Conflict determination device

Abstract

To protect an occupant on a rear seat with a simple configuration by detecting occurrence of rear lateral face collision to a vehicle lateral face where a first acceleration sensor is provided of a vehicle with a small number of acceleration sensors.SOLUTION: When rear lateral face collision to a vehicle lateral face on a driver seat side where a first acceleration sensor 2 is provided of a vehicle 1 occurs, a collision determination device determines whether rotation of the vehicle 1 occurs due to the rear lateral face collision to a vehicle lateral face on the driver seat side of the vehicle 1 by means of determination means on the basis of detection acceleration in two axial directions of a vehicle front-rear direction and a vehicle left-right direction by the first acceleration sensor 2 and a second acceleration sensor 3, and protects an occupant on the rear seat of the vehicle 1 by expanding an air bag being protection means when the determination means determines that the rotation of the vehicle 1 occurs due to the rear lateral face collision.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a collision determination device that determines whether or not a rear side collision has occurred based on acceleration detected by an acceleration detection means provided in a vehicle. [Background technology]

[0002] Conventionally, side airbags and curtain airbags are provided to protect occupants from the impact of a side collision of a vehicle, and for this purpose, a plurality of acceleration sensors are provided on the B-pillar in the center of the vehicle and the C-pillar in the rear of the vehicle to detect the acceleration generated in the vehicle 50 during a collision, as shown in Fig. 11. In particular, it is common to provide acceleration sensors on the left and right C-pillars in the rear of the vehicle as a suitable means for detecting a side collision at the rear seat position. In Fig. 11, 51 is an acceleration sensor for the B-pillar, 52 is an acceleration sensor for the C-pillar, and 53 is an airbag control unit.

[0003] Incidentally, in the case of a rear side collision, particularly next to the rear seats, a characteristic is that the rear of the vehicle rotates around the vehicle's center of gravity, which is located at the front. Therefore, it is considered that a B-pillar acceleration sensor 51 having sensitivity in two axial directions, that is, in the fore-aft and lateral directions of the vehicle, is provided, and the rotation of the vehicle during a side collision is detected based on the acceleration detected by the B-pillar acceleration sensor 51. Protective devices such as side airbags and curtain airbags are then activated under the control of an airbag control unit 53 to protect rear seat occupants (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-43838 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, for example, in the case of a B-pillarless vehicle that does not have a B-pillar on the passenger side, it is not possible to provide a B-pillar acceleration sensor 51 as shown in FIG. 11 on the passenger side, so the technology described in Patent Document 1 cannot be directly applied to a B-pillarless vehicle.

[0006] Furthermore, in order to enable rapid detection of vehicle rotation, it is desirable to locate B-pillar acceleration sensor 51 in FIG. 11 as close to the underbody as possible. If it is to be located in the upper body, however, in the case of a vehicle without a B-pillar on the passenger side, if one attempts to locate B-pillar acceleration sensor 51 in the underbody or rocker panel on the passenger side, there is a problem in that it is difficult to locate B-pillar acceleration sensor 51 in the underbody on the passenger side due to space constraints and from the standpoint of design appearance.

[0007] Furthermore, in the case of a vehicle without a B-pillar on the passenger side, it is possible to provide a door acceleration sensor in the passenger side door which has no B-pillar and use it as a substitute for B-pillar acceleration sensor 51. However, since acceleration on the door side occurs slowly, there is a problem that the door acceleration sensor cannot accurately detect vehicle rotation due to a rear side collision.

[0008] The present invention has been made in consideration of the above-mentioned problems, and has an object to make it possible to accurately determine whether or not a rear side collision has occurred using a small number of acceleration sensors. [Means for solving the problem]

[0009] In order to achieve the above-mentioned object, the collision determination device of the present invention is an occupant protection device that protects occupants in the rear seats of the vehicle by determining whether or not a rear side collision has occurred based on acceleration detected by acceleration detection means provided in the vehicle, the acceleration detection means including a first acceleration sensor provided in a central portion of the side of the vehicle in the vehicle's fore-and-aft direction and a second acceleration sensor provided on the side of the vehicle opposite the side of the vehicle on which the first acceleration sensor is provided, rearward of the central portion in the vehicle's fore-and-aft direction and a second acceleration sensor provided on the side of the vehicle opposite the side of the vehicle on which the first acceleration sensor is provided and detecting acceleration in two axial directions in the vehicle's fore-and-aft direction and the vehicle's left-and-right direction, and a determination means that determines whether the vehicle has rotated due to a rear side collision with the side of the vehicle on which the first acceleration sensor is provided, based on the accelerations detected in the two axial directions by the first acceleration sensor and the second acceleration sensor, respectively.

[0010] With this configuration, when a rear side collision occurs on the side of the vehicle on which the first acceleration sensor is provided, the determination means determines whether or not the vehicle has rotated due to the rear side collision based on the acceleration detected in two axial directions, that is, the fore-aft direction and the left-right direction, of the vehicle by the first acceleration sensor and the second acceleration sensor, respectively.The determination means determines that the vehicle has rotated due to the rear side collision, so that the occurrence of the rear side collision can be accurately detected using a small number of acceleration sensors.

[0011] In addition, the first acceleration sensor detects acceleration in a diagonally rear direction toward a vehicle fore-and-aft axis passing through the center of the vehicle, which occurs due to the rear side collision against the vehicle side on which the first acceleration sensor is provided, and the second acceleration sensor detects acceleration in the vehicle left-right direction, which occurs due to the rear side collision against the vehicle side on which the first acceleration sensor is provided.

[0012] In this case, when a rear side collision occurs against the vehicle side surface on which the first acceleration sensor is provided, the vehicle rotates about the vehicle center of gravity located at the front of the vehicle, and acceleration occurs in the diagonal rear direction toward the vehicle front-rear axis passing through the vehicle center at the position where the first acceleration sensor is disposed, and acceleration occurs in the vehicle left-right direction at the position where the second acceleration sensor is disposed. Therefore, when the first acceleration sensor detects acceleration in the diagonal rear direction toward the vehicle front-rear axis passing through the vehicle center and the second acceleration sensor detects acceleration in the vehicle left-right direction, the determination means can determine that the vehicle has rotated due to a rear side collision against the vehicle side surface on which the first acceleration sensor is provided, and the occurrence of the rear side collision can be detected using a small number of acceleration sensors.

[0013] The first acceleration sensor detects acceleration in a diagonally rearward direction and toward a central axis passing through the center of the vehicle caused by a rear side collision against the vehicle side on which the first acceleration sensor is provided by setting a threshold value that excludes at least one of the following: acceleration in the longitudinal direction of the vehicle caused by traveling on a rough road; acceleration in the rearward direction and the left-right direction of the vehicle caused by a front collision; acceleration in the left-right direction of the vehicle caused by a low-speed side collision with an object including another vehicle against the vehicle side on which the first acceleration sensor is provided; and acceleration in the left-right direction of the vehicle caused by an impact when a door is closed. It is preferable that the second acceleration sensor detects acceleration in the left-right direction of the vehicle caused by a rear side collision against the side of the vehicle on which the first acceleration sensor is provided, by setting a threshold value that excludes at least one of the following: acceleration in the front-rear direction of the vehicle caused by driving on a rough road; acceleration in the rear direction and the left-right direction of the vehicle caused by a forward collision; acceleration in the left-right direction of the vehicle caused by a low-speed side collision of a target including another vehicle against the side of the vehicle on which the first acceleration sensor is provided; and acceleration in the left-right direction of the vehicle caused by an impact when a door is closed.

[0014] In this way, when a rear side collision occurs on the vehicle side on which the first acceleration sensor is provided, the rear of the vehicle rotates about the vehicle's center of gravity located at the front of the vehicle, and acceleration is generated in the diagonal rear direction and toward the vehicle's fore-and-aft axis passing through the center of the vehicle at the position where the first acceleration sensor is provided, while acceleration is generated in the vehicle's left-right direction at the position where the second acceleration sensor is provided. However, with respect to the first and second acceleration sensors, threshold values ​​are set that exclude at least one of the following: acceleration in the vehicle fore-and-aft direction caused by driving on rough roads, acceleration in the vehicle rearward and left-right directions caused by a forward collision, acceleration in the vehicle left-right direction caused by a low-speed side collision with an object including another vehicle against the vehicle side on which the first acceleration sensor is provided, and acceleration in the vehicle left-right direction caused by an impact when the door is closed. Therefore, it becomes possible for the first and second acceleration sensors to exclude acceleration caused by driving on rough roads, etc., and to detect only the acceleration caused by the rear side collision having an impact force that should protect rear seat occupants, making it possible to more accurately detect the occurrence of the rear side collision.

[0015] Further, an occupant protection device of the present invention protects occupants in rear seats of a vehicle by determining whether or not a rear side collision has occurred based on acceleration detected by acceleration detection means provided in the vehicle, the acceleration detection means comprising a first acceleration sensor provided in a central portion of a side of the vehicle in the vehicle's fore-and-aft direction and a second acceleration sensor provided on a side of the vehicle opposite to the side of the vehicle on which the first acceleration sensor is provided, rearward of the central portion in the vehicle's fore-and-aft direction and detecting acceleration in one axial direction in the vehicle's left-and-right direction, and and , the acceleration detected in the longitudinal direction of the vehicle by the first acceleration sensor and the acceleration detected in the longitudinal direction of the vehicle by the other acceleration sensors Degree At least one andThe vehicle may also be provided with a determination means for determining whether the vehicle has rotated due to a rear side collision against the vehicle side on which the first acceleration sensor is provided, based on the above, and a protection means for protecting occupants in the rear seats of the vehicle when the determination means determines that the vehicle has rotated due to the rear side collision.

[0016] According to this configuration, when a rear side collision occurs against the vehicle side on which the first acceleration sensor is provided, the following accelerations are detected by the first acceleration sensor in two axial directions, that is, in the longitudinal direction and the lateral direction of the vehicle: the acceleration detected by the second acceleration sensor in one axial direction, that is, in the lateral direction of the vehicle: and , acceleration detected in the longitudinal direction of the vehicle by the first acceleration sensor and acceleration detected in the longitudinal direction of the vehicle by the other acceleration sensor Degree At least one and Based on this, the determination means determines whether the vehicle has rotated due to a rear side collision against the side of the vehicle on which the first acceleration sensor is provided, and when the determination means determines that the vehicle has rotated due to the rear side collision, the protection means protects the rear seat occupants of the vehicle. Therefore, the occurrence of the rear side collision can be detected using a small number of acceleration sensors to protect the rear seat occupants. Effect of the Invention

[0017] According to the present invention, it is possible to accurately detect, with a small number of acceleration sensors, the rotation of a vehicle caused by a rear side collision against the vehicle side on which the first acceleration sensor is provided. [Brief description of the drawings]

[0018] [Figure 1] 1 is a plan view showing the arrangement of an acceleration sensor in a first embodiment of an occupant protection device according to the present invention. [Diagram 2] FIG. 2 is a block diagram of the control system of FIG. 1. [Diagram 3] 5A to 5C are diagrams illustrating the operation of the first acceleration sensor of the first embodiment. [Figure 4]5A to 5C are diagrams illustrating the operation of the second acceleration sensor of the first embodiment. [Diagram 5] FIG. 2 is a logic circuit diagram of a determination means according to the first embodiment. [Figure 6] 4 is a flowchart illustrating the operation of the first embodiment. [Figure 7] FIG. 11 is an explanatory diagram of the operation of a modified example of the first embodiment. [Figure 8] 8 is a logic circuit diagram of a modification of the determining means in the modification shown in FIG. 7. FIG. [Figure 9] FIG. 11 is a plan view showing the arrangement of an acceleration sensor in a second embodiment of an occupant protection device according to the present invention. [Figure 10] FIG. 11 is a logic circuit diagram of a determination means according to the second embodiment. [Figure 11] FIG. 11 is a plan view showing the arrangement of an acceleration sensor in a conventional example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] (First embodiment) A first embodiment of an occupant protection device according to the present invention will be described with reference to Figures 1 to 6. The occupant protection device in this embodiment is applied to a B-pillarless vehicle that does not have a B-pillar on the passenger side, and protects rear seat occupants in a rear side collision on the driver's side. In this embodiment, the front-rear direction and left-right direction as viewed from a seated position are defined as the vehicle front-rear direction and vehicle left-right direction, respectively.

[0020] In the passenger protection device of this embodiment, an acceleration sensor is disposed as an acceleration detection means as shown in Fig. 1. That is, in a B-pillar-less vehicle 1 that does not have a B-pillar on the passenger side, a first acceleration sensor 2 is disposed on the B-pillar on the driver's side, which is in the center in the longitudinal direction of the vehicle, and a second acceleration sensor 3 is disposed on the C-pillar on the passenger side at the rear of the vehicle opposite the driver's seat, and an airbag control unit 4 disposed in the front of the passenger compartment controls the deployment of a right rear side airbag and a right curtain airbag based on the acceleration detected by these acceleration sensors 2, 3. Here, the first acceleration sensor 2 and the second acceleration sensor 3 each have sensitivity in two axial directions, that is, the longitudinal direction and the transverse direction of the vehicle, and detect acceleration in the longitudinal direction and the transverse direction of the vehicle.

[0021] The airbag control unit 4 is a microcomputer configuration, and as shown in Fig. 2, includes an airbag deployment means 41 for deploying a right rear side airbag 5 and a right curtain airbag 6, which are protective means for protecting rear seat occupants from an impact caused by a rear side collision (hereinafter also referred to as a rear side collision) on the driver's side of the B-pillarless vehicle 1 that does not have a B-pillar on the passenger side, a determination means 42 having a function of determining whether or not the vehicle 1 has rotated due to a rear side collision against the side of the vehicle 1 on the driver's side where the first acceleration sensor 2 is provided, based on the accelerations detected in two axial directions, that is, the front-rear direction and the left-right direction of the vehicle, by the first acceleration sensor 2 and the second acceleration sensor 3, respectively, and a third acceleration sensor 43 used for safing to prevent malfunctions in the event of failure of the first and second acceleration sensors 2 and 3, and for other vehicle control. No. Similar to the acceleration sensors 2 and 3 of 2, a sensor having sensitivity in two axial directions, that is, the longitudinal direction and the lateral direction of the vehicle, is used.

[0022] Here, the right rear side airbag 5 is embedded in a folded state in the door side end of the seat back of the right rear seat, and the right curtain airbag 6 is embedded in a folded state in the ceiling portion near the rear seat door. In the event of a side collision at the rear of the vehicle on the driver's side, the inflator constituting the airbag deployment means 41 is ignited and controlled, so that the right rear side airbag 5 deploys forward between the armpit of the rear seat occupant and the door, and the right curtain airbag 6 deploys between the head and chest of the rear seat occupant and the door glass, thereby protecting the rear seat occupant.

[0023] As shown in FIG. 1, when a rear-end collision occurs with the vehicle side on the driver's seat side where the first acceleration sensor 2 of the vehicle 1 is provided, the rear of the vehicle 1 rotates in the direction of the arrow in FIG. 1 (clockwise in a plan view) around the vehicle's center of gravity located at the front of the vehicle, indicated by an x ​​in FIG. 1.

[0024] Such rotation of the rear of the vehicle causes the first acceleration sensor 2 located on the B-pillar on the driver's side to experience acceleration composed of components in the fore-aft and lateral directions of the vehicle, as shown by the thick solid lines in FIG. 3, and the second acceleration sensor 3 located on the C-pillar on the passenger's side to experience acceleration composed almost entirely of components in the lateral direction of the vehicle, with no components in the fore-aft direction of the vehicle, as shown by the thick solid lines in FIG. 4. Therefore, it is possible to determine whether or not rotation of the rear of the vehicle 1 has occurred, based on the acceleration detected in the fore-aft and lateral directions of the vehicle by the first acceleration sensor 2, and the acceleration detected in the lateral direction of the vehicle by the second acceleration sensor 3.

[0025] At this time, when the vehicle 1 travels on a rough road with steps and bumps, acceleration occurs in a rectangular area that is mainly composed of components in the front-rear direction of the vehicle and has a certain width in the left-right direction of the vehicle, as shown by the dashed lines in Figures 3 and 4. Also, when a front collision occurs with the vehicle 1, acceleration occurs in an isosceles triangular area that spreads in the left-right direction of the vehicle toward the rear of the vehicle, as shown by the dashed lines in Figures 3 and 4. Furthermore, when a side collision occurs at a low speed (for example, 10 km / h or less) with a target including another vehicle against the side of the vehicle on the driver's seat side where the first acceleration sensor 2 is provided, and when the door on the driver's seat side is blocked, acceleration occurs in a rectangular area with a certain width toward the left of the vehicle that is different from the case of traveling on a rough road in the front-rear direction of the vehicle, as shown by the two-dot chain lines in Figures 3 and 4.

[0026] When the first and second acceleration sensors 2, 3 are detected, accelerations due to driving on rough roads and the like are excluded, and the judgment means 42 makes a judgment based only on the acceleration caused by a rear side collision with the side of the vehicle on the driver's seat side where the first acceleration sensor 2 is installed. In order to do so, threshold value T1 consisting of a judgment line having a value in the left direction of the vehicle and a judgment line having a value in the rear direction of the vehicle, as shown by thin solid lines in FIG. 3, is set as a threshold value of the detected acceleration of the first acceleration sensor 2. Also, threshold value T2 consisting of a judgment line having a value in the left direction of the vehicle and a judgment line having values ​​along the left and rear sides of an isosceles triangle representing the acceleration generation area generated by a front collision, as shown by thin solid lines in FIG. 4, is set as a threshold value of the detected acceleration of the second acceleration sensor 3.

[0027] As a result, if the acceleration detected by the first acceleration sensor 2 exceeds the threshold value T1, that is, if it is located to the lower left of the threshold value T1 in Fig. 3, it can be determined that the detected acceleration has components in the vehicle longitudinal direction and the vehicle lateral direction caused by a rear side collision against the vehicle side on the driver's seat side, and if the acceleration detected by the second acceleration sensor 3 exceeds the threshold value T2, that is, if it is located to the left of the threshold value T2 in Fig. 4, it can be determined that the detected acceleration has components in the vehicle longitudinal direction and the vehicle lateral direction caused by a rear side collision against the vehicle side on the driver's seat side. Note that it is preferable that these threshold values ​​T1 and T2 are experimentally obtained in advance for each vehicle model, and they should be mapped and stored in the memory of the airbag control unit 4.

[0028] By setting such a threshold value for the acceleration detected by the acceleration sensor, the determination means 42 determines whether or not the rear of the vehicle 1 has rotated due to a rear side collision on the driver's seat side using logic having a circuit configuration such as that shown in FIG. 5, and controls the deployment of the airbags 5, 6.

[0029] The logic circuit of the determination means 42 shown in FIG. 5 includes a determination unit 42a that performs threshold determination based on a threshold value T1 on the basis of acceleration detected by the first acceleration sensor 2 in each of the vehicle longitudinal direction and vehicle lateral direction, a determination unit 42b that performs threshold determination based on a threshold value T2 on the basis of acceleration detected by the second acceleration sensor 3 in each of the vehicle longitudinal direction and vehicle lateral direction, hold timers 42c and 42d that hold the outputs of the two determination units 42a and 42b for a preset time, an AND gate 42e to which the outputs of both the hold timers 42c and 42d are input, and an AND gate an AND gate 42f which receives the output of the third acceleration sensor 43 and the output of another hold timer 42h described later and outputs a deployment control command to the airbag deployment means 41; a comparator 42g which compares the acceleration detected in the left-right direction of the vehicle detected by the third acceleration sensor 43 to determine whether it exceeds a safing threshold value α (a constant value regardless of the type of vehicle) which is experimentally determined in advance and set in order to prevent false activation of the airbag deployment in the event of a malfunction of the first and second acceleration sensors 2, 3; and a hold timer 42h which holds the output of the comparator 42g for a preset period of time.

[0030] Here, since the acceleration by each acceleration sensor 2, 3, 43 is detected at an ECU clock period of, for example, 2 kHz, the hold timers 42c, 42d, 42h hold the judgment output of the threshold judgment units 42a, 42b and the comparison output of the comparator 42g for at least 5 ms. Even if there is a time lag in the judgment output of the threshold judgment units 42a, 42b, erroneous judgment can be prevented by holding the judgment output, and it becomes possible to reliably deploy the airbags 5, 6 within 20 ms after the occurrence of a rear side collision, for example.

[0031] Next, a procedure for controlling the deployment of the airbags 5, 6 based on the determination by the determining means 42 will be described with reference to the flowchart of FIG.

[0032] As shown in FIG. 6, when acceleration is detected by each of the acceleration sensors 2, 3, 43 (step S1), the determination means 42 determines whether the threshold value determination unit 42a in FIG. 5 has exceeded a threshold value T1 (see FIG. 3) based on the acceleration detected in the longitudinal and lateral directions of the vehicle by the first acceleration sensor 2, or whether the hold timer 42c is holding the output state of the threshold value determination unit 42a indicating that the acceleration has exceeded the threshold value T1 (step S2). If the determination result is NO, the process returns to START, and if the determination result in step S2 is YES, the process proceeds to the next step S3.

[0033] In step S3, the determination means 42 determines whether the threshold value determination unit 42b in FIG. 5 has determined, based on the acceleration detected by the second acceleration sensor 3 in the longitudinal direction and transverse direction of the vehicle, whether the acceleration detected by the second acceleration sensor 3 in the longitudinal direction and transverse direction of the vehicle has exceeded a threshold value T2 (see FIG. 4), or whether the hold timer 42d is holding the output state of the threshold value determination unit 42b that the acceleration has exceeded the threshold value T2 (step S3). If the result of this determination is NO, the process returns to START, and if the result of the determination in step S3 is YES, the process proceeds to the next step S4.

[0034] Furthermore, in step S4, the comparator 42g determines whether the magnitude of the acceleration detected in the left-right direction of the vehicle by the third acceleration sensor 43 is greater than the safing threshold value α, or whether the hold timer 42h is holding the output state of the comparator 42g that the magnitude of the acceleration detected in the left-right direction of the vehicle by the third acceleration sensor 43 is greater than the safing threshold value α (step S4). If the result of this determination is NO, the process returns to START, and if the result of the determination in step S4 is YES, the process proceeds to the next step S5.

[0035] Then, in step S5, based on the results that the acceleration detected by the first acceleration sensor 2 in the longitudinal direction and the transverse direction of the vehicle exceeds the threshold value T1, the acceleration detected by the second acceleration sensor 3 in the longitudinal direction and the transverse direction of the vehicle exceeds the threshold value T2, and the magnitude of the acceleration detected by the third acceleration sensor 43 in the transverse direction of the vehicle is greater than the safing threshold value α, it is determined that airbags should be deployed to protect the rear seat occupants, and the airbag deployment means 41 is activated to deploy the right rear side airbag 5 and the right curtain airbag 6 (step S5), and then the process returns to start.

[0036] In step S5, either or both of the right rear side airbag 5 and the right curtain airbag 6 may be deployed, and it is preferable to select which one to deploy depending on the vehicle model.

[0037] Also, the comparator 42g and the hold timer 42h in the logic circuit of FIG. 5 do not need to be provided, and in this case, the determination process of step S6 in FIG. 6 becomes unnecessary.

[0038] Therefore, according to the first embodiment described above, when a rear side collision occurs on the vehicle side on the driver's side where the first acceleration sensor 2 of the vehicle 1 is provided, the determination means 42 determines whether or not the vehicle 1 has rotated due to the rear side collision based on the acceleration detected in two axial directions, that is, the front-to-rear direction and the left-to-right direction, by the first acceleration sensor 2 and the second acceleration sensor 3, respectively, and when the determination means 42 determines that the rear of the vehicle 1 has rotated due to the rear side collision, the airbags 5, 6, which are protective means, are deployed to protect the rear seat occupants of the vehicle 1. Therefore, the occurrence of the rear side collision can be detected by the two acceleration sensors, the first acceleration sensor 2 on the B-pillar on the driver's side and the second acceleration sensor 3 on the C-pillar on the passenger's side, to protect the rear seat occupants.

[0039] In addition, when a rear side collision occurs on the vehicle side on the driver's side, the rear of the vehicle 1 rotates around the vehicle's center of gravity located at the front of the vehicle, and acceleration is generated in the diagonal rear direction and toward the vehicle's fore-and-aft axis passing through the vehicle center at the position where the first acceleration sensor 2 is located, and acceleration is generated in the vehicle's left-right direction at the position where the second acceleration sensor 3 is located.Therefore, when acceleration in the diagonal rear direction and toward the vehicle's fore-and-aft axis passing through the vehicle center is detected by the first acceleration sensor 2 and acceleration in the vehicle's left-right direction is detected by the second acceleration sensor 3, the determination means 42 can determine that the rear of the vehicle 1 has rotated due to a rear side collision on the driver's side of the vehicle 1, and the occurrence of the rear side collision can be reliably detected using a small number of acceleration sensors.

[0040] Furthermore, when a rear side collision occurs on the driver's seat side of the vehicle 1, the vehicle rotates about the center of gravity of the vehicle located at the front of the vehicle, and at the position where the first acceleration sensor 2 is disposed, acceleration occurs in the diagonally rear direction and toward the longitudinal axis of the vehicle passing through the center of the vehicle, while at the position where the second acceleration sensor 3 is disposed, acceleration occurs in the lateral direction of the vehicle. However, with regard to the first and second acceleration sensors 2 and 3, acceleration in the longitudinal direction of the vehicle caused by traveling on a rough road (the area indicated by the dashed line in FIG. 3 and FIG. 4), acceleration in the rearward direction and the lateral direction of the vehicle caused by a front collision (the area indicated by the dashed line in FIG. 3 and FIG. 4), and acceleration in the lateral direction of the vehicle caused by a front collision (the area indicated by the dashed line in FIG. 3 and FIG. 4) are detected. Since the threshold values ​​T1, T2 (see Figs. 3 and 4) are set to exclude the acceleration to the left of the vehicle caused by a low-speed side collision with an object, including another vehicle, against the side of the vehicle that has been determined, and the acceleration to the left of the vehicle caused by an impact when the driver's side door is closed (the area indicated by the two-dot chain lines in Figs. 3 and 4), the first and second acceleration sensors 2, 3 can reliably exclude acceleration caused by driving on rough roads, and detect only the acceleration caused by the rear side collision having an impact force that should protect rear seat occupants, thereby making it possible to more accurately detect the occurrence of the rear side collision.

[0041] In addition, when the magnitude of the acceleration detected in the left-right direction of the vehicle by the third acceleration sensor 43 is smaller than a preset safing threshold value α, there is a risk of malfunction due to a malfunction of the first and second acceleration sensors 2, 3. Therefore, by controlling the drive of the airbag deployment means 41 when the acceleration detected in the left-right direction of the vehicle by the first and second acceleration sensors 2, 3 exceed the threshold values ​​T1, T2 and the magnitude of the acceleration detected in the left-right direction of the vehicle by the third acceleration sensor 43 is greater than the safing threshold value α, it is possible to prevent the airbags 5, 6 from being deployed due to malfunction caused by a malfunction of the first and second acceleration sensors 2, 3.

[0042] (Modification) As a modified example of the first embodiment described above, the configurations shown in Fig. 7 and Fig. 8 may be applied. That is, the first acceleration sensor 2 detects acceleration in the vehicle longitudinal direction and acceleration in the vehicle lateral direction, and based on the detection of acceleration with the vehicle rearward direction being positive as shown in Fig. 7(a) and the magnitude of the detected acceleration exceeding a value t11 (see Fig. 3) corresponding to the determination line of the threshold value T1 in the vehicle rearward direction in Fig. 3, and based on the detection of acceleration with the vehicle leftward direction being positive as shown in Fig. 7(b) and the magnitude of the detected acceleration exceeding a value t12 (see Fig. 3) corresponding to the determination line of the threshold value T1 in the vehicle leftward direction in Fig. 3, the determination unit 42a in Fig. 8 may determine that the detected acceleration in the vehicle longitudinal direction and the vehicle lateral direction of the first acceleration sensor 2 exceeds the threshold value T1 in Fig. 3, and the determination unit 42b may similarly determine the detected acceleration in the second acceleration sensor 3.

[0043] At this time, a hold timer is used to hold that the magnitude of the acceleration detected in the vehicle's longitudinal direction by the first acceleration sensor 2 has exceeded a value t11 corresponding to the judgment line in the vehicle rearward direction of threshold value T1 in FIG. 3, and a hold timer is used to hold that the magnitude of the acceleration detected in the vehicle's lateral direction by the first acceleration sensor 2 has exceeded a value t12 corresponding to the judgment line in the vehicle rearward direction of threshold value T1 in FIG. 3. An AND gate is used to take a logical product of the outputs of both hold timers to output the judgment unit 42a. Similarly, a hold timer is used to hold that the acceleration detected in the vehicle's longitudinal direction and the acceleration detected in the vehicle's lateral direction by the second acceleration sensor 3 have each exceeded a value corresponding to the judgment line of threshold value T2, and an AND gate is used to take a logical product of the outputs of both hold timers to output the judgment unit 42b.

[0044] Second embodiment A second embodiment of the passenger protection device according to the present invention will be described with reference to Figures 9 and 10. Since the basic configuration of this embodiment is the same as that of the first embodiment, the following description will also refer to Figures 2 to 4, and the following description will mainly focus on the differences from the first embodiment.

[0045] This embodiment differs from the first embodiment in that, instead of the second acceleration sensor 3 in the first embodiment, a second acceleration sensor 3a that detects acceleration in only one axial direction in the left-right direction of the vehicle is disposed on the C-pillar on the passenger side of the vehicle 1, and whether or not the acceleration detected by the acceleration sensor disposed on the C-pillar on the passenger side exceeds a threshold value T2 shown in Fig. 4 is determined based on the acceleration detected in the left-right direction of the vehicle by this second acceleration sensor 3a and the acceleration detected in the front-rear direction of the vehicle by a third acceleration sensor 43 provided in the airbag control unit 4. Here, the third acceleration sensor 43 corresponds to the "other acceleration sensor" of the present invention, and the "other acceleration sensor" may be an acceleration sensor mounted on the vehicle other than the acceleration sensors 2, 3, and 43 described above.

[0046] As shown in the logic circuit of the determination means 42 in FIG. 10, instead of the acceleration detected in the longitudinal direction of the vehicle by the second acceleration sensor 3 in the logic circuit of the determination means 42 of the first embodiment, the acceleration detected in the longitudinal direction of the vehicle by the third acceleration sensor 43 provided in the airbag control unit 4 is used, and based on the acceleration detected in one axial direction in the left-right direction of the vehicle by the second acceleration sensor 3a and the acceleration detected in the longitudinal direction of the vehicle by the third acceleration sensor 43, a determination is made by a determination unit 42b as to whether or not the acceleration detected by the acceleration sensor disposed on the C-pillar on the passenger side exceeds the threshold value T2 shown in FIG. 4.

[0047] Therefore, according to the second embodiment, the second acceleration sensor 3a only needs to detect acceleration in one axial direction, so it is less expensive than an acceleration sensor that detects acceleration in two axial directions, and the same effects as those of the first embodiment described above can be obtained.

[0048] The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention.

[0049] In the second embodiment described above, instead of using the acceleration detected in the vehicle longitudinal direction by the third acceleration sensor 43, the acceleration detected in the vehicle longitudinal direction by the first acceleration sensor 2 may be used, and based on the acceleration detected in the vehicle lateral direction by the second acceleration sensor 3a (see FIG. 9) and the acceleration detected in the vehicle longitudinal direction by the first acceleration sensor 2, it may be determined whether the acceleration detected by the acceleration sensor disposed on the C-pillar on the passenger seat side exceeds the threshold value T2 shown in FIG. 4. Note that, as the acceleration detected in the vehicle longitudinal direction, at least one of the acceleration detected in the vehicle longitudinal direction by the third acceleration sensor 43 and the acceleration detected in the vehicle longitudinal direction by the first acceleration sensor 2 may be used. Here, when both the acceleration detected in the vehicle longitudinal direction by the third acceleration sensor 43 and the acceleration detected in the vehicle longitudinal direction by the first acceleration sensor 2 are used, for example, an average value of the detected accelerations may be used.

[0050] In addition, in the above embodiment, the present invention has been described as being applied to a vehicle that does not have a B-pillar on the passenger side, but the present invention can also be applied to a B-pillarless vehicle that does not have a B-pillar on the driver's side but has a B-pillar on the passenger side.

[0051] In the above embodiment, the protection means for protecting the occupant is an airbag, but it may be, for example, a pretensioner that removes slack in a seat belt to restrain the occupant during a collision. In the above embodiment, the determination result of whether the vehicle has rotated is used to operate the occupant protection device, but it may also be used for other purposes besides the occupant protection device, such as vehicle stability control to stabilize the vehicle. In this case, when it is determined that the vehicle has rotated due to a rear side collision, the wheel speeds of the four wheels may be brake-controlled to stabilize the behavior of the vehicle.

[0052] In the above embodiment, the third acceleration sensor 43 provided in the airbag control unit 4 is used for safing to prevent the airbag from malfunctioning, but the safing acceleration sensor is not limited to this. It is not necessary to provide a safing acceleration sensor.

[0053] Furthermore, the present invention can be applied to an occupant protection device that protects occupants in the rear seats of a vehicle by determining whether or not a rear side collision has occurred based on acceleration detected by an acceleration detection means provided in the vehicle. [Explanation of symbols]

[0054] 1 ... B-pillarless vehicle 2 ... First acceleration sensor 3 ... Second acceleration sensor 5...Right rear side airbag (protection measures) 6 … Right curtain airbag (protection measure) 42 …judgment means 43 ...Third acceleration sensor (another acceleration sensor)

Claims

1. A collision determination device for determining whether or not a rear side collision has occurred based on acceleration detected by an acceleration detection means provided in a vehicle, comprising: The acceleration detection means a first acceleration sensor provided at a center portion of a side surface of the vehicle in a longitudinal direction of the vehicle and configured to detect acceleration in two axial directions, i.e., in a longitudinal direction of the vehicle and a lateral direction of the vehicle; a second acceleration sensor that is provided on a side surface of the vehicle opposite to the side surface of the vehicle on which the first acceleration sensor is provided and is located rearward of a center portion in the vehicle longitudinal direction and detects acceleration in two axial directions, that is, in the vehicle longitudinal direction and the vehicle lateral direction; a determining means for determining whether or not the vehicle has rotated due to a rear side collision against the vehicle side on which the first acceleration sensor is provided, based on the accelerations detected in the two axial directions by the first acceleration sensor and the second acceleration sensor, respectively; A collision determination device comprising:

2. The first acceleration sensor includes: detecting an acceleration in a diagonally rearward direction and toward a longitudinal axis of the vehicle passing through a center of the vehicle, the acceleration being caused by the rear side collision against a side of the vehicle on which the first acceleration sensor is provided; The second acceleration sensor includes: The acceleration sensor detects acceleration in the left-right direction of the vehicle caused by a rear side collision against a side of the vehicle on which the first acceleration sensor is provided.

2. The collision determination device according to claim 1.

3. The first acceleration sensor includes: the acceleration sensor detects acceleration in a diagonally rearward direction and toward a central axis passing through the center of the vehicle caused by a rear side collision against the vehicle side on which the first acceleration sensor is provided by setting a threshold value that excludes at least one of the following: acceleration in the longitudinal direction of the vehicle caused by traveling on a rough road; acceleration in the rearward direction and the left-right direction of the vehicle caused by a frontal collision; acceleration in the left-right direction of the vehicle caused by a low-speed side collision with an object including another vehicle against the vehicle side on which the first acceleration sensor is provided; and acceleration in the left-right direction of the vehicle caused by an impact when a door is closed; The second acceleration sensor includes: The acceleration sensor detects the acceleration in the left-right direction of the vehicle caused by a rear side collision against the side of the vehicle on which the first acceleration sensor is provided by setting a threshold value that excludes at least one of the following: acceleration in the front-rear direction of the vehicle caused by traveling on a rough road; acceleration in the rear direction and the left-right direction of the vehicle caused by a front collision; acceleration in the left-right direction of the vehicle caused by a low-speed side collision with an object including another vehicle against the side of the vehicle on which the first acceleration sensor is provided; and acceleration in the left-right direction of the vehicle caused by an impact when a door is closed.

3. The collision determination device according to claim 2.

4. 1. An occupant protection device for protecting an occupant in a rear seat of a vehicle by determining whether or not a rear side collision has occurred based on acceleration detected by an acceleration detection means provided in the vehicle, The acceleration detection means a first acceleration sensor provided at a center portion of a side surface of the vehicle in a longitudinal direction of the vehicle and configured to detect acceleration in two axial directions, i.e., in a longitudinal direction of the vehicle and a lateral direction of the vehicle; a second acceleration sensor that is provided on a side surface of the vehicle opposite to the side surface of the vehicle on which the first acceleration sensor is provided and is located rearward of a center portion in a longitudinal direction of the vehicle and detects acceleration in one axial direction in a left-right direction of the vehicle; Equipped with a determination means for determining whether or not the vehicle has rotated due to a rear side collision against the vehicle side on which the first acceleration sensor is provided, based on at least one of the acceleration detected in two axial directions, i.e., in the longitudinal direction and the transverse direction of the vehicle, by the first acceleration sensor, the acceleration detected in one axial direction, i.e., in the transverse direction of the vehicle, by the second acceleration sensor, and the acceleration detected in the longitudinal direction of the vehicle by the first acceleration sensor and the acceleration detected in the longitudinal direction of the vehicle by another acceleration sensor; a protection means for protecting a rear seat occupant of the vehicle when the determination means determines that the vehicle has rotated due to the rear side collision; A collision determination device comprising:

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