JP7493486B2 - Driving Support Devices - Google Patents

Description

The present invention relates to a driving assistance device.

A technology has been developed that detects the moving speed and direction of a vehicle and a target, predicts the possibility of a collision between the vehicle and the target based on the moving speed and direction, and, if there is a possibility of a collision between the vehicle and the target, outputs a collision warning to alert the driver of the vehicle and activates the automatic brakes.

JP 2020-8288 A

In the above technology, when calculating the timing of automatic braking for a vehicle, in a scene where the vehicle is about to rear-end collide with a target, the timing of the operation is calculated so that the vehicle stops just before the collision point between the vehicle and the target, making it possible to avoid a collision between the vehicle and the target.

However, in a scene where a target collides with the side of a vehicle, if the activation timing is calculated so that the vehicle stops just before the collision point between the vehicle and the target, the vehicle will stop in the path of the target, which may result in the target colliding with the vehicle.

The present invention has been made in consideration of the above, and aims to provide a driving assistance device that can handle a wide variety of collision patterns between a vehicle and a target.

In order to solve the above-mentioned problems and achieve the object, the driving assistance device according to the present invention includes a vehicle position prediction unit that predicts a vehicle future position indicating the position of a vehicle equipped with the driving assistance device after a predetermined time, a target position prediction unit that predicts a target future position indicating the position of a target after a predetermined time, a determination unit that determines whether or not there is a possibility of a collision between the vehicle and the target based on the vehicle future position and the target future position, a collision type prediction unit that predicts the collision type between the vehicle and the target based on the relationship between the traveling direction of the vehicle and the traveling direction of the target when it is determined that there is a possibility of a collision between the vehicle and the target, and an execution unit that executes a predetermined control on the vehicle according to the collision type.

This configuration allows the control of the vehicle to be changed depending on the type of collision between the vehicle and a target, making it possible to deal with a wide variety of collision types between the vehicle and a target.

The driving assistance device according to the present invention further includes an area setting unit that sets areas surrounding the vehicle and the target, and the collision type prediction unit predicts the collision type including the collision site between the vehicle and the target based on the area and the angle between the traveling direction of the vehicle and the traveling direction of the target, and the execution unit executes a predetermined control based on the collision site.

This configuration allows for more appropriate control of the vehicle, as it is possible to execute predetermined control based on the collision type, including the collision location.

The driving assistance device according to the present invention also provides collision patterns including a rear-end collision pattern in which one of the vehicle and the target collide with the other without entering the path of the other, and a crossing collision pattern in which one of the vehicle and the target enters the path of the other and collides with the other.

This configuration allows for the execution of predetermined controls at suitable timing for both rear-end collision types and crossing collision types.

In addition, in the driving assistance device according to the present invention, the collision type prediction unit predicts that the collision type is a rear-end collision type in which the front of the vehicle collides with the target if the angle is smaller than a predetermined threshold value and the end point in the traveling direction of the vehicle is within the area of the target, predicts that the collision type is a rear-end collision type in which the front of the target collides with the vehicle if the angle is smaller than a predetermined threshold value and the end point in the traveling direction of the target is within the area of the vehicle, predicts that the collision type is a cross-sectional collision type in which the front of the vehicle collides with the target if the angle is equal to or greater than the predetermined threshold value and the end point in the traveling direction of the vehicle is within the area of the target, and predicts that the collision type is a cross-sectional collision type in which the front of the target collides with the vehicle if the angle is equal to or greater than the predetermined threshold value and the end point in the traveling direction of the target is within the area of the vehicle.

This configuration allows for the execution of predetermined controls at suitable timing for both rear-end collision types and crossing collision types.

In addition, in the driving assistance device according to the present invention, the predetermined control includes an automatic brake that suppresses a collision between the vehicle and a target, and the execution unit changes the timing for activating the automatic brake depending on whether the collision is a rear-end collision type or a crossing collision type.

This configuration allows automatic braking to be activated at optimal timing for both rear-end and cross-traffic collision types.

In addition, the driving assistance device according to the present invention has an execution unit that changes the timing of activating the automatic brake depending on the collision position between the vehicle and the target in a rear-end collision type and the collision position between the vehicle and the target in a cross-over collision type.

This configuration allows automatic braking to be activated at optimal timing for both rear-end and cross-traffic collision types.

The driving assistance device of the present invention has the effect of being able to handle a wide variety of collision patterns between a vehicle and a target.

FIG. 1 is a diagram showing an example of the configuration of a driving assistance system to which a driving assistance device according to this embodiment is applied. FIG. 2 is a diagram illustrating an example of a functional configuration of the driving assistance system according to the present embodiment. FIG. 3 is a diagram for explaining an example of the flow of vehicle control processing in the driving assistance system according to the present embodiment. FIG. 4 is a flowchart showing an example of the flow of the process of predicting a collision type and the process of calculating the operation timing of an automatic brake in the driving assistance system according to this embodiment. FIG. 5 is a diagram for explaining an example of a process for predicting a collision type in the driving assistance system according to this embodiment. FIG. 6 is a diagram for explaining an example of a control process for automatic braking of a vehicle in the driving assistance system according to this embodiment.

Below, an example of a driving assistance device according to the present invention is described in detail with reference to the drawings.

Figure 1 is a diagram showing an example of the configuration of a driving assistance system to which a driving assistance device according to this embodiment is applied. First, an example of the configuration of the driving assistance system 1 according to this embodiment will be described with reference to Figure 1.

The driving assistance system 1 is a system mounted on a vehicle X (see FIG. 5) and assists in driving the vehicle X. Here, the vehicle X may be, for example, an electric vehicle, a hybrid vehicle, or an autonomous vehicle. The driving assistance system 1 has a driving assistance function for avoiding a collision between the vehicle X and a target T (see FIG. 5) or reducing damage caused by the collision. Here, the target T is an object such as a vehicle, a person, or an obstacle ahead. The driving assistance function also includes a collision warning function, a primary braking function, and a secondary braking function.

The collision warning function is a function that warns of the possibility of a collision before the automatic brake is activated. The primary braking function is a function (gentle braking function) that uses the automatic brake to decelerate vehicle X at a primary target deceleration in order to encourage the driver to take action to avoid the collision. The secondary braking function is a function (hard braking function) that uses the automatic brake to decelerate vehicle X at a secondary target deceleration that is greater than the primary target deceleration in order to avoid a collision and reduce collision damage.

The driving assistance system 1 includes an ECU (Electronic Control Unit) 11. The ECU 11 is equipped with a microcontroller (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 a plurality of ECUs for controlling each part. The ECU 11 is connected to the other ECUs so as to enable two-way communication using the CAN (Controller Area Network) communication protocol.

The 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, and is installed, for example, in front of the rearview mirror in the center of the front part of the vehicle interior so as to capture a wide-angle image of the area in front of the vehicle X. The camera 21 also extracts target pixels corresponding to the same object in each image captured by the image sensors from a pair of image data input from the image sensors of the left and right eyes. The camera 21 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 object (target T) using the principle of triangulation. The output signal of the camera 21 is input to the ECU 11.

Vehicle X is further provided with a vehicle speed sensor 22, a steering angle sensor 23, and a yaw rate sensor 24. Vehicle speed sensor 22 outputs, as a detection signal, a pulse signal synchronized 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) with respect to the steering angle midpoint of the steering mechanism (e.g., a steering wheel). The steering angle takes a positive value when the steering mechanism is turned to the right from the steering angle midpoint (the steering wheel is turned to the right), and takes a negative value when it is turned to the left (the steering wheel is turned to the left).

The yaw rate sensor 24 outputs a detection signal corresponding to the yaw rate, which is the rotational angular velocity around a vertical axis passing through the center of gravity of the vehicle X. The detection signals of the vehicle speed sensor 22, the steering angle sensor 23, and the yaw rate sensor 24 are input to the ECU 11.

Vehicle X is equipped with a hydraulic brake system. The brake system includes a brake pedal, a brake booster, a master cylinder, a brake actuator 25, and brakes provided on each wheel. The brake pedal is located in a position that is convenient for the driver sitting in the driver's seat to step on it with his right foot. When the brake pedal is stepped on, the force input to the brake pedal is transmitted to the brake booster. The brake booster uses the negative pressure generated in the engine's intake system, and the pressure difference between the negative pressure and atmospheric pressure amplifies the force applied to the brake pedal.

The force amplified by the brake booster is transmitted from the brake booster to the master cylinder, and hydraulic pressure corresponding to that force is generated from the master cylinder. The hydraulic pressure of the master cylinder is transmitted to the brake actuator 25, which supplies hydraulic pressure to the wheel cylinders of the brakes provided on each wheel, and the hydraulic pressure causes each brake to apply braking force to the wheel. The brake actuator 25 also has a built-in 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.

The vehicle X is also equipped with an alarm 26. The alarm 26 outputs various types of alarms, which may be output by light, sound, or voice.

Figure 2 is a diagram showing an example of the functional configuration of the driving assistance system according to this embodiment. Next, an example of the functional configuration of the driving assistance system 1 according to this embodiment will be described with reference to Figure 2.

In the driving assistance system 1 according to the present embodiment, the CPU 13 executes various programs stored in the memory 14 to realize each functional unit such as the vehicle position prediction unit 201, the target position prediction unit 202, the judgment unit 203, the collision type prediction unit 204, and the execution unit 205, as shown in FIG. 2. In the driving assistance system 1 according to the present embodiment, the CPU 13 executes various programs stored in the memory 14 to realize each functional unit such as the vehicle position prediction unit 201, the target position prediction unit 202, the judgment unit 203, the collision type prediction unit 204, and the execution unit 205, but this is not limited thereto, and each functional unit can also be realized by hardware.

The vehicle position prediction unit 201 predicts a future position (hereinafter referred to as the vehicle future position) indicating the position of the vehicle X after a predetermined time. Here, the predetermined time is a time set in advance. In this embodiment, the vehicle position prediction unit 201 predicts the vehicle future position based on 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. Also, in this embodiment, the vehicle position prediction unit 201 predicts the vehicle future position at each small time interval from the current time until a predetermined time later.

The target position prediction unit 202 predicts the future position (hereinafter referred to as the target future position) indicating the position of the target T after a predetermined time. In this embodiment, the target position prediction unit 202 predicts the target future position based on the distance to the target T calculated by the camera 21. That is, the target position prediction unit 202 predicts the target future position based on the captured image data. In this embodiment, the target position prediction unit 202 predicts the target future position at each small time from the current time until a predetermined time later.

The determination unit 203 determines whether or not there is a possibility of a collision between the vehicle X and the target T based on the vehicle future position and the target future position. In this embodiment, the determination unit 203 sets a rectangular vehicle area surrounding the vehicle X located at the vehicle future position. If the target future position is included in the set vehicle area, the determination unit 203 determines that there is a possibility of a collision between the vehicle X and the target T. Furthermore, in this embodiment, the determination unit 203 determines whether or not there is a possibility of a collision between the vehicle X and the target T based on the vehicle future position and the target future position at each small time interval from the current time to a predetermined time later.

When it is determined that there is a possibility of a collision between the vehicle X and the target T, the collision type prediction unit 204 predicts the collision type between the vehicle X and the target T based on the relationship between the traveling direction of the vehicle X and the traveling direction of the target T. In this embodiment, the collision type prediction unit 204 also functions as an example of an area setting unit that sets a vehicle area surrounding the periphery of the vehicle future position of the vehicle X and a target area surrounding the target future position of the target T. Next, the collision type prediction unit 204 predicts a collision type (e.g., full-wrap frontal collision, offset frontal collision, side collision) including the collision part of the target T on the vehicle X based on the set vehicle area and target area and the angle θ. This enables control processing of the vehicle X based on the collision part of the target T with respect to the vehicle X, making it possible to deal with a wider variety of collision types between the vehicle X and the target T.

Here, the angle θ (see FIG. 5) is the angle between the traveling direction of the vehicle X and the traveling direction of the target T. In this embodiment, the collision type prediction unit 204 sets a vehicle area and a target area, but it is sufficient if it predicts the collision type based on an area surrounding at least one of the vehicle future position and the target future position.

In this embodiment, the collision types include a rear-end collision type and a crossing collision type. Here, the rear-end collision type is a collision type (rear-end collision type) in which one of the vehicle X and the target T collides with the other without entering the path of the other. In other words, the rear-end collision type is a collision type in which the front of one of the vehicle X and the target T collides with the other. The crossing collision type is a collision type other than a rear-end collision, in which one of the vehicle X and the target T enters the path of the other and collides. In other words, the crossing collision type is a collision type in which the front of one of the target T and the vehicle X collides with the side of the other.

The execution unit 205 executes a predetermined control on the vehicle X according to the predicted collision type. This allows the control processing on the vehicle X to be changed according to the collision type between the vehicle X and the target T, making it possible to deal with a wide variety of collision types between the vehicle X and the target T. In other words, since the predetermined control can be executed at a timing that matches the collision type between the vehicle X and the target T, the predetermined control can be executed at a timing that can avoid a collision with the target T while ensuring a minimum required safety margin in each collision type.

The predetermined control here is a control that is set in advance, such as the timing (hereinafter referred to as the activation timing) of activating an automatic brake (so-called AEB: Autonomous Emergency Braking) and changing the type of warning given to the driver. Here, the automatic brake is a brake that suppresses a collision between the vehicle X and the target T. In other words, the predetermined control is a control that avoids a collision between the vehicle X and the target T.

In this embodiment, the execution unit 205 executes a predetermined control on the vehicle X based on the collision location predicted by the collision type prediction unit 204. This allows the execution unit 205 to execute a predetermined control on the vehicle X based on the collision type including the collision location, so that more suitable control can be executed on the vehicle X.

Specifically, the execution unit 205 changes the timing of automatic braking depending on the rear-end collision type and crossing collision type predicted by the collision type prediction unit 204. More specifically, the execution unit 205 changes the timing of automatic braking depending on the collision position due to the rear-end collision type and the collision position due to the crossing collision type. For example, when the predicted collision type is the rear-end collision type, the execution unit 205 activates the automatic brake so that the vehicle X stops before the collision position between the vehicle X and the target T according to the time to collision (TTC). That is, the execution unit 205 activates the automatic brake from a position away from the collision position between the vehicle X and the target T in the opposite direction to the traveling direction of the vehicle X, by the braking distance of the automatic brake.

On the other hand, if the predicted collision type is a crossing collision type, the execution unit 205 activates the automatic brakes in accordance with the collision margin time so that the vehicle X stops before the collision position between the vehicle X and the target T. Alternatively, the execution unit 205 activates the automatic brakes in accordance with the brake margin time (TTB: Time To Brake) so that the vehicle X stops before the collision position between the vehicle X and the target T and before the path of the target T. In other words, the execution unit 205 activates the automatic brakes from a position away from the path of the target T in the opposite direction to the traveling direction of the vehicle X, by the braking distance of the automatic brakes. This makes it possible to activate the automatic brakes at an appropriate timing for each of the rear-end collision type and the crossing collision type.

Figure 3 is a diagram for explaining an example of the flow of control processing for a vehicle in the driving assistance system according to this embodiment. Next, an example of the flow of control processing for vehicle X in the driving assistance system 1 according to this embodiment will be explained using Figure 3.

In this embodiment, the target position prediction unit 202 calculates the target position, which is the position of the target T, based on image data captured by the camera 21 (step S301). 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 201 acquires driving information such as the vehicle speed, steering angle, and rotational angular velocity of the vehicle X (step S301).

Next, the vehicle position prediction unit 201 predicts the vehicle future position indicating the position of the vehicle X after a predetermined time based on the acquired driving information (step S302). Also, the target position prediction unit 202 predicts the target future position indicating the position of the target T after a predetermined time based on the calculated target position (step S302).

The determination unit 203 determines whether or not there is a possibility of a collision between the vehicle X and the target T based on the vehicle future position and the target future position (step S303). If it is determined that there is a possibility of a collision between the vehicle X and the target T, the collision type prediction unit 204 predicts the type of collision between the vehicle X and the target T based on the relationship between the traveling direction of the vehicle X and the traveling direction of the target T (step S303).

The execution unit 205 determines other conditions to be used for the predetermined control, such as the timing of automatic brake activation, according to the collision type predicted by the collision type prediction unit 204 (step S304). Next, the execution unit 205 transmits activation requests, control instruction values, etc. to various actuators of the vehicle X according to the determined conditions, and executes the predetermined control of the vehicle X (step S305).

Figure 4 is a flowchart showing an example of the flow of the process of predicting a collision type and the process of calculating the operation timing of the automatic brake in the driving assistance system according to this embodiment. Figure 5 is a diagram for explaining an example of the process of predicting a collision type in the driving assistance system according to this embodiment. Next, details of an example of the flow of the process of predicting a collision type and the process of calculating the operation timing of the automatic brake of vehicle X in the driving assistance system 1 according to this embodiment will be described using Figures 4 and 5.

When the determination unit 203 determines that there is a possibility of a collision between the vehicle X and the target T, the collision mode prediction unit 204 calculates the angle θ between the vehicle travel direction vector Vvec, which is a vector representing the travel direction of the vehicle X, and the target travel direction vector Gvec, which is a vector representing the travel direction of the target T. In other words, the angle θ is the angle between the travel direction of the vehicle X and the travel direction of the target T.

Specifically, the collision mode prediction unit 204 calculates the vehicle traveling direction vector Vvec based on the current position VUT(t-1) of the vehicle X at the current time t-1 and the vehicle future position VUT(t) 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 mode prediction unit 204 calculates the target traveling direction vector Gvec based on the current position GVT(t-1) of the target T at the current time t-1 and the target future position GVT(t) of the target T at the future time t, as shown in the following equation (2).
Gvec = GVT(t) - GVT(t-1) ... (2)

Next, the collision mode prediction unit 204 obtains an angle θ between 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)

Next, the collision mode prediction unit 204 determines whether the angle θ is smaller than a threshold value θt (e.g., 10 degrees) (step S401). Here, the threshold value (an example of a predetermined threshold value) θt is, for example, 10 degrees, which is the threshold value of the angle θ at which it is determined that the vehicle travel direction vector Vvec and the target travel direction vector Gvec are almost the same, and that the vehicle X and the target T will collide in a collision mode other than a rear-end collision.

If the angle θ is smaller than the threshold value θt (step S401: Yes), the collision type prediction unit 204 predicts that the collision type between the vehicle X and the target T is a rear-end collision type (step S402). Next, the collision type prediction unit 204 determines whether the end point of the vehicle X in the traveling direction is within the target area of the target T (step S403). In this embodiment, as shown in FIG. 5, when the vehicle area of the vehicle X is a rectangular area, the collision type prediction unit 204 sets the corners A, B, C, and D of the rectangular area based on the center position OX of the vehicle X as the end points of the vehicle area. Also, as shown in FIG. 5, when the target area of the target T is a rectangular area, the collision type prediction unit 204 sets the corners E, F, G, and H of the rectangular area based on the center position OT of the target T as the end points of the target area.

In this embodiment, the collision type prediction unit 204 determines whether or not the end points A, B, C, and D of the vehicle area at future time t are within a target area based on the center position OT of the target T at future time t. For example, the collision type prediction unit 204 calculates the cross products of EF x EA, FG x FA, GH x GA, and HE x HA, and determines that the end point A is within the target area if the signs of the calculated cross products match. The collision type prediction unit 204 can similarly determine whether or not the end points B, C, and D of the vehicle area are within the target area.

Returning to FIG. 4, if an end point on the traveling direction side of vehicle X (e.g., at least one of end points A and B shown in FIG. 5) is within the target area of target T (step S403: Yes), the collision type prediction unit 204 predicts that the collision type between vehicle X and target T is a rear-end collision type in which the front surface (front part) of vehicle X collides with the rear surface (rear part) of target T (step S404).

In this case, the execution unit 205 calculates the timing of automatic braking operation according to the time to collision (TTC) so that the vehicle X stops just before the collision position where the vehicle X collides with the target T (step S405).

On the other hand, if the end point in the traveling direction of vehicle X is not within the target area of target T (step S403: No), the collision type prediction unit 204 predicts that the collision type between vehicle X and target T is a rear-end collision type in which the front (front part) of target T collides with the rear (rear part) of vehicle X (step S406). In this case, the execution unit 205 does not execute the specified control on vehicle X, and allows vehicle X to continue traveling as is. Alternatively, the execution unit 205 may issue a warning (an example of the specified control) to the driver of vehicle X to notify the driver that target T will rear-end vehicle X.

In other words, it is difficult to determine whether vehicle X will collide with target T from the angle θ between the vehicle travel direction vector Vvec and the target travel direction vector Gvec alone, or whether vehicle X will not collide with target T from the rear. In the case of a non-collision, there is little need to activate the automatic brakes of vehicle X, so it is necessary to determine which part of vehicle X the target T will collide with.

Therefore, in this embodiment, as shown in step S402, the collision type prediction unit 204 predicts whether the collision type between the vehicle X and the target T is a collision type in which the front of the vehicle X collides with the target T by judging whether or not at least one of the end points on the traveling direction side of the vehicle X is within the target area of the target T. That is, when the angle θ is smaller than the threshold value θt and the end point on the traveling direction side of the vehicle X is within the target area, the collision type prediction unit 204 predicts that the collision type between the vehicle X and the target T is a collision type in which the front of the vehicle X collides with the rear surface of the forward vehicle, which is an example of the target T. On the other hand, when the angle θ is smaller than the threshold value θt and the end point on the traveling direction side of the vehicle X is not within the target area, the collision type prediction unit 204 predicts that the collision type between the vehicle X and the target T is a collision type in which the front of the target T collides with the rear surface of the vehicle X.

In addition, in step S401, if the angle θ is equal to or greater than the threshold value θt (step S401: No), the collision type prediction unit 204 predicts that the collision type between the vehicle X and the target T is a crossing collision type (a collision type other than a rear-end collision type) (step S407). Next, the collision type prediction unit 204 determines whether the end point of the vehicle X in the traveling direction is within the target area of the target T (step S408). The collision type prediction unit 204 determines whether the end point of the vehicle X in the traveling direction is within the target area of the target T in the same manner as in step S402.

If the end point of the vehicle X in the direction of travel is within the target area of the target T (step S408: Yes), the collision type prediction unit 204 predicts that the collision type between the vehicle X and the target T is a cross-sectional collision type (side impact) in which the front (front part) of the vehicle X collides with the side (side part) of the target T (step S409). In this case, the execution unit 205 calculates the activation timing of the automatic brake according to the time to collision (TTC) so that the vehicle X stops before the collision position between the vehicle X and the target T (step S410).

On the other hand, if the end point on the traveling direction side of the vehicle X is not within the target area of the target T (step S408: No), the collision type prediction unit 204 judges whether the end point of the target T is within the vehicle area of the vehicle X (step S411). In this embodiment, the collision type prediction unit 204 judges whether the end points E, F, G, and H of the target area of the target T at future time t are within the vehicle area based on the center position OX of the vehicle X at future time t. For example, the collision type prediction unit 204 calculates the cross products of AB×AE, BC×BE, CD×CE, and DA×DE, and judges that the end point E is within the vehicle area if the signs of the calculated cross products match. The collision type prediction unit 204 similarly judges whether the end points F, G, and H of the target T are within the vehicle area.

Returning to FIG. 4, if the end point of the target T in the direction of travel, i.e., at least one of the end points E and F shown in FIG. 5, is not within the vehicle area of the vehicle X (step S411: No), the collision type prediction unit 204 determines that the vehicle X and the target T will not collide. On the other hand, if the end point of the target T in the direction of travel, i.e., at least one of the end points E and F shown in FIG. 5, is within the vehicle area of the vehicle X (step S411: Yes), the collision type prediction unit 204 predicts that the collision type between the vehicle X and the target T is a cross-sectional collision type (side impact) in which the front (front part) of the target T collides with the side (side part) of the vehicle X (step S412).

In this case, the execution unit 205 calculates the timing of automatic braking operation so that the vehicle X stops just before the path of the target T according to the braking margin time (TTB) (step S413).

Even when one of vehicle X and target T crosses the path of the other, the timing at which the automatic brake needs to be activated differs depending on whether the collision type is one in which the front of vehicle X collides with target T or one in which the front of target T collides with the side of vehicle X. For example, if the collision type between vehicle X and target T is one in which the target collides with the side of vehicle X, there is a possibility that the target T may be slipped through by the driver's operation, and it is necessary to calculate the activation timing of the automatic brake while respecting the driver's intention.

Therefore, in this embodiment, as shown in step S411, the collision type prediction unit 204 predicts whether the collision type between the vehicle X and the target T is a collision type in which the front of the target T collides with the side of the vehicle X by judging whether the end points E and F on the traveling direction side of the target T are within the vehicle area. That is, when the angle θ is equal to or greater than the threshold value θt and the end point on the traveling direction side of the vehicle X is within the target area, the collision type prediction unit 204 predicts that the collision type between the vehicle X and the target T is a collision type in which the front of the vehicle X collides with the side of the target T. On the other hand, when the angle θ is equal to or greater than the threshold value θt, the end point on the traveling direction side of the vehicle X is not within the target area, and the end point on the traveling direction side of the target T is within the vehicle area, the collision type prediction unit 204 predicts that the collision type between the vehicle X and the target T is a collision type in which the front of the target T collides with the side of the vehicle X.

Figure 6 is a diagram for explaining an example of a control process for automatic braking of a vehicle in the driving assistance system according to this embodiment. Next, an example of a control process for automatic braking of vehicle X in the driving assistance system 1 according to this embodiment will be explained using Figure 6.

In a conventional driving assistance system, when calculating the timing of automatic braking of vehicle X, regardless of the collision mode between vehicle X and another vehicle Y, which is an example of a target T, the timing of automatic braking is calculated to be a distance d2 before the stopping position P2 so that vehicle X stops at stopping position P2, which is a distance d1 before the collision position P1 between vehicle X and another vehicle Y in the traveling direction Z of vehicle X. Here, distance d2 is the braking distance of the automatic brake. Therefore, when vehicle X enters the path of other vehicle Y and the front of other vehicle Y collides with the side of vehicle X, in the conventional driving assistance system, as shown in FIG. 6(a), vehicle X stops at stopping position P2 in the path of other vehicle Y, so that the front of other vehicle Y may collide with the side of vehicle X.

Therefore, in this embodiment, when vehicle X enters the path of other vehicle Y and the front of the other vehicle Y collides with the side of vehicle X, the execution unit 205 calculates the activation timing of the automatic brake to be a distance d2 before the stop position P3 so that vehicle X stops at stop position P3 before the path of other vehicle Y, as shown in FIG. 6(b). This makes it possible to stop vehicle X without entering the path of other vehicle Y when it is determined that there is a possibility that the front of other vehicle Y will collide with the side of vehicle X. As a result, it becomes possible to avoid a collision between vehicle X and other vehicle Y even if the front of other vehicle Y collides with the side of vehicle X.

In this way, according to the driving assistance system 1 of this embodiment, when it is determined that there is a possibility of a collision between the vehicle X and the target T, the collision type between the vehicle X and the target T is predicted based on the relationship between the traveling direction of the vehicle X and the traveling direction of the target T, and a predetermined control is executed on the vehicle X according to the predicted collision type. This makes it possible to change the control over the vehicle X according to the collision type between the vehicle X and the target T, thereby making it possible to deal with a wide variety of collision types between the vehicle X and the target T.

In addition, according to the driving assistance system 1 of this embodiment, the collision type including the collision site between the vehicle X and the target T is predicted based on the areas surrounding the vehicle X and the target T and the angle between the traveling direction of the vehicle X and the traveling direction of the target T, and a predetermined control is executed based on the collision site, so that more appropriate control can be executed for the vehicle X when there is a possibility of a collision between the vehicle X and the target T.

In addition, according to the driving assistance system 1 of the present invention, the collision type includes a rear-end collision type and a crossing collision type, so that a predetermined control can be executed at an appropriate timing for each of the rear-end collision type and the crossing collision type. In addition, according to the driving assistance system 1 of the present invention, when the angle θ is smaller than the threshold θt and the end point of the vehicle X in the traveling direction is within the area of the target T, the collision type is predicted to be a rear-end collision type in which the front of the vehicle X collides with the target T, when the angle θ is smaller than the threshold θt and the end point of the target T in the traveling direction is within the area of the vehicle X, the collision type is predicted to be a rear-end collision type in which the front of the target T collides with the vehicle X, when the angle θ is equal to or greater than the threshold θt and the end point of the vehicle X in the traveling direction is within the area of the target T, the collision type is predicted to be a cross-sectional collision type in which the front of the vehicle X collides with the target T, and when the angle θ is equal to or greater than the threshold θt and the end point of the target T in the traveling direction is within the area of the vehicle X, the collision type is predicted to be a cross-sectional collision type in which the front of the target T collides with the vehicle X. In this way, it is possible to execute a predetermined control at a suitable timing for each of the rear-end collision type and the cross-sectional collision type.

Furthermore, according to the driving assistance system 1 of the present invention, the predetermined control includes an automatic brake that suppresses a collision between the vehicle X and the target T, and by changing the timing at which the automatic brake is activated between the rear-end collision type and the crossing collision type, the automatic brake can be activated at a suitable timing for each of the rear-end collision type and the crossing collision type. Furthermore, according to the driving assistance system 1 of the present invention, by changing the timing at which the automatic brake is activated between the collision position between the vehicle X and the target T in the rear-end collision type and the collision position between the vehicle X and the target T in the crossing collision type, the automatic brake can be activated at a suitable timing for each of the rear-end collision type and the crossing collision type.

1 Driving assistance system 11 ECU
12 microcomputer 13 CPU
14 Memory 21 Camera 22 Vehicle speed sensor 23 Steering angle sensor 24 Yaw rate sensor 25 Brake actuator 26 Alarm 201 Vehicle position prediction unit 202 Target position prediction unit 203 Determination unit 204 Collision type prediction unit 205 Execution unit X Vehicle T Target

Claims (4)

A driving assistance device,
a vehicle position prediction unit that predicts a future vehicle position indicating a position of a vehicle equipped with the driving assistance device after a predetermined time;
a target position prediction unit for predicting a future target position indicating a position of the target after the predetermined time has elapsed;
a determination unit that determines whether or not there is a possibility of a collision between the vehicle and the target based on the vehicle future position and the target future position;
a collision type prediction unit that predicts a collision type between the vehicle and the target based on a relationship between a traveling direction of the vehicle and a traveling direction of the target when it is determined that there is a possibility of a collision between the vehicle and the target;
an execution unit that executes a predetermined control in accordance with the collision mode;
a region setting unit that sets a region surrounding each of the vehicle and the target,
the collision type prediction unit predicts the collision type including a collision site of the vehicle with the target based on the area and an angle between a traveling direction of the vehicle and a traveling direction of the target;
The execution unit executes the predetermined control based on the collision site,
The collision type includes a rear-end collision type in which one of the vehicle and the target collide with each other without entering the path of the other, and a crossing collision type in which one of the vehicle and the target enter the path of the other and collide with each other.
Driving assistance device. The collision mode prediction unit
predicting that the collision type is a collision type in which the front side of the vehicle collides with the target object among the rear-end collision types when the angle is smaller than a predetermined threshold value and an end point of the vehicle in the traveling direction is within the area of the target object;
predicting that the collision type is a rear-end collision type in which a front surface of the target collides with the vehicle when the angle is smaller than the predetermined threshold value and an end point of the target in the traveling direction is within the area of the vehicle;
predicting that the collision type is a lateral collision type in which the front side of the vehicle collides with the target when the angle is equal to or greater than the predetermined threshold value and an end point of the vehicle in the traveling direction is within the area of the target;
2. The driving assistance device according to claim 1, wherein, when the angle is equal to or greater than the predetermined threshold value and an end point of the target in the traveling direction is within the area of the vehicle, the collision type is predicted to be a lateral collision type in which a front surface of the target collides with the vehicle. the predetermined control includes an automatic brake to suppress a collision between the vehicle and the target;
The driving support device according to claim 1 , wherein the execution unit changes a timing for activating the automatic brake depending on whether the collision type is the rear-end collision type or the crossing collision type. 4. The driving support device according to claim 3, wherein the execution unit changes a timing for activating the automatic brake depending on a collision position between the vehicle and the target in the rear-end collision type and a collision position between the vehicle and the target in the cross - sectional collision type.

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