JP4946807B2 - Lane departure prevention control device - Google Patents

Description

  The present invention relates to a lane departure prevention control apparatus that performs control to prevent a departure when the host vehicle is likely to depart from a traveling lane.

  Conventionally, it recognizes the white line of the road, recognizes the traveling lane where the host vehicle is traveling, determines whether the host vehicle deviates from the traveling lane, and warns the driver if it is likely to deviate. There is known a driving assistance device that performs the above. When this type of driving support device is operated, as shown in FIG. 8, if the large vehicle 202 is traveling in the lane 303 adjacent to the lane 304 in which the host vehicle 100 is traveling, the driver The driving support device warns the driver that there is a possibility of deviating from the lane 304 because he tries to take the course 400 near the oncoming lane 310 on which the oncoming vehicle 201 is traveling in order to keep a distance from the car 202. The driver feels annoyed. Therefore, in the device disclosed in Patent Document 1, when the driver's arousal level is high, the departure warning may be prohibited, so that the vehicle may deviate from the driving lane due to a lane change based on the driver's intention. It is described that the occurrence of an alarm that the driver feels annoying when there is a problem is suppressed.

On the other hand, there is known a lane departure prevention control device that has a function of canceling the departure prevention control by determining that the driver is willing to drive when the driver performs a driving operation such as a steering operation.
Japanese Patent Laid-Open No. 11-34773

  However, even if the driver's arousal level is high, the driver is not paying enough attention to the surrounding situation and may deviate from the lane, and it is not preferable to prohibit the warning in general. Further, even when the driver performs a driving operation, the driving operation is not necessarily performed based on the will of the driver paying attention.

  Accordingly, an object of the present invention is to provide a lane departure prevention control device that can perform appropriate driving support according to the state of the driver.

In order to solve the above-described problem, the lane departure prevention control device according to the present invention performs a departure prevention control by warning to the driver or deviation avoidance control when the host vehicle is likely to depart from the driving lane. In the lane departure prevention control device that cancels the departure prevention control when the intention to drive is determined and it is determined that there is an intention to operate, the lane departure prevention control device includes a determination unit that determines the driver's arousal level, and is determined by the determination unit. When the awakening level is equal to or lower than the first predetermined value, it is difficult to cancel the departure prevention control as compared with the case where the determined awakening level is higher than the first predetermined value .

  That is, even when the driving operation is performed under the condition that the departure prevention control is canceled when the determined arousal level is higher than the first predetermined value, the determined arousal level is lower than the first predetermined value and the driving operation is performed. When the amount is small, the departure prevention control is not canceled and the execution of the departure prevention control is continued.

When the arousal level determined by the determination unit is equal to or lower than a second predetermined value that is lower than the first predetermined value, the execution timing of at least one of the departure prevention controls is advanced . Thereby, when the arousal level is equal to or less than the second predetermined value, it is difficult to cancel the departure prevention control, and when departure is predicted, at least one of the departure prevention control is executed early. It will be.

Further, the departure prevention control includes both warning control to the driver and departure avoidance control by steering control. The departure prevention control that advances the execution timing when the arousal level is equal to or less than the second predetermined value is It is only alarm control to the person . As a result, warning is first performed, and then departure avoidance control is performed when the avoidance operation by the driver is insufficient.

  According to the present invention, the departure prevention control is performed even when the driver's arousal level is high, and the prevention control can be easily canceled, so that the execution of the unintended prevention control can be suppressed and the annoyance can be avoided. can do. On the other hand, when the driver's arousal level is low, it is difficult to cancel the departure prevention control, so the departure prevention control is not canceled by an unintended driving operation. Thus, departure prevention control according to the driver's arousal level can be performed, and the reliability of the operation is improved.

Furthermore, when the wakefulness of the driver is reduced in particular, by advancing at least one of the execution timing of departure prevention control, to avoid the risk of the deviation. Control that accelerates the execution timing is an alarm to the driver , which is preferable because the driver can be alerted.

  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.

  FIG. 1 is a block diagram showing a configuration of a preferred embodiment of a lane departure prevention control apparatus according to the present invention. The departure alarm ECU 1 is a control unit of the present apparatus, and is configured by combining a ROM, a RAM, and a CPU, and includes a departure prediction unit 11, a departure determination unit 12, an alarm output unit 13, and an alarm cancellation determination unit 14. Each of the units 12 to 14 in the departure alarm ECU 1 may be divided by hardware, but may share part of hardware or may be realized by software using the same hardware. Good. When implemented by software, the software that executes the functions of each unit is not limited to being independent of each other, and may share part of the software or be implemented by the same software. Good.

  The departure warning ECU 1 is connected with a risk determination means 2, a wakefulness determination means 3, various vehicle sensors 41 to 45, an alarm means 5, and a notification means 6. The danger level determination means 2 includes a peripheral millimeter wave sensor 21 that detects an obstacle around the vehicle and a risk level determination ECU 22. The arousal level determination means 3 includes a driver monitor camera 31 that acquires the state of the driver as a moving image and an awakening level determination ECU 32. The risk determination ECU 22 and the arousal determination ECU 32 are each composed of a ROM, a RAM, a CPU, and the like as in the departure alarm ECU 1. Each of the risk determination ECU 22 and the arousal determination ECU 32 may be configured independently of the departure warning ECU 1 in terms of hardware, but either one or both may be incorporated in the departure warning ECU 1. The peripheral millimeter wave sensors 21 may be arranged, for example, in the vicinity of the four corners of the vehicle so as to cover the entire periphery of the vehicle.

  The alarm means 5 includes an assist torque motor 53 as an assist steering means in addition to a display 51 as a display device and a speaker 52 as an audio output device. The notification means 6 includes an inter-vehicle communication device 61 that performs mutual communication with other vehicles, and a hazard lamp 62.

  As a vehicle sensor, a white line recognition sensor 41 for recognizing a white line that divides a traveling lane, a vehicle speed sensor 42 for detecting the vehicle speed of the host vehicle, a yaw rate sensor 43 for detecting a yaw rate acting on the vehicle, and an acceleration sensor for detecting acting acceleration 44. A steering torque sensor 45 for detecting the steering input of the driver is provided. As the white line recognition sensor 41, in addition to a system that acquires white line position information by extracting a white line by image recognition from an image acquired by a front camera, a system that acquires white line information by road-to-vehicle communication or the like can be used. .

  The outputs of the white line recognition sensor 41, the vehicle speed sensor 42, the yaw rate sensor 43, and the acceleration sensor 44 are input to the departure prediction unit 11. The prediction result of the departure prediction unit 11 is input to the departure determination unit 12, and the determination result of the departure determination unit 12 is output to the alarm output unit 13. On the other hand, the alarm cancellation determination unit 14 receives the output of the steering torque sensor 45 and the determination results of the risk determination unit 2 and the arousal determination unit 3. The output is input to the alarm output unit 13. Is done. The alarm output unit 13 outputs an alarm to each of the alarm unit 5 and the notification unit 6.

  Next, a specific mode of departure prevention control that is the operation of the present apparatus will be described. First, basic deviation prevention control modes will be described. FIG. 2 is a diagram for explaining the situation of the vehicle in this basic control. This control is performed by the departure warning ECU 1 in cooperation with the risk determination ECU 22 and the arousal determination ECU 32, and is repeated at a predetermined timing from when the vehicle is turned on until it is turned off. Executed.

  First, the departure prediction unit 11 predicts the course of the host vehicle from the vehicle speed acquired by the vehicle speed sensor 42, the yaw rate of the vehicle acquired by the yaw rate sensor 43, and the vehicle acceleration acquired by the acceleration sensor 44. An expected point where the lane line (white line) of the travel lane 301 in which the vehicle is traveling determined from the acquired white line position information intersects is obtained. The departure determination unit 12 obtains the time until the host vehicle reaches the predicted point, determines that there is a possibility of departure when the vehicle is within the predetermined time, and has no possibility of departure when the predetermined time is exceeded. judge. When the departure determination unit 12 determines that there is a possibility of departure and the alarm cancellation determination unit 14 has not canceled the alarm, the alarm output unit 13 provides the alarm unit 5 and the notification unit 6 respectively. Instructs alarms and notifications. Specifically, a departure warning is displayed on the display 51, while a warning or alarm is output from the speaker 52, and the steering is vibrated by the assist torque motor 53, so that the driver is warned. In addition, the inter-vehicle communication device 61 notifies that there is a possibility that a nearby vehicle may deviate, while the hazard lamp 62 is turned on to issue a warning to the driver of the following vehicle.

  Hereinafter, some specific examples of the alarm cancellation (cancellation) operation by the alarm cancellation determination unit 14 will be described. FIG. 3 is a flowchart showing the first embodiment, and FIG. 4 is a timing chart showing the driver's arousal level and the time change of the determination result during the control.

  Prior to this processing, the outputs of the sensors 41 to 45 are input to the departure warning ECU 1, the output of the surrounding millimeter wave sensor 21 is input to the risk determination ECU 22, and the output image of the driver monitor camera 31 is input to the awakening determination ECU 32. The above-described processing is performed in the departure prediction unit 11 and the departure determination unit 12.

  First, the wakefulness determination ECU 32 determines the driver's wakefulness based on the video acquired from the driver monitor camera 31 (step S1). For example, as disclosed in Patent Document 1, the arousal level detection means detects and cuts out the driver's face area and the eye area therein, and detects the arousal level from the number of blinks and the half-eye state. At the same time, the face direction and the line-of-sight direction may be recognized. This arousal level determination may be performed in multiple stages, and the arousal level may be expressed numerically.

Next, the warning cancellation determination unit 14 of the departure warning ECU 1 compares the obtained wakefulness determination result with a predetermined value (step S2). For example, as shown in FIG. 4, when the arousal level is equal to or higher than the D2 level, it is determined that the awakening level is high, and when it is equal to or lower than the D3 level, it is determined that the awakening level is low. In the example shown in FIG. 4, it is determined that the arousal level is high before time t ₁ , in other words, there is no decrease in the arousal level, and after time t ₁ , the arousal level is low, in other words, the arousal level is decreased. It is determined that there is.

  If it is determined that the degree of arousal is high, the process after step S3 is skipped and the process is terminated. For this reason, the conditions for canceling the deviation warning are the prescribed conditions. Specifically, when the steering torque obtained from the steering torque sensor 45 is greater than or equal to a predetermined value, it may be determined that the driver has a intention to deviate and the deviation alarm is canceled.

  If it is determined that the arousal level is low, the process proceeds to step S3, and the risk level determination ECU 22 determines the risk level based on the situation of the peripheral obstacle acquired from the peripheral millimeter wave sensor 21. Specifically, the detection results of the distance, direction, and relative speed from the peripheral millimeter wave sensor 21 to the obstacle are obtained, and it is determined that there is a risk when there is a possibility of collision within a predetermined time. The predetermined time in this case may be varied depending on the direction to the obstacle. For example, if the direction in which an obstacle exists is likely to be a blind spot from the driver or on the rear side of the vehicle, take a long time, and if the driver is steering, especially about the steering direction Should be shorter.

Next, the warning cancellation determination unit 14 of the departure warning ECU 1 performs a branching process according to the risk determination result (step S4). In the example shown in FIG. 4, after time t ₂ after time t ₁ , it is determined that the degree of risk is high, the process proceeds to step S6, and before that, it is determined that the degree of risk is not high (= low). To step S5.

In step S5, the warning cancellation determination unit 14 raises the cancellation threshold of the departure warning more than when the arousal level is high, and makes it difficult to cancel the warning. For example, if the departure warning cancellation condition when the arousal level is high is that the steering torque is equal to or greater than a predetermined value T _th1 , the departure warning is canceled in step S5 when the steering torque is equal to or greater than T _th2 greater than T _th1. To do. Thereby, when it is determined that the degree of arousal is low, the steering torque that cancels the deviation warning when it is determined that the degree of arousal is high, even if it is determined that the degree of danger at the time of departure is low. Even if it becomes T _th1 or more, the departure warning is not canceled immediately, and beyond this, the departure warning is canceled only when the steering torque becomes T _th2 or more.

  In step S6, the warning cancellation determination unit 14 invalidates the cancellation of the departure warning, and further advances the timing at which the warning output unit 13 issues a warning. When the arousal level is low and the risk level at the time of departure is high, there is a high possibility that the driver's operation itself does not depend on the driver's will. Therefore, even if an operation is performed, canceling the warning is suppressed, and the warning is given to the driver effectively by issuing the warning earlier than when the degree of arousal is high. On the other hand, since the alarm timing when the degree of arousal is high or when the risk of departure is small can be set to an appropriate time, the alarm timing is too early and the driver does not feel bothered. That is, it is possible to perform an appropriate departure warning according to the arousal level, the driver is less annoyed, and an effective warning can be issued, so that the reliability of the device is improved.

  Alarm cancellation by the alarm cancellation determination unit 14 and the alarm output unit 13 is not limited to the first embodiment. FIGS. 5 and 6 are flowcharts of the second and third embodiments, and FIG. 7 is a diagram showing the relationship between the degree of risk, the magnitude of the alarm, and the alarm timing setting in these processes.

  First, the second embodiment will be described. Steps S1 to S4 are basically the same as those in the first embodiment. However, in this embodiment, the same processing as step S5 of the first embodiment is executed before step S3 (step S5a). Accordingly, when the arousal level is low, the departure warning is less likely to be canceled than when the arousal level is high. If it is determined in step S4 that the degree of risk at the time of departure is low, the process is terminated without performing any particular process. On the other hand, if it is determined that the degree of danger at the time of departure is not low, the process proceeds to step S8, and processing for changing the size of the alarm according to the level of the degree of danger is performed. Specifically, when the risk level S is equal to or less than the predetermined value Sw, the alarm level W is not changed. When the risk level S is exceeded, the alarm level W is increased as the risk level S increases. The size of the alarm means that the volume of the alarm issued from the speaker 52, the amount of steering vibration by the assist torque motor 53, the number of blinking displays on the display 51, etc. are increased to make it easier for the driver to recognize the alarm. Prompt. Here, an example in which the size of the alarm is changed has been described, but processing for advancing the timing of the alarm may be performed. In this embodiment, the same effect as in the first embodiment can be obtained, and more effective warning can be performed when the arousal level is low.

  In the third embodiment, the processes up to step S8 are the same as those in the second embodiment. After step S8, the driver's steering direction is compared with the departure direction (step S9). If the steering direction and the departure direction are the same, the process ends. On the other hand, when the steering direction and the departure direction are opposite directions, the process proceeds to step S10 to perform processing for changing the alarm timing. Specifically, the warning by vibrating the steering by the assist torque motor 53 is not accelerated, but only the alarm by the display 51 or the speaker 52 is accelerated. When vibration is applied to the steering wheel when the arousal level is low, the driver may unintentionally steer in the direction opposite to the steering direction so far. The process of step S10 is performed when the driver is steering in a direction to avoid the departure. In this embodiment, the process of step S10 is performed to steer the departure in the reverse direction. Can be prevented. Furthermore, the same effects as those of the first and second embodiments can be obtained.

  The processing in the first to third embodiments described above is merely an example, and as long as the essence does not change, the order of some of the processing may be changed, or may be overlapped or divided into a plurality of programs. May be. Moreover, you may vary ECU which takes charge of a process about one part or all processes. Further, a part of the processing of each embodiment may be combined or replaced.

  The departure prevention control device of the present invention is suitable as one of driving support devices mounted on a vehicle.

It is a block diagram which shows the structure of suitable embodiment of the lane departure prevention control apparatus which concerns on this invention. It is a figure explaining the condition of the vehicle in the basic control of the deviation prevention by the apparatus of FIG. 2 is a flowchart showing a first embodiment of lane departure prevention control by the apparatus of FIG. 1. It is a timing chart which shows the time change of the driver's arousal level in the 1st example, and its judgment result. It is a flowchart which shows 2nd Example of the lane departure prevention control by the apparatus of FIG. It is a flowchart which shows 3rd Example of lane departure prevention control by the apparatus of FIG. It is a timing chart which shows the time change of the degree of danger and alarm amount in the 2nd example. It is a figure explaining the problem of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Deviation alarm ECU, 2 ... Risk level determination means, 3 ... Arousal level determination means, 5 ... Warning means, 6 ... Notification means, 11 ... Deviation prediction part, 12 ... Deviation determination part, 13 ... Alarm output part, 14 ... Alarm cancellation determination unit, 22 ... Risk determination ECU, 21 ... Peripheral millimeter wave sensor, 32 ... Arousal determination ECU, 31 ... Driver monitor camera, 41 ... White line recognition sensor, 42 ... Vehicle speed sensor, 43 ... Yaw rate sensor, 44 ... acceleration sensor, 45 ... steering torque sensor, 51 ... display, 52 ... speaker, 53 ... assist torque motor, 61 ... inter-vehicle communication device, 62 ... hazard lamp, 100 ... own vehicle, 201 ... oncoming vehicle, 202 ... large vehicle , 301 to 304 ... lane, 310 ... opposite lane, 400 ... course.

Claims (1)

When likely to depart the vehicle from the travel lane, performs deviation prevention control by alarm and deviation preventing control to the driver, to determine the driving operation intention of the driver, when it is determined that there is manipulation intention is In the lane departure prevention control device for canceling the departure prevention control,
A determination means for determining a driver's arousal level,
With alertness determined by the determining means in the case of equal to or less than the first predetermined value, the determined degree of awakening to Gataku performs cancellation of the departure prevention control in comparison to higher than the first predetermined value When the arousal level determined by the determination unit is equal to or lower than a second predetermined value lower than the first predetermined value, the execution timing of only the alarm control for the driver in the departure prevention control is advanced. Lane departure prevention control device.

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