JP5146243B2 - Lane departure control device - Google Patents

Description

  The present invention relates to a lane departure suppressing device that suppresses a vehicle from deviating from a lane composed of a pair of lane markings.

In order to assist the driving of the driver, a device that determines whether or not the vehicle may deviate from the lane, and suppresses the vehicle from deviating from the lane by an alarm output or the like when there is a possibility of deviating. There is. In this device, it is important to detect the left and right lane markings (white lines, etc.) for dividing the lane in which the vehicle is traveling, but there are cases where only one side of the lane markings on both the left and right sides can be detected. In this way, when only one lane line can be detected, lane departure cannot be determined on the other side, so a technique for estimating the other lane line (or road boundary line) has been developed. The apparatus described in Patent Document 1 recognizes roadside objects provided at both ends of a road as reflecting objects detected by a laser radar, and recognizes left and right road boundary lines from the roadside objects at both ends. Further, in the devices described in Patent Documents 2 and 3, when only one lane marking can be recognized, the other lane marking is estimated based on the recognized lane marking position and lane width.
JP 2007-310595 A JP 2002-163642 A JP-A-10-261065

  In the lane line (road boundary line) estimation methods such as those described above, since the lane line is estimated under certain conditions, it may not be an appropriate lane line depending on the driver's condition and the situation around the vehicle. is there. For this reason, an appropriate alarm cannot be output, and an alarm unnecessary for the driver may be output or a necessary alarm may not be output.

  Then, this invention makes it a subject to provide the lane departure suppression apparatus which can estimate the other lane marking suitable when only one lane marking can be detected.

A lane departure restraint device according to the present invention is a lane departure restraint device that restrains a vehicle from deviating from a lane composed of a pair of lane markings, a lane marking detection means for detecting a lane marking ahead of the vehicle, Arousal level detection means for detecting the driver's awakening level, and when the lane line detection means detects only one lane line of the pair of lane lines, and the driver's awakening level detected by the awakening level detection means When it is high, it comprises virtual line estimating means for estimating a virtual line corresponding to the other dividing line.

  In this lane departure restraint device, a lane marking in front of the vehicle (for example, a white solid line or broken line, a yellow solid line or broken line) is detected by a lane marking detection unit. When such a lane marking is detected, only the lane markings on the left and right sides may be detected. For example, if the lane marking on the other side of the left and right has disappeared, has become thin, or only the center line has been drawn, or the road width is not sufficient for two vehicles, the lane marking on the right side (Center line) may not be present. In addition, the driver travels so as not to depart from the lane when the arousal level is high. However, when the driver's arousal level is low, the driver is more likely to deviate from the lane. Therefore, the driver's arousal level is very important in estimating a virtual line that is a reference for determining lane departure. Therefore, in the lane departure suppression device, the driver's arousal level is detected by the arousal level detection means. In the lane departure restraint device, when the lane line detection unit detects only one lane line of the pair of lane lines, the lane departure detection unit detects the other side lane line based on the driver's arousal level by the virtual line estimation unit. The virtual line corresponding to is estimated, and the vehicle is prevented from deviating from the one-side lane line that can be detected and the estimated other-side virtual line. In this way, in the lane departure restraint device, by estimating the virtual line corresponding to the lane line on the undetectable side in consideration of the driver's arousal level, the appropriate lane according to the state of the driver for the undetectable side The line can be estimated and an appropriate lane departure determination can be made.

The lane departure suppression device of the present invention includes an oncoming vehicle detection means for detecting an oncoming vehicle, and the virtual line estimation means detects only the left lane line of the pair of lane lines by the lane line detection means. If the driver's arousal level detected by the arousal level detection means is high , the virtual line is preferably estimated based on the oncoming vehicle when the oncoming vehicle is detected by the oncoming vehicle detection means.

  If it is not possible to detect the lane marking on the right side of the vehicle (especially the center line), it is the oncoming vehicle that needs to pay the most attention on the right side of the vehicle. Therefore, in this lane departure suppressing device, the oncoming vehicle is detected by the oncoming vehicle detection means. In the lane departure restraint device, if only the left lane line of the pair of lane lines is detected by the lane line detection means, and there is an oncoming vehicle, the virtual line estimation means determines the right side based on the oncoming vehicle. An imaginary line corresponding to the lane marking is estimated, and the vehicle is prevented from deviating from the detected left lane line and the estimated right imaginary line. In this way, the lane departure restraint apparatus estimates the virtual line corresponding to the right lane line (center line) that cannot be detected in consideration of the oncoming vehicle, so that the appropriate right lane line corresponding to the situation of the oncoming vehicle (Corresponding to the center line) can be estimated.

The lane departure suppression device of the present invention includes obstacle detection means for detecting an obstacle ahead of the vehicle, and the virtual line estimation means detects only the right lane line of the pair of lane lines by the lane line detection means. If the driver's arousal level detected by the arousal level detection means is high and the obstacle detection means detects an obstacle on the left side ahead of the vehicle, it is preferable to estimate the virtual line based on the obstacle It is.

  If only the lane marking on the right side of the vehicle can be detected, it is the obstacle on the left that needs the most attention on the left side of the vehicle. Therefore, in this lane departure restraint device, obstacle detection means detects an obstacle ahead of the vehicle. In the lane departure suppressing device, when only the right lane line of the pair of lane lines is detected by the lane line detecting means, an obstacle (for example, a power pole, a post box, a guard rail, a wall, , Pedestrian, bicycle), the virtual line estimation means estimates a virtual line corresponding to the left lane line based on the obstacle, and the vehicle is detected from the detected right lane line and the estimated left imaginary line. To deviate. In this way, the lane departure restraint device estimates an appropriate left lane line according to the situation of the left obstacle by estimating the virtual line corresponding to the left lane line that cannot be detected in consideration of the obstacle. it can.

  The present invention can estimate an appropriate lane line for an undetectable side by estimating a virtual line corresponding to the undetectable side lane line in consideration of the state of the driver, etc., and perform an appropriate lane departure determination be able to.

  Embodiments of a lane departure restraint device according to the present invention will be described below with reference to the drawings.

  In the present embodiment, the lane departure suppressing device according to the present invention is applied to a lane departure warning device mounted on a vehicle. The lane departure warning device according to the present embodiment detects a lane composed of a pair of white lines (division lines), and outputs an alarm when there is a possibility that the host vehicle departs from the lane. In addition, this Embodiment is a suitable form for the 1.5 lane road where the center line is not drawn as a target road, and the road of one lane (a road of 2 lanes combined with an opposite lane) or a center line.

  A lane departure warning device 1 according to the present embodiment will be described with reference to FIGS. FIG. 1 is a configuration diagram of a lane departure warning device according to the present embodiment. FIG. 2 shows an example of a road with a white line, where (a) is a road that can detect both left and right lines, and (b) is a road that can detect only the center line (white line on the right side). (C) is a road that can detect only the right end line of the road (white line on the right side), and (d) is a road that can detect only the left end line of the road (white line on the left side). FIG. 3 is an explanatory diagram of a method for determining the right side white line. FIG. 4 is an explanatory diagram of a method for setting a virtual line on the left side when the driver arousal level is high when only the right side white line (center line) is detected. FIG. 5 is an explanatory diagram of a method for setting a virtual line on the left side when the driver arousal level is low when only the right side white line (center line) is detected. FIG. 6 is an explanatory diagram of a method for setting a virtual line on the left side when there is no oncoming vehicle when only the right one side white line (road right end line) is detected. FIG. 7 is an explanatory diagram of a method for setting the left and right virtual lines when there is an oncoming vehicle and the driver's arousal level is high when only the right one side white line (road right end line) is detected. FIG. 8 is an explanatory diagram of a method for setting a virtual line on the right side when there is an oncoming vehicle and the driver's arousal level is high when only the white line on the left side is detected. FIG. 9 is an explanatory diagram of a method for setting the right and left virtual lines when there is an oncoming vehicle and the driver arousal level is high when only the left one-side white line is detected.

  The lane departure warning device 1 basically performs lane departure determination based on the detected white lines on both the left and right sides. However, when only one of the left and right white lines can be detected, the lane departure warning device 1 estimates a virtual line corresponding to the white line on the other side, and based on the white line on one side and the virtual line on the other side, Deviation judgment is performed.

  The lane departure warning device 1 includes a white line recognition camera 10, a millimeter wave sensor 11, a navigation device 12, a driver monitor 13, a yaw angle sensor 14, a vehicle speed sensor 15, an alarm device 20, and an ECU [Electronic Control Unit] 30. A lane condition determination unit 31 and a lane departure determination unit 32 are configured.

  In the present embodiment, the white line recognition camera 10 corresponds to the lane marking detection means described in the claims, and the millimeter wave sensor 11 corresponds to the oncoming vehicle detection means and the obstacle detection means described in the claims. The driver monitor 13 corresponds to the arousal level detection means described in the claims, and the lane condition determination unit 31 of the ECU 30 corresponds to the virtual line estimation means described in the claims.

  The white line recognition camera 10 is a sensor for recognizing a white line ahead of the host vehicle, and includes a camera and a calculation device. The camera is attached in front of the host vehicle so that the optical axis direction coincides with the traveling direction of the vehicle. The camera has a wide imaging range in the left-right direction, and can sufficiently capture the road on which it is traveling. The camera images the road ahead of the host vehicle and outputs the captured image to the arithmetic device. Every time an image is input from the camera, the arithmetic device recognizes a white line ahead of the host vehicle from the image. As this recognition method, a conventional method is applied. Then, the arithmetic device determines whether the recognized white line is the left and right sides of the host vehicle or only one of the left and right sides. When both the left and right sides can be recognized, the arithmetic unit, from the pair of recognized white lines, the lane width, the line passing through the center of the pair of white lines (that is, the center of the lane), the center line of the lane, or the curve radius or curve curvature of each white line The distance (offset) from the vehicle center to each white line is calculated. When only one side can be recognized, the computing device calculates the recognized curve radius and curve curvature of the white line on one side and the distance (offset) from the vehicle center to the white line on one side. The white line recognition camera 10 transmits the recognized white line and various calculated information to the ECU 30 as a white line recognition signal. In the present embodiment, the curve radius, the curve curvature, and the offset are expressed as positive values on the right side with respect to the right turn direction and the own vehicle center, and on the left side with respect to the left turn direction and the own vehicle center. The value shall be expressed as a negative value. Therefore, it is possible to determine whether the recognized white line is the right side or the left side of the host vehicle based on the plus / minus value of the offset.

  The millimeter wave sensor 11 is a sensor that detects an obstacle ahead of the host vehicle using millimeter waves, and includes a millimeter wave transmission / reception device and an arithmetic device. The transmission / reception device is attached at a predetermined height position in the center of the front side of the host vehicle. In the transmission / reception apparatus, the millimeter wave is transmitted forward from the own vehicle while scanning in the left-right direction, and the reflected millimeter wave is received. The transmission / reception apparatus transmits millimeter wave information (scanning azimuth angle in the left and right direction, transmission time, reception time, reflection intensity, etc.) about each reflection point (detection point) that has received the reflected millimeter wave to the arithmetic unit. . The arithmetic device uses the millimeter wave information at the current time (t), and calculates the relative distance to the obstacle ahead based on the time from transmission to reception of the millimeter wave. Further, in the arithmetic device, the relative speed with respect to the obstacle ahead is based on the change of the distance calculated at the current time (t) and the distance calculated at the past time (for example, the previous time (t-1)). Is calculated. Further, the computing device uses the millimeter wave information at the current time (t), detects the direction of the millimeter wave that is reflected most strongly among the reflected millimeter waves, and determines the traveling direction of the host vehicle from that direction. An angle formed with the direction of the obstacle is obtained, and a distance (lateral position) from the host vehicle is calculated from the angle. Then, the millimeter wave sensor 11 transmits the detected obstacle and various calculated information to the ECU 30 as a millimeter wave detection signal. Examples of the detected obstacle include an oncoming vehicle, a preceding vehicle, a utility pole, a post box, a guardrail, a wall, a pedestrian, and a bicycle.

  The navigation device 12 calculates the current position and traveling direction of the host vehicle, displays the current position and traveling direction on a map, searches for a route to the destination set by the driver, and performs guidance according to the searched route. Device. For this purpose, the navigation device 12 includes a map database, and map information for display, route guidance, and the like is stored in the map database. The map information includes road information. The road information includes at least information such as the shape of the road, the lane width (road width), the number of lanes, and the road type. The navigation device 12 transmits a navigation information signal including road information around the current position to the ECU 30 together with the current position information.

  The driver monitor 13 is a device that detects the state of the driver (particularly the arousal level), and includes a camera and a computing device. The camera is attached at a position and angle at which the periphery of the driver's face can be imaged in the passenger compartment of the vehicle. Each time an image is input from the camera, the arithmetic device extracts a face area or a face part area (eyes, mouth, eyebrows, etc.) from the image, and estimates the arousal level based on the extracted area images. As this estimation method, a conventional method is applied, for example, a method of detecting changes in facial expression by comparing each facial part image when the degree of arousal is high or low with each extracted facial part region image There is. Then, the driver monitor 13 transmits the driver's arousal level to the ECU 30 as a driver monitor signal.

  The yaw angle sensor 14 is a sensor that detects the yaw angle of the host vehicle. The yaw angle sensor 14 detects the yaw angle and transmits the detected yaw angle to the ECU 30 as a yaw angle signal.

  The vehicle speed sensor 15 is a sensor that detects the vehicle speed of the host vehicle. The vehicle speed sensor 15 detects the vehicle speed and transmits the detected vehicle speed to the ECU 30 as a vehicle speed signal.

  The alarm device 20 is a device that outputs a buzzer sound as an alarm to the driver. When the alarm device 20 receives an alarm output signal from the ECU 30, the alarm device 20 outputs a buzzer sound according to the alarm output signal.

  The ECU 30 is an electronic control unit including a CPU [Central Processing Unit], a ROM [Read Only Memory], a RAM [Random Access Memory], and the like, and comprehensively controls the lane departure warning device 1. The ECU 30 configures the lane condition determination unit 31 and the lane departure determination unit 32 by loading an application program stored in the ROM into the RAM and executing it by the CPU. The ECU 30 receives the signals from the various detection means 10 to 15 and performs processing in the lane condition determination unit 31 and the lane departure determination unit 32 based on the signals. Then, the ECU 30 transmits an alarm output signal to the alarm device 20 when the host vehicle may deviate from the lane.

  The lane situation determination unit 31 will be described. First, the lane condition determination unit 31 performs a recognition white line determination process to determine at which position the white line recognized by the white line recognition camera 10 is located with respect to the host vehicle. The white line pattern that can be recognized is a pattern that can recognize the white line LL on the left side and the white line (center line) RL1 on the left side of the host vehicle MV as shown in FIG. 2A, as shown in FIG. A pattern capable of recognizing only the white line (center line) RL1 on the right side of the own vehicle MV, a pattern capable of recognizing only the white line (right end line of the road) RL2 on the right side of the own vehicle MV, as shown in FIG. ), There is a pattern that can recognize only the white line LL on the left side of the host vehicle MV.

  In the case of a road that can recognize the white line LL on the left side and the white line RL1 on the right side as shown in FIG. 2A, the width of the road is considered to be sufficiently wider than that of two vehicles. In the case of a road that can recognize only the white line (center line) RL1 on the right side of the host vehicle MV as shown in FIG. 2B, the width of the road is considered to be sufficiently wider than the two vehicles, but the left side of the host vehicle MV Since there is no white line, it is necessary to pay attention to obstacles on the left side (for example, utility poles, pedestrians). In the case of a road that can recognize only the white line (road right end line) RL2 on the right side of the host vehicle MV as shown in FIG. 2C, or the road that can recognize only the white line LL on the left side of the host vehicle MV as shown in FIG. In the case of (on a road without a center line), when the oncoming vehicle OV arrives, it is not considered that the width of the road is sufficiently wide relative to the two vehicles, so when the oncoming vehicle OV passes the oncoming vehicle OV It is necessary to pay attention to obstacles on the left side.

  The recognition white line determination process will be described. The lane condition determination unit 31 determines whether the white lines on both the left and right sides can be recognized or only one of the white lines can be recognized based on the white line information recognized from the white line recognition camera 10. If the white lines on both the left and right sides can be recognized, the process proceeds to the lane departure determination process in the lane departure determination unit 32 using the white lines on both sides.

  When only one white line can be recognized, the lane condition determination unit 31 determines that the recognized white line on the right side of the own vehicle is based on the plus / minus value of the offset from the center of the own vehicle to the one white line. It is determined whether the white line on the left side or the white line on the left side. In the case of the white line on the left side, the lane condition determination unit 31 proceeds to the left side white line handling process.

  In the case of the white line on the right side, the lane condition determination unit 31 extracts information on the right obstacle of the host vehicle based on the obstacle information from the millimeter wave sensor 11. In the lane condition determination unit 31, as shown in FIG. 3, the difference between the offset A from the own vehicle MV to the right white line RL and the distance B (lateral position) from the own vehicle MV to the right obstacle RO ( B-A) is calculated. When this difference (B−A) is wide enough to allow the vehicle to pass, it can be estimated that an opposite lane exists between the obstacle RO on the right side and the white line RL, so the white line RL is set as the center line. On the other hand, if the difference (B−A) is so narrow that the vehicle cannot pass, it can be assumed that there is no opposite lane between the obstacle RO on the right side and the white line RL, so the white line RL is set as the right end line of the road.

  Therefore, the lane condition determination unit 31 determines whether or not the difference (B−A) is greater than or equal to a threshold value. The threshold is set in advance based on the vehicle width and lane width of a general vehicle. When the difference (B−A) is equal to or larger than the threshold value, the lane condition determination unit 31 proceeds to the right-side white line center line correspondence process. On the other hand, when the difference (B−A) is less than the threshold value, the lane condition determination unit 31 shifts to right-hand side white line road right end correspondence processing.

  The right side white line center line correspondence processing will be described. The lane condition determination unit 31 determines whether or not the awakening level is high based on the driver's awakening level from the driver monitor 13. When the driver's arousal level is high, the driver drives while paying sufficient attention to obstacles on the left and oncoming vehicles. However, if the driver's arousal level is low, the driver will miss or notice the obstacles on the left side and will be late to notice. Judgment).

  When the arousal level is high, the lane condition determination unit 31 determines whether there is an obstacle on the left side of the host vehicle based on the obstacle information from the millimeter wave sensor 11. When there is an obstacle on the left side, as shown in FIG. 4, the lane condition determination unit 31 determines the left side based on the distance (lateral position) from the host vehicle MV to the left obstacle LO (for example, a utility pole). An imaginary line ILL (a line corresponding to the white line on the left side of the host vehicle MV) parallel to the white line RL1 on the right side is set at a position on the center side by a predetermined distance C from the position of the obstacle LO. The predetermined distance C is set in advance by experiments or the like, and is, for example, about several tens of centimeters. Then, the process proceeds to the lane departure determination process in the lane departure determination unit 32 using the recognized left imaginary line ILL as the recognized right white line RL1. On the other hand, when there is no obstacle on the left side, it is assumed that a driver with a high arousal level will drive while paying sufficient attention to the obstacle on the left side, and the lane condition determination unit 31 does not set the left virtual line. And it transfers to the lane departure determination process in the lane departure determination part 32 using only the recognized white line RL1 of the right side.

  When the awakening level is low, the lane condition determination unit 31 determines whether the driver's awakening level is high (particularly when there is an obstacle on the left side) and the history of offsets from the own vehicle to the center line. The average value D of the offset is calculated. Further, the lane condition determination unit 31 is a virtual line parallel to the right white line RL1 at a position left by a distance (2 × D) twice the average value D from the recognized right white line (center line) RL1. Set ILL. Here, a value slightly smaller than the average value D may be used in order to make the determination condition of lane departure more severe. Then, the process proceeds to the lane departure determination process in the lane departure determination unit 32 using the recognized left imaginary line ILL as the recognized right white line RL1. Note that the lane condition determination unit 31 stores offset data from the host vehicle to the center line when the driver's arousal level is high (particularly when there is an obstacle on the left side).

  Incidentally, a driver with a high arousal level usually drives to drive closer to the center line in order to avoid the obstacle LO when there is an obstacle LO on the left side. Therefore, by setting the left virtual line ILL using the offset history as described above, the left virtual line ILL can be set closer to the center line sufficiently away from the left obstacle LO.

  The right-hand side white line road right end correspondence processing will be described. When the center line cannot be detected, it is the oncoming vehicle that needs to pay the most attention on the right side of the host vehicle. Therefore, the lane condition determination unit 31 determines whether there is an oncoming vehicle based on the obstacle information from the millimeter wave sensor 11.

  When there is no oncoming vehicle, the lane condition determination unit 31 determines whether there is an obstacle on the left side of the host vehicle based on the obstacle information from the millimeter wave sensor 11. When there is an obstacle on the left side, as shown in FIG. 6, the lane condition determination unit 31 determines the position of the left obstacle LO based on the distance (lateral position) from the host vehicle MV to the left obstacle LO. A virtual line ILL1 parallel to the white line RL2 on the right side is set at a position a predetermined distance C from the center. Then, the process proceeds to the lane departure determination process in the lane departure determination unit 32 by using the recognized right side white line RL2 and the estimated left virtual line ILL1. On the other hand, when there is no obstacle on the left side, the lane condition determination unit 31 determines the right side at the position separated from the white line RL2 on the right side by the lane width (or road width) E based on the road information from the navigation device 12. A virtual line ILL2 parallel to the white line RL2 is set. Then, the process proceeds to the lane departure determination process in the lane departure determination unit 32 by using the recognized right side white line RL2 and the estimated left virtual line ILL2. In this case, since there is no oncoming vehicle, there is no need to set a virtual line corresponding to the center line, and it is only necessary to travel so as not to deviate from the lanes at both ends of the road.

  When there is an oncoming vehicle, first, in order to confirm the state of the driver, the lane condition determination unit 31 determines whether or not the arousal level is high based on the awakening level of the driver from the driver monitor 13.

When the driver's arousal level is high, the lane condition determination unit 31 sets the left virtual line ILL based on the left obstacle LO or the lane width by the same processing as described above. Further, as shown in FIG. 7, the lane condition determination unit 31 determines the left virtual line ILL based on the horizontal position of the left virtual line ILL and the distance (horizontal position) from the host vehicle MV to the oncoming vehicle OV. A difference L between the lateral position and the lateral position of the oncoming vehicle OV is calculated. And in the lane condition determination part 31, it is determined whether the difference L is wider than the vehicle width W of the own vehicle MV. When the difference L is wider than the vehicle width W, a virtual line corresponding to the center line can be set (road width is wide), so the lane condition determination unit 31 is left by a predetermined distance F from the lateral position of the oncoming vehicle OV. Is set to a virtual line IRL parallel to the right white line RL2. The predetermined distance F is set in advance by experiments or the like, and is, for example, about several tens of centimeters. Then, the lane departure determination process in the lane departure determination unit 32 is performed using the estimated left imaginary line ILL and right imaginary line (center line) IRL. On the other hand, when the difference L is narrower than the vehicle width W, there is an oncoming vehicle, but the virtual line corresponding to the center line cannot be set (the road width is narrow), and the lane departure judgment for the right lane cannot be made. It is necessary to inform the driver of the situation immediately. Therefore, the lane condition determination unit 31 sets an alarm output signal for outputting a buzzer sound by the alarm device 20 and transmits the alarm output signal to the alarm device 20.

  When the driver's awakening level is low, there is an oncoming vehicle and the driver's awakening level is low, so it is necessary to immediately inform the driver of the situation and stop the vehicle. Therefore, the lane condition determination unit 31 sets an alarm output signal for outputting a buzzer sound by the alarm device 20 and transmits the alarm output signal to the alarm device 20.

  The left side white line handling process will be described. As in the case of the right-hand side white line road right end correspondence processing, since the center line has not been detected, the lane condition determination unit 31 determines whether there is an oncoming vehicle based on the obstacle information from the millimeter wave sensor 11. Determine whether.

  When there is no oncoming vehicle, it is not necessary to set a virtual line corresponding to the center line, and it is sufficient to travel at least so as not to deviate from the lane at both ends of the road, so using the recognized white line LL on the left side, The process proceeds to a lane departure determination process in the lane departure determination unit 32. If the white line at the right end line of the road is also recognized, the process proceeds to the lane departure determination process in the lane departure determination unit 32 using the white line at the right end of the road on the right side.

  When there is an oncoming vehicle, first, in order to confirm the state of the driver, the lane condition determination unit 31 determines whether or not the arousal level is high based on the awakening level of the driver from the driver monitor 13.

  When the driver's arousal level is high, the lane condition determination unit 31 determines the left side based on the lateral position of the left white line LL and the distance (lateral position) from the host vehicle MV to the oncoming vehicle OV, as shown in FIG. A difference L between the lateral position of the white line LL and the lateral position of the oncoming vehicle OV is calculated. And in the lane condition determination part 31, it is determined whether the difference L is wider than the vehicle width W of the own vehicle MV. When the difference L is wider than the vehicle width W, the lane condition determination unit 31 sets an imaginary line IRL parallel to the left white line LL at a position left by a predetermined distance F from the lateral position of the oncoming vehicle OV. Then, using the recognized left-side white line LL and the estimated right-side imaginary line (center line) IRL, the process proceeds to the lane departure determination process in the lane departure determination unit 32. On the other hand, when the difference L is narrower than the vehicle width W, the lane condition determination unit 31 determines that the lane condition determination unit 31 has a virtual position parallel to the left white line LL at a position left by a predetermined distance F from the lateral position of the oncoming vehicle OV. Set the line IRL. Further, as shown in FIG. 9, the lane condition determination unit 31 extracts the information of the obstacle LO on the left side of the own vehicle MV from the information of the obstacle from the millimeter wave sensor 11, and the left obstacle from the own vehicle MV. Based on the distance to the LO (lateral position), an imaginary line ILL parallel to the left white line LL is set at a center position a predetermined distance C from the position of the left obstacle LO. Then, using the estimated right imaginary line (center line) IRL and the left imaginary line ILL, the process proceeds to the lane departure determination process in the lane departure determination unit 32.

  When the driver's awakening level is low, there is an oncoming vehicle and the driver's awakening level is also low. Therefore, the lane situation determination unit 31 transmits a warning output signal to the warning device 20 as described above.

  The lane departure determination unit 32 will be described. In the lane departure determination unit 32, when the white lines on both the left and right sides are recognized, the lane departure determination process is performed for each of the two white lines, the one side white line is recognized and the other side virtual line is set. Lane departure judgment processing is performed for each of the white line and the virtual line, and when the one side white line is recognized and the other side virtual line is not set, the lane only for the white line is set. Deviation determination processing is performed.

  The lane departure determination process will be described. In the lane departure determination unit 32, based on the yaw angle of the host vehicle from the yaw angle sensor 14 and the vehicle speed of the host vehicle from the vehicle speed sensor 15, the position of the host vehicle or the position of the host vehicle after a predetermined time (for example, several seconds later). Predict the course. Then, the lane departure determination unit 32 determines that the own vehicle is a white line based on the distance or curve radius of the recognized white line or the set virtual line from the own vehicle and the position of the own vehicle or the course of the own vehicle after a predetermined time. Alternatively, it is determined whether or not there is a possibility of deviating from the virtual line. When it is determined that there is a possibility of departure, the lane departure determination unit 32 sets an alarm output signal for outputting a buzzer sound in the alarm device 20 and transmits the alarm output signal to the alarm device 20.

  The operation of the lane departure warning device 1 will be described with reference to FIGS. In particular, the recognition white line determination process in the ECU 30 will be described with reference to the flowchart of FIG. 10, the right side white line centerline correspondence process in the ECU 30 will be described with reference to the flowchart in FIG. 11, and the right side white line road right end correspondence process in the ECU 30 will be described. The flowchart will be described with reference to the flowchart of FIG. 12, and the left side white line response process in the ECU 30 will be described with reference to the flowchart of FIG. 13.

  The white line recognition camera 10 images the front of the host vehicle at regular intervals, performs white line recognition based on the captured image, calculates various information about the recognized white line, and transmits a white line recognition signal to the ECU 30. doing.

  The millimeter wave sensor 11 transmits a millimeter wave in front of the host vehicle and receives the reflected millimeter wave at predetermined time intervals, calculates various information about the obstacle based on the transmission / reception data of the millimeter wave, A millimeter wave detection signal is transmitted to the ECU 30.

  The navigation device 12 detects the current position of the host vehicle at regular time intervals and transmits a navigation information signal including road information around the current position to the ECU 30.

  The driver monitor 13 images the periphery of the driver's face at regular intervals, estimates the driver's arousal level based on the captured image, and transmits a driver monitor signal to the ECU 30.

  The yaw angle sensor 14 detects the yaw angle of the host vehicle at regular intervals and transmits a yaw angle signal to the ECU 30. The vehicle speed sensor 15 detects the vehicle speed of the host vehicle at regular intervals and transmits a vehicle speed signal to the ECU 30.

  At certain time intervals, the ECU 30 acquires information on the recognized white line based on the white line recognition signal from the white line recognition camera 10 (S10). Then, the ECU 30 determines whether the recognized white line is one side or both left and right sides (S11).

  If it is determined in S11 that only one side of the white line can be recognized, the ECU 30 determines whether the white line on one side is the white line on the right side or the left side of the vehicle based on the offset of the white line on the one side (S12). ).

  When it is determined in S12 that the white line on one side is the right side of the host vehicle, the ECU 30 acquires various types of information on the right obstacle based on the millimeter wave detection signal from the millimeter wave sensor 11 (S13). The ECU 30 estimates the position of the white line on the right side based on the difference between the distance from the host vehicle to the obstacle on the right side and the offset from the host vehicle to the white line on the right side (S14). It is determined whether the line is a center line or a road right end line (S15). If it is determined in S15 that the white line on the right side is the center line, the ECU 30 proceeds to a process corresponding to the right side white line center line (S16). On the other hand, when it is determined in S15 that the white line on the right side is the road right end line, the ECU 30 proceeds to the right side white line road right end correspondence process (S17).

  When it is determined in S12 that the white line on one side is the left side of the host vehicle, the ECU 30 shifts to the left-side white line handling process (S18).

  If it is determined in S11 that the white line can be recognized on both the left and right sides, the ECU 30 proceeds to a lane departure determination process for each white line on both the left and right sides (S19). In this case, since the white lines on the left and right sides of the host vehicle are detected, normal lane departure determination is performed.

  When the process proceeds to the process for handling the right side white line center line, the ECU 30 acquires the driver's arousal level based on the driver monitor signal from the driver monitor 13 (S20). Then, the ECU 30 determines whether or not the driver's arousal level is high (S21).

  If it is determined in S21 that the driver's arousal level is high, the ECU 30 acquires various pieces of information on the obstacle based on the millimeter wave detection signal from the millimeter wave sensor 11 (S22). Then, the ECU 30 determines whether there is an obstacle on the left side of the host vehicle (S23).

  If it is determined in S23 that there is an obstacle on the left side, the ECU 30 sets a virtual line on the left side based on the position of the left obstacle (S24). Then, the ECU 30 proceeds to a lane departure determination process for the right side white line (center line) and the left side virtual line (S25). In this case, since only the white line (center line) on the right side of the host vehicle is detected, a normal lane departure determination is performed on the right side white line, and a virtual line corresponding to the position of the left side obstacle on the left side. Based on this, a lane departure determination is performed.

  If it is determined in S23 that there is no obstacle on the left side, the ECU 30 proceeds to a lane departure determination process for only the white line on the right side (center line) (S26). In this case, since only the white line (center line) on the right side of the host vehicle is detected, the normal lane departure determination is performed for the white line on the right side, there is no obstacle on the left side for the left side, and the driver awakens. Since it is too high, lane departure judgment is not performed.

  If it is determined in S21 that the driver's awakening level is low, the ECU 30 sets a virtual line on the left side based on the history of the offset between the host vehicle and the center line when the driver is awake (S27). Then, the ECU 30 proceeds to a lane departure determination process for the right side white line (center line) and the left side imaginary line (S28). In this case, since only the white line (center line) on the right side of the host vehicle is detected, a normal lane departure determination is performed for the white line on the right side, and a virtual line corresponding to the past driving performance of the driver is performed on the left side. Based on this, a lane departure determination is performed. As a result, the driver's arousal level is low, but the departure can be determined based on the driving feeling when the driver is driving normally.

  When the process proceeds to the right-hand side white line road right end handling process, the ECU 30 acquires various pieces of information on the obstacle based on the millimeter wave detection signal from the millimeter wave sensor 11 (S30). Then, the ECU 30 determines whether there is an oncoming vehicle (S31).

  If it is determined in S31 that there is no oncoming vehicle, the ECU 30 determines whether there is an obstacle on the left side of the host vehicle (S32). When it is determined in S32 that there is an obstacle on the left side, the ECU 30 sets a virtual line on the left side based on the position of the left obstacle (S33). On the other hand, when it is determined in S32 that there is no obstacle on the left side, the ECU 30 sets the left virtual line based on the lane width (S34). Then, the ECU 30 proceeds to a lane departure determination process for the right side white line (road right end line) and the left side imaginary line (S35). In this case, only the white line on the right side of the vehicle (the right end line of the road) is detected, and there is no oncoming vehicle. Therefore, the right side of the vehicle is determined to deviate based on the white line at the right end of the road, and the left side is the obstacle on the left side. Lane departure determination is performed based on a virtual line corresponding to the position or lane width.

  When it is determined in S31 that there is an oncoming vehicle, the ECU 30 acquires the driver's arousal level based on the driver monitor signal from the driver monitor 13 (S36). Then, the ECU 30 determines whether or not the driver's arousal level is high (S37).

  When it is determined in S37 that the driver's arousal level is high, the ECU 30 determines whether there is an obstacle on the left side of the host vehicle (S38). When it is determined in S38 that there is an obstacle on the left side, the ECU 30 sets a virtual line on the left side based on the position of the left obstacle (S39). On the other hand, if it is determined in S38 that there is no obstacle on the left side, the ECU 30 sets the left virtual line based on the lane width (S40).

  Further, the ECU 30 calculates the distance between the virtual line on the left side and the oncoming vehicle, and determines whether or not the distance is wider than the vehicle width of the host vehicle (S41). When it is determined in S41 that the distance is wider than the vehicle width, the ECU 30 sets a right virtual line (corresponding to the center line) based on the position of the oncoming vehicle (S42). Then, the ECU 30 proceeds to a lane departure determination process for the left virtual line and the right virtual line (S43). In this case, only the white line on the right side of the vehicle (the right end line of the road) is detected, and there is an oncoming vehicle, so the lane departure determination is performed on the right side based on the virtual line according to the position of the oncoming vehicle, The lane departure determination is performed based on a virtual line corresponding to the position of the left obstacle or the lane width.

  On the other hand, when it determines with the distance being narrower than a vehicle width in S41, ECU30 transmits a warning output signal to the warning device 20 (S44). When this alarm output signal is received, the alarm device 20 outputs a buzzer sound. With this buzzer sound, the driver pays attention to the oncoming vehicle and stops the vehicle by moving it to the left side as necessary. In this case, although there is an oncoming vehicle, the lane departure from the center line cannot be determined, but the driver is alerted by a buzzer sound.

  When it is determined in S37 that the driver's arousal level is low, the ECU 30 transmits an alarm output signal to the alarm device 20 (S45). When this alarm output signal is received, the alarm device 20 outputs a buzzer sound. Due to this buzzer sound, the driver has a high arousal level from a low arousal level. Then, the driver notices the oncoming vehicle and stops the vehicle by moving it to the left side as necessary. In this case, although the driver's arousal level is low despite the presence of an oncoming vehicle, the driver's awakening level is recovered by the buzzer sound, and the driver is alerted.

  When the process proceeds to the left one-side white line handling process, the ECU 30 acquires various pieces of information on the obstacle based on the millimeter wave detection signal from the millimeter wave sensor 11 (S50). Then, the ECU 30 determines whether there is an oncoming vehicle (S51).

  If it is determined in S51 that there is no oncoming vehicle, the ECU 30 proceeds to a lane departure determination process for the left one-side white line (however, if the white line at the right end of the road is recognized, the white line at the right end of the road) (S52). . In this case, since only the white line on the left side of the host vehicle is detected, a normal lane departure determination is performed on the left white line, and there is no oncoming vehicle on the right side. Is done.

  When it is determined in S51 that there is an oncoming vehicle, the ECU 30 acquires the driver's arousal level based on the driver monitor signal from the driver monitor 13 (S53). Then, the ECU 30 determines whether or not the driver's arousal level is high (S54).

  If it is determined in S54 that the driver's arousal level is high, the ECU 30 calculates the distance between the white line on the left side and the oncoming vehicle, and determines whether the distance is wider than the vehicle width of the host vehicle (S55).

  When it is determined in S55 that the distance is wider than the vehicle width, the ECU 30 sets a right virtual line (corresponding to the center line) based on the position of the oncoming vehicle (S56). Then, the ECU 30 proceeds to a lane departure determination process for the left white line and the right virtual line (S57). In this case, since only the white line on the left side of the host vehicle is detected and there is an oncoming vehicle, a normal lane departure determination is performed for the left white line, and the right side is based on a virtual line corresponding to the position of the oncoming vehicle. Lane departure judgment is performed.

  If it is determined in S55 that the distance is narrower than the vehicle width, the ECU 30 sets a right virtual line (corresponding to the center line) based on the position of the oncoming vehicle (S58). Further, the ECU 30 sets the left virtual line based on the position of the left obstacle (S59). In this case, only the white line on the left side of the host vehicle is detected, there is an oncoming vehicle, and the road width is narrow, so the lane departure determination is performed on the right side based on the virtual line according to the position of the oncoming vehicle, The lane departure determination is performed based on the virtual line corresponding to the position of the obstacle on the left side.

  When it is determined in S54 that the driver's arousal level is low, the ECU 30 transmits an alarm output signal to the alarm device 20 (S61). When this alarm output signal is received, the alarm device 20 outputs a buzzer sound. Due to this buzzer sound, the driver has a high arousal level from a low arousal level. Then, the driver notices the oncoming vehicle and stops the vehicle by moving it to the left side as necessary. In this case, the driver's awakening level is low despite the presence of an oncoming vehicle, but the driver's awakening level is restored by the buzzer sound, and the driver is alerted.

  When shifting to the lane departure determination process, the ECU 30 predicts the position of the host vehicle after a predetermined time based on the yaw angle signal from the yaw angle sensor 14 and the vehicle speed signal from the vehicle speed sensor 15. Then, in the ECU 30, based on the distance or curve radius of the left white line or virtual line from the host vehicle and the position of the host vehicle after a predetermined time, may the host vehicle depart from the left white line or virtual line? Determine whether or not. In addition, the ECU 30 may cause the own vehicle to deviate from the right white line or virtual line based on the distance or curve radius of the right white line or virtual line from the own vehicle and the position of the own vehicle after a predetermined time. Determine whether or not. When it is determined that there is a possibility of deviating, the ECU 30 sets an alarm output signal for outputting a buzzer sound by the alarm device 20, and transmits the alarm output signal to the alarm device 20. With this buzzer sound, the driver notices that he is about to deviate from the lane, and performs a steering operation so as not to deviate from the lane.

  According to this lane departure warning device 1, when only the white lines on the left and right sides of the own vehicle can be detected, the virtual line is estimated according to the state of the driver and the surroundings of the own vehicle. Can be estimated and an appropriate lane departure determination can be made. As a result, the alarm output unnecessary for the driver can be prevented and the necessary alarm output can be performed.

  In particular, the lane departure warning device 1 can estimate an appropriate virtual line according to the driver's state by estimating the virtual line according to the driver's arousal level. Further, in the lane departure warning device 1, when only the white line on the right side of the host vehicle can be detected, the virtual line is estimated according to the obstacle on the left side, so that an appropriate left side according to the obstacle on the left side is estimated. Virtual lines can be estimated. In addition, when the lane departure warning device 1 can detect only the white line on the left side or the white line at the right end of the road with respect to the host vehicle, the lane departure warning device 1 performs an appropriate estimation according to the situation of the oncoming vehicle by estimating the virtual line according to the oncoming vehicle. A right virtual line (corresponding to a center line) can be estimated.

  As mentioned above, although embodiment which concerns on this invention was described, this invention is implemented in various forms, without being limited to the said embodiment.

  For example, in this embodiment, the present invention is applied to a lane departure warning device that outputs a warning when there is a possibility of deviating from the lane, but steering control is performed to suppress deviation when there is a possibility of deviating from the lane. The present invention may be applied to other lane departure control devices.

  In the present embodiment, a lane composed of a pair of white lines is targeted as a dividing line, but the present invention can also be applied to other lines such as yellow lines other than white lines.

  In the present embodiment, the white line recognition camera that detects the image of the front of the vehicle is applied as means for detecting the white line (division line). However, the lane line may be detected by other methods.

  In the present embodiment, the driver monitor that detects from the captured image of the face is applied as a means for detecting the driver's arousal level. However, other methods such as a method that detects from the driver's biological information (heartbeat, blood pressure, etc.) can be used. The driver's arousal level may be detected.

  In this embodiment, a millimeter wave sensor is applied as a means for detecting an oncoming vehicle or a roadside obstacle. However, a method for detecting from an image obtained by imaging the front of the vehicle, information on surrounding vehicles by road-to-vehicle communication or vehicle-to-vehicle communication. An oncoming vehicle or a roadside obstacle may be detected by other methods such as a method of acquiring the vehicle.

  Also, in this embodiment, an example of a virtual line estimation method using the driver's arousal level, information on obstacles (information on oncoming vehicles, information on obstacles on the left side), etc. when only one white line can be detected is shown. However, the virtual line may be estimated by a method other than this estimation method.

It is a lineblock diagram of the lane departure warning device concerning this embodiment. It is an example of the road where the white line is drawn, (a) is a road which can detect the line of both right and left sides, (b) is a road which can detect only a center line (right one side white line), (c) Is a road that can detect only the right end line of the road (white line on the right side), and (d) is a road that can detect only the left end line of the road (white line on the left side). It is explanatory drawing of the determination method of a right one side white line. It is explanatory drawing of the setting method of the left virtual line when the driver arousal level is high when only the right one side white line (center line) is detected. It is explanatory drawing of the setting method of the left virtual line when the driver arousal level is low when only the right one side white line (center line) is detected. It is explanatory drawing of the setting method of the left virtual line when the oncoming vehicle does not exist when only the right one side white line (road right end line) is detected. It is explanatory drawing of the setting method of the virtual line of the left side and the right side when an oncoming vehicle exists when only the right one side white line (road right end line) is detected and the driver arousal level is high. It is explanatory drawing of the setting method of the virtual line of the right side when the oncoming vehicle exists when only the left one side white line is detected and the driver arousal level is high. It is explanatory drawing of the setting method of the virtual line of the right side and the left side when an oncoming vehicle exists when only the left one side white line is detected and the driver arousal level is high. It is a flowchart of the recognition white line determination process in ECU of FIG. It is a flowchart of the right side white line center line corresponding | compatible process in ECU of FIG. It is a flowchart of the right side white line road right end corresponding | compatible process in ECU of FIG. It is a flowchart of the left side white line response process in ECU of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Lane departure warning device, 10 ... White line recognition camera, 11 ... Millimeter wave sensor, 12 ... Navigation device, 13 ... Driver monitor, 14 ... Yaw angle sensor, 15 ... Vehicle speed sensor, 20 ... Alarm device, 30 ... ECU, 31 ... lane situation determination unit, 32 ... lane departure determination unit

Claims (3)

A lane departure suppression device that suppresses a vehicle from departing from a lane composed of a pair of lane markings,
Lane marking detection means for detecting a lane marking ahead of the vehicle;
Wakefulness detection means for detecting the wakefulness of the driver of the vehicle;
When the lane line detection means detects only one lane line of the pair of lane lines and the driver's arousal level detected by the awakening level detection means is high, it corresponds to the other side lane line. A lane departure suppression device comprising: virtual line estimation means for estimating a virtual line. An oncoming vehicle detection means for detecting an oncoming vehicle,
The imaginary line estimation means detects the opposite when the lane line detection means detects only the left lane line of the pair of lane lines and when the driver's arousal level detected by the awakening level detection means is high The lane departure restraint device according to claim 1, wherein when the oncoming vehicle is detected by the vehicle detection means, the virtual line is estimated based on the oncoming vehicle. An obstacle detection means for detecting an obstacle ahead of the vehicle;
The imaginary line estimation means detects the fault when the lane line detection means detects only the right lane line of the pair of lane lines and when the driver's arousal level detected by the arousal level detection means is high. The lane departure restraint device according to claim 1 or 2, wherein an imaginary line is estimated based on the obstacle when the obstacle detection means detects an obstacle on the left side in front of the vehicle.

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