Conflict avoidance support device

Abstract

Provided is a collision avoidance assistance device with which it is possible to prevent sudden braking of a host vehicle, thereby also preventing an accident of serial collision from a trailing vehicle that is following behind the host vehicle. When a collision between a moving body and an obstacle is predicted to occur, and where there are predicted to be circumstances such that the moving body will decelerate and circumstances such that sudden braking of a host vehicle will occur due to the deceleration of the moving body, a collision determination unit 203 determines a control index in accordance with moving-body information detected by a forward detection unit 201, and a control unit 207 controls the host vehicle on the basis of the control index.

Description

[Technical Field]

[0001] The present invention relates to a collision avoidance assistance device that assists a driver in avoiding a vehicle collision. [Background technology]

[0002] Collision avoidance assistance systems use cameras and radar to detect preceding vehicles and pedestrians (hereinafter referred to as "obstacles" where appropriate) in front of the vehicle. They calculate the ground distance and ground speed of the detected obstacle to determine whether the vehicle will collide with the obstacle, and if it is determined that the vehicle will collide with the obstacle, they first prompt the driver of the vehicle to apply the brakes using sounds and warning lights. If there is still no braking and it is determined that a rear-end collision or collision is highly likely, the system will apply the brakes at the limit distance at which the collision can be avoided, thereby reducing the damage caused by the collision.

[0003] The collision avoidance support device described in Patent Document 1 determines whether or not the vehicle will collide with an obstacle, and avoids the collision within a limit distance where the collision can be avoided by braking alone. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-137116 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the collision avoidance support device described in Patent Document 1 only determines whether the host vehicle will collide with an obstacle, and does not predict the possibility of collision between the detected obstacle and the obstacle (for example, a preceding vehicle and a bicycle coming perpendicular to the preceding vehicle).As a result, for example, when the distance between the host vehicle and the preceding vehicle that the host vehicle is following is short and a bicycle coming perpendicular is about to collide with the preceding vehicle, if the driver of the preceding vehicle applies sudden braking or the collision avoidance support device applies sudden braking to stop the vehicle, the possibility of the host vehicle having to brake suddenly also increases.

[0006] Furthermore, there is a problem in that sudden braking of the vehicle increases the possibility of a chain reaction accident with vehicles behind.

[0007] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a collision avoidance support device that can prevent sudden braking of the vehicle, thereby preventing a chain reaction accident caused by a following vehicle following behind the vehicle. [Means for solving the problem]

[0008] In order to achieve the above object, the present invention is configured as follows: That is, a vehicle includes a forward detection unit that detects a moving body and an obstacle ahead of the host vehicle, a collision determination unit that determines a collision between the moving body and the obstacle based on detection information from the forward detection unit, and a control unit that controls the host vehicle, wherein when the collision determination unit predicts a situation in which a collision between the moving body and the obstacle is predicted and the moving body will decelerate, and a situation in which the deceleration of the moving body will cause the host vehicle to suddenly brake, the collision determination unit determines a control index according to the moving body information detected by the forward detection unit, and the control unit controls the host vehicle based on the control index. [Effects of the Invention]

[0009] The present invention not only predicts a collision with the vehicle itself, but also predicts a collision between an obstacle (moving body) other than the vehicle itself and the obstacle (for example, a preceding vehicle and a bicycle that is likely to collide with the preceding vehicle), and if the collision is predicted to cause the obstacle to brake suddenly and the vehicle itself may need to brake suddenly due to deceleration, an alarm is issued to the driver of the vehicle itself, or light braking is applied to the vehicle itself.

[0010] According to the present invention, by predicting the possibility of a collision with a vehicle other than the own vehicle and, for example, warning the driver of the own vehicle, it is possible to prevent sudden braking by the driver's brake or sudden braking by the system, thereby preventing a chain reaction accident caused by a following vehicle following behind the own vehicle.

[0011] Problems, configurations, and effects other than those described above will become apparent from the following description of the embodiments. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a diagram illustrating an example of the configuration of a vehicle equipped with an embodiment of a collision avoidance support device to which the present invention is applied; [Figure 2] 1 is a functional block diagram of an embodiment of a collision avoidance assistance device to which the present invention is applied; [Figure 3] 10 is a flowchart showing a process for avoiding an obstacle for a preceding vehicle. [Figure 4] 10 is an example of the amount of change in vehicle speed and deceleration indication values ​​between a vehicle equipped with the present invention and a vehicle not equipped with the present invention. [Figure 5] FIG. 10 is a time chart when the present invention is applied. [Figure 6] FIG. 10 is an explanatory diagram of whether the present invention can be implemented depending on the difference in the overlap rate between the vehicle and the preceding vehicle (a situation in which a bicycle is crossing from the left side of the preceding vehicle). [Figure 7] FIG. 10 is an explanatory diagram of whether the present invention can be implemented depending on the difference in the overlap rate between the vehicle and the preceding vehicle (a situation in which a bicycle is crossing from the right side of the preceding vehicle). [Figure 8] 10A and 10B are diagrams for explaining whether the present invention can be implemented depending on the road shape and the behavior of obstacles. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all drawings used to explain the embodiments, parts having the same functions are designated by the same reference numerals, and repeated description thereof may be omitted.

[0014] FIG. 1 is a schematic diagram showing a vehicle equipped with an embodiment of a collision avoidance support device according to the present invention.

[0015] The collision avoidance assistance device is a device that is mounted on a vehicle (host vehicle) 001 and assists in avoiding a collision with an obstacle around the vehicle 001. The vehicle 001 is equipped with a forward camera 002 (hereinafter, may be simply referred to as camera 002) mounted on the front of the vehicle, a radar 003, a right front wheel speed sensor 005FR that detects the wheel speed of a right front wheel 004FR, a right rear wheel speed sensor 005RR that detects the wheel speed of a right rear wheel 004RR, a left rear wheel speed sensor 005RL that detects the wheel speed of a left rear wheel 004RL, a left front wheel speed sensor 005FL that detects the wheel speed of a left front wheel 004FL, a steering angle sensor 006, a yaw rate sensor 007, a meter 008, a buzzer 009, a collision avoidance assistance device 010, and a braking control device 011.

[0016] The front camera 002 has a lens and an image sensor, and is appropriately positioned so as to capture an image of the environment surrounding the host vehicle 001. The image captured by the front camera 002 is transmitted to the collision avoidance support device 010, where it undergoes image processing. The collision avoidance support device 010 identifies the object type of an obstacle (hereinafter referred to as an object as appropriate) around the host vehicle 001 based on the image transmitted from the front camera 002. Examples of object types include automobiles, bicycles, pedestrians, and motorcycles. In this embodiment, one camera 002 is disposed to capture an image of an object in front of the host vehicle 001, but multiple cameras may also be disposed. The camera 002 may be a monocular camera or a stereo camera, and the type of camera and the functions of the camera may be changed as necessary.

[0017] The radars 003 are arranged at the four corners of the host vehicle 001. Each radar 003, for example, emits electromagnetic waves and receives reflected waves from surrounding targets to measure the position and speed of targets around the host vehicle 001 and transmits the measurement results to the collision avoidance support device 010. The radar 003 may be, for example, a millimeter-wave radar or a laser radar, or an ultrasonic sensor or LiDAR instead of the radar. Furthermore, a combination of multiple sensors may be used to measure the speed and position of a target. In this embodiment, as an example, a combination of the camera 002 and the radar 003 is used as a means for acquiring information about targets around the host vehicle 001. However, for example, a LiDAR may be combined instead of the radar 003, or multiple sensors may be used. Furthermore, although the radars 003 are arranged at the four corners of the host vehicle 001, the number of radars may be changed as needed.

[0018] The vehicle 001 has a right front wheel 004FR, a right rear wheel 004RR, a left rear wheel 004RL, and a left front wheel 004FL arranged on the front, rear, left, and right sides of its body. A right front wheel speed sensor 005FR, a right rear wheel speed sensor 005RR, a left rear wheel speed sensor 005RL, and a left front wheel speed sensor 005FL are provided on each of the wheels 004FR, 004RR, 004RL, and 004FL. The wheel speed sensors 005FR, 005RR, 005RL, and 005FL detect the respective wheel speeds and transmit the detected wheel speeds to the collision avoidance assistance device 010. The collision avoidance assistance device 010 calculates the speed of the vehicle 001 based on the information on the respective wheel speeds. Hereinafter, unless otherwise specified, the right front wheel 004FR, right rear wheel 004RR, left rear wheel 004RL, and left front wheel 004FL will be referred to as wheels 004, and the right front wheel speed sensor 005FR, right rear wheel speed sensor 005RR, left rear wheel speed sensor 005RL, and left front wheel speed sensor 005FL will be referred to as wheel speed sensor 005.

[0019] The steering angle sensor 006 is a sensor that detects the rotation angle (steering angle) of the steering wheel of the host vehicle 001 , and the steering angle detected by the steering angle sensor 006 is transmitted to the collision avoidance assistance device 010 .

[0020] The yaw rate sensor 007 detects the yaw rate of the host vehicle 001 , and the yaw rate detected by the yaw rate sensor 007 is transmitted to the collision avoidance assistance device 010 .

[0021] For example, when the collision avoidance support device 010 determines that there is a high possibility of a collision between the vehicle 001 and a target, the meter 008 displays a warning image to notify the driver of the high possibility of a collision. In this embodiment, the meter 008 is provided as an example of a means for displaying a warning image, but instead of the meter 008, for example, a part of a car navigation system may be used, or an image may be displayed using a head-up display.

[0022] The buzzer 009 emits a warning sound to notify the driver of the high possibility of collision when, for example, the collision avoidance assistance device 010 determines that there is a high possibility of collision between the vehicle 001 and a target. In this embodiment, the buzzer 009 is provided as an example of a means for emitting a warning sound, but instead of the buzzer 009, for example, a part of a car navigation system may be used, or the warning sound may be emitted from a speaker.

[0023] The collision avoidance support device 010 is configured to be capable of performing a collision avoidance support operation to avoid a collision between the host vehicle 001 and a target or to reduce damage caused by the collision. The collision avoidance support device 010 is configured to be capable of outputting control signals for activating the meter 008, the buzzer 009, and the braking control device 011 based on information received from the above-mentioned plurality of sensors. In this embodiment, the collision avoidance support device 010 is configured as, for example, an ECU (Electronic Control Unit) mounted on the host vehicle 001, and to perform the collision avoidance support operation, the collision avoidance support device 010 displays a warning image on the meter 008, causes the buzzer 009 to emit a warning sound, or automatically activates the brakes via the braking control device 011.

[0024] The braking control device 011 controls the braking device of the host vehicle 001. The braking control device 011 is a component that can adjust the braking force of the braking device in response to a control signal output from the collision avoidance support device 010, and includes, for example, a brake actuator such as a hydraulic pump or a valve unit.

[0025] FIG. 2 shows the internal functional block configuration of the collision avoidance support device 010 shown in FIG. 1. Such functional blocks are realized by hardware, software, or a combination of these. Each function of the collision avoidance support device 010 is realized by a processor such as a CPU (Central Processing Unit) executing a program stored in a ROM (Read Only Memory). A RAM (Random Access Memory) stores data including intermediate data of calculations performed by the program executed by the processor.

[0026] 2, the collision avoidance support device 010 includes a forward detection unit 201, a host vehicle information calculation unit 202, a collision determination unit 203, a braking operation determination unit 204, a collision warning instruction unit 205, and a braking instruction unit 206. The collision warning instruction unit 205 and the braking instruction unit 206 constitute a control unit 207.

[0027] The forward detection unit 201 calculates target information required for the collision judgment unit 203, such as the target's ground speed and acceleration, from the target type (e.g., vehicle, bicycle, pedestrian), target position, and target speed information acquired from the camera 002 and radar 003, respectively.

[0028] The host vehicle information calculation unit 202 calculates the turning radius of the host vehicle necessary for the collision judgment unit 203 to predict the host vehicle's path based on the host vehicle's speed (hereinafter referred to as host vehicle speed as appropriate) acquired from the wheel speed sensor 005, the host vehicle's steering angle (hereinafter referred to as host vehicle steering angle as appropriate) acquired from the steering angle sensor 006, and the host vehicle's yaw rate (hereinafter referred to as host vehicle yaw rate as appropriate) acquired from the yaw rate sensor 007.

[0029] The collision determination unit 203 predicts the paths of the host vehicle 001 and the target based on, for example, the target position, target speed, and target acceleration acquired from the forward detection unit 201, and the host vehicle 001's speed, turning radius, host vehicle 001's position, host vehicle steering angle, and host vehicle yaw rate calculated by the host vehicle information calculation unit 202. The collision determination unit 203 calculates the time (hereinafter referred to as the predicted collision time) at which the host vehicle 001 will collide with the target based on the predicted host vehicle 001's path (hereinafter referred to as the predicted host vehicle path, as appropriate) and the predicted target path (hereinafter referred to as the predicted target path, as appropriate). The point (hereinafter referred to as the predicted collision point, as appropriate) at which the host vehicle 001 will collide with the target is calculated from the calculated predicted target path and predicted collision time, and determines whether or not there is a possibility of the host vehicle 001 colliding with the target (hereinafter referred to as the collision determination, as appropriate).

[0030] The braking operation determination unit 204 requests activation of an alarm and braking in accordance with the time when a collision with a target is predicted (collision prediction time) based on the collision prediction time, predicted vehicle course, predicted collision point, and collision determination result calculated by the collision judgment unit 203.

[0031] The control unit 207 controls the vehicle based on the judgment of the collision judgment unit 203 and the judgment of the braking operation judgment unit 204, and has a collision warning instruction unit 205 that issues a warning to the driver of the vehicle and a braking instruction unit 206 that controls the braking force of the vehicle.

[0032] The collision warning instruction unit 205 outputs a request to display a warning image to the meter 008, or a request to sound a warning sound to the buzzer 009, or both a request to display a warning image and a request to sound a warning sound, based on the warning activation request (also called a control index) obtained from the braking operation determination unit 204.

[0033] The braking instruction unit 206 outputs to the braking control device 011 a braking command value (control signal) required to avoid collision with the target based on the braking operation request (also called a control index) acquired from the braking operation determination unit 204.

[0034] The internal functional block configuration of the collision avoidance assistance device 010 is not limited to the illustrated example. For example, the collision determination unit 203 and the braking operation determination unit 204 may be integrated (in other words, the collision determination unit 203 may include the braking operation determination unit 204).

[0035] FIG. 3 is an example of a flowchart for avoiding a collision and / or avoiding sudden braking of the vehicle in which the collision avoidance assist device 010 is installed.

[0036] 3, in step S301, the distance that the host vehicle will travel from the current time until it stops due to emergency braking (hereinafter referred to as the host vehicle predicted travel distance before stopping) is calculated based on the host vehicle speed acquired from the host vehicle information calculation unit 202. An example of a method for calculating the host vehicle predicted travel distance before stopping is the following equation (1), which calculates the travel distance that the host vehicle will travel from the current time if it stops due to emergency braking.

number

[0037] The host vehicle stopping time is the time it takes for the host vehicle to stop due to emergency braking, and is calculated from the host vehicle speed and emergency braking deceleration. An example of a method for calculating the host vehicle stopping time is the following equation (2).

number

[0038] In step S302, it is determined whether a target has been detected. If it is determined that a target has been detected, step S303 and subsequent steps are carried out. The target is detected using the sensors and cameras described above. If it is determined that a target has not been detected, the flow ends and the processing of step S301 is started.

[0039] In step S303, the ground speed and target acceleration of the target are calculated from the target position and target speed acquired by the forward detection unit 201. The target type acquired, such as a vehicle, bicycle, or pedestrian, and the format and coordinate system of the current target position and speed information are unified. As an example, the coordinate system used in this embodiment determines the current longitudinal position of the target (hereinafter referred to as the target longitudinal position as appropriate) and the target speed (hereinafter referred to as the target ground speed as appropriate) with the center of the front end of the vehicle 001 as the origin, the overall length direction of the vehicle as the longitudinal direction, and the overall width direction as the lateral direction. The calculated target longitudinal position is expressed as X TGT , the target ground speed is V TGT , the target longitudinal acceleration is A TGT The subscripts represent the detected target number. For example, if the vehicle detects two targets, a preceding vehicle and a bicycle that is perpendicular to the preceding vehicle, the longitudinal position of the preceding vehicle is calculated as X TGT (0), target ground speed is V TGT (0), target acceleration is A TGT (0), the target vertical position of the bicycle that is perpendicular to the preceding vehicle is X TGT (1) The target ground speed is V TGT (1) The target longitudinal acceleration is A TGT Hereafter, assuming that a preceding vehicle and a bicycle have been detected, the target number of the preceding vehicle will be written as (0) and the target number of the bicycle will be written as (1).

[0040] In step S304, the predicted time to collision between the host vehicle and the preceding vehicle is calculated from the current position of the target and the target ground speed calculated in step S303. An example of a method for calculating the predicted time to collision is given by the following equation (3).

number

[0041] In step S305, a predicted distance that the target will travel before stopping, assuming that the target moves at a constant acceleration linear motion (hereinafter referred to as a target stop predicted movement distance as appropriate), is calculated from the current target longitudinal position detected by the forward detection unit 201 and the target ground speed and target longitudinal acceleration calculated in step S303. An example of a method for calculating the target stop predicted movement distance is the following equation (4), which calculates the movement distance if the preceding vehicle travels at a constant acceleration motion at the current target acceleration from the current time to the target stop movement distance predicted time.

number

[0042] The target stopping movement distance predicted time is the time until the target stops, and is calculated from the longitudinal acceleration and longitudinal position of the target. An example of a method for calculating the target stopping movement distance predicted time is the following equation (5).

number

[0043] In step S306, the possibility of a collision between the host vehicle and the obstacle is predicted. If there is a possibility of a collision between the host vehicle and the obstacle, the judgment is made true and the process proceeds to step S307, and if the judgment is not made true, the process starts in step S310. The method of judging the possibility of a collision between the host vehicle and the obstacle is to judge whether or not the host vehicle can stop with a target distance from the target, and if it can stop with the target distance, the process proceeds to step S310, and if it is judged that it cannot stop with the target distance, the host vehicle is predicted to collide with the target, and the process proceeds to step S307. One example of a method of judging the possibility of a collision is to judge whether or not the host vehicle can stop with a target distance Y ego and target stop predicted movement distance X MOV The probability of collision is calculated from (0). The probability of collision is established when the following equation (6) is true.

number

[0044] In step S307, a braking operation determination is made to determine whether or not to brake the host vehicle 001. In the braking operation determination, it is determined whether the host vehicle 001 has reached a limit position where the driver can avoid a collision by steering and braking, based on the distance between the host vehicle 001 and the obstacle, the relative speed, the ground speed, etc. If the braking operation determination is established, the process proceeds to step S308, and if the braking operation determination is not established, the process proceeds to step S309.

[0045] In step S308, an operation request (control index) is generated according to the braking operation determination, a collision warning instruction unit 205 issues an instruction to issue an alarm and display an alarm to notify the driver of the vehicle of the possibility (risk) of collision, and a braking force is instructed by a braking instruction unit 206. The braking force is a calculated value instructed according to the time when a collision with a target is predicted (predicted collision time).

[0046] In step S309, an operation request (control index) is generated according to the braking operation determination, and the collision warning instruction unit 205 instructs the driver of the host vehicle to issue a warning and display a warning to notify the driver of the host vehicle of the possibility (risk) of a collision. This is because, although the possibility of a collision was determined in step S306, the host vehicle 001 is positioned so that the driver can avoid the collision by steering and / or braking, and the meter 008 and buzzer 009 notify the driver of the host vehicle of the risk of a collision and urge them to avoid the collision.

[0047] If there is no possibility of collision between the host vehicle and the obstacle in step S306 (if a collision between the host vehicle and the obstacle is not predicted), it is determined in step S310 whether the host vehicle is following the preceding vehicle. If it is determined that the host vehicle is following the preceding vehicle, the flow proceeds to step S311, and if it is determined that the host vehicle is not following the preceding vehicle, the flow ends and the process of step S301 is started.

[0048] In step S311, a predicted collision time between the preceding vehicle determined to be being followed in step S310 and a target other than the preceding vehicle (for example, a preceding vehicle and a bicycle) is calculated. One example of a method for calculating the predicted collision time is the following equation (7).

number

[0049] Step S311 calculates the time of a target colliding with the preceding vehicle, and therefore differs from step S304 for calculating the predicted time of collision with a target colliding with the host vehicle.

[0050] In step S312, the distance that the preceding vehicle will travel from the current time until it applies emergency braking and stops (hereinafter referred to as the preceding vehicle's predicted travel distance for stopping) is calculated. One example of a method for calculating the preceding vehicle's predicted travel distance for stopping is the following equation (8), which calculates the preceding vehicle's predicted travel distance for stopping, assuming that the preceding vehicle will apply emergency braking and stop from the current time.

number

[0051] The preceding vehicle travel distance time is a time equivalent to the distance traveled by the preceding vehicle from the current time until emergency braking is applied and the vehicle is stopped.

[0052] In step S313, the possibility of a collision between the preceding vehicle and the bicycle traveling perpendicular to the preceding vehicle is predicted. If there is a possibility of a collision between the preceding vehicle and the bicycle, the judgment is made true and the process proceeds to step S314, but if the judgment is not true, the flow ends and the process of step S301 is started. One example of a method for judging the possibility of a collision is to use the target stop predicted movement distance X of the preceding vehicle calculated in step S305 as a TGT (0) and the predicted moving distance of the bicycle target X TGT The probability of collision is calculated from (1). The probability of collision is established when the following equation (9) is true.

number

[0053] In step S314, the system predicts sudden braking of the host vehicle due to a collision between the preceding vehicle and the bicycle or sudden deceleration of the preceding vehicle. In other words, it predicts a situation in which a collision between the preceding vehicle (moving body) and the bicycle (obstacle) is predicted, the preceding vehicle will decelerate, and a situation in which sudden braking will be applied to the host vehicle due to the deceleration of the preceding vehicle is predicted. If sudden braking of the host vehicle is predicted, the system proceeds to step S315, but if sudden braking of the host vehicle is not predicted, the flow ends and the processing of step S301 begins. One example of a method for predicting sudden braking of the host vehicle is to use the predicted movement distance T' of the preceding vehicle to stop calculated in step S312. MOV and the predicted travel distance X of the vehicle when it stops calculated in step S301. ego Based on this, it is determined whether the host vehicle can stop with a target distance when the preceding vehicle stops due to emergency braking. The prediction of sudden braking is established when the following equation (10) is satisfied.

number

[0054] Step S315 performs a braking operation determination to determine whether to issue an alarm and apply the brakes to the host vehicle 001. In the braking operation determination, in addition to determining whether the host vehicle 001 has reached the limit position where the driver can avoid a collision by steering and braking, as in step S307, it also determines whether the overlap rate between the front end of the host vehicle and the rear end of the preceding vehicle at the time of collision (hereinafter referred to as the overlap rate as appropriate) is within a threshold, and whether the road shape on which the host vehicle is traveling is a straight road (in other words, whether the host vehicle is traveling on a curve). If the host vehicle is within the avoidance limit position, the overlap rate with the preceding vehicle is within the threshold, and the road is a straight road, the process proceeds to step S316; if the determination is not established, the flow ends and the process of step S301 begins.

[0055] Step S316 is a step to be taken when sudden braking of the host vehicle is predicted. As in step S308, an operation request (control index) is generated in accordance with the braking operation determination, the collision warning instruction unit 205 issues an instruction to issue an alarm and display an alarm to notify the driver of the host vehicle of the possibility (risk) of a collision, and the braking instruction unit 206 instructs braking force. The braking force instructed to the braking instruction unit 206 is a braking force that applies gradual deceleration (gradual braking) that is weaker than sudden braking. This braking force that applies gradual deceleration is a braking force that stops the host vehicle at a distance that will prevent a collision with a decelerating preceding vehicle.

[0056] If the preceding vehicle suddenly brakes, the host vehicle is likely to be unable to stop without suddenly braking as well, but by performing gradual deceleration (gradual braking) at a stage when the risk of collision is not yet imminent for the host vehicle in step S316, the host vehicle can be prevented from suddenly braking, thereby preventing a chain reaction accident caused by vehicles following the host vehicle.

[0057] As an example, in Figure 4, (A) of 401 shows the movement of a vehicle not equipped with the present invention and the amount of change in the vehicle speed and deceleration command value, and (B) of 411 shows the movement of a vehicle equipped with the present invention and the amount of change in the vehicle speed and deceleration command value. The preceding vehicle is assumed to be equipped with a collision avoidance support device.

[0058] In section 402, the host vehicle 421 is following a preceding vehicle 422, and a bicycle (obstacle) 423 is approaching the preceding vehicle 422. The host vehicle 421 and the preceding vehicle 422 are traveling at a constant speed, and the deceleration command value is 0. At this time, the preceding vehicle 422 is unaware of the obstacle 423 and is not applying the brakes.

[0059] In section 403, a bicycle 423 collides with a preceding vehicle 422, which stops due to sudden braking by the system or the driver (section 409 of sudden deceleration of the preceding vehicle). 406 indicates sudden deceleration, 407 indicates gradual deceleration, and 408 indicates a deceleration instruction value of 0.

[0060] In section 404, the preceding vehicle 422 suddenly stops, increasing the possibility that the host vehicle 421 will collide with the preceding vehicle 422. The collision avoidance support function applies sudden deceleration (sudden braking) 406 to the host vehicle 421 during section 410, bringing it to an abrupt stop.

[0061] In section 412, as in section 402, the host vehicle 421 is following a preceding vehicle 422, and the preceding vehicle 422 is unaware of a bicycle 423 approaching the preceding vehicle 422.

[0062] In section 413, similar to section 403, the preceding vehicle 422 is brought to an abrupt stop during section 418 by sudden deceleration (sudden braking) 416 due to the collision avoidance support function. Since the braking operation determination is established in step S315 for the host vehicle 421, an alarm is issued and gradual deceleration (slow braking) 417 is performed during section 419. Due to gradual deceleration (slow braking) 417, the host vehicle 421 can stop in section 414 without sudden braking.

[0063] FIG. 5 shows an example of a time chart from when the host vehicle detects a preceding vehicle and a bicycle, predicts a collision between the preceding vehicle and the bicycle, and gradually decelerates the host vehicle.

[0064] (a) shows the change in the host vehicle speed, and (b) shows the host vehicle's predicted travel distance until stopping calculated from the host vehicle speed in step S301. The host vehicle speed (a) is calculated by the host vehicle information calculation unit 202, and the host vehicle travels at a constant speed from section 550 to section 552, starts decelerating at timing 541, and stops in section 553.

[0065] (c) shows the ground speed of the target calculated from the target speed of the target detected by the forward detection unit 201, (d) shows the target longitudinal acceleration calculated from the target acceleration, and (e) shows the target longitudinal position calculated from the target position. In order to calculate the number of targets detected by the forward detection unit 201, a preceding vehicle (solid line) and a bicycle (dotted line) are shown. The preceding vehicle proceeds at a constant speed until time 541 and suddenly decelerates between 541 and 542. The bicycle accelerates until time 541 and collides with the preceding vehicle at time 541.

[0066] (f) shows the predicted collision time between the host vehicle and the target. 528 represents an invalid value of the predicted collision time, indicating that the host vehicle and the preceding vehicle, or the host vehicle and the bicycle, will not collide until section 553.

[0067] (g) represents the predicted target stopping movement distance calculated in step S305.

[0068] (h) shows the collision detection between the vehicle and the preceding vehicle, and between the vehicle and the bicycle. There is no possibility of a collision between the vehicle and the preceding vehicle, or between the vehicle and the bicycle.

[0069] (i) shows the predicted time of collision between the preceding vehicle and the bicycle calculated in step S311. The possibility of a collision begins in section 550, and the collision occurs in section 552 (at time 541) where the predicted time of collision becomes 0.

[0070] (j) represents the predicted travel distance of the preceding vehicle when it stops, calculated in step S312.

[0071] (k) indicates the possibility of a collision between a preceding vehicle and a bicycle. A collision is determined in section 552 (before timing 541), so the operation of the present invention is initiated.

[0072] (l) indicates the deceleration command value. In section 552 where a collision is determined, control is started by gradual deceleration 536 (weaker than sudden deceleration 535), and the host vehicle gradually stops in section 553 (see also (a) and (b)).

[0073] Next, the feasibility of implementing the present invention depending on the difference in the overlap rate (overlap rate) between the host vehicle and the preceding vehicle will be described with reference to FIGS.

[0074] 601 shows a situation in which a vehicle 603 is following a preceding vehicle 604, and a bicycle (obstacle) 605 is approaching the preceding vehicle 604 from the left side at right angles.

[0075] 611 describes the overlap ratio between the vehicle and the preceding vehicle. In a situation like 601 where a bicycle is approaching perpendicularly from the left, when the vehicle 603 is in the section of 621, 621 is defined as an overlap ratio of 25% or less, 622 as an overlap ratio of 25% to 100%, and 623 as an overlap ratio of 100% or more. As an example, the coordinate axes have the center of the rear end of the preceding vehicle 604 as the origin, with the positive direction from the origin to the right and the negative direction from the origin to the left. One example of how to calculate the overlap ratio is half the overall width of the vehicle - (left / right position of the preceding vehicle - width of the preceding vehicle / 2).

[0076] 612 shows a situation where the overlap ratio between the host vehicle and the preceding vehicle is 25% or less. When the left edge of the host vehicle is in the negative direction from 624, the overlap ratio is 25% or less.

[0077] 613 shows a situation where the overlap ratio between the host vehicle and the preceding vehicle is 25% to 100%. When the left edge of the host vehicle is in the positive direction from 625 and the right edge of the host vehicle is in the negative direction from 626, the overlap ratio is 25% to 100%.

[0078] 614 shows a situation where the overlap rate between the vehicle and the preceding vehicle is 100% or more. When the left edge of the vehicle is in the positive direction from 627, the overlap rate is 100% or more.

[0079] In a situation like 601, the warning and gentle braking instruction in step S316 applies when the overlap rate between the host vehicle and the preceding vehicle is between 25% and 100%. When it is 25% or less (612), it is not applicable because the host vehicle can avoid the overlap by steering, and when it is 100% or more (614), it is not applicable because there is a high possibility that the bicycle 605 will not be visible.

[0080] 701 shows a situation in which a vehicle 703 is following a preceding vehicle 704, and a bicycle (obstacle) 705 is approaching the preceding vehicle 704 from the right side at right angles.

[0081] 711 describes the overlap ratio between the vehicle and the preceding vehicle, and in a situation where a bicycle is approaching perpendicularly from the right as in 701, when the vehicle 703 is in the section 721, the overlap ratio is defined as 25% or less, 722 as an overlap ratio between 25% and 100%, and 723 as an overlap ratio of 100% or more. An example of the overlap ratio calculation method is the same as in Figure 6.

[0082] 712 shows a situation where the overlap ratio between the vehicle and the preceding vehicle is 25% or less. When the right edge of the vehicle is in the positive direction from 724, the overlap ratio is 25% or less.

[0083] 713 shows a situation where the overlap ratio between the host vehicle and the preceding vehicle is 25% to 100%. When the left edge of the host vehicle is in the positive direction from 725 and the right edge of the host vehicle is in the negative direction from 726, the overlap ratio is 25% to 100%.

[0084] 714 indicates a situation where the overlap rate between the vehicle and the preceding vehicle is 100% or more. When the left edge of the vehicle is in the negative direction from 727, the overlap rate is 100% or more.

[0085] In a situation like 701, the operation of the present invention applies when the overlap rate between the vehicle and the preceding vehicle is between 25% and 100%. When the overlap rate is below 25% (712), the vehicle is not subject to the situation because it can be avoided by steering, and when the overlap rate is above 100% (714), the bicycle 705 is not subject to the situation because it is highly likely that it will not be visible.

[0086] Next, the feasibility of implementing the present invention depending on the road shape will be explained with reference to FIG.

[0087] Reference numeral 801 represents a situation where a host vehicle 804 is following a preceding vehicle 803 on a curved road, and an obstacle 802 for the preceding vehicle 803 is crossing in front of the preceding vehicle 803. The curvature of the road is calculated from the yaw rate of the host vehicle calculated by the host vehicle information calculation unit 202 and the white line detected by the forward detection unit 201, and it is determined in step S315 whether the road is curved (in other words, whether the vehicle is traveling on a curve). For example, if the curvature of the road is equal to or greater than a threshold value, it is determined that the road is curved.

[0088] On a curved road, it is difficult to predict the behavior of the preceding vehicle and obstacles, and there is a high possibility that the vehicle itself can avoid a collision by steering, so the operation of the present invention does not apply. Obstacle 802 can be a bicycle, pedestrian, or vehicle.

[0089] Using the overlap rate (overlap rate) between the vehicle and the preceding vehicle described above, and the shape of the road on which the vehicle is traveling, a braking operation determination can be performed in step S315 to determine the control content (control index).

[0090] As explained above, the collision avoidance assistance device 010 of this embodiment comprises a forward detection unit 201 that detects a moving body (preceding vehicle) and an obstacle ahead of the host vehicle, a collision judgment unit 203 that judges a collision between the moving body and the obstacle based on detection information from the forward detection unit 201, and a control unit 207 that controls the host vehicle, and when the collision judgment unit 203 predicts a situation in which a collision between the moving body and the obstacle is predicted and the moving body will decelerate, and a situation in which the deceleration of the moving body will cause sudden braking to be applied to the host vehicle, the collision judgment unit 203 determines a control index in accordance with the moving body information detected by the forward detection unit 201, and the control unit 207 controls the host vehicle based on the control index.

[0091] The collision determination unit 203 determines the control index based on the distance, relative speed, or ground speed between the host vehicle and the moving object.

[0092] The collision judgment unit 203 determines the control index based on the overlap rate (lap rate) between the vehicle and the moving object, or the shape of the road on which the vehicle is traveling (whether the vehicle is traveling on a curve or not).

[0093] The collision judgment unit 203 judges a collision of the host vehicle with the moving body and the obstacle based on the detection information of the forward detection unit 201, and if a collision of the host vehicle with the moving body or the obstacle is predicted, determines a first control index according to the moving body information or obstacle information detected by the forward detection unit 201. If a collision of the host vehicle with the moving body or the obstacle is not predicted and the host vehicle is following the moving body, the collision judgment unit 203 judges a collision of the moving body and the obstacle based on the detection information of the forward detection unit 201, and if a collision of the moving body with the obstacle is predicted and a situation in which the moving body will decelerate and a situation in which the deceleration of the moving body will cause the host vehicle to suddenly brake is predicted, determines a second control index according to the moving body information detected by the forward detection unit 201.

[0094] In addition, situations in which sudden braking is applied to the vehicle due to deceleration of the moving body include situations in which sudden braking is applied by the driver operating the vehicle, or situations in which sudden braking is applied by a braking instruction unit that automatically drives the vehicle or provides driving assistance for the vehicle.

[0095] This embodiment not only predicts a collision with the host vehicle, but also predicts a collision between an obstacle (moving body) other than the host vehicle and the obstacle (for example, a preceding vehicle and a bicycle that is likely to collide with the preceding vehicle), and if the collision is predicted to cause the obstacle to brake suddenly and the host vehicle may need to brake suddenly due to deceleration, an alarm is issued to the driver of the host vehicle or a light brake is applied to the host vehicle.

[0096] According to this embodiment, the possibility of a collision with another vehicle other than the own vehicle is predicted, and by, for example, warning the driver of the own vehicle, sudden braking by the driver brake or sudden braking by the system can be prevented, thereby preventing a chain reaction accident caused by a following vehicle following behind the own vehicle.

[0097] In other words, the collision avoidance support system only operates at the limit distance where the driver can avoid a collision, so if the system is activated and the driver does not brake, the system will apply sudden braking. Because sudden braking involves high deceleration, if the system of the leading vehicle is activated when the distance between the host vehicle and the leading vehicle is short, the host vehicle is more likely to brake suddenly. Furthermore, there is a problem that the sudden braking by the system of the host vehicle may prevent the vehicle behind the host vehicle from stopping completely, increasing the possibility of a chain reaction.

[0098] This embodiment predicts a collision between an obstacle (moving body) other than the host vehicle and the obstacle (for example, a preceding vehicle and a bicycle that is likely to collide with the preceding vehicle), and if the collision predicts that the obstacle will brake suddenly and the host vehicle may need to brake suddenly due to deceleration, the system issues a warning to the driver of the host vehicle or applies light braking to the host vehicle. By encouraging the driver to brake using the warning or light braking, the system prevents the host vehicle from applying emergency braking. By preventing the host vehicle from suddenly decelerating, it is possible to prevent a chain reaction accident caused by a vehicle behind.

[0099] It should be noted that the present invention is not limited to the above-described embodiment and includes various modifications. For example, the above-described embodiment has been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to an embodiment having all of the described configurations.

[0100] Furthermore, the above-mentioned configurations, functions, processing units, processing means, etc. may be realized in part or in whole in hardware, for example by designing them as integrated circuits, or may be realized in software by a processor interpreting and executing a program that realizes each function.

[0101] Information such as programs, tables, and files that realize each function can be stored in a storage device such as a memory, a hard disk, or an SSD (Solid State Drive), or in a recording medium such as an IC card, an SD card, or a DVD.

[0102] In addition, the control lines and information lines shown are those that are considered necessary for explanation, and do not necessarily represent all the control lines and information lines that are necessary for implementation. In reality, it can be assumed that almost all components are interconnected. [Explanation of symbols]

[0103] 001 Vehicle 002 Front camera 003 Radar 004FR Right front wheel 004RR right rear wheel 004FL Left front wheel 004RL Left rear wheel 004 Wheels 005FR Right front wheel speed sensor 005FL Left front wheel speed sensor 005RL Left rear wheel speed sensor 005RR Right rear wheel speed sensor 005 Wheel speed sensor 006 Steering angle sensor 007 Yaw rate sensor 008 Meter 009 Buzzer 010 Collision avoidance support device 011 Braking control device 201 Forward detection unit 202 Vehicle information calculation unit 203 Collision Judgment Department 204 Braking action determination section 205 Collision warning instruction section 206 Braking instruction section 207 Control Unit

Claims

1. a forward detection unit that detects moving objects and obstacles ahead of the vehicle; a collision determination unit that determines a collision between the moving object and the obstacle based on detection information from the forward detection unit; a control unit that controls the host vehicle, the collision determination unit determines a collision of the host vehicle with the moving body or the obstacle based on the detection information of the forward detection unit, and when a collision of the host vehicle with the moving body or the obstacle is predicted, determines a first control index that indicates a braking force calculated according to a time when a collision with the moving body or the obstacle is predicted, in accordance with the moving body information or obstacle information detected by the forward detection unit; the collision determination unit determines a collision between the moving body and the obstacle based on detection information from the forward detection unit when a collision between the host vehicle and the moving body or the obstacle is not predicted and the host vehicle is following the moving body; and when a collision between the moving body and the obstacle is predicted and a situation in which the moving body will decelerate and the deceleration of the moving body will cause sudden braking to be applied to the host vehicle is predicted, the collision determination unit determines a second control index in accordance with the moving body information detected by the forward detection unit, the second control index instructing a braking force to stop the host vehicle at a distance that will prevent a collision with the decelerating moving body while applying braking that is weaker than sudden braking; The collision avoidance assistance device is characterized in that the control unit controls the braking force of the host vehicle based on the first or second control index.

2. The collision avoidance assistance device according to claim 1, the control unit includes a collision warning instruction unit that issues a warning to the host vehicle based on the determination by the collision determination unit, The collision avoidance support device is characterized in that the collision warning instruction unit notifies the host vehicle of a possibility of a collision by issuing a warning based on the first or second control index.

3. The collision avoidance assistance device according to claim 1, The collision avoidance support device is characterized in that the collision determination unit determines the first or second control index based on a distance, a relative speed, or a ground speed between the host vehicle and the moving object.

4. The collision avoidance assistance device according to claim 3, A collision avoidance support device characterized in that the collision judgment unit determines the first or second control index based on the overlap rate between the vehicle and the moving object or the shape of the road on which the vehicle is traveling.

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