JP4175080B2 - Vehicle control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle control device that detects an obstacle on a course and controls the operation of the vehicle based on the relationship between the obstacle and the vehicle.
[0002]
[Prior art]
In order to prevent a collision or rear-end collision, a technology has been proposed that detects obstacles ahead of the vehicle and automatically issues a warning to the driver or brakes depending on the situation. (For example, refer to Patent Document 1). In the technique described in this document, when a collision (a rear-end collision) with a detected obstacle is predicted, the braking is automatically performed to prevent the collision. This technology further creates a history of obstacle information, for example, when there is a relative distance to the obstacle before the full braking start condition is satisfied when the distance to the obstacle approaches. If the slow braking performed in the above is not performed, it is unlikely that the obstacle was approaching properly, so if an obstacle is suddenly detected at such a close position, it will be treated as noise. This suppresses erroneous braking.
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-129438 (pages 2 to 5, FIGS. 1 to 13)
[0004]
[Problems to be solved by the invention]
However, the range of obstacles that are actually expected to collide and crash is limited to a relatively limited range of the vehicle's path, while obstacles that are expected to crash and crash are only stationary. Not limited to an oncoming vehicle, a preceding vehicle, or a vehicle that enters the course by merging or changing lanes. With the above-described technology, it is difficult to accurately determine a rear-end collision with such a vehicle. On the other hand, if it is attempted to accurately determine a rear-end collision with such a vehicle, there is a problem that the possibility of erroneous detection of an obstacle outside the lane increases.
[0005]
Therefore, an object of the present invention is to provide a vehicle control device that can effectively prevent erroneous detection and effectively perform operation control on an obstacle.
[0009]
[Means for Solving the Problems]
In order to solve the above-described problem, a vehicle control apparatus according to the present invention includes an obstacle detection unit that detects an obstacle, an estimated collision time calculation unit that calculates an estimated collision time with the obstacle, and an estimated collision time threshold value. An operation control means for controlling the operation of the vehicle when the vehicle is less than the vehicle, further comprising a lane determination means for determining a lane area in which the host vehicle is traveling, wherein the operation control means includes the same lane area. When the running is continued, the threshold value is set to a third predetermined value that is longer than the normal first predetermined value.
[0010]
If it is expected that the vehicle will continue to travel in the same lane area, the driver's attention is likely to be distracted and may become careless. Therefore, when the reaction is delayed from the normal time due to the driver's carelessness (that is, when traveling in the same lane area is continued), the operation control means sets the threshold value longer than the normal first predetermined value. By setting to a predetermined value of 3, vehicle control for an obstacle is started early.
[0011]
The lane determination means preferably includes image acquisition means for acquiring an image ahead of the vehicle and image recognition means for acquiring lane area information from the acquired image by image recognition. By acquiring lane area information by image recognition, no special infrastructure is required on the road side, and it is possible to flexibly cope with lane changes associated with construction regulations.
[0012]
The operation control means preferably controls the operation of at least one of brake assist means, automatic braking means, seat belt control means, and airbag control means. In addition to collision avoidance by braking and speed control, the risk of passengers can be reduced by appropriately controlling the seat belt and airbag even in the event of a collision.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. In order to facilitate the understanding of the description, the same reference numerals are given to the same components in the drawings as much as possible, and duplicate descriptions are omitted.
[0014]
FIG. 1 is a schematic configuration diagram showing a vehicle control device according to the present invention together with a vehicle equipped with the control device, and FIG. 2 is a block configuration diagram thereof. A collision mitigation device 2 that is a vehicle control device mounted on a vehicle 1 includes a millimeter wave radar 21 serving as an obstacle detection means that detects an obstacle by scanning the front of the vehicle with radio waves, and a lane for recognizing a lane. It comprises a recognition means 22, and a seat belt device 23, an airbag device 24, and a brake device 25 as risk reduction means for reducing the danger to the occupant at the time of a collision. Here, FIG. 1 shows an example of a right-hand drive vehicle. As the seat belt device 23, only the seat belt device 23b for the driver's seat and the seat belt device 23a for the passenger seat are shown, and the airbag device 24 is an assistant. Only the airbag device for the seat is shown.
[0015]
The lane recognition unit 22 includes a camera 221 that is an image acquisition unit that acquires an image (video) in front of the vehicle and a lane ECU 222 that is an image recognition unit that acquires lane area (travel lane) information by image recognition from the acquired image. . The seat belt devices 23a and 23b include a seat belt main body 231a and 231b and a seat belt retractor 230a and 230b, respectively. Hereinafter, the symbols a and b are omitted unless particularly distinguished. The airbag device 24 includes an airbag control device 240 including an airbag body 241 and a seating sensor (not shown). The brake device 25 includes a disc brake or drum brake (not shown) attached to each wheel, a hydraulic wheel cylinder 251 that operates each brake, and a brake actuator 250 that controls the hydraulic pressure applied to each wheel cylinder 251. .
[0016]
The outputs of the millimeter wave radar 21 and the lane ECU 222 are input to a pre-crash ECU 20 that is a control means, and the pre-crash ECU 20 controls the operation of the airbag control device 240, the seat belt retractor 230, and the brake actuator 250. . Further, various state quantities of the vehicle are input from the yaw rate sensor 51, the G sensor 52, the vehicle speed sensor 53, the brake switch 54, the winker switch 55, and the like.
[0017]
As shown in FIG. 3, the collision mitigation device 2 scans a target area 31 in the traveling area 3 with a millimeter wave radar 21, thereby causing an obstacle 4 (oncoming road 40, leading vehicle 41, roadside such as a guardrail). The object 42) is detected, the possibility of collision is determined from the relative speed with the host vehicle 1, and when a collision is expected, each danger mitigating means is controlled to perform a predetermined danger mitigation operation. is there.
[0018]
Hereinafter, specific collision mitigation control will be described with reference to FIGS. FIG. 4 is a flowchart of this control, FIG. 5 is a diagram for explaining the control timing of collision mitigation control at the time of lane departure in the prior art, and FIG. 6 is a diagram of collision mitigation control at the time of lane departure in this embodiment. FIG. 7 is a diagram for explaining the control timing of collision mitigation control when the same lane travel is continued in the present embodiment.
[0019]
This control process is performed by the pre-crash ECU 20 in cooperation with the lane ECU 222, and is repeatedly executed at a predetermined timing from when the ignition switch is turned on until it is turned off.
[0020]
In step S1, a white line that is a boundary of a lane in which the host vehicle 1 is traveling is detected by image recognition processing based on an image acquired by the lane ECU 222 with the camera 221. The white line here is not limited to a continuous line painted in white, but a driver with a line painted in a different color such as yellow, an intermittent painting line, guardrails, concrete blocks, tiles, etc. Is a concept including all visually identifiable boundary lines when the outer boundary of the lane can be visually recognized.
[0021]
In step S2, the lane position where the vehicle 1 is traveling is detected based on the detected white line (boundary line) position. In addition to the image recognition result, it is possible to estimate the curve state based on the outputs of the yaw rate sensor 51 and the G sensor 52, and to utilize the previous recognition result based on the output of the vehicle speed sensor 53, thereby further improving the accuracy. High lane position detection can be performed.
[0022]
In the next step S3, the presence / absence of an obstacle in the scan area 31 and the position thereof are detected from the detection result of the millimeter wave radar 21. When there is an obstacle, the distance and direction (angle) to the obstacle can be obtained from the output of the millimeter wave radar 21. In step S4, an estimated collision time t _crash is calculated for each obstacle. This can be obtained by dividing the distance to the obstacle by the relative speed between the obstacle and the host vehicle 1.
[0023]
In step S5, it is determined whether or not there is a lane departure contrary to the intention. This determination is performed by comparing the operation result of the winker switch by the driver with the behavior of the vehicle. Specifically, if the driver operates the blinker switch 55 and moves in the direction indicated by the direction indicator, it is estimated that the lane departs intentionally, and otherwise, that is, without instructing by the direction indicator. Alternatively, in the case of moving in the direction opposite to the designated direction, this is performed by estimating the lane departure that is not intended.
[0024]
When it is determined that there is no lane departure contrary to the intention, the process moves to step S6 to determine whether or not the same lane traveling is continued. It may be determined that traveling in the same lane is continuing when the vehicle continues traveling for a predetermined time or more without a lane departure or lane change and the winker switch or the steering wheel is not operated. If it is determined that traveling on the same lane is continuing, the process proceeds to step S7, where the threshold t _{th of the} expected collision time is set to a predetermined value t _A. This t _A is set relatively longer than the limit time (normal collision unavoidable time) in which a collision can be avoided when the driver is paying sufficient attention. On the other hand, if it is determined that the vehicle is not continuing to travel on the same lane, the process proceeds to step S8, where the threshold t _{th of the} expected collision time is set to a predetermined value t _B. This t _B is set shorter than t _A , and is set equal to a limit time (normal collision unavoidable time) at which a collision can be avoided when the driver is paying sufficient attention.
[0025]
On the other hand, if it is determined in step S5 that there is a lane departure contrary to the intention, the process proceeds to step S9, and the threshold t _{th of the} expected collision time is set to a predetermined value t _C. This t _C is set longer than t _B , and for example, is set to a limit time (a collision unavoidable time when carelessness) can be avoided even when the driver is careless. t _C may be equal to t _A , but the case of unintentionally deviating from the lane as described later is a case where the risk of collision is relatively high, so t _C should be longer than t _A. It is preferable that it is set.
[0026]
After the threshold value t _th is set in steps S7 to S9, the process proceeds to step S10 in any case, and the obtained t _crash is compared with the set threshold value t _th . If t _crash exceeds the threshold t _th , it means that there is enough time for the driver to take collision avoidance action before the collision with the obstacle. In this case, the subsequent collision mitigation control is performed. Without ending the process.
[0027]
On the other hand, when t _crash is less than the threshold value t _th , the collision avoidance action of the driver is not in time, and there is a high possibility of a collision as it is, so the process proceeds to step S11 and collision mitigation control is performed.
[0028]
As the collision mitigation control performed here, first, as the control of the brake device 25, the brake actuator 250 is operated, the brake hydraulic pressure is applied to each wheel cylinder 251 to automatically perform braking, and automatic braking control to decelerate is performed. is there. Alternatively, when the brake switch 54 is turned on, the assist hydraulic pressure is set to be larger than that in the normal case, so that the response characteristic to the driver's depression of the brake pedal is improved, and the pre-crash brake assist that enables quicker deceleration. Control may be performed.
[0029]
In the seat belt device 23, the seat belt 231 is taken up by the seat belt take-up device 230, so that the occupant is restrained to the seat before the collision, the movement of the occupant at the time of the collision is suppressed, and the damage at the time of the collision is reduced. To do. In addition, since it is possible to warn the occupant that the danger of a collision is imminent due to restraint, the occupant can prepare for the collision even in the event of a collision, which is effective in reducing the danger.
[0030]
In the airbag device 24, the airbag control device 24 controls the airbag 241 to operate at the most appropriate timing and state based on the posture, physique, collision direction, and collision timing of the occupant. By performing airbag control together with seat belt control, the occupant is surely restrained to the seat, and the shock to the occupant due to the operation of the airbag is alleviated, effectively reducing damage during a collision.
[0031]
As described above, in the present embodiment, the threshold tth of the predicted collision time is adjusted based on the relationship between the driver's intention to change lanes and the vehicle behavior. When this threshold value tth is constant as in the prior art, there are many misjudgments that determine the roadside object 42 on the curved road as an obstacle at the entrance of the curve or the like, so the threshold value tth must be set relatively short. If the driver inadvertently deviates from the lane, the collision mitigation / avoidance operation may not be in time (see FIG. 5).
[0032]
On the other hand, in this embodiment, when the lane is deliberately deviated (see FIG. 6), the threshold value tth is set to a long inadvertent collision inevitable time (t _C ), Because risk mitigation control is started at the same time or immediately after lane departure, the possibility of collision avoidance is increased, and even if a collision occurs, the passenger's shock can be reduced and the danger can be sufficiently reduced. .
[0033]
In addition, when the vehicle continues to travel on the same lane with few steering wheel operations, the driver's attention is likely to be distracted and may be inadvertent. On the other hand, in this case, since the accuracy of obstacle detection by the millimeter wave radar 21 is improved, by setting the threshold t _th to be relatively long (t _A ), the risk mitigation control is set to t _th at t _B. By starting earlier than the case where it is set, the possibility of collision avoidance is improved, and even in the event of a collision, the shock of the occupant is reduced, thereby sufficiently reducing the risk (see FIG. 7).
[0034]
On the other hand, when driving on a curve, before or after changing lanes, or when the lane is changed relatively frequently, it is estimated that the driver is driving with careful attention to the direction of the course. Therefore, the collision inevitable time is shortened. Therefore, by setting the threshold t _th to be short (t _B ), it is possible to improve the reliability of the system by performing reliable risk mitigation control while suppressing erroneous detection.
[0035]
In the above description, the case of switching to three types according to the state of the lane and the vehicle has been described as an example. However, only control for switching between an unintended lane departure and other cases may be performed. Further, the control may be switched between when the single lane traveling is continued and in other cases.
[0036]
Here, an example in which an obstacle on a route is detected using a millimeter wave radar has been described, but an obstacle may be detected by infrared rays, ultrasonic waves, radio waves, or the like. It is also possible to recognize an obstacle by image recognition. In addition to using an image, the determination of the lane may be performed by receiving from outside the vehicle by communication means, or by installing a marker at the lane boundary or the center of the lane and detecting this. Alternatively, map information may be stored in advance, and the lane information may be called from the position information of the host vehicle determined by the navigation system.
[0037]
In addition to the blinker switch, the lane change intention can also be estimated based on the vehicle operation status of the driver, changes in the driver's line of sight and posture when the lane is changed, and the like.
[0038]
The operation control means according to the present invention informs the driver of a device that reduces the danger to the occupant, a device that avoids contact with an obstacle, or the presence of an obstacle in the unlikely event that contact with the obstacle cannot be avoided. It controls the operation of the device. In the above description, an example in which the brake, the seat belt, and the airbag are all controlled has been described. However, the risk to the occupant during a collision can be reduced by controlling at least one of them. Further, an alarm function for notifying the occupant of the danger of collision using voice or the like may be used in combination.
[0039]
【The invention's effect】
As described above, according to the present invention, since the operation state of the vehicle control for the obstacle is changed according to the correspondence between the driver's intention to change the lane and the driving lane, the malfunction during normal driving is suppressed. In case of inadvertent departure from the lane or traveling on the same lane where attention is likely to be distracted, it is possible to effectively operate the vehicle operation control against obstacles by facilitating the operation control of the vehicle against the collision object. it can.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing a vehicle control device according to the present invention together with a vehicle on which the vehicle control device is mounted.
FIG. 2 is a block diagram of the apparatus shown in FIG.
FIG. 3 is a schematic diagram for explaining the outline of the operation of the apparatus of FIG. 1;
4 is a flowchart showing the operation of the apparatus of FIG. 1, ie, control processing.
FIG. 5 is a diagram for explaining a control timing of collision mitigation control at the time of departure from a lane in the prior art.
FIG. 6 is a diagram for explaining a control timing of collision mitigation control at the time of departure from a lane in the present embodiment.
FIG. 7 is a diagram illustrating a control timing of collision mitigation control when the same lane travel is continued in the present embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Vehicle, 2 ... Collision mitigation device, 3 ... Lane area, 4 ... Obstacle, 20 ... Pre-crash ECU, 21 ... Millimeter wave radar, 22 ... Lane recognition means, 23 (a, b) ... Seat belt apparatus, 24 DESCRIPTION OF SYMBOLS ... Airbag device, 25 ... Brake device, 31 ... Scan target area, 32 ... Obstacle area, 40 ... Oncoming vehicle, 41 ... Preceding vehicle, 42 ... Roadside object, 51 ... Yaw rate sensor, 52 ... G sensor, 53 ... Vehicle speed Sensor, 54 ... Brake switch, 55 ... Winker switch, 221 ... Camera, 222 ... Lane ECU, 230 ... Seat belt retractor, 231 ... Seat belt body, 240 ... Air bag control device, 241 ... Air bag body, 250 ... Brake actuator, 251 ... wheel cylinder.

Claims (4)

An obstacle detection means for detecting an obstacle, an expected collision time calculation means for calculating an expected collision time with the obstacle, an operation control means for controlling the operation of the vehicle when the estimated collision time is less than a threshold, In a vehicle control device comprising:
A lane determining means for determining a lane area in which the host vehicle is traveling is further provided, and the operation control means sets the threshold value to a normal first predetermined value when traveling in the same lane area is continued. The vehicle control apparatus which sets to the 3rd predetermined value longer than a value. 2. The vehicle control device according to claim 1, wherein the lane determination unit includes an image acquisition unit that acquires an image ahead of the vehicle and an image recognition unit that acquires lane area information from the acquired image by image recognition. Said operation control means, brake assist means, the automatic braking means, the seat belt control unit, a vehicle control device according to claim 1 or 2 for controlling a single actuating at least one of the air bag control unit. The vehicular control device according to any one of claims 1 to 3 , wherein the first predetermined value is set to a limit time at which a collision can be avoided when the driver is sufficiently careful.

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