Vehicle control device

Abstract

To provide a vehicular control device that can deal with a wide variety of collision forms of a vehicle and a target, and suppress a risk that occurs due to unwanted actuation of an automatic brake.SOLUTION: The vehicular control device is provided with: a collision determining part 103 that determines whether or not a vehicle is likely to collide with a target on the basis of a vehicle future position predicted by a vehicle position predicting part 101 and a target future position predicted by a target position predicting part 102; a collision form predicting part 104 that when it is determined that the vehicle is likely to collide with the target, predicts a collision form on the basis of a relation between a travelling direction of the vehicle and a travelling direction of the target; an actuation determining part 105 that primarily determines a timing of actuating an alarm and an automatic brake in accordance with the predicted collision form, and secondarily determines whether only alarm should be outputted or the alarm and the automatic brake should be actuated, under an additional determination condition corresponding to the collision form, with respect to the primarily determined result; and an executing part 106 that executes a secondarily determined result, at a timing when it is predicted that the vehicle is likely to collide with the target.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a vehicle control device that can deal with a wide variety of collision patterns between a vehicle and an object and can reduce the risk of unnecessary operation of an automatic brake. [Background technology]

[0002] A technology has been developed that detects the speed and direction of movement of a vehicle and a target, predicts the possibility of a collision between the vehicle and the target based on the speed and direction of movement, 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 automatic brakes. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-8288 Summary of the Invention [Problem to be solved by the invention]

[0004] 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 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, thereby making it possible to avoid a collision between the vehicle and the target.

[0005] 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 could result in the target colliding with the vehicle.

[0006] For this reason, it is more time-consuming to determine the collision position between the vehicle and the target, and the operation timing is calculated so that the vehicle stops outside the path of the target, thereby avoiding a collision between the vehicle and the target.

[0007] In this case, the earlier the automatic braking is activated, the further away the automatic braking will be, which increases the risk of unnecessary activation. Such early activation not only makes driving more cumbersome for the driver, but also has the potential to cause a secondary collision in which the following vehicle crashes into the rear due to sudden braking. Furthermore, when there is a high possibility of a head-on collision, it is often possible for the driver to apply the brakes themselves and avoid the collision by passing through.

[0008] The present invention has been made in consideration of the above, and aims to provide a vehicle control device that can deal with a wide variety of collision types between a vehicle and an object and can reduce the risk of unnecessary operation of the automatic brake. [Means for solving the problem]

[0009] In order to solve the above-mentioned problems and achieve the object, a vehicle control device according to the present invention is a vehicle control device comprising: a vehicle position prediction unit that predicts a vehicle future position, which indicates the position of a vehicle on which the vehicle control device is mounted after a predetermined time; a target position prediction unit that predicts a target future position, which indicates the position of a target after the predetermined time; a collision 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, when it is determined that there is a possibility of a collision between the vehicle and the target, 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; an operation determination unit that makes a primary determination of the timing of an alarm and an automatic brake activation to avoid a collision with the target according to the collision type predicted by the collision type prediction unit, and further makes a secondary determination based on the primary determination result on an additional determination condition according to the collision type, as to whether to issue only an alarm or to activate the alarm and the automatic brake; and an execution unit that executes the secondary determination result determined by the operation determination unit when it is predicted that there will be a collision between the vehicle and the target.

[0010] In addition, in the vehicle control device of the present invention, in the above invention, the additional judgment condition is for a predetermined social loss amount, and the activation judgment unit makes a secondary judgment to only issue the warning and not activate the automatic brake in the case of a collision type in which the social loss amount is smaller than a predetermined amount.

[0011] In addition, in the vehicle control device according to the present invention, in the above invention, the additional judgment condition is for a target type, and the activation judgment unit makes a secondary judgment based on the target type as to whether to output only an alarm or to activate an alarm and an automatic brake.

[0012] In addition, in the vehicle control device of the present invention, in the above invention, when the automatic brake is activated in the secondary judgment, the operation judgment unit makes a judgment to adjust the activation timing of the automatic brake or a judgment to adjust the braking strength depending on the additional judgment condition. [Effects of the Invention]

[0013] According to the present invention, it is possible to deal with a wide variety of collision patterns between a vehicle and a target, and to reduce the risk of unnecessary operation of the automatic brake. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a block diagram showing the configuration of a vehicle control device according to this embodiment. [Figure 2] FIG. 2 is a functional block diagram showing the internal configuration of the vehicle control device. [Figure 3] FIG. 3 is a flowchart showing a vehicle control processing procedure performed by the vehicle control device. [Figure 4] FIG. 4 is an explanatory diagram showing an example of a process for predicting a collision type and a process for calculating an automatic braking timing of a vehicle. [Figure 5] FIG. 5 is an explanatory diagram showing an example of a control process for automatic braking of a vehicle in a vehicle control device. [Figure 6]FIG. 6 is a time chart showing an example of the timing of warning and automatic braking. [Figure 7] FIG. 7 is a diagram illustrating an example of the secondary determination table. [Figure 8] FIG. 8 is a diagram showing an example of a secondary determination table used in the modified example. DETAILED DESCRIPTION OF THE INVENTION

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle control device according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

[0016] <Overall structure> FIG. 1 is a block diagram showing the configuration of a vehicle control device 1 according to this embodiment. The vehicle control device 1 is a device that is mounted on a vehicle X (see FIG. 4) 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 vehicle control device 1 has a driving assistance function for avoiding a collision between the vehicle X and a target T (see FIG. 4) or for 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.

[0017] The collision warning function 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 prompt 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 the collision and reduce the damage caused by the collision (see Figure 6).

[0018] The vehicle control device 1 includes an ECU (Electronic Control Unit) 11. The ECU 11 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 a plurality of ECUs for controlling various parts. The ECU 11 is connected to other ECUs so as to be able to perform two-way communication using a CAN (Controller Area Network) communication protocol.

[0019] 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 at the center of the front of the vehicle interior so as to be able to capture images of the area ahead of the vehicle X at a wide angle. The camera 21 extracts target pixels corresponding to the same target object in each image captured by the image sensors from a pair of image data input from the image sensors of both the left and right eyes. Next, the camera 21 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 object (target T) using the principle of triangulation. An output signal from the camera 21 is input to the ECU 11.

[0020] The vehicle X is further provided with a vehicle speed sensor 22, a steering angle sensor 23, and a yaw rate sensor 24. The 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 the vehicle X travels. The steering angle sensor 23 outputs a detection signal corresponding to the steering angle (absolute steering angle) of the steering mechanism (e.g., a steering wheel) of the vehicle X relative to the steering angle midpoint. 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 takes a negative value when it is turned to the left (the steering wheel is turned to the left).

[0021] 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.

[0022] 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 operate it with his / her right foot. When the brake pedal is depressed, the force input 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 force applied to the brake pedal.

[0023] 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 brake actuator 25, which supplies hydraulic pressure to the wheel cylinders of the brakes provided on each wheel, causing each brake to apply braking force to the wheel. Brake actuator 25 also contains an electric pump, which is driven by power from the battery when the automatic brake is activated, and hydraulic pressure generated by the electric pump is supplied to each wheel cylinder.

[0024] The vehicle X is also provided with an alarm 26. The alarm 26 outputs various types of alarms, and the alarms may be output by light, sound, or voice.

[0025] <Internal function configuration> Fig. 2 is a functional block diagram showing the internal configuration of the vehicle control device 1. In the vehicle control device 1, the CPU 13 executes various programs stored in the memory 14 to realize various functional units such as a vehicle position prediction unit 101, a target position prediction unit 102, a collision determination unit 103, a collision type prediction unit 104, an operation determination unit 105, and an execution unit 106, as shown in Fig. 2. In the vehicle control device 1 according to this embodiment, the CPU 13 executes various programs stored in the memory 14 to realize various functional units such as the vehicle position prediction unit 101, the target position prediction unit 102, the collision determination unit 103, the collision type prediction unit 104, the operation determination unit 105, and the execution unit 106, but this is not limiting, and each functional unit can also be realized by hardware.

[0026] The vehicle position prediction unit 101 predicts a future position indicating the position of the vehicle X after a predetermined time (hereinafter referred to as the vehicle future position). Here, the predetermined time is a time set in advance. In this embodiment, the vehicle position prediction unit 101 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 101 predicts the vehicle future position at each minute time from the current time until a predetermined time has elapsed.

[0027] The target position prediction unit 102 predicts a future position indicating the position of the target T after a predetermined time (hereinafter referred to as the target future position). In this embodiment, the target position prediction unit 102 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 102 predicts the target future position based on captured image data. In this embodiment, the target position prediction unit 102 predicts the target future position at each short time from the current time until a predetermined time later.

[0028] The collision determination unit 103 determines whether or not there is a possibility of collision between the vehicle X and the target T, based on the vehicle future position and the target future position. In this embodiment, the collision determination unit 103 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 collision determination unit 103 determines that there is a possibility of collision between the vehicle X and the target T. Furthermore, in this embodiment, the collision determination unit 103 determines whether or not there is a possibility of collision between the vehicle X and the target T, based on the vehicle future position and the target future position, at each short time interval from the current time until a predetermined time has elapsed.

[0029] 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 104 predicts a 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 104 also functions as an example of an area setting unit that sets a vehicle area surrounding the periphery of the future vehicle position of the vehicle X and a target area surrounding the future target position of the target T. Next, the collision type prediction unit 104 predicts a collision type (e.g., a full-overlap frontal collision, an offset frontal collision, or a side collision) including a collision portion 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 portion 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.

[0030] Here, the angle θ (see FIG. 4) 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 104 sets a vehicle area and a target area, but it is sufficient if it predicts a collision type based on an area surrounding at least one of the vehicle future position and the target future position.

[0031] In this embodiment, the collision types include a rear-end collision type and a cross-sectional 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. Furthermore, the cross-sectional 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 cross-sectional 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. This cross-sectional collision type also includes a head-on collision with an angle θ of 180 degrees.

[0032] The activation determination unit 105 performs a primary determination of the timing of issuing an alarm and activating the automatic brake to avoid collision with the target T, based on the collision type predicted by the collision type prediction unit 104. Furthermore, the activation determination unit 105 performs a secondary determination based on the primary determination result, determining whether to issue only an alarm or to activate the automatic brake and avoid collision with the target T, based on additional determination conditions corresponding to the collision type. In this embodiment, a predetermined social loss amount is used as the additional determination condition. The social loss amount is set for each collision type and is a value obtained by multiplying the damage amount of one collision type by the number of occurrences. Therefore, a head-on collision causes large damage but occurs infrequently, resulting in a small social loss amount. On the other hand, a collision type causes relatively small damage but occurs frequently, resulting in a large social loss amount. The damage amount is an amount paid based on the degree of death, serious injury, minor injury, sequelae, medical treatment, etc., and is, for example, an amount calculated by an insurance company. For a collision type for which the social loss amount is smaller than a predetermined amount, the activation determination unit 105 performs a secondary determination to issue only an alarm and not activate the automatic brake. When the automatic brake is to be activated in the secondary determination, the activation determination unit 105 may make a determination to advance the timing of activation of the automatic brake in accordance with the additional determination condition.

[0033] The execution unit 106 executes predetermined control on the vehicle X based on the secondary determination result corresponding 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 and suppressing unnecessary operation of the automatic brake based on the additional determination conditions. In other words, when an alarm and automatic braking are activated in the secondary determination, predetermined control can be executed at a timing that matches the collision type between the vehicle X and the target T, and when only an alarm is output in the secondary determination, unnecessary operation of the automatic brake can be suppressed and a secondary collision can be prevented.

[0034] Here, the predetermined control 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) or changing the type of warning 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.

[0035] In this embodiment, the execution unit 106 executes a predetermined control on the vehicle X based on the collision location predicted by the collision type prediction unit 104, in accordance with the primary determination result of the operation determination unit 105. However, in accordance with the secondary determination result of the operation determination unit 105, unnecessary operation of the automatic brake can be suppressed depending on the collision type, and more appropriate control can be executed.

[0036] Specifically, the predetermined control by the execution unit 106 changes the timing of activation of the automatic brake depending on whether the collision type is a rear-end collision type or a crossing collision type predicted by the collision type prediction unit 104. More specifically, the execution unit 106 changes the timing of activation of the automatic brake 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 a rear-end collision type, the execution unit 106 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). In other words, the execution unit 106 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.

[0037] On the other hand, if the predicted collision type is a cross-sectional collision type, the execution unit 106 activates the automatic brakes in accordance with the time to collision so that the vehicle X stops before the collision position between the vehicle X and the target T. Alternatively, the execution unit 106 activates the automatic brakes in accordance with the time to brake (TTB) 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 106 activates the automatic brakes from a position just before the path of the target T, in the opposite direction to the traveling direction of the vehicle X, at a distance equal to the braking distance of the automatic brakes. This makes it possible to activate the automatic brakes at appropriate timing for both a rear-end collision type and a cross-sectional collision type.

[0038] <Vehicle control processing> 3 is a flowchart showing a vehicle control processing procedure performed by the vehicle control device 1. As shown in FIG. 3, first, the target position prediction unit 102 calculates the target position, which is the position of the target T, based on image data captured by the camera 21, and the vehicle position prediction unit 101 acquires traveling information (step S11). Here, the target position is the position of the target T relative to the center position of the vehicle X. In addition, the traveling information includes the vehicle speed, steering angle, rotational angular velocity, etc. of the vehicle X.

[0039] Thereafter, the target position prediction unit 102 predicts a target future position indicating the position of the target T after a predetermined time based on the calculated target position, and the vehicle position prediction unit 101 predicts a vehicle future position indicating the position of the vehicle X after a predetermined time based on the acquired traveling information (step S12).

[0040] Thereafter, the collision determination unit 103 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 S13). If the collision determination unit 103 determines that there is no possibility of a collision between the vehicle X and the target T (step S13: No), this process ends. On the other hand, if the collision determination unit 103 determines that there is a possibility of a collision between the vehicle X and the target T (step S13: Yes), the collision type prediction unit 104 predicts a 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 (step S14).

[0041] Thereafter, the activation determination unit 105 makes a primary determination of the timing to issue an alarm and activate the automatic brake to avoid collision with the target T, in accordance with the collision type predicted by the collision type prediction unit 104 (step S15). Furthermore, the activation determination unit 105 makes a secondary determination of the result of this primary determination, referring to a secondary determination table TB1 (see FIG. 7), based on an additional determination condition in accordance with the collision type, in this case, the social loss amount, as to whether to issue only an alarm or activate the alarm and the automatic brake (step S16).

[0042] Then, the execution unit 106 outputs only an alarm or issues an alarm and performs collision avoidance control using automatic braking based on the secondary determination result (step S16), and ends this process. Note that this process is repeated at predetermined time intervals.

[0043] <Specific collision avoidance control> 4 is an explanatory diagram showing an example of a process for predicting a collision type and a process for calculating the activation timing of an automatic brake of the vehicle X. First, when the collision determination unit 103 determines that there is a possibility of a collision between the vehicle X and the target T, the collision type prediction unit 104 calculates the angle θ formed between a vehicle traveling direction vector Vvec, which is a vector representing the traveling direction of the vehicle X, and a target traveling direction vector Gvec, which is a vector representing the traveling direction of the target T. In other words, the angle θ is the angle formed between the traveling direction of the vehicle X and the traveling direction of the target T.

[0044] Specifically, the collision mode prediction unit 104 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 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)

[0045] In addition, the collision type prediction unit 104 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)

[0046] Then, the collision type prediction unit 104 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)

[0047] Furthermore, the collision type prediction unit 104 determines whether the angle θ is smaller than a threshold value θt (for example, 10 degrees). 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 traveling direction vector Vvec and the target traveling direction vector Gvec are substantially the same and that the vehicle X and the target T will collide in a collision type other than a rear-end collision.

[0048] If the angle θ is smaller than the threshold value θt, the collision type prediction unit 104 predicts that the collision type between the vehicle X and the target T will be a rear-end collision type. Next, the collision type prediction unit 104 determines whether or not an end point of the vehicle X in the traveling direction is within the target area of ​​the target T. In this embodiment, as shown in FIG. 4, if the vehicle area of ​​the vehicle X is a rectangular area, the collision type prediction unit 104 sets 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. 4, if the target area of ​​the target T is a rectangular area, the collision type prediction unit 104 sets 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.

[0049] Then, the collision type prediction unit 104 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 104 calculates the cross products of EF×EA, FG×FA, GH×GA, and HE×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 104 can similarly determine whether or not the end points B, C, and D of the vehicle area are within the target area.

[0050] When an end point on the traveling direction side of the vehicle X (for example, at least one of the end points A and B shown in FIG. 4) is within the target area of ​​the target T, the collision type prediction unit 104 predicts that the collision type between the vehicle X and the target T is a rear-end collision type in which the front surface (front part) of the vehicle X collides with the rear surface (rear part) of the target T.

[0051] In this case, the operation determination unit 105 performs a primary determination to calculate the timing to operate the automatic brake so that the vehicle X stops before the collision position where the vehicle X collides with the target T, according to the time to collision (TTC).

[0052] On the other hand, if the end point in the traveling direction of vehicle X is not within the target area of ​​target T, the collision type prediction unit 104 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 target T collides with the rear surface (rear part) of vehicle X. In this case, the operation determination unit 105 performs a primary determination to notify the driver of vehicle X that target T will collide with vehicle X from the rear without executing predetermined control, or to allow vehicle X to continue traveling as is by issuing a warning (an example of predetermined control) to the driver of vehicle X.

[0053] That is, it is difficult to determine whether the vehicle X will collide with the target T from the angle θ between the vehicle traveling direction vector Vvec and the target traveling direction vector Gvec alone, or whether the vehicle X will not be hit from the rear by the target T. In the case of a non-collision, there is little need to activate the automatic brake of the vehicle X, so it is necessary to determine which part of the vehicle X the target T will collide with.

[0054] For this reason, the collision type prediction unit 104 predicts whether the collision type between vehicle X and target T will be a collision type in which the front of vehicle X collides with target T by determining whether at least one of the endpoints in the traveling direction of vehicle X is within the target area of ​​target T. That is, if the angle θ is smaller than the threshold value θt and the endpoint in the traveling direction of vehicle X is within the target area, the collision type prediction unit 104 predicts that the collision type between vehicle X and target T will be a collision type in which the front of vehicle X collides with the rear of a preceding vehicle, which is an example of target T. On the other hand, if the angle θ is smaller than the threshold value θt and the endpoint in the traveling direction of vehicle X is not within the target area, the collision type prediction unit 104 predicts that the collision type between vehicle X and target T will be a collision type in which the front of target T collides with the rear of vehicle X.

[0055] Furthermore, if the angle θ is equal to or greater than the threshold value θt, the collision type prediction unit 104 predicts that the collision type between the vehicle X and the target T will be a crossing collision type (a collision type other than a rear-end collision type). Next, the collision type prediction unit 104 determines whether or not the end point of the vehicle X in its traveling direction is within the target area of ​​the target T. The collision type prediction unit 104 determines whether or not the end point of the vehicle X in its traveling direction is within the target area of ​​the target T.

[0056] When the end point of the vehicle X in the traveling direction is within the target area of ​​the target T, the collision type prediction unit 104 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. In this case, the operation determination unit 105 performs a primary determination to calculate the operation timing of 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).

[0057] On the other hand, if the end point in the traveling direction of vehicle X is not within the target area of ​​target T, the collision type prediction unit 104 determines whether the end point of target T is within the vehicle area of ​​vehicle X. The collision type prediction unit 104 determines whether end points E, F, G, and H of the target area of ​​target T at future time t are within a vehicle area based on the center position OX of vehicle X at future time t. For example, the collision type prediction unit 104 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 end point E is within the vehicle area. The collision type prediction unit 104 similarly determines whether end points F, G, and H of target T are within the vehicle area.

[0058] When the end point of the target T in the traveling direction, i.e., at least one of the end points E and F shown in Fig. 4, is not within the vehicle area of ​​the vehicle X, the collision type prediction unit 104 determines that the vehicle X will not collide with the target T. On the other hand, when the end point of the target T in the traveling direction, i.e., at least one of the end points E and F shown in Fig. 4, is within the vehicle area of ​​the vehicle X, the collision type prediction unit 104 predicts that the collision type between the vehicle X and the target T will be 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.

[0059] In this case, the operation determination unit 105 performs a primary determination to calculate the timing of automatic braking so that the vehicle X stops before the path of the target T according to the time to brake (TTB).

[0060] Even when one of vehicle X and target T crosses the other's path, 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 target T collides with the side of vehicle X, there is a possibility that vehicle X may be able to pass through target T by operating the vehicle driver, and the timing at which the automatic brake needs to be activated must be calculated while respecting the driver's intentions.

[0061] For this reason, the collision type prediction unit 104 determines whether or not the end points E and F of the target T in the traveling direction are within the vehicle area, thereby predicting whether or not the collision type between the vehicle X and the target T will be a collision type in which the front of the target T collides with the side of the vehicle X. That is, if the angle θ is equal to or greater than the threshold value θt and the end point of the vehicle X in the traveling direction is within the target area, the collision type prediction unit 104 predicts that the collision type between the vehicle X and the target T will be a collision type in which the front of the vehicle X collides with the side of the target T. On the other hand, if the angle θ is equal to or greater than the threshold value θt, the end point of the vehicle X in the traveling direction is not within the target area, and the end point of the target T in the traveling direction is within the vehicle area, the collision type prediction unit 104 predicts that the collision type between the vehicle X and the target T will be a collision type in which the front of the target T collides with the side of the vehicle X. When the angle θ is 180 degrees, the collision type prediction unit 104 determines that the collision type between the vehicle X and the target T is a head-on collision.

[0062] FIG. 5 is an explanatory diagram showing an example of a control process for the automatic braking of a vehicle in a vehicle control device 1. In a conventional vehicle control device, when calculating the timing for applying the automatic brake of vehicle X, regardless of the type of collision between vehicle X and another vehicle Y, which is an example of a target T, the timing for applying the automatic brake is calculated to be a distance d2 before the stopping position P2 so that vehicle X stops at a stopping position P2 that is a distance d1 before the collision position P1 between vehicle X and another vehicle Y in the traveling direction of vehicle X. Here, distance d2 is the braking distance of the automatic brake. Therefore, when vehicle X enters the path of another vehicle Y and the front of the other vehicle Y collides with the side of vehicle X, the conventional vehicle control device stops vehicle X at the stopping position P2 in the path of the other vehicle Y, as shown in FIG. 5(a), which may result in the front of the other vehicle Y colliding with the side of vehicle X.

[0063] In contrast, in the vehicle control device 1, when vehicle X enters the path of another vehicle Y and the front of the other vehicle Y collides with the side of vehicle X, the operation determination unit 105 performs a primary determination to calculate the timing for automatic braking to occur a distance d2 before the stopping position P3 so that vehicle X will stop at stopping position P3 just before the path of the other vehicle Y, as shown in FIG. 5(b). As a result, when it is determined that there is a possibility that the front of the other vehicle Y will collide with the side of vehicle X, vehicle X can be stopped without entering the path of the other vehicle Y. As a result, even if the front of the other vehicle Y collides with the side of vehicle X, it is possible to avoid a collision between vehicle X and other vehicle Y.

[0064] In this way, according to the vehicle control device 1, when it is determined that there is a possibility of a collision between the vehicle X and the target T, the type of collision 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 predetermined control (normal control) is executed on the vehicle X in accordance with the predicted type of collision. This makes it possible to change the control on the vehicle X in accordance with the type of collision between the vehicle X and the target T, and therefore makes it possible to deal with a wide variety of types of collision between the vehicle X and the target T.

[0065] FIG. 6 is a time chart showing an example of the timing of warning and automatic braking activation. As shown in FIG. 6, if a possibility of collision is predicted at the current time t0, a warning is issued at time t1, which is a time T1 back from time t10 when the vehicle stops, corresponding to the time to collision (TTC). Furthermore, the primary brake is activated at time t2, which is a time (T2+T3) back from time t10 corresponding to the time to brake (TTB), and the secondary brake, which is stronger than the primary brake, is activated at time t3. The primary and secondary brakes are integrated, and the automatic brake is activated from time t2. Note that the secondary brake can be further changed to maximum braking as time passes depending on the stopping position.

[0066] In this embodiment, the operation determination unit 105 performs a secondary determination of the control content primarily determined by the above, based on an additional determination condition (social loss amount) according to the collision type, to determine whether to issue only a warning or to activate a warning and the automatic brake. This secondary determination corrects the control content primarily determined by the social loss amount for each collision type, thereby reducing the risk of unnecessary activation of the automatic brake.

[0067] Fig. 7 is a diagram showing an example of the secondary determination table TB1. As shown in Fig. 7, the secondary determination table TB1 associates the collision type, which is a combination of the host vehicle behavior at the current time (straight ahead, right turn, left turn), the host vehicle collision position at the time of the predicted collision (front, right side, left side, rear), and the opponent collision position at the time of the predicted collision (front, right side, left side, rear), with the social loss amount for each collision type and the secondary determination content for each collision type.

[0068] For example, in the case of a head-on collision where the host vehicle is traveling straight, the host vehicle collides at the front, and the other vehicle collides at the front, the social loss amount is "small," so only an alarm is output based on the secondary judgment. This alarm-only output is output at the alarm timing determined by the primary judgment for alarm and automatic braking. On the other hand, in the case of a head-on collision where the host vehicle is traveling straight, the host vehicle collides at the front, and the other vehicle collides at the right side, the social loss amount is "large," so the secondary judgment determines that an alarm and automatic braking will be activated. The primary judgment activation timing is used for the control content of this alarm and automatic braking. Similarly, in the case of a right-turning vehicle where the host vehicle is traveling right, the host vehicle collides at the right side, and the other vehicle collides at the front, the social loss amount is "large," so the secondary judgment determines that an alarm and automatic braking will be activated.

[0069] <Modification> 8 is a diagram showing an example of a secondary judgment table TB2 used in the modified example. In this modified example, target types such as vehicle, motorcycle, bicycle, and pedestrian are set as additional judgment conditions, and secondary judgment is performed based on the secondary judgment content for each target type for each collision type.

[0070] For example, in the case of a head-on collision where the vehicle behavior is straight ahead, the vehicle collision position is at the front, and the collision position is at the front of the other vehicle, the object type is further classified as a vehicle, motorcycle, bicycle, or pedestrian, and in the case of a vehicle or motorcycle, only an alarm is output as a secondary judgment, while in the case of a bicycle or pedestrian, an alarm and automatic braking are activated as a secondary judgment. This is because, for example, the social loss amount is greater in the case of a bicycle or pedestrian than in the case of a vehicle or motorcycle.

[0071] Furthermore, when the vehicle is turning right, the collision location is on the right side of the vehicle, and the collision location is on the front of the vehicle (turning right), the object is further classified into vehicle, motorcycle, bicycle, and pedestrian, and an alarm and automatic braking are activated for each classification. However, in the case of motorcycles, the relative speed is easily misrecognized due to their small size, so the timing of automatic braking is advanced. In other words, the timing of automatic braking is adjusted for each object type. Note that the strength of the automatic braking may also be increased. In this case, the strength of the automatic braking is adjusted.

[0072] Furthermore, in this modified example, a secondary determination may be performed in which other additional determination conditions, such as the amount of social loss, are added to the target type.

[0073] In the above-described embodiment and modified examples, the primary determination can handle a wide variety of collision patterns between the vehicle and the target, and the secondary determination can reduce the risk of unnecessary operation of the automatic brake. This secondary determination is not limited to unnecessary operation of the automatic brake, and may also adjust the timing and strength of automatic brake operation based on additional determination conditions.

[0074] Note that the configurations illustrated in the above-described embodiments and modifications are merely functional schematics and do not necessarily have to be physically configured as shown. In other words, the distribution and integration of each device and component is not limited to that illustrated, and all or part of them can be functionally or physically distributed and integrated in any unit depending on various usage situations, etc. [Explanation of symbols]

[0075] 1 Vehicle control device 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 101 Vehicle position prediction unit 102 Target position prediction unit 103 Collision determination section 104 Collision Pattern Prediction Unit 105 Operation determination unit 106 Executive Department T target TB1,TB2 Secondary judgment table X,Y vehicle θ angle

Claims

1. A vehicle control device, a vehicle position prediction unit that predicts a future vehicle position indicating a position of a vehicle equipped with the vehicle control device after a predetermined time; a target position prediction unit that predicts a future target position indicating a position of the target after the predetermined time; a collision 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 operation determination unit that performs a primary determination of the timing of issuing an alarm and activating an automatic brake to avoid a collision with the target in accordance with the collision type predicted by the collision type prediction unit, and further performs a secondary determination based on the result of the primary determination on an additional determination condition in accordance with the collision type as to whether to issue an alarm only or to activate the automatic brake; an execution unit that executes the secondary determination result determined by the operation determination unit at a time when a collision between the vehicle and the target is predicted; A vehicle control device comprising:

2. The additional judgment condition is for a predetermined social loss amount, 2. The vehicle control device according to claim 1, wherein the activation determination unit performs a secondary determination to only issue the warning and not activate the automatic brake when the collision type is such that the social loss amount is smaller than a predetermined amount.

3. The additional determination condition is for a target type, The vehicle control device according to claim 1 or 2, wherein the activation determination unit performs a secondary determination as to whether to issue only an alarm or to activate an alarm and an automatic brake, depending on the type of the target object.

4. A vehicle control device as described in any one of claims 1 to 3, wherein when the automatic brake is activated in the secondary judgment, the activation judgment unit makes a judgment to adjust the activation timing of the automatic brake or a judgment to adjust the braking strength depending on the additional judgment condition.

Images