JP4584097B2 - Rollover judgment device - Google Patents

Description

  The present invention relates to a rollover determination device that detects the possibility of rollover of a vehicle based on the roll angular velocity and roll angle of the vehicle.

Conventionally, as a rollover determination device, a threshold line is set two-dimensionally using the roll angle and roll angular velocity of the vehicle as parameters, and the threshold is determined by the magnitude of the lateral acceleration of the vehicle. There is a method for obtaining the vehicle speed and the steering angle without using (see, for example, Patent Document 1).
Conventionally, as a rollover determination device, the rollover mode of a vehicle is limited to tripover, the type of tripover is determined by the lateral acceleration of the vehicle, the determination condition is changed, the amount of change in lateral acceleration of the vehicle, There is a type in which the type of trip over is determined based on the maximum value of acceleration, the duration of lateral acceleration, the speed of the vehicle, or the lateral speed before the occurrence of lateral acceleration, and the threshold value is changed according to this type (for example, see Patent Document 2). ).

Conventionally, as a rollover determination method, when the lateral acceleration or lateral speed of the vehicle acts in a direction that promotes the rollover of the vehicle, there is a method of moving the threshold line in a direction approaching the origin (see, for example, Patent Document 3). ).
Conventionally, as a rollover determination method, there is a method in which the threshold line is moved in a direction toward or away from the origin according to the roll angular acceleration of the vehicle (see, for example, Patent Document 4).
Conventionally, as a rollover determination method, there is a method in which rollover in a tripover system is detected early and a threshold line is moved by a roll angular differential value of roll angular velocity or a temporal differential value of roll angular velocity (for example, Patent Document 5). reference).
That is, in the conventional examples of Patent Documents 2 to 5, the threshold line is set according to the magnitude of the roll angle differential value of the lateral acceleration, the lateral velocity or the roll angular velocity or the time differential value of the roll angular velocity, and the roll angle of the vehicle and It translates in the direction of the origin of the two-dimensional map using the roll angular velocity as a parameter.

JP 2005-1522 A JP 2004-262410 A JP 2001-71844 A JP 2001-74442 A JP 2001-260701 A

By the way, it is well known that the determination of the rollover of the vehicle occurs when the sum of the rotational energy and the potential energy of the vehicle exceeds the rollover limit energy, and this relationship uses the roll angle and roll angular velocity of the vehicle as parameters. It can be represented by the roll limit curve of the map in two dimensions.
On the other hand, the rollover determination device deploys a curtain airbag in order to prevent an occupant from directly colliding with a side window and a pillar portion when a rollover occurs and to prevent injury due to release from the vehicle.

  Therefore, the curtain airbag needs to be deployed in the gap between the side window and the occupant, but the above-mentioned energy determination can determine the rollover of the vehicle, but the amount of movement of the occupant associated with the inclination or lateral acceleration of the vehicle can be predicted. Therefore, at the above judgment timing, when the curtain airbag is deployed, the leading edge (lower part) of the curtain airbag is caught on the head and shoulders of the occupant and the curtain airbag does not deploy normally. There was a problem that occurred.

  The present invention has been made in order to solve the above-described problems. A vehicle rollover prediction function is added to the determination of a two-dimensional map using the roll angle and roll angular velocity of the vehicle as parameters. It is an object of the present invention to obtain a rollover determination device that can normally deploy a curtain airbag by determining the possibility of rollover.

A rollover determination device according to the present invention includes a lateral acceleration detection unit that detects a lateral acceleration of a vehicle, and a roll angular velocity of the vehicle according to a magnitude of the lateral acceleration detected by the lateral acceleration detection unit. Threshold inclination changing means for changing the inclination without changing the intercept of the threshold value set on the two-dimensional map with the roll angle as a parameter and the roll angle axis is provided.

According to the present invention, the inclination of the threshold judgment line is changed according to the magnitude of the lateral acceleration without changing the intercept with the roll angle axis, so that a rollover with a small vehicle inclination angle can be judged early and quickly. In addition, there is an effect that the curtain airbag can be reliably deployed.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
Embodiment 1 FIG.
FIG. 1 is a block diagram showing a rollover determination device according to Embodiment 1 of the present invention.
In FIG. 1, the rollover determination device according to the first embodiment includes a roll angular velocity sensor 10 as a roll angular velocity detection means for detecting a rotational speed around the longitudinal axis of the vehicle, that is, a roll angular velocity ω, and an acceleration generated in the width direction of the vehicle. That is, a lateral acceleration sensor 20 as a lateral acceleration detecting means for detecting the lateral acceleration Gy, and a vertical acceleration sensor 30 as a vertical acceleration means for detecting an acceleration generated in the vertical axis direction of the vehicle, that is, a vertical acceleration Gz. And a controller 40 that determines whether the vehicle rolls over based on the detection outputs of the roll angular velocity sensor 10 and the directional acceleration sensors 20 and 30, and the controller 40 that operates in response to an activation command from the controller 40, that is, the determination result of the controller 40. Depending on the deployment of the vehicle curtain airbag (not shown) And a curtain air bag deployment unit 50.

  The controller 40 integrates the roll angular velocity ω detected by the roll angular velocity sensor 10 to calculate the roll angle Θ of the vehicle and calculates the roll angle Θ of the vehicle, and the vehicle detected by the roll angular velocity sensor 10. As the threshold line inclination changing means for inputting the roll angular velocity ω of the vehicle and the lateral acceleration Gy of the vehicle detected by the lateral acceleration sensor 20 and changing the inclination of the reference threshold ωth line set on the two-dimensional map described later. Two-dimensional, for example, the vertical axis represents the roll angular velocity ω (deg / s) on the threshold value changing function unit 42 and the roll angle velocity ω of the vehicle from the roll angle calculating unit 41 and the roll angular velocity ω from the threshold changing function unit 42 as parameters. ), Using the map as shown in FIG. 3 (hereinafter referred to as ω-Θ map) with the horizontal axis as the roll angle Θ (deg), and the origin side of the reference threshold ωth line Non rollover area, and a omega-theta map determination section 43 as determined rollover judgment means whether a rollover occurrence of the vehicle opposite the rollover area. ωo is a critical angular velocity threshold. Here, the threshold value changing function unit 42 tilts the reference threshold line ωth of the ω-Θ map in the ω-Θ map determination unit 43 according to the magnitude of the lateral acceleration Gy of the vehicle detected by the lateral acceleration sensor 20. Has a function of changing A to B and A to C.

  Further, the controller 40 determines that the product of the roll angular velocity ω and the lateral acceleration Gy of the vehicle is 0 based on the roll angular velocity ω detected by the roll angular velocity sensor 10 and the lateral acceleration Gy of the vehicle detected by the lateral acceleration sensor 20. A lateral acceleration Gy that determines a side collision of the vehicle based on the lateral acceleration Gy detected by the lateral acceleration sensor 20 and the polarity determination unit 44 that determines whether the vehicle is greater than, that is, ω × Gy ″> 0. Is a side collision determination unit 45 that determines a side collision by | Gy | ≧ S. The polarity determination unit 44 and the side collision determination unit 45 substantially have a roll angular velocity ω and a lateral acceleration. A determination prohibiting means having a function of prohibiting determination for a predetermined time t when the Gy signal does not match the sign or the lateral acceleration Gy exceeds a predetermined value s is configured.

  Further, the controller 40 multiplies the change amount dω of the roll angular velocity ω detected by the roll angular velocity sensor 10 by the vertical acceleration Gz detected by the vertical acceleration sensor 30, and compares the multiplied value with a predetermined value n. A comparison operation unit 46 as an airbag deployment control means, an AND circuit 48 that takes the logical product of the output of the side collision determination unit 45 and the output of the comparison operation unit 46, the output of the ω-Θ map determination unit 43, and the side collision determination AND circuit 49A which takes the logical product of the output of unit 45 and the output of polarity determination unit 44, and OR circuit 49B which takes the logical sum of the output of AND circuit 48 and the output of AND circuit 49A, and the output of OR circuit 49B is The curtain airbag deployment unit 50 is supplied.

  In FIG. 6, the case where the polarity of each sensor is positive is indicated by an arrow. In the case of the roll angular velocity sensor 10, the roll angular velocity ω is rotated to the right, and in the case of the lateral acceleration sensor 20, the lateral acceleration Gy is directed to the right. In the case of the direction acceleration sensor 30, the case where the vertical acceleration Gz is upward indicates that each is a positive signal.

Next, the operation will be described with reference to FIGS.
FIG. 2 is a schematic diagram of the configuration of the controller 40 in FIG. 1 (excluding the roll angle calculation unit 41). In the threshold change function unit 42, the lateral acceleration of the vehicle detected by the lateral acceleration sensor 20 is illustrated. According to the magnitude of Gy, as shown in FIG. 3, ω-Θ having a two-dimensional map with the vehicle roll angle Θ from the roll angle calculation unit 41 and the roll angular velocity ω from the threshold change function unit 42 as parameters. The inclination of the reference threshold line ωth of the map determination unit 43 is changed. At this time, the threshold changing function unit 42 converts the lateral acceleration Gy from the lateral acceleration sensor 20 into a lateral acceleration Gy ′ used for changing the threshold, using a map as shown in FIG. In FIG. 4, the broken line characteristic represents Gy ′ = Gy in the case where no conversion is performed, and the lateral acceleration Gy is converted into a lateral acceleration Gy ′ indicated by a solid line. The lateral acceleration Gy ′ is regarded as 0 G when it is below a certain value a (for example, 1 G), and is regarded as constant acceleration when it exceeds a certain value b (for example, 2 G). In other words, the lateral acceleration Gy ′ is used as threshold change information. When the lateral acceleration Gy is small below a certain value a, it is ignored. The direction acceleration sensor 20 is designed to avoid noise removal in the low level region and excessive threshold value change in the high level region.

  The threshold value changing function unit 42 multiplies the converted lateral acceleration Gy ′ by the roll angular velocity ω from the roll acceleration sensor 10, and multiplies the multiplication value Gy ′ × ω to the subtracter 43 a in the ω-Θ map determination unit 43. The value of ωth−Gy ′ × ω is calculated by subtracting from the reference threshold value ωth. Then, the value of ωth−Gy ′ × ω from the subtractor 43a is input to one input terminal of the comparator 43b, and the comparator 43b receives the value of ωth−Gy ′ × ω input to this one input terminal. And the value of the roll angular velocity ω from the roll acceleration sensor 10 input to the other input terminal. When ω> ωth−Gy ′ × ω, the positive signal “1” is output from the AND circuit 49A. 1 to the input terminal.

FIG. 3 shows a state in which the inclination of the reference threshold value ωth line is changed by the threshold value changing function unit 42 in accordance with the magnitude of the lateral acceleration Gy detected by the lateral acceleration sensor 20, and is indicated by a solid line a. The inclination of the reference threshold value ωth is changed to a threshold value as indicated by a broken line b or c. That is, in FIG. 3, a broken line b or c indicates a product ω × (Gy−a) of a vehicle roll angular velocity ω described later and a lateral acceleration Gy under a certain condition with respect to the reference threshold ωth line indicated by the solid line a. ) Or the threshold change result by the ratio 1 / Gy.
Here, a rollover prediction function is added to the determination of the ω-Θ map in the ω-Θ map determination unit 43, and the possibility of rollover is determined at an early stage so that the curtain airbag can be normally deployed. . The rollover prediction function is the product of the roll angular velocity ω of the vehicle and the lateral acceleration Gy under a certain condition ω × (Gy−a) or the ratio 1 / Gy, and the inclination of the judgment threshold line, that is, the inclination of the reference threshold ωth Are realized by changing each according to the following equation.

When ω ≧ 0, ω ≧ ωth−ω × Gy ′ (1)
When ω <0, ω ≦ −ωth + ω × Gy ′ (2)
Here, Gy ′ is defined by a conversion map as shown in FIG. 4 and | Gy ′ | ≦ b.

Further, as will be described later, when the lateral acceleration Gy is equal to or greater than a certain threshold, that is, | Gy | ≧ s, determination is made by a side collision determination algorithm in the side determination unit 45, and further, the lateral acceleration Gy is a certain threshold. When the product of the change amount (dω) of the roll angular velocity ω and the vertical acceleration Gz exceeds a certain value, that is, the threshold value represented by the following equation (3), after the occurrence of the above, for a certain time t, The comparison calculation unit 46 performs airbag deployment control.
dω × (Gz−1) ≧ n (3)

  Further, the lateral acceleration Gy from the lateral acceleration sensor 20 is supplied to the multiplying unit 44a of the polarity determining unit 44, and the lateral acceleration Gy from the lateral acceleration sensor 20 is converted into polarity using a map as shown in FIG. It is converted into lateral acceleration Gy ″ for determination. In FIG. 5, the broken line characteristic represents Gy ′ = Gy in the case of non-conversion, and the lateral acceleration Gy is converted to Gy ″ along the solid line characteristic. The For example, c = 0.2 on the horizontal axis indicates that the bias is applied by 0.2 in order to remove noise.

  Next, the multiplication unit 44a of the polarity determination unit 44 multiplies the converted lateral acceleration Gy ″ by the roll angular velocity ω from the roll acceleration sensor 10 and uses the multiplied value Gy ″ × ω as one input terminal of the comparator 44b. In the comparator 44b, the multiplication value Gy ″ × ω input to one of the input terminals is compared with the value of 0 input to the other input terminal, and Gy ″ × ω> 0. In this case, a positive signal “1” is supplied to the second input terminal of the AND circuit 49A.

  In the side collision determination unit 45, the comparator 45a compares the absolute value | Gy | of the lateral acceleration Gy from the lateral acceleration sensor 20 with a constant value s. If | Gy | ≧ s, the ON timer 45b The positive output “1” is held for a certain time t. The output of the ON timer 45b is supplied as a negative signal “0” by the inverter 45c to the third input terminal of the AND circuit 49A of the AND circuit 49A, and the rollover determination is prohibited for a certain period of time.

  Further, the comparison calculation unit 46 multiplies the change amount dω of the roll angular velocity ω detected by the roll angular velocity sensor 10 by the vertical acceleration Gz−1 detected by the vertical acceleration sensor 30 by the multiplier 46a, and the multiplication value. dω × (Gz−1) and a predetermined value n are compared by the comparator 46 b and input to the other input terminal of the AND circuit 48. The output of the ON timer 45 b of the side collision determination unit 45 is input to one input terminal of the AND circuit 48.

  Therefore, when the absolute value | Gy | of the lateral acceleration exceeds a certain value s, the rollover determination is prohibited for a certain time as described above, and the product of the change amount dω of the roll angular velocity ω and the vertical acceleration Gz during that time is When a certain threshold value is exceeded, airbag deployment control is performed via the curtain airbag deployment section 50. That is, when the absolute value | Gy | of the lateral acceleration exceeds a certain value s, it is determined as a side collision, and the deployment of the airbag is determined and controlled by the side collision. Rollover judgment based on is prohibited. However, after that, when the product of the change amount dω of the roll angular velocity ω and Gz−1 obtained by correcting the vertical acceleration by the gravitational acceleration exceeds a certain value, it is determined that the rollover has occurred and the development can be determined.

  As described above, according to the present embodiment, by changing the inclination of the threshold line according to the amount of change in the lateral acceleration, vertical acceleration, and roll angular velocity of the vehicle, the two-dimensional By adding a vehicle rollover prediction function to the map determination and determining the possibility of vehicle rollover at an early stage, a rollover determination device that can normally deploy the curtain airbag can be obtained. As a result, even if a non-rollover impact indicated by the curve d in FIG. 3 is applied, the rollover indicated by the curve D only changes in the inclination of the threshold ωth line of the ω-Θ map as A → B and A → C. The curtain airbag will not be inadvertently deployed on the history line of a vehicle that returns without being restored. For this reason, as shown by an imaginary line, in the conventional apparatus in which the threshold ωth line is translated as shown by the curves B ′ and C ′, it is possible to eliminate the deployment of the curtain airbag.

It is a block diagram which shows the rollover determination apparatus by Embodiment 1 of this invention. It is a schematic diagram which shows the structure of the principal part in the rollover determination apparatus by Embodiment 1 of this invention. It is a characteristic view which shows the change of the determination threshold value for demonstrating operation | movement of the rollover determination apparatus by Embodiment 1 of this invention. It is a figure for converting lateral direction acceleration Gy into Gy 'in the rollover judging device by Embodiment 1 of this invention. It is a figure for determining whether the roll angular velocity (omega) and the polarity of the lateral direction acceleration Gy correspond in the roll over determination apparatus by Embodiment 1 of this invention. It is a figure which shows the case where the polarity of each sensor in the rollover determination apparatus by Embodiment 1 of this invention is positive.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Roll angular velocity sensor, 20 Lateral acceleration sensor, 30 Vertical acceleration sensor, 40 Controller, 41 Roll angle calculating part, 42 Threshold change function part, 43 omega-theta map determination part, 44 Polarity determination part, 45 Side collision determination part 46 Comparison operation unit, 48, 49A AND circuit, 49B OR circuit, 50 curtain airbag deployment unit.

Claims (4)

Roll angular velocity detecting means for detecting the roll angular velocity of the vehicle, and roll angle calculating means for calculating the roll angle of the vehicle based on the detection output of the roll angular velocity detecting means, wherein the roll angular velocity and roll angle of the vehicle are parameters In the rollover determination device that determines rollover based on whether or not the threshold value indicated by the two-dimensional map is exceeded,
Lateral acceleration detection means for detecting lateral acceleration of the vehicle;
A roll comprising threshold inclination changing means for changing the inclination without changing the intercept of the threshold with respect to the roll angular axis according to the magnitude of the lateral acceleration detected by the lateral acceleration detecting means. Over determination device.   The vehicle is provided with determination prohibiting means for prohibiting determination by the rollover determination means for a certain time when the signs of the roll angular velocity and lateral acceleration signals of the vehicle do not match or the lateral acceleration exceeds a certain value. The rollover determination device according to claim 1.   The threshold inclination changing means considers 0G when the lateral acceleration used for changing the inclination of the threshold is not more than a certain value, and regards it as a constant acceleration when exceeding a certain value. The rollover determination device according to claim 2. The vertical acceleration detection means for detecting the vertical acceleration of the vehicle, and the vertical acceleration detected by the vertical acceleration detection means and the roll angular velocity detection means while the determination is prohibited for a certain time by the determination prohibiting means. 3. The rollover determination device according to claim 2, further comprising an airbag deployment control means for performing airbag deployment control when the product of the detected changes in roll angular velocity exceeds a certain threshold value.

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