when detecting whether the seat belt is fastened or not fastened. (7) The reference value setting means of the comparison processing means is configured to stop update setting of the reference value when the content of the holding means indicates that the seat belt is fastened. attachment detection device. (8) The seat belt attachment detection device according to claim (1), wherein the capacitance detection means includes oscillation means that generates a signal with a frequency corresponding to the capacitance. (9) The oscillation means generates a signal whose frequency decreases as the capacitance increases.
Seat belt attachment detection device described in ). (10) The seat is an in-vehicle seat, and the seat belt is an in-vehicle seat belt.
), (2), (3), or (8).