JP2019018658A - Collision detector and collision detection method - Google Patents

Abstract

To prevent an occupant protection device from being erroneously activated.SOLUTION: A collision detector comprises: an activation determination section; an acquisition section; and a switching section. The activation determination section activates an occupant protection device mounted to a vehicle, when a sensor value from a sensor detecting impact shock applied to the vehicle exceeds a prescribed collision determination threshold value. The acquisition section acquires a vehicle door state. The switching section switches the collision determination threshold value to a prescribed low threshold value corresponding to a normal time threshold value, when the vehicle door state has been acquired in a normal manner by the acquisition section, and the vehicle door state indicates a closed door state, whereas the collision determination threshold value is switched to a prescribed high threshold value which is greater than the low threshold value, when the vehicle door state is not acquired in a normal manner by the acquisition section.SELECTED DRAWING: Figure 2

Description

  Embodiments disclosed herein relate to a collision detection apparatus and a collision detection method.

  Conventionally, airbags and pretensioners are widely known as occupant protection devices mounted on vehicles. Such an occupant protection device is activated by a collision detection device that detects a vehicle collision.

  The collision detection device activates the occupant protection device when, for example, a collision is detected based on an output value of an acceleration sensor mounted on the vehicle. However, since the occupant protection device is a device that requires high reliability due to the characteristic of protecting the occupant, the collision detection device needs to accurately distinguish between a collision and an event other than a collision for the activation determination. .

  For example, one of the events that should be determined as other than a collision is the strong closing of the door in which the door is strongly closed. In order to prevent the occupant protection device from being activated due to such a strong door closure being detected as a collision, for example, the door open / close state is detected from the ON / OFF state of the door switch, and a predetermined time has elapsed since the door was opened. In the meantime, a technique has been proposed in which an occupant protection device is deactivated even when an acceleration sensor detects an impact (see, for example, Patent Document 1).

JP-A-5-278563

  However, the above-described conventional technology has room for further improvement in preventing erroneous activation of the occupant protection device.

  Specifically, when the above-described conventional technology is used, for example, when the door open / close state cannot be normally detected due to a door switch failure or disconnection, the occupant protection device is regarded as an inoperative state. Otherwise, the passenger protection device may be accidentally activated.

  One aspect of the embodiments has been made in view of the above, and an object thereof is to provide a collision detection device and a collision detection method that can prevent erroneous activation of an occupant protection device.

  A collision detection device according to an aspect of an embodiment includes an activation determination unit, an acquisition unit, and a switching unit. The activation determination unit activates an occupant protection device mounted on the vehicle when a sensor value from a sensor that detects an impact applied to the vehicle exceeds a predetermined collision determination threshold. The acquisition unit acquires a state of the vehicle door. The switching unit switches the collision determination threshold to a predetermined low threshold corresponding to a normal threshold when the state is normally acquired by the acquisition unit and the state indicates the closed state of the door. At the same time, when the state is not normally acquired by the acquisition unit, the collision determination threshold is switched to a predetermined high threshold larger than the low threshold.

  According to one aspect of the embodiment, erroneous activation of the occupant protection device can be prevented.

Drawing 1A is an outline explanatory view (the 1) of a collision detection method concerning an embodiment. FIG. 1B is a schematic explanatory diagram (part 2) of the collision detection method according to the embodiment. FIG. 1C is a schematic explanatory diagram (part 3) of the collision detection method according to the embodiment. FIG. 1D is a schematic explanatory diagram (part 4) of the collision detection method according to the embodiment. FIG. 1E is a schematic explanatory diagram (No. 5) of the collision detection method according to the embodiment. FIG. 2 is a block diagram of the occupant protection system according to the embodiment. FIG. 3 is a flowchart illustrating a processing procedure executed by the collision detection apparatus according to the embodiment.

  Hereinafter, embodiments of a collision detection device and a collision detection method disclosed in the present application will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited by embodiment shown below.

  In the following description, the occupant protection device is the airbag 20 (see FIG. 2), and the case where the airbag 20 is deployed at the time of a side collision of the vehicle C will be described as a main example. Note that “side collision” may be referred to as “side collision”.

  Moreover, below, after describing the outline | summary of the collision detection method which concerns on this embodiment using FIG. 1A-FIG. 1E, the collision detection apparatus 10 which applied the collision detection method which concerns on this embodiment, and an occupant protection system provided with the same The specific configuration and processing procedure of 1 will be described with reference to FIGS.

  First, the outline | summary of the collision detection method which concerns on this embodiment is demonstrated using FIG. 1A-FIG. 1E. 1A to 1E are schematic explanatory views (No. 1) to (No. 5) of a collision detection method according to the present embodiment.

  For ease of explanation, FIG. 1A shows a three-dimensional orthogonal coordinate system including a Z-axis having a vertical upward direction as a positive direction and a vertical downward direction as a negative direction.

  As shown in FIG. 1A, the vehicle C includes a body ECU (Electronic Control Unit) 2, an impact sensor 3, and a collision detection device 10. The body ECU 2 is a control device for controlling an electrical component of the vehicle C (for example, a door lock, a mirror, illumination, a security device, etc.) and a power source.

  The impact sensor 3 is a sensor provided for side collision detection, for example, an acceleration sensor. Of the impact sensors 3, the impact sensor 3a is disposed, for example, at a site M1 near the lower end of a center pillar (so-called B pillar) of the vehicle C.

  Further, the impact sensor 3b of the impact sensor 3 is disposed, for example, in the opening of the rear side door and the part M2 in the vicinity of the rear wheel house. Here, two impact sensors 3a and 3b are illustrated, but the location and number of the impact sensors 3a and 3b are not limited.

  The collision detection device 10 is provided so as to be able to communicate with each of the body ECU 2 and the impact sensor 3. The collision detection device 10 deploys the airbag 20 when the impact sensor 3 detects an impact greater than a predetermined value (hereinafter referred to as “collision determination threshold”) that acts mainly on the side surface of the vehicle body from the Y direction. Let

  However, the impact sensor 3 may detect a certain degree of impact even when an event other than a collision occurs. As an event other than such a collision, for example, the door is closed.

  Needless to say, the collision detection for deploying the airbag 20 requires high reliability. Therefore, it is necessary to prevent the airbag 20 from being deployed even if the airbag 20 is mistaken due to daily strong door closure.

  Therefore, in the collision detection device 10, the collision determination threshold is basically set so that the airbag 20 is not deployed due to the impact when the door is strongly closed. An example is shown in FIG. 1B. In FIG. 1B, for convenience of explanation, the impact waveform of “when the door is strongly closed” and the impact waveform of “at the time of collision” when the door is strongly closed or collided at time t1 are shown superimposed. ing.

  As shown in FIG. 1B, the collision determination threshold value is set so that a sufficient margin m is vacated from the impact “when the door is strongly closed”. Therefore, in the example shown in FIG. 1B, at the time of “collision” that occurred at time t1, a collision is detected at time t3 based on the collision determination threshold value, and the airbag is deployed.

  However, increasing the collision determination threshold so that the margin m is free means that the airbag 20 is difficult to be deployed. For this reason, there is a risk of causing a delay in the deployment of the airbag 20 during an actual collision.

  Therefore, in the collision detection method according to the present embodiment, the door state is acquired, the door is strongly closed based on the door state, and the high threshold at which the margin m is vacant when the door is strongly closed is otherwise. The collision determination threshold is switched so that a low threshold smaller than the high threshold is set for each.

  Specifically, in the collision detection method according to the present embodiment, the collision detection device 10 periodically acquires the door state from, for example, the body ECU 2 after the ignition is turned on. Then, as shown in FIG. 1C, for example, if a “door open state”, which is a state in which the door is open at time t0, is acquired (step S1), the collision determination threshold is switched from the low threshold to the high threshold (step S2). .

  For example, if a “door closed state”, which is a state in which the door is closed at time t1, is acquired (step S3), the collision determination threshold is switched from the high threshold to the low threshold after a predetermined delay time D1 has elapsed. (Step S4).

  Thus, when the door is strongly closed, a high threshold with a sufficient margin m is set as the collision determination threshold with respect to the shock waveform when the door is strongly closed, and the low threshold is set as the collision determination threshold except when the door is strongly closed. Can be set.

  Therefore, when the door is strongly closed, it is possible to prevent the airbag 20 from being unintentionally deployed due to an impact at that time. In addition, since the threshold value is switched after waiting for the elapse of the predetermined delay time D1 corresponding to the convergence time of vibration immediately after the door is strongly closed, it is possible to reliably prevent the airbag 20 from being unintentionally deployed.

  On the other hand, since the collision determination is performed with a low threshold during normal driving other than when the door is strongly closed, for example, as shown in FIG. 1D, when a collision occurs at time t1, collision detection is performed at time t3 with a high threshold. And the airbag deployment can be made to respond early at time t2. Therefore, the airbag 20 can be deployed with high responsiveness during an actual collision.

  Furthermore, in the collision detection method according to the present embodiment, “door type” and “acquisition status” are acquired regarding the door state to be acquired. Whether or not it is at least a hinge door is determined based on “door type”. Further, it is determined from the “acquisition status” whether or not at least the door state has been normally acquired.

  In the collision detection method according to the present embodiment, the impact sensor 3 does not detect a shock value higher than that of a hinge door when the door is strongly closed by a slide door other than a hinge door. To be switched. Moreover, it is not set as a switching object except hinge doors, for example, a collision determination threshold value is always set to a low threshold value.

  Specifically, in the collision detection method according to the present embodiment, as shown in FIG. 1E, when the door type is other than the hinge door, regardless of the door open / close state and the impact waveform of “when the hinge door is strongly closed”, The collision determination threshold can be fixed at a low threshold (step S5). Thereby, in the case of other than the hinge door, the airbag 20 can be deployed with high responsiveness in the event of an actual collision without reducing the sensitivity of collision detection.

  Further, in the collision detection method according to the present embodiment, when the door state cannot be normally acquired, that is, when the door state acquisition is abnormal, the collision determination threshold is set to a high threshold that the airbag 20 is difficult to deploy.

  Specifically, in the collision detection method according to the present embodiment, as shown in FIG. 1E, when the door state acquisition is abnormal, the collision determination threshold value may be fixed to a high threshold value regardless of the door open / closed state that cannot be acquired. Yes (step S6).

  As a result, a door state acquisition abnormality may occur. For example, when the vehicle C is in a primary state, which is an initial diagnosis state immediately after the ignition is turned on, or when a failure occurs in the body ECU 2 or a disconnection occurs. For example, the airbag 20 can be prevented from being accidentally deployed.

  Note that when the door state acquisition status changes from abnormal to normal, the collision determination threshold value can be switched, for example, as appropriate according to the example illustrated in FIG. 1C.

  Hereinafter, the collision detection apparatus 10 to which the collision detection method according to the present embodiment described above is applied and the occupant protection system 1 including the collision detection apparatus 10 will be described more specifically.

  FIG. 2 is a block diagram of the occupant protection system 1 according to the present embodiment. In FIG. 2, only components necessary for explaining the features of the present embodiment are represented by functional blocks, and descriptions of general components are omitted.

  In other words, each component illustrated in FIG. 2 is functionally conceptual and does not necessarily need to be physically configured as illustrated. For example, the specific form of distribution / integration of each functional block is not limited to the one shown in the figure, and all or a part thereof is functionally or physically distributed in arbitrary units according to various loads or usage conditions.・ It can be integrated and configured.

  As shown in FIG. 2, the occupant protection system 1 includes a body ECU 2, an impact sensor 3, a collision detection device 10, and an airbag 20. Since the body ECU 2 and the impact sensor 3 have already been described, description thereof is omitted here. In the present embodiment, the impact sensor 3 is an acceleration sensor, but may be a pressure sensor or the like as long as it can output a signal corresponding to an impact received by a collision.

  The air bag 20 is a device that, when a collision of the vehicle C is detected, expands the bag body by exploding explosives inside and reduces the impact applied to the occupant. Examples of the airbag 20 corresponding to the side collision include a side airbag and a curtain airbag.

  The collision detection device 10 is communicably connected to the body ECU 2 and the impact sensor 3. Further, the collision detection device 10 is provided so as to be able to ignite a squib (not shown) that is an ignition device of the airbag 20.

  The collision detection device 10 includes a control unit 11 and a storage unit 12. The control unit 11 includes a door state acquisition unit 11a, a strong closing determination unit 11b, a switching unit 11c, and an activation determination unit 11d.

  The storage unit 12 is a storage device such as a hard disk drive, a nonvolatile memory, or a register, and stores type information 12a and threshold information 12b. The type information 12a is information including the “door type” described above. The threshold information 12b is information including the above-described high threshold and low threshold, the current value of the collision determination threshold, and the like.

  The control unit 11 controls the entire collision detection device 10. The door state acquisition unit 11a acquires the door state from the body ECU 2. The door state includes a door open / close state. Further, when the door state acquisition unit 11a has successfully acquired the door state, the door state acquisition unit 11a notifies the strongly closed determination unit 11b of the acquired door state.

  Further, when the door state cannot be normally acquired, the door state acquisition unit 11a notifies the strong closing determination unit 11b to that effect. In the example illustrated in FIG. 2, the door type is acquired from the type information 12 a, but the door state acquisition unit 11 a may be acquired from the body ECU 2.

  The hard closing determination unit 11b refers to the type information 12a, and when the door type is a hinge door, the collision determination threshold is set to the switching unit 11c based on the door state notified from the door state acquisition unit 11a. To switch between.

  For example, if the door type is a hinge door and the door state acquisition unit 11a notifies the door open state, the strong close determination unit 11b causes the switching unit 11c to switch the collision determination threshold to a high threshold.

  In addition, when the door type is a hinge door and the door closing state is notified from the door state acquisition unit 11a, the strong closing determination unit 11b notifies the switching unit 11c of the collision determination threshold value after a predetermined delay time D1 has elapsed. Is switched to a low threshold.

  Further, when the door type is other than a hinged door, the strong closing determination unit 11b causes the switching unit 11c to fix the collision determination threshold value to a low threshold value.

  Moreover, the strong closing determination part 11b makes the switching determination part 11c fix a collision determination threshold value to a high threshold value, when the notification to the effect that the door state was not normally acquired from the door state acquisition part 11a is received.

  The switching unit 11c switches the current value of the collision determination threshold included in the threshold information 12b based on the switching instruction from the strong closure determination unit 11b.

  The activation determination unit 11d determines that the airbag 20 needs to be activated and deploys the airbag 20 when the impact value input from the impact sensor 3 exceeds the collision determination threshold of the threshold information 12b.

  Next, a processing procedure executed by the collision detection apparatus 10 according to the present embodiment will be described with reference to FIG. FIG. 3 is a flowchart showing a processing procedure executed by the collision detection apparatus 10 according to the present embodiment. FIG. 3 shows a processing procedure that is periodically repeated after the ignition is turned on. Therefore, when the ignition is turned off, the process is terminated.

  As shown in FIG. 3, first, the ignition is turned on (step S101). Then, the strong closing determination unit 11b determines whether or not the door type is a hinge door (step S102).

  Here, when the door type is a hinge door (step S102, Yes), the door state acquisition unit 11a acquires the door state from the body ECU 2 (step S103). Moreover, the door state acquisition part 11a determines whether this door state was able to be acquired normally (step S104).

  Here, when it can acquire normally (step S104, Yes), the strong closing determination part 11b determines whether the open / closed state of the door included in the acquired door state is a door closed state (step S105). ).

  If the door is closed (Yes at Step S105), the strong-close determining unit 11b waits for a predetermined time delay (Step S106), that is, a predetermined delay time D1, and then sets a collision determination threshold to the switching unit 11c. Switch to the low threshold (step S107). “Collision determination threshold ← low threshold” in step S107 represents that a low threshold is set as the collision determination threshold. Here, the delay processing in step S106 is performed only when the door is closed from opening, that is, when the answer is No after step S105, and the door is not opened and the door is not opened in step S105. If it is determined that the door is closed, that is, if the ignition is turned on when the door is closed, the process proceeds to step S107 without performing the delay process of step S106.

  Even when the door type is other than the hinged door in step S102 (No in step S102), the strong closing determination unit 11b causes the switching unit 11c to switch the collision determination threshold to a low threshold (step S107).

  On the other hand, when the door state cannot be normally acquired in step S104 (step S104, No), or when the open / closed state of the door is other than the door closed state in step S105 (step S105, No), the strongly closed determination unit 11b causes the switching unit 11c to switch the collision determination threshold value to the high threshold value (step S108). “Collision determination threshold ← high threshold” in step S108 represents that a high threshold is set as the collision determination threshold.

  Then, the activation determination unit 11d performs a collision determination based on the current value of the collision determination threshold included in the threshold information 12b and the impact value from the impact sensor 3 (step S109). Although not shown here, when it is determined by the collision determination that the airbag 20 needs to be activated, the airbag 20 is deployed. If the airbag 20 is not deployed, that is, if no collision is detected, the processing from step S102 is repeated.

  As described above, the collision detection apparatus 10 according to the present embodiment includes the activation determination unit 11d, the door state acquisition unit 11a (corresponding to an example of “acquisition unit”), and the switching unit 11c.

  The activation determination unit 11d is mounted on the vehicle C when an impact value from the impact sensor 3 that detects an impact applied to the vehicle C (corresponding to an example of “sensor value from the sensor”) exceeds a predetermined collision determination threshold value. The airbag 20 (corresponding to an example of “occupant protection device”) is activated. The door state acquisition unit 11a acquires the state of the door of the vehicle C.

  When the door state is normally acquired by the door state acquisition unit 11a and the door state indicates the door closed state, the switching unit 11c sets the collision determination threshold value to a predetermined low threshold value corresponding to the normal threshold value. When the door state acquisition unit 11a does not normally acquire the door state, the collision determination threshold value is switched to a predetermined high threshold value that is larger than the low threshold value.

  Therefore, according to the collision detection device 10 according to the present embodiment, erroneous activation of the airbag 20 can be prevented even when the door state is not normally acquired.

  In addition, when the door state acquired by the door state acquisition unit 11a indicates the closed state of the door, the switching unit 11c switches the collision determination threshold to a low threshold after a predetermined delay time D1 has elapsed.

  Therefore, according to the collision detection device 10 according to the present embodiment, the threshold value is switched after waiting for the elapse of the predetermined delay time D1 corresponding to the convergence time of the vibration immediately after the door is strongly closed. It can be surely prevented from being done.

  Moreover, the switching part 11c fixes a collision determination threshold value to a low threshold value when it determines with the kind of door being other than a hinge door.

  Therefore, according to the collision detection device 10 according to the present embodiment, the airbag 20 can be deployed with high responsiveness in the event of an actual collision without reducing the sensitivity of collision detection in cases other than hinge doors.

  The switching unit 11c switches the collision determination threshold to a high threshold when the door state is normally acquired by the door state acquisition unit 11a and the door state indicates the door open state.

  Therefore, according to the collision detection device 10 according to the present embodiment, it is possible to prevent the airbag 20 from being unintentionally deployed due to an impact when the door is strongly closed, which is predicted to continue in the door open state.

  In the above-described embodiment, the hinge door is tightly closed as a determination material for switching the collision determination threshold, but the present invention is not limited to this. For example, road information that is currently prone to accidents is acquired based on navigation information and VICS (registered trademark) (Vehicle Information and Communication System). In order to increase, the collision determination threshold value may be decreased.

  In the above-described embodiment, the door open / close state is acquired from the body ECU 2 and used as the determination material for switching the collision determination threshold. However, the acquired door open / close state is recorded in, for example, the storage unit 12. May be. Currently, there is a function to record various data before and after the occurrence of a collision or abnormal operation of the driver, but by adding the opening / closing state of the door to the recorded object, analysis of the situation at the time of the collision and the driver's operation Can contribute to strengthening.

  In addition, the recording of the open / closed state of the door may be associated with the sensor value from the impact sensor 3 or for each driver. By analyzing such records, for example, it is possible to derive the characteristics of the door opening / closing operation for each driver, and it is possible to take measures such as adjusting the high threshold value for each driver according to such characteristics.

  In the above-described embodiment, the predetermined delay time D1 corresponds to the convergence time of vibration immediately after the door is strongly closed, but may be a time until the vehicle C starts to move.

  In the embodiment described above, the case where the occupant protection device is the airbag 20 has been mainly described. However, as with the airbag 20, other occupant protection such as a pretensioner that is activated when a collision of the vehicle C is detected. You may apply this embodiment about an apparatus.

  Further effects and modifications can be easily derived by those skilled in the art. Thus, the broader aspects of the present invention are not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications can be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

1 Crew protection system 2 Body ECU
DESCRIPTION OF SYMBOLS 3 Impact sensor 10 Collision detection apparatus 11 Control part 11a Door state acquisition part 11b Strongly closed determination part 11c Switching part 11d Starting determination part 12 Storage part 12a Type information 12b Threshold information 20 Airbag C Vehicle D1 Delay time

Claims (5)

An activation determination unit that activates an occupant protection device mounted on the vehicle when a sensor value from a sensor that detects an impact applied to the vehicle exceeds a predetermined collision determination threshold;
An acquisition unit for acquiring a state of the door of the vehicle;
When the state is normally acquired by the acquisition unit and the state indicates a closed state of the door, the collision determination threshold is switched to a predetermined low threshold corresponding to a normal threshold, and the acquisition unit And a switching unit that switches the collision determination threshold value to a predetermined high threshold value that is larger than the low threshold value when the state is not acquired normally. The switching unit is
The collision determination threshold value is switched to the low threshold value after a predetermined delay time has elapsed when the state acquired by the acquisition unit indicates a closed state of the door. Collision detection device. The switching unit is
The collision detection apparatus according to claim 1, wherein when the door type is determined to be other than a hinged door, the collision determination threshold value is fixed to the low threshold value. The switching unit is
The collision determination threshold value is switched to the high threshold value when the state is normally acquired by the acquisition unit and the state indicates an open state of the door. The collision detection device described. An activation determination step of activating an occupant protection device mounted on the vehicle when a sensor value from a sensor for detecting an impact applied to the vehicle exceeds a predetermined collision determination threshold;
An acquisition step of acquiring a state of the door of the vehicle;
When the state is normally acquired by the acquisition step and the state indicates a closed state of the door, the collision determination threshold is switched to a predetermined low threshold corresponding to a normal threshold, and the acquisition step And a switching step of switching the collision determination threshold value to a predetermined high threshold value that is larger than the low threshold value when the state is not acquired normally by the collision detection method.

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