JP2009208505A - Lane keep assist system, lane keep assist method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lane keep assist system and a lane keep assist method controlling a LKAS to stop or continue according to a travel scene when an obstacle is detected during the operation of the LKAS. <P>SOLUTION: The lane keep assist system 100 supporting steering so as to run a traveling lane 13 divided by lane division lines 61, 62 has an obstacle detection means 22 acquiring the positional information of the obstacle 12, a horizontal positioning means 51 determining a horizontal position of the obstacle 12 in the width direction of the traveling lane 13 based on the positional information of the obstacle and the positional information of a vehicle 11 in the traveling lane 13, an effectiveness determination means 52 determining the effectiveness of a lane keep assist control based on the horizontal position, and an assist control determination means 54 determining the lane keep assist control to stop or continue by making a comparison between the effectiveness and a threshold value. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lane keeping support device that supports steering so as to run while maintaining a travel lane divided by a lane marking line, and more particularly, to a lane keeping support device that can stop lane keeping support control when an obstacle is detected. .

  There is known a lane keeping assist device (hereinafter referred to as LKAS (Lane Keeping Assist System)) that assists a driver to steer a vehicle along a traveling lane. In addition to LKAS, the vehicle is equipped with a pre-crash safety system (hereinafter referred to as PCS) that executes control such as stopping the vehicle when there is a risk of abnormal approach by detecting obstacles in front of the vehicle. May be.

  When both the PCS and the LKAS are operating, the LKAS is often controlled to stop when the PCS detects a front obstacle and operates. This is to prevent the additional torque generated by the LKAS from becoming a minute resistance when the driver steers to avoid the obstacle. Here, since the additional torque of automatic steering by LKAS is actually very small, it is considered that the additional torque of LKAS does not become an obstacle when the driver avoids an obstacle.

  However, the decrease in the additional torque due to LKAS may make the driver feel uncomfortable. FIG. 11 shows an example where the LKAS is stopped while the PCS and the LKAS are activated. PCS detects obstacles ahead, but the road shape ahead is curved to the right, so obstacles can be avoided naturally by traveling along the lane. In the situation shown in FIG. 11, when the LKAS is stopped, the additional torque in the avoidance direction expected by the driver becomes zero, so the driver must give a larger steering torque than before. For this reason, it is not preferable to stop the LKAS when the traveling lane and the obstacle avoidance direction coincide with each other as shown in FIG.

With regard to this point, a technique has been proposed that reduces unnecessary alarms even when an obstacle is detected during control by LKAS (see, for example, Patent Document 1). Patent Document 1 describes an automatic traveling vehicle that determines a future traveling locus from a magnetic nail embedded in a road and detects obstacle detection by an obstacle sensor within a traveling lane.
JP 2000-305625 A

  However, in order to realize the automatic traveling vehicle described in Patent Document 1, position detection using magnetic nails and road shape information based on a map database are necessary, and thus there is a problem that it is difficult to realize in reality.

  In view of the above problems, the present invention provides a lane keeping assist device and a lane keeping assist method for controlling whether to stop or continue an LKAS according to a traveling scene when an obstacle is detected during LKAS operation. Objective.

  In view of the above problems, in a lane keeping assist device for assisting steering so as to run while maintaining a travel lane divided by lane markings, obstacle detection means for acquiring obstacle position information, and obstacle position information And lateral position determination means for determining the lateral position of the obstacle in the width direction of the traveling lane based on the position information of the vehicle in the traveling lane, and the effectiveness determination for determining the effectiveness of the lane keeping support control based on the lateral position. And means for determining whether to stop or continue the lane keeping support control by comparing the effectiveness and the threshold.

  According to the present invention, since the lane keeping support control is determined when the effectiveness of the lane keeping support control determined based on the lateral position of the obstacle is high, the driver feels uncomfortable even when the driver steers to avoid the obstacle. Can be prevented.

  In one embodiment of the present invention, the effectiveness is determined when an obstacle is detected at a lateral position that has less influence on the traveling of the vehicle than when an obstacle is detected at the lateral position that has a large influence on the traveling of the vehicle. Is largely determined.

  According to the present invention, the obstacle in the lateral position that has little influence on the driving of the vehicle increases the effectiveness, so that the lane keeping support control can be continued when the driver does not need to perform avoidance steering, and a sense of incongruity You can prevent them from being held.

  Specifically, the effectiveness map is associated with the width direction of the travel lane, and the effectiveness is associated with a greater efficiency in the vicinity of the lane marking than in the vicinity of the center in the width direction of the travel lane. ing.

  When an obstacle is detected during the LKAS operation, it is possible to provide a lane keeping assist device and a lane keeping assist method that control whether to stop or continue the LKAS according to the traveling scene.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a diagram illustrating a driving scene in which the lane keeping assist device 100 according to the present embodiment turns off the additional torque of the lane keeping assist device 100 according to the position of the obstacle 12. An obstacle 12 is present in front of the vehicle 11, and a pre-crash safety system (hereinafter referred to as PCS) detects this and operates (for example, automatically brakes). When the obstacle 12 exists at the position A or the position C, the direction in which the vehicle 11 avoids the obstacle 12 is the same as the direction in which the lane keeping assist device 100 steers so as to travel along the travel lane 13. On the other hand, when the obstacle 12 exists at the position B, the obstacle 12 exists in the direction in which the lane keeping assist device 100 is steered so as to travel along the travel lane 13. When the lane keeping assist device 100 of the present embodiment detects the obstacle 12 at the position A and the position C, the lane keeping assist device 100 does not turn off the additional torque (continues the lane keeping assist control) and detects the obstacle 12 at the position B. Turns off the additional torque (stops lane keeping support control). Thereby, since the assist by the additional torque is obtained in the direction of avoiding the obstacle 12, it is possible to prevent the driver from feeling uncomfortable. Actually, the torque of the automatic steering by LKAS is very small. However, when the obstacle 12 is in the vicinity of the center of the lane, the lane keeping support control is stopped, so the additional torque is a minute resistance for avoiding the obstacle 12. It will never be.

  FIG. 2 shows an example of a schematic configuration diagram of the lane keeping assist device 100. The lane keeping assist device 100 includes various ECUs such as a lane keeping assist ECU (Electronic Control Unit) 24 that recognizes a lane marking (hereinafter simply referred to as a white line) and a distance control ECU 25 that controls the inter-vehicle distance. ) And the like are connected by an in-vehicle LAN. The illustrated configuration is an example, and the ECUs are not necessarily configured separately, and the arrangement of the ECUs is not limited.

[Lane maintenance support control]
First, white line recognition and lane keeping support control will be described. Lane maintenance support control is called LKAS (Lane Keeping Assist System) that steers the steering wheel with the motor 34 to maintain the driving lane, and LDW (Lane Departure Warning) that warns the driver when there is a risk of deviating from the white line. In this embodiment, LKAS will be mainly described.

  A switch 23 is connected to the lane keeping assist ECU 24. When the switch 23 is turned on, the LKAS is operated under a predetermined condition. The lane keeping assist ECU 24 is connected to, for example, a front camera 21 that is mounted on an indoor mirror and that captures a region extending in a predetermined angular range horizontally downward toward the front of the vehicle. The front camera 21 outputs image data of a predetermined luminance gradation (for example, 256 gradations) using a photoelectric conversion element such as a CMOS (Complementary Metal Oxide Semiconductor) or a CCD (Charge Coupled Device).

  The lane keeping assist ECU 24 performs image processing on the image data sequentially captured by the front camera 21 at a predetermined cycle time, and detects left and right white lines that delimit the travel lane 13 drawn on the road that is projected.

  FIG. 3 shows an example of image data and white line information captured by the front camera 21. The left and right white lines photographed in the image data have a substantially square shape in which the left white line 62 and the right white line 61 intersect the vehicle 11 at the top. The lane keeping assist ECU 24 determines white line information from a white line in a predetermined range (for example, 10 to 30 m) ahead of the vehicle in the image data.

  Since one white line has edges that are high-frequency components at both ends, if the luminance value of the image data ahead of the vehicle is differentiated in the horizontal direction, peaks are obtained at both ends of the white line, and an edge line that connects them in the front-rear direction can be estimated. . A plurality of sets of white line candidate lines are extracted from a plurality of estimated edge lines, and a threshold value, a white line width threshold value, and a linear shape are determined from brightness and contrast with the road surface from the plurality of white line candidate lines. A single white line that is recognized as a white line is selected by applying a matching method or the like based on features such as.

  By extracting a plurality of edges of the determined white line and performing Hough transform, a straight line expression of the left and right white lines is obtained, and each straight line is expressed as a model expression. Since the height of the front camera 21 from the road surface and the angle formed by the optical axis with respect to the road surface are known, the correspondence between each pixel of the image data and the position on the road surface is also known. Since the model formula includes information such as the vanishing point of the left and right white lines, the road curvature, the yaw angle, the width, and the offset amount in the coefficient, the road curvature, the yaw angle, the width W, the offset amount D, the target travel will be calculated from now on. White line information such as a line (for example, center line) O is obtained.

  The lane keeping assist ECU 24 requests the electric power steering ECU 27 for an additional torque in the opposite direction according to the offset amount D of the vehicle 11 in the white line information, and assists the steering wheel 31 to travel near the center of the travel lane 13. To do. This additional torque is, for example, a value proportional to the offset amount D with reference to the target travel line.

  The steering wheel 31 is provided with a torque sensor 32 and a gear reduction mechanism 33 that detect the steering torque coaxially with the shaft, and a motor 34 is connected to the gear reduction mechanism 33 in series. The electric power steering ECU 27 drives the motor 34 based on the additional torque requested from the lane keeping assist ECU 24. When the motor 34 rotates, the rack gear meshed with the pinion gear in the gear box 35 swings the rack bar to the left and right, and the left and right tie rods are driven to steer the steered wheels FL and FR.

  The electric power steering ECU 27 detects the steering torque and the steering direction when the driver steers the steering wheel 31, and performs the steering assist control by driving the motor 34 in a direction that assists the steering torque of the driver.

  In the case of LDW, the lane keeping assist ECU 24 warns when the vehicle 11 may deviate from the white line after a predetermined time (for example, 1 second) from the vehicle speed detected by the vehicle speed sensor 29 and the yaw angle of the vehicle 11. To prompt the driver to return to the driving lane.

  Further, in this embodiment, an additional torque is applied to the steering to support the maintenance of the traveling lane. However, the braking force of each wheel is individually controlled, for example, using the difference between the braking forces on the inner wheel side and the outer wheel side. The traveling direction of the vehicle 11 may be controlled. The braking force of each wheel is controlled by the brake ECU 28.

[PCS]
Next, PCS will be described. The millimeter wave radar device 22 is installed in, for example, the front grill of the vehicle 11 and transmits the millimeter wave toward the front of the vehicle, receives the millimeter wave reflected by the obstacle 12, and continues until the transmitted millimeter wave is received. The relative speed is detected based on the difference between the relative distance from the vehicle ahead and the frequency of the transmitted wave and the received wave. Specifically, a transmission wave modulated by a triangular wave is output from an antenna, and a reflected wave reflected by the obstacle 12 is received by the antenna and mixed to obtain a beat signal. Since the waveform of the beat signal changes due to interference generated according to the distance to the obstacle 12 and the relative speed, the relative distance and the relative speed are calculated from the waveform. The obstacle 12 is a three-dimensional object such as a forward vehicle, a guardrail, or a sidewalk feature.

  The distance control ECU 25 sends the direction and distance (hereinafter referred to as position information) of the obstacle 12 to the lane keeping assist ECU 24. The lane keeping support ECU 24 calculates the position of the obstacle 12 in the width direction (hereinafter referred to as a lateral position in the lane) from the position information, determines the effectiveness of the lane keeping support by a method described later, and continues the lane keeping support control. It is determined whether or not.

  The distance control ECU 25 controls the millimeter wave radar device 22 to irradiate a laser pulse while scanning a predetermined angle range in the left-right direction centering on the vehicle length direction, for example. Since the reflected wave is received if the obstacle 12 exists in the irradiation direction, the direction and relative distance of the obstacle 12 existing in front of the vehicle 11 can be detected.

  A seat belt ECU 26 that controls the seat belt hoisting device 40 is connected to the distance control ECU 25. The seat belt hoisting device 40 includes a webbing 43, a rotating unit 47 that winds the webbing 43, a worm gear 46 that meshes with the rotating unit 47, a motor 44 that rotationally drives the worm gear 46 via the speed reduction mechanism 45, and the rotation of the rotating unit 47. And a clutch part 41 that transmits the torque to the shaft 42.

  Until the seat belt ECU 26 controls, the clutch portion 41 does not lock the shaft 42. Therefore, even if the rotating portion 47 rotates, the webbing 43 is not wound up and can be mounted by, for example, the operation of the occupant. . When the clutch portion 41 locks the shaft 42, the rotating portion 47 and the shaft 42 rotate together, so that the webbing 43 is wound up by the rotation of the motor 44.

  Also, the brake ECU 28 controls the brake actuator, and independently controls the wheel cylinder pressure of each wheel without depending on the driver's operation of the brake pedal. The distance control ECU 25 calculates TTC (Time To Collation) from the relative distance and relative speed with the obstacle 12, and when the possibility of collision with the obstacle 12 increases, the seat control ECU 25 requests the seat belt ECU 26 to wind up the seat belt. . This alerts the occupant to the presence of the obstacle 12, so the occupant is expected to steer the steering wheel 31 to avoid it. When the vehicle 11 further approaches the obstacle 12 and the possibility of a collision increases, the distance control ECU 25 requests the brake ECU 28 to brake the vehicle 11 and urgently brakes the vehicle 11. Note that an alarm sound may be sounded or a warning may be displayed on the meter panel when the possibility of a collision with the obstacle 12 becomes high.

[Effectiveness]
FIG. 4A shows an example of a functional block diagram of the lane keeping assist device 100. The lane keeping assist ECU 24 is a computer having a CPU, a RAM, a ROM, a nonvolatile memory, an input / output interface, and an inter-ECU communication unit, and the CPU executes a program or hardware such as an ASIC (Application Specific Integrated Circuit). A horizontal position determination unit 51, an effectiveness extraction unit 52, and a threshold change unit 55, which are realized by hardware. Further, an effectiveness map 53 is stored in the nonvolatile memory. The threshold changing unit 55 will be described in the second embodiment.

  The lateral position determination unit 51 determines the lateral position of the obstacle 12 in the lane in the width direction of the travel lane 13. FIG. 4B is a diagram for explaining the determination of the lateral position in the lane. From the white line information, both the offset and the yaw angle with respect to the center line of the vehicle 11 are clear. Further, since the distance and direction from the position information of the obstacle 12 to the obstacle 12 with respect to the vehicle 11 is clear, the direction of the obstacle 12 is corrected based on the yaw angle of the vehicle 11, and further, the offset amount is shifted left and right. By correcting, the lateral position of the obstacle 12 in the lane is obtained.

  The effectiveness extraction unit 52 refers to the effectiveness map 53 based on the lateral position in the lane and determines whether or not the lane keeping support control is effective. FIG. 5A shows an example of the effectiveness map 53. In the effectiveness map 53, the horizontal axis indicates the lateral position in the lane, and the vertical axis indicates the effectiveness. The effectiveness has a value from 0 (minimum) to 1 (maximum), but since this is a relative value, it may be from 0 (minimum) to 100 (maximum). The effectiveness indicates the degree of effectiveness of the lane keeping support control. The lateral position in the lane takes a positive value in the right direction and a negative value in the left direction with respect to the center of the lane 13 as a reference (zero). The effectiveness shows a symmetrical value on the left and right, zero in the vicinity of the center line, and gradually increases with distance from the center to the left and right.

  That is, the effectiveness of the obstacle 12 at a position having a large influence on the traveling of the vehicle 11 is smaller than that of the obstacle 12 at a position having a small influence on the traveling of the vehicle 11. In this way, by determining the effectiveness, the lane keeping assist control is stopped when the driver needs to steer and avoid the obstacle 12, and the additional torque is reduced to the driver's small resistance of steering. Can be prevented.

  The effectiveness becomes zero when the lateral position of the obstacle 12 in the lane is near the center of the lane 13, so that if the vehicle 11 is driving near the center line, the lane is maintained. This means that the necessity of applying torque to the steering wheel 31 is small. The assistance control determination unit 54 compares the validity read from the validity map 53 based on the lateral position in the lane with a threshold (for example, 0.5), and if the validity is equal to or greater than the threshold, the lane maintenance assistance is performed. Decide to continue control. Accordingly, the lane keeping assist control is stopped when the obstacle 12 is detected near the center line, and the lane keeping assist control is performed when the obstacle 12 is detected at a lateral position in the lane farther from the center line. Can continue.

[Operation Procedure of Lane Keeping Support Device 100]
Based on the above configuration, a procedure in which the lane keeping assist device 100 stops or continues the lane keeping assist control will be described based on the flowchart of FIG. The flowchart in FIG. 6 starts when the ignition is turned on, for example.

  First, the distance control ECU 25 detects the obstacle 12 (S10). Whether or not the obstacle 12 has been detected in step S10 is a case where the obstacle 12 and the vehicle 11 have come close to the extent that the PCS is activated and, for example, the seat belt is wound up. That is, if the PCS does not need to operate, it is not necessary to determine whether to stop the lane keeping assist control.

  Next, the lateral position determination unit 51 determines the lateral position in the lane based on the position information of the obstacle 12, and the effectiveness extraction unit 52 refers to the effectiveness map 53 to determine the effectiveness (S20). The support control determination unit 54 compares the effectiveness with a threshold (for example, 0.5) (S30), and if the effectiveness is equal to or greater than the threshold (Yes in S30), the lane keeping support control is continued (S40). If the effectiveness is not greater than or equal to the threshold (No in S30), the lane keeping support control is stopped (S50).

  According to this embodiment, when the lane keeping assist control is effective for avoiding the obstacle 12, the lane keeping assist control can be continued, so that the additional torque in the avoiding direction does not suddenly become zero, and the driver Can prevent the user from feeling uncomfortable.

[Modification]
4 (a) and 4 (b), the lateral position in the lane and the validity map 53 are used for determining the effectiveness. You may calculate based on. FIG. 7 is a schematic explanatory diagram for calculating the effectiveness based on the lane shape, the position of the obstacle 12, and the motion state. The lane shape as shown in FIG. 7 is registered in the road map information. The road map information is a table-like database in which links and nodes are associated with each other, and a road network can be formed by connecting nodes associated with coordinates. Since the position and traveling direction of the vehicle 11 are known by position detection means such as GPS (Global Pointing System), the lane keeping assist device 100 can grasp the lane shape in front of the vehicle. The road map information may be stored in the on-board map DB, or may be downloaded from the server via a communication network.

  Further, since the lane keeping assist device 100 acquires the position information of the obstacle 12, the movement state (speed / acceleration) of the obstacle 12 is detected from the temporal change of the plurality of position information. In FIG. 7, the speed of the obstacle 12 is indicated by V [m / s].

  Accordingly, the lane keeping assist device 100 determines the future position of the obstacle 12 from the lane shape, the current position of the obstacle 12 and the motion state, for example, whether or not the obstacle 12 is lane-changed to the travel lane 13. Can be predicted. For example, the position of the obstacle 12 when the vehicle 11 is closest to the obstacle 12 (when traveling a relative distance) is predicted, and the effectiveness extraction unit 52 determines from the effectiveness map 53 based on the predicted position. If the effectiveness is extracted, the effectiveness for the future position of the obstacle 12 can be determined.

  The subsequent steps are the same as those in FIGS. 4 to 6, and the in-lane maintenance support control is continued if the effectiveness is equal to or greater than the threshold value. According to this modification, even if the obstacle 12 moves, the post-movement position with respect to the lane shape can be predicted, so that the effectiveness can be determined more accurately.

  In the first embodiment, the threshold value for determining whether or not to continue the lane keeping support is fixed. However, in the present embodiment, the threshold value is made variable so that the lane keeping assist device can more appropriately reduce the driver's uncomfortable feeling. 100 will be described.

  When the obstacle 12 is detected and the PCS is activated, when the driver is steering the steering wheel 31, it is considered that the driver does not feel uncomfortable when there is no lane keeping assist control. For example, even when there is an obstacle 12 near the white line or outside the travel lane, it is considered that the driver may steer larger to avoid the obstacle 12. In such a case, if an additional torque is applied so as to maintain the traveling in the traveling lane, the driving direction becomes opposite to the driver's steering direction, which gives the driver a feeling of strangeness.

  Therefore, the lane keeping assist device 100 according to the present embodiment continues the lane keeping assist when the obstacle 12 is detected and the PCS is activated and the driver is steering the steering wheel 31. By increasing the threshold for determining whether or not, the lane keeping assist control is easily stopped. That is, the lane keeping assist device 100 according to the present embodiment stops the lane keeping assist control by changing the threshold value for determining whether or not to continue the lane keeping assist control according to the presence or absence of the driver's steering. Whether to continue or continue can be determined flexibly according to the steering of the driver.

  Note that since the driver's steering is detected by the torque sensor 32, the lane keeping assist device 100 detects that the driver is steering when the torque sensor 32 detects a steering torque of a predetermined value or more. The detected value of the steering angle sensor may be used for the driver's steering. When the torque sensor 32 detects a steering torque greater than or equal to a predetermined value, the threshold changing unit 55 described with reference to FIG.

  FIG. 5A shows the relationship between the effectiveness map 53 and the threshold when the driver does not detect steering, and FIG. 5B shows the effectiveness map 53 and the threshold when the driver detects steering. Each relationship is shown. FIG. 5A shows that the lane keeping assist control is continued to the right or left from the position where the threshold is fixed at 0.5 and the effectiveness is 0.5 or more. On the other hand, in FIG. 5B, as a result of increasing the threshold (for example, 0.8), the lateral position in the lane where the lane keeping support control is continued is moved outward (the lane keeping support control is stopped). The lateral position in the lane is expanded). Therefore, when the driver is steering the steering wheel 31, it becomes easy to stop the lane keeping support, and it is possible to easily reduce the driver from feeling uncomfortable.

  Note that the threshold in FIG. 5B when steering by the driver is detected is an example, and the threshold may be larger than 1 when steering is detected. In this case, the lane keeping assist control can always be stopped when steering by the driver is detected. Further, the threshold value may be increased according to the steering torque. In this case, the threshold value can be increased as the driver steers more strongly in order to avoid the obstacle 12. Therefore, when the driver steers rapidly, the additional torque is set to zero to prevent a minute resistance due to the additional torque from occurring. it can.

  For example, the lane keeping assist device 100 allows the driver to perform lane change steering or obstacle avoidance steering. Therefore, the lane keeping assist device 100 has a torque sensor 32 of a predetermined value or more (for example, 2.5 [Nm] or more). When the torque is detected, the lane keeping assist control is often set to stop.

  FIG. 8A shows an example of a functional block diagram of the lane keeping assist device 100. When the PCS is activated, the support control determination unit 54 of the present embodiment compares the steering torque detected by the torque sensor 32 with a predetermined value, and determines whether to stop or continue the lane keeping support control.

  FIG. 9 is an example of a flowchart illustrating a procedure for stopping the lane keeping assist control in accordance with the presence or absence of the driver's steering.

  First, the distance control ECU 25 detects the obstacle 12 (S10). Whether or not the obstacle 12 has been detected in step S10 is a case where the obstacle 12 and the vehicle 11 have come close to the extent that the PCS is activated and, for example, the seat belt is wound up. That is, if the PCS does not need to operate, it is not necessary to determine whether to stop the lane keeping assist control.

  Next, the lane keeping assist device 100 determines whether or not steering by the driver is detected (S120). In the steering detection, the torque sensor 32 may detect the steering torque, or the steering angle sensor may detect the steering angle.

  Then, the lane keeping assist device 100 determines whether or not the steering torque is equal to or greater than a predetermined value (S130). If the steering torque is equal to or greater than the predetermined value (Yes in S130), the lane keeping support control is stopped (S140), and if not greater than the predetermined value (No in S130), the lane keeping assist control is continued (S150).

  Therefore, when the driver steers to avoid the obstacle 12, the lane keeping assist control is stopped, so that it is possible to prevent the additional torque from becoming a minute resistance of the steering of the driver, and the driver removes the obstacle 12. When the steering is not performed so as to avoid, the lane keeping assist control is continued and the additional torque is added in the avoiding direction, so that it is possible to prevent the driver from feeling uncomfortable.

[Modification of Example 3]
In the third embodiment, the predetermined value for determining whether or not steering by the driver is detected is a fixed value. However, when the PCS is activated, the predetermined value is lowered to easily stop the lane keeping assist control. can do. Therefore, when the PCS is activated, it is possible to easily prevent the additional torque by the lane keeping assist control from becoming a minute resistance of the driver's steering.

  FIG. 8B shows an example of a functional block diagram of the lane keeping assist device 100. The predetermined value changing unit 56 decreases the predetermined value when the PCS is activated. Then, the assistance control determination unit 54 of the present modification compares the steering torque detected by the torque sensor 32 with a predetermined value set to be small, and determines whether to stop or continue the lane keeping assistance control.

  It should be noted that the lower the predetermined value for determining whether or not steering by the driver is detected, the lower the degree of steering interference by the driver. However, if the value is too low, the lane keeping assist control during normal driving (PCS is not activated) is frequently stopped, so the value is generally set to a relatively high value. Therefore, when the PCS is activated, lowering the predetermined value can reduce the additional torque to zero even if relatively small steering is detected by the driver. Therefore, when the obstacle 12 is detected, the degree of interference is greatly reduced. be able to.

  FIG. 10 is an example of a flowchart illustrating a procedure for stopping the lane keeping assist control by reducing a predetermined value for determining whether the driver is steering or not when the PCS is activated. In FIG. 10, the same steps as those in FIG. 9 are denoted by the same reference numerals, and the description thereof is omitted.

  In FIG. 10, when the distance control ECU 25 detects the obstacle 12 (S10), the predetermined value changing unit 56 sets a predetermined value for determining whether the driver is steering or not. Thereafter, the procedure is the same as in FIG. 9, but the predetermined value is reduced, so that the driver's steering torque easily exceeds the predetermined value, and the lane keeping assist control can be easily stopped.

  Therefore, when the PCS is activated, it can be easily prevented that the additional torque by the lane keeping assist control becomes a minute resistance of the driver's steering, and when the driver does not steer to avoid the obstacle 12, the lane keeping assist is performed. Since the control is continued and the additional torque is applied in the avoidance direction, it is possible to prevent the driver from feeling uncomfortable.

It is a figure explaining the driving | running | working scene in which a lane keeping assistance apparatus turns off applied torque according to the position of an obstruction. It is an example of the schematic block diagram of a lane keeping assistance apparatus. It is a figure which shows an example of the image data and white line information which a front camera image | photographs. It is an example of the functional block diagram of a lane maintenance assistance apparatus (Example 1, 2). It is a figure which shows an example of an effectiveness map. It is a flowchart figure which shows the procedure in which a lane keeping assistance apparatus stops or continues lane keeping assistance control. It is explanatory drawing of the outline which calculates effectiveness by a lane shape, the position of an obstruction, and a movement state. (Example 3) which is an example of the functional block diagram of a lane keeping assistance apparatus. It is an example of the flowchart figure which shows the procedure which stops lane maintenance assistance control according to the presence or absence of a driver | operator's steering. It is an example of the flowchart figure which shows the procedure which makes the predetermined value which determines the presence or absence of a driver | operator's steering small and stops lane maintenance assistance control when PCS act | operates. It is a figure which shows an example in case LKAS stops in the state which PCS and LKAS act | operated.

Explanation of symbols

11 Vehicle 12 Obstacle 13 Travel Lane 24 Lane Keeping Support ECU
25 Distance control ECU
51 lateral position determination unit 52 effectiveness extraction unit 53 effectiveness map 54 support control determination unit 55 threshold change unit 100 lane keeping support device

Claims (7)

In a lane keeping assist device that assists steering so as to travel on a traveling lane divided by a lane marking line,
Obstacle information detecting means for acquiring obstacle position information;
Lateral position determining means for determining the lateral position of the obstacle in the width direction of the traveling lane based on the positional information of the obstacle and the positional information of the vehicle in the traveling lane;
Effectiveness determining means for determining the effectiveness of the lane keeping support control based on the lateral position;
A support control determination means for comparing the effectiveness with a threshold and determining whether to stop or continue the lane keeping support control;
A lane keeping assist device characterized by comprising: The effectiveness is determined to be greater when the obstacle is detected in a lateral position that has less influence on the traveling of the vehicle than when the obstacle is detected in a lateral position that has a great influence on the traveling of the vehicle.
The lane keeping assist device according to claim 1. An effectiveness map that determines the effectiveness in association with the lateral position of the travel lane in the width direction,
An effectiveness map that is associated with the effectiveness greater in the vicinity of the lane marking than in the vicinity of the center in the width direction of the travel lane,
The lane keeping assist device according to claim 1. Steering detection means for detecting steering by the driver;
A threshold changing means for changing the threshold when steering is detected by the steering detecting means;
The lane keeping assist device according to any one of claims 1 to 3. The threshold value changing means changes the threshold value to a larger value than before the change when the steering is detected by the steering detection means.
The lane keeping assist device according to claim 4, wherein Lane keeping support control means for assisting steering so as to run while maintaining the traveling lane divided by the lane dividing line;
Steering amount detection means for detecting the steering amount by the driver;
In the lane keeping assist device, comprising: a support control determining means for determining stop of the lane keeping assist control by the steering assist control when the steering amount is a predetermined value or more
Obstacle information detecting means for acquiring obstacle position information;
A predetermined value changing means for reducing the predetermined value when the obstacle is detected;
A lane keeping assist device characterized by comprising: In a lane keeping support method for assisting steering so as to run while maintaining a traveling lane divided by a lane marking,
An obstacle information detecting means for acquiring obstacle position information;
Lateral position determining means, based on the position information of the obstacle and the position information of the vehicle in the travel lane, determining the lateral position of the obstacle in the width direction of the travel lane;
An effectiveness determining means determining the effectiveness of the lane keeping support control based on the lateral position;
A lane keeping support method, comprising: a step of comparing the effectiveness with a threshold value to determine whether to stop or continue the lane keeping support control.

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