JP2014129623A - Occupant crash protector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To determine the occurrence of a collision at a timing earlier than fall or overturn of an occupant of a vehicle.SOLUTION: An occupant crash protector 12 worn by an occupant of a vehicle includes: an air bag; an acceleration sensor 15 for detecting acceleration of three axes, that is an axis in the longitudinal direction, an axis in the horizontal direction orthogonal to the longitudinal direction, and an axis in the vertical direction of the occupant; an angular velocity sensor 16 for detecting the angular velocity around the horizontal axis; and a control part 13 for outputting a signal for deploying the air bag on detecting a collision of the vehicle. The control part 13 calculates the acceleration which the occupant receives from the triaxial acceleration input from the acceleration sensor 15, and the angular velocity input from the angular velocity sensor 16, and determines the occurrence of a collision of the vehicle when the acceleration of the occupant exceeds a predetermined threshold.

Description

  The present invention relates to an occupant protection device for reducing injury to a vehicle occupant (especially an occupant of a saddle type vehicle). Here, the saddle-ride type vehicle includes a motorcycle (including a scooter), a rough terrain vehicle such as a four-wheel buggy, and a snowmobile.

  An airbag jacket is known as a garment for reducing injury to a passenger of a saddle-ride type vehicle such as a motorcycle. For example, when an acceleration sensor or the like provided on the vehicle body or the airbag jacket detects that an external force exceeding a predetermined value is applied to the vehicle body, the airbag built in the airbag jacket is inflated.

  The technique disclosed in Patent Document 1 calculates a risk function value from signals from a plurality of angular velocity sensors provided in an airbag jacket. When the value of the risk function exceeds a predetermined value, it is determined that the occupant falls from the vehicle, and a signal for expanding the airbag (hereinafter referred to as an airbag expansion signal) is generated.

  The technique of Patent Document 1 calculates a risk function value mainly by a square linear combination of two-axis angular velocities in order to predict the occupant fall (for example, lines 15-16 on page 3). However, when aiming at occupant protection when a vehicle collides, the technique of Patent Document 1 has a problem that the output timing of the airbag inflation signal is delayed.

  For example, when a motor vehicle and a motorcycle collide, in many cases, a motorcycle occupant protrudes from the motorcycle and falls to the road surface. Therefore, a method of detecting an impact at the time of collision by an acceleration sensor and outputting an airbag expansion signal at an earlier timing than the occupant falls or falls is conceivable. However, there are cases where acceleration occurs due to the vehicle being pushed up due to road surface conditions (such as traveling on rough roads and oversteps in the normal driving range) while the motorcycle is traveling. Therefore, there is a problem that it is difficult to distinguish between an increase in acceleration due to a collision and an increase in acceleration due to road surface conditions.

International Publication No. 2008/050290

  An object of the present invention is to determine the occurrence of a collision at a timing earlier than that of a vehicle occupant falling or falling.

  The present invention has the following configuration as one means for achieving the above object.

  The invention of claim 1 is an occupant protection device worn by an occupant of a vehicle, the acceleration detecting the airbag and the three-axis acceleration in the anteroposterior direction, the horizontal direction perpendicular to the anteroposterior direction, and the vertical direction. A sensor, an angular velocity sensor that detects an angular velocity around the horizontal axis, and a control unit that outputs a signal for inflating the airbag when a collision of the vehicle is detected, the control unit including the acceleration sensor The vehicle receives a collision when the acceleration of the occupant exceeds a predetermined threshold by calculating the acceleration received by the occupant from the three-axis acceleration input from the angular velocity and the angular velocity input from the angular velocity sensor. It is characterized by determining that it has been.

  The invention according to claim 2 is characterized in that the angular velocity is used to adjust the weight of the acceleration in the vertical direction in the calculation.

  The invention according to claim 3 is characterized in that weighting of the acceleration in the vertical direction is performed by multiplying the acceleration in the vertical direction by a function that changes stepwise according to the magnitude of the angular velocity.

  The invention according to claim 4 is characterized in that the angular velocity sensor is arranged at a position of the occupant protection device corresponding to the vicinity of the occupant's waist. Occupant protection device.

  The invention of claim 5 is characterized in that an inflator of the airbag is disposed at a position of the occupant protection device corresponding to the back of the occupant, and the angular velocity sensor is disposed below the inflator.

  The invention of claim 6 is characterized in that the acceleration sensor and the angular velocity sensor are fixed to a fastening belt for fastening the occupant protection device to the occupant.

  According to the invention of claim 1, it is possible to determine the occurrence of a collision at a timing earlier than the drop or fall of the vehicle occupant.

  According to the invention of claim 2, it is possible to reduce a risk of erroneous determination due to a thrusting impact from the road surface during normal traveling.

  According to the invention of claim 3, the thrusting impact at the time of the vehicle collision can be effectively used for the determination.

  According to the fourth and fifth aspects of the present invention, the angular velocity at the time of the vehicle collision can be detected earlier, and the time from the occurrence of the collision to the determination of the collision can be shortened.

  According to the invention of claim 6, it is possible to detect the movement of the occupant without delay and to shorten the time from the occurrence of the collision to the determination of the collision.

The figure which shows a mode that the passenger | crew who mounted the passenger | crew protection device of the Example boarded the motorcycle. The figure which shows the detail of a passenger | crew protection device. The block diagram which shows the structural example of a control circuit. The figure which shows the example of a relationship between the raise of the acceleration Gz and the raise of angular velocity (omega) y. The figure which shows an example of a weight function.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an occupant protection device according to an embodiment of the present invention will be described in detail with reference to the drawings. The occupant protection device is a so-called airbag jacket that can protect an occupant who has fallen or fallen from a vehicle at the time of a vehicle collision from obstacles such as a colliding vehicle, guardrails, signs, curbs, road surfaces (ground), and buildings. is there.

[Device configuration]
FIG. 1 is a view showing a state in which an occupant 11 wearing the occupant protection device 12 of the embodiment gets on a motorcycle 10. FIG. 2 is a diagram showing details of the occupant protection device 12. The motorcycle 10 is an example of a saddle type vehicle. In addition, although FIG. 1 shows an example of single passenger, a passenger (non-driver) can also wear the occupant protection device 12 in the case of two passengers.

  A control circuit 13 and an inflator 17 for inflating the airbag are provided on the back surface of the occupant protection device 12 (the back side of the occupant 11). Although not shown, the airbag is disposed substantially over the occupant protection device 12 in order to protect the occupant 11. The fastening belt 14 is a means for fastening the occupant protection device 12 to the occupant 11. A triaxial acceleration sensor 15 and a uniaxial angular velocity sensor 16 are provided on the back side of the fastening belt 14 (below the occupant protection device 12 and near the waist of the occupant 11).

  The acceleration sensor 15 includes an acceleration Gx in the front-rear direction (x direction) related to the traveling direction of the motorcycle 10 shown in FIG. 2, and an acceleration Gy in the horizontal direction (y direction, lateral direction with respect to the traveling direction) orthogonal to the x direction. The acceleration Gz in the vertical direction (z direction) related to the push-up direction is detected. Further, the angular velocity sensor 16 detects an angular velocity ωy in the pitch direction (around the y axis) shown in FIG.

  The occupant protection device 12 of this embodiment includes means for detecting a vehicle collision inside thereof, and uses external information such as a wire connected to the vehicle for detecting the fall of the occupant 11 and vehicle speed and vehicle body acceleration. The collision of the vehicle can be detected without doing so.

[Control circuit]
FIG. 3 is a block diagram illustrating a configuration example of the control circuit 13.

  The signal acquisition circuit 21 is a sensor interface that acquires acceleration signals Gx, Gy, Gz output from the acceleration sensor 15 at a predetermined interval and an angular velocity signal ωy output from the angular velocity sensor 16. The signal acquisition circuit 21 amplifies the acquired signal to an appropriate signal level (for example, a voltage level) when the subsequent stage is an analog processing circuit, and converts the acquired signal into a digital signal when the subsequent stage is a digital processing circuit. Perform digital (AD) conversion. When the sensor requires power, the signal acquisition circuit 21 has a function of supplying power to the sensor.

  The filter circuit 22 performs necessary filter processing on each signal input from the signal acquisition circuit 21. The arithmetic circuit 23 calculates an acceleration Gr received by the occupant 11 by performing an operation described later on each signal input from the filter circuit 22. The determination circuit 24 determines that a vehicle collision has occurred when the acceleration signal Gr input from the arithmetic circuit 23 exceeds a predetermined threshold value, and outputs an airbag inflation signal to the inflator 17 in order to inflate the airbag. .

  The power supply for the control circuit 13 is supplied from a battery (not shown). As this battery, a primary battery such as a dry battery, for example, a secondary battery that can be charged from the battery of the motorcycle 10, a secondary battery that can be charged from a solar battery disposed on the surface of the occupant protection device 12, or the like can be used. is there.

[Calculation circuit]
The arithmetic circuit 23 calculates the acceleration Gr by the square linear combination of the acceleration signals according to, for example, the equation (1).
Gr = √ (Gx ² + Gy ² + W (ωy) ・ Gz ² )… (1)

  In the equation (1), accelerations Gx and Gz are mainly for the purpose of detecting a collision in the longitudinal direction of the vehicle 10, and the acceleration Gy is mainly for the purpose of detecting a collision in the side direction of the vehicle 10. In particular, the acceleration Gz is multiplied by a weight function value W (ωy) having the angular velocity ωy as a variable.

  The multiplication of the acceleration Gz in the push-up direction and the weighting function value W (ωy) takes into consideration the road surface condition (such as traveling on a bad road in the normal traveling range or stepping over a step) while the motorcycle 10 is traveling. In other words, the occupant 11 receives a push-up impact that occurs when the rear wheel of the motorcycle 10 passes through the road gap when traveling on rough roads or oversteps.

  FIG. 4 is a diagram showing an example of the relationship between the increase in acceleration Gz and the increase in angular velocity ωy. In the behavior of the occupant 11 when subjected to the thrust impact, as shown in FIG. 4 (a), the increase in the angular velocity ωy is delayed with respect to the increase in the acceleration Gz. On the other hand, in the behavior of the occupant 11 at the time of the vehicle collision, as shown in FIG. 4 (b), the time delay of the increase in the angular velocity ωy with respect to the increase in the acceleration Gz is larger than that in the case of a thrust impact during normal driving. And few. Furthermore, as shown in FIG. 4, the absolute value of the angular velocity ωy during normal traveling including traveling on rough roads and oversteps is smaller than that during vehicle collision. Therefore, if the calculation circuit 23 performs a calculation in which the acceleration Gz is weighted by the angular velocity ωy, an acceleration Gr that is a calculation result in which the influence of the acceleration Gz during normal traveling is reduced can be obtained.

  As described above, the weighting function W has a role of weighting the acceleration Gz in the push-up direction according to the magnitude of the angular velocity ωy. In other words, the angular velocity ωy is used to adjust the weight of the acceleration Gz in the push-up direction in the calculation of the acceleration Gr. As a result, the risk of misjudgment of the determination circuit 24 due to a thrusting impact from the road surface during normal traveling can be reduced, and the thrusting impact at the time of a vehicle collision can be effectively used for determination.

FIG. 5 is a diagram illustrating an example of the weight function W. The weighting function W shown in FIG. 5 (a) shows a stepwise weight change due to conditional branching as shown in the equation (2).
if (ωy <th)
W (ωy) = W _Lo ;
else
W (ωy) = W _Hi ；… (2)
Here, W _Lo <W _Hi .

Further, the weighting function W shown in FIG. 5 (b) shows a weight change having a gradient using an exponential function as shown in the equation (3).
W (ωy) = (W _Hi -W _Lo ) / [1 + exp {-a (ωy-th)}] + W _Lo … (3)
Where a is a coefficient that determines the slope.

[Filter circuit]
The filter circuit 22 performs a filtering process on each signal acquired from the acceleration sensor 15 and the angular velocity sensor 16 in order to remove spike noise and the like to reduce the risk of erroneous determination. As the filter, a band pass filter, a median filter, a moving average, a piecewise integration, or the like can be applied. Of course, these filters can be used in combination.

  Further, a circuit for filtering the acceleration signal Gr output from the arithmetic circuit 23 may be provided in the determination circuit 24 in order to reduce the risk of erroneous determination due to spike noise or the like. As the filter, a band pass filter, a median filter, a moving average, a piecewise integration, or a combination of these filters can be used.

[Sensor arrangement]
As described above, the triaxial acceleration sensor 15 and the uniaxial angular velocity sensor 16 are disposed in the lower rear portion of the occupant protection device 12 (near the waist of the occupant 11). It should be noted that only the uniaxial angular velocity sensor 16 may be disposed at the lower back of the occupant protection device 12. Alternatively, the airbag inflator and the control circuit 13 may be disposed at the position of the occupant protection device 12 corresponding to the back of the occupant 11, and at least the angular velocity sensor 16 may be disposed below the inflator.

  Note that a protector may be interposed between the fastening belt 14, the triaxial acceleration sensor 15, and the uniaxial angular velocity sensor 16. The triaxial acceleration sensor 15 and the uniaxial angular velocity sensor 16 may be incorporated in the control circuit 13.

  When the vehicle collides, there is a high possibility that the occupant 11 is protruded in the traveling direction of the motorcycle 10. Therefore, compared to the case where the angular velocity sensor 16 is disposed on the front surface of the occupant protection device 12 (near the abdomen of the occupant 11) or on the upper portion of the occupant protection device 12 (near the chest, shoulder, or neck of the occupant 11), Can be detected earlier. That is, by arranging the angular velocity sensor 16 at the lower back of the occupant protection device 12, the time from the occurrence of a collision until the determination of the collision can be shortened.

  Further, the movement of the occupant protection device 12 worn by the occupant 11 may be slightly delayed with respect to the movement of the occupant 11. In this embodiment, since the acceleration sensor 15 and the angular velocity sensor 16 are fixed to the fastening belt 14 that fastens the occupant protection device 12 to the occupant 11, the movement of the occupant 11 can be detected without delay, and a collision occurs. The time from collision to collision determination can be shortened.

  In this way, by detecting the collision of the vehicle mainly using the acceleration calculation, it solves the problem that the output timing of the airbag inflation signal is delayed when detecting the fall of the person 11 mainly using the angular velocity calculation. be able to.

  Furthermore, the acceleration Gz in the push-up direction is weighted by the angular velocity ωy without simply synthesizing the three-axis accelerations to obtain the acceleration received by the personnel 11. As a result, it is possible to reduce the risk of erroneous determination due to the thrust impact during normal travel, and to effectively use the thrust impact during vehicle collision for determination.

Claims (6)

An occupant protection device worn by a vehicle occupant,
An airbag,
An acceleration sensor that detects three-axis acceleration in the front-rear direction of the occupant, the horizontal direction orthogonal to the front-rear direction, and the vertical direction;
An angular velocity sensor for detecting an angular velocity around the horizontal axis;
A controller that outputs a signal for inflating the airbag when a collision of the vehicle is detected;
The control unit calculates the acceleration received by the occupant from the triaxial acceleration input from the acceleration sensor and the angular velocity input from the angular velocity sensor, and the acceleration of the occupant exceeds a predetermined threshold value. In this case, it is determined that a collision of the vehicle has occurred.   2. The occupant protection device according to claim 1, wherein the angular velocity is used for adjusting a weight of the acceleration in the vertical direction in the calculation.   3. The occupant protection according to claim 2, wherein the weighting of the acceleration in the vertical direction is performed by multiplying the acceleration in the vertical direction by a function that changes stepwise according to the magnitude of the angular velocity. apparatus.   4. The occupant protection device according to claim 1, wherein the angular velocity sensor is disposed at a position of the occupant protection device corresponding to the vicinity of the waist of the occupant.   4. The air bag inflator is disposed at a position of the occupant protection device corresponding to the back of the occupant, and the angular velocity sensor is disposed below the inflator. The occupant protection device according to one item.   4. The occupant protection device according to any one of claims 1 to 3, wherein the acceleration sensor and the angular velocity sensor are fixed to a fastening belt that fastens the occupant protection device to the occupant.

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