JP7812261B2 - Vehicle control device - Google Patents

Description

The present invention relates to a vehicle control device that controls the deployment of a side-impact airbag installed on the side of a vehicle.

Conventionally, there have been pre-collision control devices that perform pre-collision control to prepare for a collision with an obstacle when there is a possibility that the vehicle will collide with the obstacle. Examples of pre-collision control include control to deploy airbags and brake assist control that applies the brakes to reduce the speed of the vehicle before it collides with the obstacle in order to avoid a collision with the obstacle or reduce the speed at which it will collide with the obstacle (see, for example, Patent Document 1).

JP 2018-154285 A

For example, when deploying a side impact airbag, such as a side airbag or curtain airbag installed on the side of a vehicle, an acceleration sensor detects the lateral (left-right) acceleration of the vehicle. An airbag ECU (Electronic Control Unit) inside the vehicle determines whether the acceleration detected by the acceleration sensor exceeds a preset deployment threshold, and if it does, it decides to deploy the side impact airbag, deploying it and thereby protecting the occupants.

When deploying a side-impact airbag when an obstacle collides with the side of a vehicle, it is preferable for the airbag to deploy as quickly as possible in narrow vehicles due to the small gap between the occupant and the vehicle body. However, if the deployment threshold for deploying the airbag is reduced, there is a risk that the airbag will deploy due to G-forces generated during normal driving or when opening and closing a door.

In addition, for vehicles with a width of 1,500 mm or less, the impact speed limit for pole side impacts under the UN-R135 regulation was relaxed to 26 km/h, but this will be strengthened to 32 km/h for new vehicles from January 2023 onwards, increasing the need for side impact airbags to be deployed earlier.

The object of the present invention is to provide a vehicle control device that can prevent unnecessary deployment of side impact airbags during normal vehicle driving or when the doors are opened or closed, while quickly deploying side impact airbags to protect occupants when an object collides with the side of the vehicle.

In order to achieve the above-mentioned object, a vehicle control device according to the present invention is a vehicle control device that is mounted on a vehicle and deploys a side impact airbag provided on a side of the vehicle based on acceleration occurring in the vehicle and a deployment threshold for deploying the airbag, the vehicle control device comprising: a vehicle position prediction unit that predicts a future vehicle position indicating a position of the vehicle after a predetermined time; a target detection unit that detects targets within a limited detection range in front of the vehicle; a target position prediction unit that predicts a future target position indicating a position of the target detected by the target detection unit after the predetermined time; a collision type prediction unit that predicts, based on a vehicle traveling direction vector derived from a change in the future vehicle position and a target traveling direction vector derived from a change in the future position of the target within the detection range of the target detection unit, whether a collision type between the vehicle and the target after the target leaves the detection range will be a side impact in which the target collides with the side of the vehicle; and a deployment threshold change unit that lowers the deployment threshold when the collision type is predicted to be a side impact.

According to this configuration, even when the detection range of the target by the target detection unit is limited to the front of the vehicle, by setting the deployment threshold before a side impact in which the target collides with the side of the vehicle to a relatively large value, it is possible to prevent unnecessary deployment of the side impact airbag during normal vehicle driving, when the door is opened or closed, etc. Furthermore, since the deployment threshold before a side impact is predicted to be a relatively large value prevents unnecessary deployment of the side impact airbag during normal vehicle driving, when the door is opened or closed, etc., while the deployment threshold after a side impact is predicted to be a relatively small value, it is possible to deploy the side impact airbag early in the event of a side impact to protect the occupant.

In addition , the vehicle control device may further include a collision time prediction unit that predicts a predicted collision time at which the vehicle will collide with the target, and the deployment threshold change unit may set the deployment threshold to a lowered value assuming that the collision type is a side impact, at least until the predicted collision time has passed.

Because a vehicle will be facing diagonally toward a target near the side of the vehicle, a target detection unit whose target detection range is limited to the front of the vehicle will be unable to detect a target approaching the side of the vehicle. However, as in the above configuration, by keeping the deployment threshold for the side impact airbag at a lower value at least until the predicted collision time has passed, it is possible to deploy the side impact airbag early in the event of a side collision to protect occupants, even if the target detection unit's target detection range is limited to the front of the vehicle.

The deployment threshold change unit may also set the deployment threshold to a lowered value, assuming that the collision type is a side impact, until a time equal to the predicted collision time plus a specific time has passed.

With this configuration, the deployment threshold for the side impact airbag is kept at a lowered value until the time equal to the predicted collision time plus a specific time has passed. This allows the side impact airbag to be deployed early in the event of a side collision to protect the occupant, even if the actual collision time is delayed by the specific time from the predicted collision time.

According to the present invention, by setting the deployment threshold before a side impact in which an object collides with the side of the vehicle to a relatively large value, unnecessary deployment of the side impact airbag during normal vehicle driving or when the door is opened or closed can be prevented. Furthermore, by setting the deployment threshold before a side impact is predicted to a relatively large value to prevent unnecessary deployment of the side impact airbag during normal vehicle driving or when the door is opened or closed, the deployment threshold after a side impact is predicted to be a relatively small value can be set, allowing the side impact airbag to be deployed early in the event of a side impact to protect the occupants.

1 is a block diagram showing the configuration of a vehicle equipped with a vehicle control device according to an embodiment of the present invention; FIG. 2 is an external view showing the exterior of the vehicle shown in FIG. 1 . 2 is a functional block diagram showing a functional configuration of a control relating to deployment of a side collision airbag by a CPU in FIG. 1; FIG. 4 is a flowchart showing a processing procedure for controlling change of a deployment threshold of a side collision airbag by a CPU of FIG. 1 . 4 is a flowchart showing a processing procedure for controlling deployment of a side collision airbag by a CPU of FIG. 1 . 4 is an explanatory diagram for explaining a collision type prediction process by the CPU of FIG. 1; FIG.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

The configuration of a vehicle X equipped with a vehicle control device 1 according to one embodiment of the present invention will be described with reference to Figures 1 and 2. Note that in this embodiment, the terms front, back, left, and right refer to the front, back, left, and right of a person seated in a seat in vehicle X.

Vehicle control device 1 is a device that is mounted on vehicle X and performs control related to the deployment of a side collision airbag mounted on vehicle X. Here, vehicle X may be, for example, an electric vehicle, a hybrid vehicle, or an autonomous vehicle.

The vehicle control device 1 is configured to include an ECU 11. The ECU 11 has multiple functions, such as a stereo camera ECU function and an airbag ECU function, but an ECU may be provided for each function, such as a stereo camera ECU or an airbag ECU.

Vehicle X is equipped with side impact airbags 3, including a left side impact airbag 3L and a right side impact airbag 3R, provided on the left and right sides of vehicle X, such as side airbags embedded in a folded state in the door-side edges of the seat backs of the driver's seat, passenger seat, and rear seats, and curtain airbags embedded in a folded state in the ceiling near the front and rear doors.

Vehicle X is also equipped with acceleration sensors 20, including a left acceleration sensor 20L and a right acceleration sensor 20R, which are mounted on the B-pillars on both the left and right sides of vehicle X and detect acceleration occurring in vehicle X. The acceleration sensors 20 (20L, 20R) are capable of detecting lateral (left-right) acceleration occurring in vehicle X and longitudinal (front-rear) acceleration occurring in vehicle X. The acceleration sensors 20 (20L, 20R) output detection signals corresponding to the detected acceleration. The detection signals of the acceleration sensors 20 (20L, 20R) are input to the ECU 11.

Vehicle X is also equipped with a camera 21. The camera 21 is, for example, a stereo camera capable of continuously capturing still images at a predetermined frame rate. It is installed, for example, in front of the rearview mirror in the center of the front part of the vehicle interior so that it can capture wide-angle images of the area ahead of vehicle X, and the detection range of this camera 21 for a target T (see Figure 6) is limited to the area ahead of vehicle X. The camera 21 outputs a pair of image data captured by the left and right image sensors that make up the camera 21 as output signals. The output signal from camera 21 is input to ECU 11. In this embodiment, the target T is another vehicle (a vehicle other than vehicle X). The camera 21 corresponds to the "target detection unit" of the present invention.

Vehicle X is also equipped with a vehicle speed sensor 22, a steering angle sensor 23, and a yaw rate sensor 24. Vehicle speed sensor 22 outputs a detection signal in pulse synchronization with the rotation of a rotating body (e.g., a drive shaft) that rotates as vehicle X travels. Steering angle sensor 23 outputs a detection signal corresponding to the steering angle (absolute steering angle) relative to the steering angle midpoint of vehicle X's steering mechanism (e.g., a steering wheel). The steering angle takes a positive value when the steering mechanism is turned to the right (the steering wheel is turned to the right) from the steering angle midpoint, and a negative value when it is turned to the left (the steering wheel is turned to the left). Yaw rate sensor 24 outputs a detection signal corresponding to the yaw rate, which is the angular velocity of rotation around a vertical axis passing through the center of gravity of vehicle X. The detection signals from vehicle speed sensor 22, steering angle sensor 23, and yaw rate sensor 24 are input to ECU 11.

Vehicle X is equipped with a hydraulic brake system. The brake system includes a brake pedal, brake booster, master cylinder, brake actuator 25, and brakes provided on each wheel. The brake pedal is located in a convenient position for the driver in the driver's seat to operate with their right foot. When the brake pedal is depressed, the force applied to the brake pedal is transmitted to the brake booster. The brake booster utilizes the negative pressure generated in the engine's intake system, and the pressure difference between this negative pressure and atmospheric pressure amplifies the brake pedal force.

The force amplified by the brake booster is transmitted from the brake booster to the master cylinder, which generates hydraulic pressure corresponding to that force. The hydraulic pressure from the master cylinder is transmitted to the brake actuator 25, which supplies hydraulic pressure to the wheel cylinders of the brakes installed on each wheel. This hydraulic pressure causes each brake to apply braking force to the wheel. The brake actuator 25 also contains an electric pump, which is driven by power from the battery when the automatic brake is activated, and the hydraulic pressure generated by the electric pump is supplied to each wheel cylinder.

Vehicle X is also equipped with an alarm 26. The alarm 26 is controlled by the ECU 11 to output various types of alarms, which may be output as light, sound, or voice.

The ECU 11 that constitutes the vehicle control device 1 controls the deployment of the side impact airbags 3 (3L, 3R) based on the detection results of the acceleration sensors 20 (20L, 20R), and is equipped with a microcontroller 12. The microcontroller 12 has a built-in CPU 13 and memory 14. In addition to the ECU 11, the vehicle X is equipped with multiple ECUs that control various parts. The ECU 11 is connected to other ECUs to enable two-way communication using the CAN (Controller Area Network) communication protocol.

Next, the functional configuration of the CPU 13, which controls the deployment of the side impact airbags 3 (3L, 3R) based on the detection results of the acceleration sensors 20 (20L, 20R), will be described with reference to Figure 3.

By executing the various programs stored in memory 14, the CPU 13 realizes various functional units such as a vehicle position prediction unit 31, a target position prediction unit 32, a judgment unit 33, a collision type prediction unit 34, a deployment threshold change unit 35, and a deployment unit 36, as shown in FIG. 3. In this embodiment, by executing the various programs stored in memory 14, the CPU 13 realizes various functional units such as a vehicle position prediction unit 31, a target position prediction unit 32, a judgment unit 33, a collision type prediction unit 34, a deployment threshold change unit 35, and a deployment unit 36, but this is not limited to this, and each functional unit can also be realized by hardware.

The vehicle position prediction unit 31 predicts, at a predetermined interval, the future position of vehicle X (hereinafter referred to as the "future vehicle position"), which indicates the position of vehicle X at a predetermined time. Here, the predetermined time is a time that is set in advance. In this embodiment, the vehicle position prediction unit 31 predicts the future vehicle position based on the vehicle position, which is the position of vehicle X at the current time, the vehicle speed corresponding to the detection signal output from the vehicle speed sensor 22, the steering angle corresponding to the detection signal output from the steering angle sensor 23, the rotational angular velocity corresponding to the detection signal output from the yaw rate sensor 24, etc. Furthermore, in this embodiment, the vehicle position prediction unit 31 predicts the future vehicle position at each small time interval from the current time until a predetermined time has elapsed.

The target position prediction unit 32 periodically predicts the future position of the target T (hereinafter referred to as the "target future position"), indicating the position of the target T at a predetermined time. In this embodiment, the target position prediction unit 32 predicts the target future position based on a pair of image data captured by the left and right image sensors constituting the camera 21, which are input from the camera 21. More specifically, the target position prediction unit 32 extracts target pixels corresponding to the same target (target T) from each image of the pair of image data captured by the left and right image sensors constituting the camera 21, which are input from the camera 21. The target position prediction unit 32 then detects the amount of deviation in the position of the target pixel between the pair of images and calculates the distance to the same target (target T) using the principles of triangulation. The target position prediction unit 32 then calculates the target position, which is the position of the target T at the current time, based on the vehicle position, which is the position of the vehicle X at the current time, the direction of the target T relative to the vehicle X, and the distance to the target T. Next, the target position prediction unit 32 predicts the future position of the target based on the target position, which is the position of the target T at a time a predetermined time before the current time, and the target position, which is the position of the target T at the current time (based on the distance and direction traveled by the target T from a time a predetermined time before the current time). In this embodiment, the target position prediction unit 32 predicts the future position of the target at each short time interval from the current time until a predetermined time later.

The determination unit 33 determines, at a predetermined interval, whether there is a possibility of a collision between vehicle X and target T based on the vehicle future position and target future position. In this embodiment, the determination unit 33 sets a rectangular vehicle area surrounding vehicle X, which is located at the vehicle future position. If the target future position is included in the set vehicle area, the determination unit 33 determines that there is a possibility of a collision between vehicle X and target T. Furthermore, in this embodiment, the determination unit 203 determines whether there is a possibility of a collision between vehicle X and target T based on the vehicle future position and target future position at each small time interval from the current time until a predetermined time has elapsed.

When it is determined that there is a possibility of a collision between vehicle X and target T, the collision type prediction unit 34 predicts, based on the vehicle future position and the target future position, whether the collision type between vehicle X and target T will be a collision type in which target T (in this embodiment, the front of target T) collides with the side of vehicle X (hereinafter referred to as a "side collision"). The prediction processing procedure by this collision type prediction unit 34 will be described in steps S6 to S8 of Figure 4.

When the collision type prediction unit 34 predicts that the collision type between vehicle X and target T will be a side impact (a collision type in which target T (in this embodiment, the front of target T) collides with the side of vehicle X), the deployment threshold change unit 35 changes the set deployment threshold stored in memory 14 from a first deployment threshold to a second deployment threshold that is smaller than the first deployment threshold. Here, the first deployment threshold and second deployment threshold are preset accelerations, and are determined by experimentally measuring, for example, the lateral (left-right) acceleration that occurs on vehicle X during normal driving, the lateral (left-right) acceleration that occurs on vehicle X when a door is opened or closed, and the lateral (left-right) acceleration that occurs on vehicle X when the front of target T collides with the side of vehicle X.

Furthermore, after changing the set deployment threshold stored in memory 14 from the first deployment threshold to the second deployment threshold, if a predetermined condition for changing the set deployment threshold stored in memory 14 back from the second deployment threshold to the first deployment threshold is met, the deployment threshold change unit 35 changes the set deployment threshold stored in memory 14 back from the second deployment threshold to the first deployment threshold.

Here, the following (Condition 1) and (Condition 2) can be given as examples of predetermined conditions for returning the set deployment threshold stored in memory 14 from the second deployment threshold to the first deployment threshold. (Condition 1) is a condition that the predicted collision time at which the front of target T is predicted to collide with the side of vehicle X has passed. (Condition 2) is a condition that the time obtained by adding a specific time to the predicted collision time at which the front of target T is predicted to collide with the side of vehicle X has passed. Here, the specific time is a time that has been set in advance.

When (Condition 1) or (Condition 2) is used as the predetermined condition, the deployment threshold modification unit 35 predicts the predicted time of collision between vehicle X and target T and determines whether the predetermined condition is met using the predicted predicted time of collision. The deployment threshold modification unit 35 predicts the predicted time of collision between vehicle X and target T based on, for example, the distance between vehicle X and target T in a direction perpendicular to the vehicle's traveling direction and the relative speed between vehicle X and target T in the direction perpendicular to the vehicle's traveling direction, or predicts the earliest time at which the target's future position falls within the vehicle area set by the determination unit 33 as the predicted time of collision between vehicle X and target T. The function of the deployment threshold modification unit 35 to predict the predicted time of collision between vehicle X and target T corresponds to the "collision time prediction unit" of this invention.

The deployment unit 36 deploys the side impact airbags 3 (3L, 3R) based on the acceleration occurring in the vehicle X and a set deployment threshold (first deployment threshold or second deployment threshold) stored in the memory 14. In this embodiment, when the lateral (left-right) acceleration of the vehicle X detected by the acceleration sensor 20 (20L, 20R) exceeds the set deployment threshold (first deployment threshold or second deployment threshold) stored in the memory 14, the deployment unit 36 determines to deploy the side impact airbags 3 (3L, 3R) and deploys the side impact airbags 3 (3L, 3R). Here, the side impact airbags 3 (3L, 3R) are equipped with inflators, and the inflators are equipped with squips (ignition devices) and drive circuits that drive the squips. An ignition control signal is output from the deployment unit 36 to the drive circuit, and when the squip ignites in accordance with the ignition control signal, high-pressure gas is generated by the ignition of the gas generating agent, and the side impact airbags 3 (3L, 3R) instantly inflate (deploy).

Next, the processing procedure for controlling the change of the deployment threshold of the side impact airbags 3 (3L, 3R) by the CPU 13 will be explained with reference to Figure 4.

The target position prediction unit 32 monitors the area ahead of the vehicle X using a pair of image data captured by the left and right image sensors of the camera 21 (step S1) and confirms whether or not a target T is present ahead of the vehicle X (step S2). If it is not possible to confirm that a target T is present ahead of the vehicle X (S2: NO), the process returns to step S1. On the other hand, if it is possible to confirm that a target T is present ahead of the vehicle X (S2: YES), the process proceeds to step S3.

The target position prediction unit 32 calculates the target position, which is the position of the target T at the current time, based on a pair of image data captured by the left and right image sensors that make up the camera 21. Here, the target position is the position of the target T relative to the center position of the vehicle X. In addition, the vehicle position prediction unit 31 acquires driving information such as the vehicle speed, steering angle, and rotational angular velocity of the vehicle X based on the detection results of the vehicle speed sensor 22, steering angle sensor 23, and yaw rate sensor 24 (step S3).

The vehicle position prediction unit 31 predicts the future vehicle position, which indicates the position of vehicle X after a predetermined time, based on the driving information acquired in step S3. Furthermore, the target position prediction unit 32 predicts the future target position, which indicates the position of target T after a predetermined time, based on the target position calculated in step S3 (step S4).

The determination unit 33 determines whether there is a possibility of a collision between vehicle X and target T based on the vehicle future position and the target future position (step S5). If it is determined that there is no possibility of a collision between vehicle X and target T (S5: NO), the process returns to step S1. On the other hand, if it is determined that there is a possibility of a collision between vehicle X and target T (S5: YES), the process proceeds to step S6.

The collision type prediction unit 34 calculates the angle θ between the vehicle traveling direction vector Vvec, which represents the traveling direction of vehicle X, and the target traveling direction vector Gvec, which represents the traveling direction of target T (step S6). In other words, the angle θ is the angle between the traveling direction of vehicle X and the traveling direction of target T (see Figure 6).

Specifically, the collision mode prediction unit 34 calculates the vehicle traveling direction vector Vvec based on the vehicle position (hereinafter referred to as the "current vehicle position") VUT(t-1), which is the position of the vehicle X at the current time t-1, and the vehicle position (future vehicle position) VUT(t), which is the position of the vehicle X at a future time t that is a predetermined time after the current time, as shown in the following equation (1).
Vvec=VUT(t)-VUT(t-1)...(1)

In addition, the collision type prediction unit 34 calculates the target traveling direction vector Gvec based on the target position (hereinafter referred to as the "target current position") GVT(t-1), which is the position of the target T at the current time t-1, and the target position (target future position) GVT(t), which is the position of the target T at a future time t, as shown in the following equation (2).
Gvec=GVT(t)-GVT(t-1)...(2)

Next, the collision type prediction unit 34 calculates the angle θ formed by the vehicle traveling direction vector Vvec and the target traveling direction vector Gvec, as shown in the following equation (3).
cosθ=Vvec・Gvec/|Vvec||Gvec|...(3)
The angle θ is equal to or greater than 0 degrees and equal to or less than 180 degrees.

The collision type prediction unit 34 determines whether the angle θ is greater than or equal to a threshold value θta and less than or equal to a threshold value θtb (step S7). Here, the threshold values θta and θtb are preset threshold values for the angle θ that determine that, if the angle θ is greater than or equal to the threshold value θt and less than or equal to the threshold value θtb, one of the vehicle X and the target object T will enter the path of the other and collide (in other words, a cross-sectional collision in which the front of one of the vehicle X and the target object T collides with the side of the other). In a cross-sectional collision in which one of the vehicle X and the target object T enters the path of the other and collide (in other words, a cross-sectional collision in which the front of one of the vehicle X and the target object T collides with the side of the other), the vehicle traveling direction Vvec and the target traveling direction vector Gvec are not approximately in the same direction or in opposite directions. Therefore, the threshold values θta and θtb are set to, for example, 10 degrees and 170 degrees.

If it is determined that the angle θ is smaller than the threshold value θta or larger than the threshold value θtb (S7: NO), the process returns to step S1. On the other hand, if it is determined that the angle θ is equal to or larger than the threshold value θta and equal to or smaller than the threshold value θtb (S7: YES), the process proceeds to step S8. Here, if it is determined that the angle θ is equal to or larger than the threshold value θta and equal to or smaller than the threshold value θtb, the target object T is a vehicle (intersecting vehicle) that intersects with the vehicle X at, for example, an intersection.

The collision type prediction unit 34 predicts whether the collision type between vehicle X and target T will be a collision type (side impact) in which the front of target T collides with the side of vehicle X (step S8). In this embodiment, for this prediction, the collision type prediction unit 34 determines whether at least one of the endpoints in the traveling direction of target T at future time t is within the vehicle area of vehicle X at future time t. Here, if at least one of the endpoints in the traveling direction of target T at future time t is within the vehicle area of vehicle X at future time t, the collision type prediction unit 34 predicts that the collision type will be a collision type in which the front of target T will collide with the side of vehicle X (side impact). If none of the endpoints in the traveling direction of target T at future time t is within the vehicle area of vehicle X at future time t, the collision type prediction unit 34 predicts that the collision type will not be a collision type in which the front of target T will collide with the side of vehicle X (side impact).

In this embodiment, as shown in FIG. 6, if the vehicle area of vehicle X is a rectangular area, the collision type prediction unit 34 sets corners A, B, C, and D of the rectangular area based on the center position OX of vehicle X as the end points of the vehicle area. Also, as shown in FIG. 6, if the target area of target T is a rectangular area, the collision type prediction unit 34 sets corners E, F, G, and H of the rectangular area based on the center position OT of target T as the end points of the target area.

The collision type prediction unit 34 determines whether the end points E, F, G, and H of the target area of the target T at future time t are within a vehicle area based on the center position OX of the vehicle X at future time t. For example, the collision type prediction unit 34 calculates the cross products of AB×AE, BC×BE, CD×CE, and DA×DE, and if the signs of the calculated cross products match, determines that the end point E is within the vehicle area. The collision type prediction unit 34 similarly determines whether the end points F, G, and H of the target T are within the vehicle area.

If the collision type between vehicle X and target T is predicted to be a collision type (side impact) in which the front of target T collides with the side of vehicle X, that is, if it is determined that at least one of the endpoints in the direction of travel of target T at future time t (at least one of endpoints E and F shown in FIG. 6) is within the vehicle area of vehicle X at future time t (step S8: YES), proceed to processing in step S9. On the other hand, if the collision type between vehicle X and target T is predicted not to be a collision type (side impact) in which the front of target T collides with the side of vehicle X, that is, if it is determined that neither of the endpoints in the direction of travel of target T at future time t (neither endpoint E nor endpoint F shown in FIG. 6) is within the vehicle area of vehicle X (step S8: NO), return to processing in step S1.

The deployment threshold change unit 35 changes the set deployment threshold stored in the memory 14 from the first deployment threshold to a second deployment threshold that is smaller than the first deployment threshold, thereby lowering the set deployment threshold (step S9).

The unfolding threshold change unit 35 determines whether a predetermined condition for returning the set unfolding threshold stored in memory 14 from the second unfolding threshold to the first unfolding threshold is met (step S10). If it is determined that the predetermined condition is not met (S10: NO), the process returns to step S10. On the other hand, if it is determined that the predetermined condition is met (S10: YES), the process proceeds to step S11.

The unfolding threshold change unit 35 changes the set unfolding threshold stored in the memory 14 from the second unfolding threshold to the first unfolding threshold, resets the set unfolding threshold to its original value (step S11), and returns to the processing of step S1.

Next, the processing procedure for controlling the deployment of the side impact airbags 3 (3L, 3R) by the CPU 13 will be explained with reference to Figure 5.

The deployment unit 36 determines whether the lateral (left-right) acceleration of vehicle X detected by the acceleration sensor 20 (20L, 20R) exceeds the set deployment threshold stored in memory 14 (step S101).

Here, the set deployment threshold stored in memory 14 is the second deployment threshold during the period from when the collision type is predicted to be a side impact in which the front of target T collides with the side of vehicle X in the flowchart of Figure 4 and the set deployment threshold is lowered from the first deployment threshold to the second deployment threshold (step S9) until a predetermined condition is met for returning the set deployment threshold stored in memory 14 from the second deployment threshold to the first deployment threshold and the set deployment threshold is returned from the second deployment threshold to the first deployment threshold (step S11), and the set deployment threshold is the first deployment threshold during other periods.

If it is determined that the lateral (left-right) acceleration of vehicle X does not exceed the set deployment threshold stored in memory 14 (S101: NO), the process returns to step S101. On the other hand, if it is determined that the lateral (left-right) acceleration of vehicle X exceeds the set deployment threshold stored in memory 14 (S101: YES), the deployment unit 36 determines to deploy the side impact airbags 3 (3L, 3R) and deploys the side impact airbags 3 (3L, 3R) (step S102).

In the above-described embodiment, by setting the deployment threshold before the collision type is predicted to be one in which the front of the target object T collides with the side of the vehicle X, and the deployment threshold after the above-described predetermined condition is met (i.e., the collision type is predicted to be one in which the front of the target object T collides with the side of the vehicle X, but it is predicted that the front of the target object T does not collide with the side of the vehicle X), to a relatively large value, it is possible to prevent unnecessary deployment of the side impact airbags 3 (3L, 3R) during normal vehicle driving or when the doors are opened or closed.

In addition, the deployment threshold before the collision type is predicted to be one in which the front of the target T collides with the side of the vehicle X, and the deployment threshold after the above-mentioned specified conditions are met can be set to relatively large values to prevent unnecessary deployment of the side impact airbags during normal vehicle driving or when the doors are opened or closed, while the deployment threshold from the time the collision type is predicted to be a side impact until the above-mentioned specified conditions are met can be set to a relatively small value, so that the side impact airbags 3 (3L, 3R) can be deployed early to protect the occupants when the front of the target T collides with the side of the vehicle X.

Furthermore, because vehicle X is facing obliquely toward target T located near the side of the vehicle, camera 21, whose detection range for target T is limited to the front of the vehicle, will be unable to detect target T approaching the side of vehicle X. However, by setting the predetermined condition for returning the set deployment threshold stored in memory 14 from the second deployment threshold to the first deployment threshold as condition 1 (i.e., passing the predicted collision time when the front of target T is predicted to collide with the side of vehicle X), or condition 2 (i.e., passing the predicted collision time when the front of target T is predicted to collide with the side of vehicle X plus a specific time), side impact airbags 3 (3L, 3R) can be deployed early to protect occupants when the front of target T collides with the side of vehicle X, even when the detection range for target T by camera 21 is limited to the front of the vehicle.

Furthermore, by setting the predetermined condition for returning the set deployment threshold stored in memory 14 from the second deployment threshold to the first deployment threshold to be that a specific time has passed since the predicted collision time at which the front of target T is predicted to collide with the side of vehicle X (condition 2), even if a situation arises in which the actual collision time is delayed by an amount within the specific time from the predicted collision time, the side impact airbags 3 (3L, 3R) can be deployed early when the front of target T collides with the side of vehicle X to protect the occupants.

In addition, various design modifications may be made to the above-described configuration within the scope of the claims.

For example, in the above embodiment, the target object T was described as another vehicle (a vehicle other than vehicle X), but it is not limited to this and may be, for example, a feature such as a pole or guardrail. In this case, if a target object such as a pole or guardrail is predicted to collide with the side of the vehicle, the set deployment threshold stored in memory 14 is lowered.

In addition, in the above embodiment, the left side impact airbag 3L and the right side impact airbag 3R share the same set deployment threshold stored in memory 14. However, this is not limited to this. The left side impact airbag 3L and the right side impact airbag 3R may not share the same set deployment threshold, and the set deployment threshold for the left side impact airbag 3L and the set deployment threshold for the right side impact airbag 3R may be stored separately in memory 14. In this case, for example, if the collision type between vehicle X and target T is predicted to be a collision type in which the front of the target collides with the side of vehicle X (side impact), if target T is located to the left front of vehicle X when detected by camera 21, the set deployment threshold for left side impact airbag 3L may be lowered in memory 14, and if target T is located to the right front of vehicle X when detected by camera 21, the set deployment threshold for right side impact airbag 3R may be lowered in memory 14.

In addition, the contents described in the above embodiment and the contents described in the above modified example may be combined as appropriate.

The present invention is widely applicable to vehicle control devices that control the deployment of side-impact airbags installed on the sides of a vehicle.

X: Vehicle T: Target 1: Vehicle control device 3: Side collision airbag 11: ECU
13: CPU
14: Memory 20: Acceleration sensor 31: Vehicle position prediction unit 32: Target position prediction unit 33: Determination unit 34: Collision type prediction unit 35: Deployment threshold change unit 36: Deployment unit

Claims (3)

A vehicle control device that is mounted on a vehicle and deploys a side collision airbag provided on a side of the vehicle based on an acceleration occurring in the vehicle and a deployment threshold for deploying the side collision airbag, the vehicle control device comprising:
a vehicle position prediction unit that predicts a future vehicle position indicating a position of the vehicle after a predetermined time;
a target detection unit that detects targets within a limited detection range in front of the vehicle;
a target position prediction unit that predicts a future target position indicating a position of the target detected by the target detection unit after the predetermined time;
a collision type prediction unit that predicts whether a collision type between the vehicle and the target after the target leaves the detection range of the target detection unit will be a side collision in which the target collides with a side of the vehicle, based on a vehicle traveling direction vector derived from a change in the vehicle future position and a target traveling direction vector derived from a change in the target future position of the target within the detection range of the target detection unit;
a deployment threshold change unit that lowers the deployment threshold when the collision type is predicted to be a side collision. The vehicle control device further includes a collision time prediction unit that predicts a collision time when the vehicle will collide with the target,
2. The vehicle control device according to claim 1, wherein the deployment threshold change unit keeps the deployment threshold at a lowered value based on the assumption that the collision type is the side impact, at least until the predicted collision time has passed.
3. The vehicle control device according to claim 2, wherein the deployment threshold change unit keeps the deployment threshold at a lowered value, assuming that the collision type is the side impact, until a time equal to the predicted collision time plus a specific time has passed.