JP6647361B2 - Vehicle driving support device - Google Patents

Description

  The present invention relates to a vehicle driving support device that performs automatic driving control including lane change control.

  2. Description of the Related Art In recent years, in a vehicle driving assistance device, a technology of a lane keeping (lane keeping) control technology for maintaining the own vehicle in a lane and a technology of performing an automatic driving control including a lane change control for changing the own vehicle to a next lane. Has been proposed.

  In such automatic driving control, as a technique for changing lanes from a current driving lane to an adjacent target lane, for example, Patent Document 1 discloses a vehicle speed of the own vehicle, a time required for changing lanes, and the like. In consideration of the above, the final point of the target trajectory (the point at which the lane change of the own vehicle ends) is calculated, and the travel route from the start point at which the lane change starts to the final point at the desired time is determined as the target route ( There is disclosed a technology of setting a target lane as a target travel route and assisting the vehicle to change lanes to a target lane according to the target route. Further, Patent Literature 1 discloses a technique in which a final point is recalculated in accordance with a change in a traveling state of a vehicle existing in a target lane, and a target traveling route is recalculated based on the recalculated final point. ing.

  By the way, when the lane change is performed as a part of the automatic driving control in the above-described driving support device, the lane change is realized without suppressing an abrupt yaw moment or the like and giving anxiety to a driver or other occupants. Therefore, it is common to set a limit (upper limit) on the steering speed by the automatic steering. In this type of driving support device, if it is determined that the lane change is difficult based on the steering speed, and it is determined that it is difficult to perform further automatic driving, the vehicle is evacuated to a road shoulder or the like. Execute the automatic evacuation mode.

JP 2014-61792 A

  However, for example, when the lane change should be performed even if the ride quality is slightly degraded, such as when it is necessary to change the lane to avoid an obstacle existing on the target travel route. In the above, giving up the lane change and executing the automatic evacuation mode may rather give the occupant a feeling of strangeness.

  The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a vehicle driving support device capable of performing an appropriate lane change without giving an occupant an uncomfortable feeling.

A driving support device for a vehicle according to one aspect of the present invention includes a driving environment recognizing unit that recognizes a driving environment of a host vehicle, and a target driving route setting unit that sets a target driving route on a host vehicle lane based on the driving environment. Traveling control means having an automatic driving mode for performing driving support control that does not require steering by the driver based on the target driving route; and a lane based on a condition set in advance during traveling in the automatic driving mode. When the necessity of the change is determined, based on the lane change route setting means for setting a lane change route for changing the lane of the own vehicle from the own vehicle travel lane to an adjacent lane, the lane change route, And a lane change control unit that performs lane change control with steering control. Degrees is configured to form a restriction in steering speed so as not to exceed the threshold value, based on the information of the traffic environment recognizing means, urgency lane change when obstacles within the front of the set distance of the target traveling path exists further comprising a lane change urgency judging means for judging the associated, when the threshold value of the maximum steering speed when it is determined that there is a high urgency by the lane change urgency judging means determines that there is not high urgency When the maximum steering speed is changed to a second threshold larger than the first threshold which is the threshold of the maximum steering speed and the maximum steering speed exceeds the second threshold when setting a route by the lane changing route setting means. it is intended to prohibit the execution of the lane change.

  ADVANTAGE OF THE INVENTION According to the driving support apparatus of the vehicle of this invention, an appropriate lane change can be performed, without giving an occupant a feeling of strangeness.

Schematic configuration diagram of the driving support device Flow chart showing a lane change execution determination routine in the automatic driving mode Flow chart showing a lane change permission determination subroutine Explanatory diagram illustrating a target traveling route set when changing lanes Explanatory diagram illustrating a target traveling route set when changing lanes Explanatory diagram exemplifying a time change of a steering wheel angle when changing lanes. Map showing thresholds for steering speed Transition diagram to each operation mode

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 is a schematic configuration diagram of a driving support device, FIG. 2 is a flowchart illustrating a lane change execution determination routine in an automatic driving mode, FIG. 3 is a flowchart illustrating a lane change permission determination subroutine, 4 and 5 are explanatory diagrams illustrating a target traveling route set when performing a lane change, FIG. 6 is an explanatory diagram illustrating a time change of a steering wheel angle at the time of a lane change, and FIG. 7 illustrates a threshold value of a steering speed. FIG. 8 is a transition diagram for each operation mode.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The driving support device 1 shown in FIG. 1 is mounted on a vehicle (own vehicle) such as an automobile. This driving support device 1 has a locator unit 11 and a camera unit 21 as a sensor unit (traveling environment recognition means) for recognizing the traveling environment outside the vehicle, and the two units 11 and 21 depend on each other. There are no completely independent multiplex systems. The driving support device 1 includes a driving control unit (hereinafter, referred to as “driving_ECU”) 22, an engine control unit (hereinafter, referred to as “E / G_ECU”) 23, and a power steering control unit (hereinafter, “PS_ECU”). ) 24 and a brake control unit (hereinafter referred to as “BK_ECU”) 25. Each of these control units 22 to 25, together with the locator unit 11 and the camera unit 21, communicates in a vehicle such as a CAN (Controller Area Network). It is connected via a line 10.

  The locator unit 11 is for estimating the position of the own vehicle on the road map, and has a locator calculating unit 12 for estimating the position of the own vehicle.

  On the input side of the locator calculation unit 12, a longitudinal acceleration sensor 13 for detecting the longitudinal acceleration of the own vehicle, a wheel speed sensor 14 for detecting the rotational speed of each of the front, rear, left and right wheels, and a gyro for detecting the angular velocity or the angular acceleration of the own vehicle Sensors necessary for estimating the position of the own vehicle (own vehicle position), such as a sensor 15 and a GNSS receiver 16 for receiving positioning signals transmitted from a plurality of positioning satellites, are connected.

  The locator calculation unit 12 is connected to a high-precision road map database 18 as storage means. The high-precision road map database 18 is a large-capacity storage medium such as an HDD, and stores high-precision road map information (dynamic map). The high-precision road map information has lane width data, lane center position coordinate data, lane advancing azimuth data, speed limit, and the like as lane data required for automatic driving. The lane data is stored at intervals of several meters in each lane on the road map.

  The locator calculating unit 12 includes a host vehicle position estimating unit 12a for estimating the host vehicle position, and a map information obtaining unit 12b.

  The map information acquisition unit 12b acquires route map information from the current location to the destination from the map information stored in the high-precision road map database 18 based on the destination set by the driver during automatic driving, for example. Further, the map information acquisition unit 12b transmits the acquired route map information (lane data on the route map) to the host vehicle position estimation unit 12a. The host vehicle position estimating unit 12a acquires the position coordinates of the host vehicle based on the positioning signal received by the GNSS receiver 16. In addition, the vehicle position estimating unit 12a performs map matching of the acquired position coordinates on the route map information, estimates the vehicle position on the road map and specifies the traveling lane, and is stored in the road map data. Get the road curvature at the center of the driving lane.

  Further, in an environment in which an effective positioning signal cannot be received from a positioning satellite due to a decrease in sensitivity of the GNSS receiver 16 such as traveling in a tunnel, the vehicle position estimating unit 12a detects the wheel detected by the wheel speed sensor 14. Switching to autonomous navigation, which estimates the position of the vehicle based on the vehicle speed obtained based on the speed, the angular velocity detected by the gyro sensor 15, and the longitudinal acceleration detected by the longitudinal acceleration sensor 13, estimates the vehicle position on the road map.

  The camera unit 21 is fixed to the upper center of the front part of the vehicle interior, and is a vehicle-mounted camera (stereo camera) including a main camera 21a and a sub camera 21b arranged symmetrically with respect to the center in the vehicle width direction. And an image processing unit (IPU) 21c and a traveling environment recognition unit 21d.

  The IPU 21c performs predetermined image processing on the forward running environment image information in front of the host vehicle captured by the two cameras 21a and 21b, and forward running environment image information (distance image) including distance information obtained from a shift amount of a corresponding target position. Information).

  The traveling environment recognizing unit 21d calculates a road curvature [1 / m] of a lane marking that separates the left and right of a traveling path (own vehicle traveling path) on which the own vehicle travels, based on the distance image information and the like received from the IPU 21c, and the left and right divisions. Find the width between lines (vehicle width). Various methods are known for obtaining the road curvature and the vehicle width. For example, the driving environment recognition unit 21d calculates the road curvature by performing binarization processing based on a luminance difference based on the front driving environment image information. The line is recognized, the curvature of the left and right lane markings is obtained for each predetermined section by a curve approximation formula or the like by the least squares method, and the vehicle width is calculated from the difference in the curvature between the two lane markings.

  Then, the traveling environment recognition unit 21d calculates the road curvature at the center of the lane based on the curvature and the lane width of the left and right section lines, and further calculates the lateral position deviation of the vehicle with respect to the center of the lane. , The own vehicle lateral position deviation Xdiff which is the distance from the vehicle to the center of the own vehicle in the vehicle width direction is calculated. In the present embodiment, the road curvature at the center of the lane is referred to as “camera curvature”.

  The traveling environment recognition unit 21d performs a predetermined pattern matching or the like on the distance image information, and recognizes a guardrail, a curb, and a three-dimensional object existing along the road. Here, in the recognition of the three-dimensional object by the traveling environment recognition unit 21d, for example, the type of the three-dimensional object, the distance to the three-dimensional object, the speed of the three-dimensional object, the relative speed between the three-dimensional object and the own vehicle, and the like are performed.

  Further, the camera unit 21 has side rear cameras 211 and 21r for imaging the rear left and right sides of the vehicle. When the side running environment image information of the own vehicle captured by the side rear cameras 211 and 21r is input to the IPU 21c, the IPU 21c performs predetermined image processing such as edge detection. Further, the traveling environment recognition unit 21d performs a predetermined pattern matching or the like on the edge information detected by the IPU 21c, and performs three-dimensional objects such as a parallel running vehicle existing on the side of the own vehicle and a following vehicle existing behind. Perform recognition.

  The running_ECU 22 reads the own vehicle position estimated by the own vehicle position estimating unit 12a of the locator calculating unit 12, the own vehicle lateral position deviation Xdiff obtained by the running environment recognizing unit 21d of the camera unit 21, the three-dimensional object information, and the like. In addition, on the input side of the traveling_ECU 22, an automatic operation switch 31 for the driver to turn on / off automatic driving (driving support control) as various switches and sensors, and the driver to hold (grip) the steering wheel. A steering wheel touch sensor 32 that is turned on when the vehicle is on, a steering torque sensor 33 that detects a steering torque as a driving operation amount by the driver, and a brake sensor 34 that detects a brake depression amount as a driving operation amount by the driver are connected. I have.

  In the travel_ECU 22, a manual driving mode, a first driving support mode, a second driving support mode, and an evacuation mode are set as driving modes.

  Here, the manual driving mode is a steering-required driving mode that requires the driver to maintain the steering. For example, a driving operation in which the vehicle travels according to driving operations such as a steering operation, an accelerator operation, and a brake operation performed by the driver. Mode.

  Similarly, the first driving support mode is a steering-required driving mode that requires the driver to maintain steering. That is, the first driving assistance mode mainly reflects the driving operation by the driver and, for example, through the control of the E / G_ECU 23, the PS_ECU 24, the BK_ECU 25, and the like, mainly performs the following control (Adaptive Cruise Control) and the lane keeping (Lane). This is a semi-automatic driving mode in which the host vehicle travels along the target traveling route by performing a combination of the Keep Assist control and the Lane Departure Prevention control.

  In the second driving support mode, the driver does not need to maintain steering, for example, through the control of the E / G_ECU 23, the PS_ECU 24, the BK_ECU 25, and the like, mainly the preceding vehicle following control (Adaptive Cruise Control) and the lane keeping. This is an automatic driving mode in which the vehicle travels along a target traveling route by performing a combination of (Lane Keep Assist) control and Lane Departure Prevention control.

  The evacuation mode is, for example, when traveling in the second driving assistance mode cannot be continued during the traveling in the second driving assistance mode and the driver cannot take over the driving operation (that is, in the manual driving mode or the second driving assistance mode). This is a mode for automatically stopping the own vehicle in a roadside zone or the like when the vehicle cannot transition to the first driving support mode).

  Each of the operation modes set as described above can be selectively switched in the traveling_EUC 22.

  At the time of this mode switching, the traveling_ECU 22 constantly compares the lateral position of the own vehicle position estimated by the own vehicle position estimating unit 12a from the center of the lane on the road map with the own vehicle lateral position obtained by the traveling environment recognizing unit 21d. I do. When the absolute value of the difference exceeds a preset threshold value, the reliability of one of the own vehicle position estimated by the own vehicle position estimating unit 12a and the own vehicle lateral position obtained by the traveling environment recognizing unit 21d. Is determined to have decreased, and it is determined that the system condition for performing the automatic operation is not satisfied. Then, the traveling_ECU 22 performs switching control of the operation mode to be executed based on the determination result regarding the success or failure of the above-described system conditions and input information from various switches and sensors.

  For example, as shown in FIG. 8, when the current driving mode is the manual driving mode and the system conditions are satisfied and the driver turns on the automatic driving switch 31 as shown in FIG. Is determined to make a transition to the driving support mode.

  In addition, when the current driving mode is the first driving support mode, the traveling_ECU 22 performs the steering wheel operation by the driver on the assumption that the system conditions are satisfied and that the automatic driving switch 31 is kept on. If the release state from the vehicle has continued for the set time or longer and the state where the driver has not performed the brake operation has continued for the set time or longer, it is determined that the state should shift to the second driving support mode. .

  In addition, when the current driving mode is the first driving support mode, the traveling_ECU 22 determines that the system condition is not satisfied, that the automatic driving switch 31 is turned off by the driver, that the driving_ECU 22 is lower than the set threshold value Pbth1 by the driver. When a brake operation is performed with a large brake depression amount or when the driver performs a steering operation with a steering torque larger than the set threshold value Psth1, it is determined that a transition to the manual operation mode is to be performed.

  In addition, when the current driving mode is the second driving support mode, the traveling_ECU 22 determines that the system condition is satisfied and that the automatic driving switch 31 is maintained in the ON state. When the brake operation with the brake depression amount larger than Pbth2 (however, the setting threshold value Pbth2> the setting threshold value Pbth1) is continuously performed for the setting time or more, or from the setting threshold value Psth2 (where the setting threshold value Psth2> Psth1) by the driver. If the steering with the large steering torque is continuously performed for the set time or more, it is determined that the state should be shifted to the first driving support mode.

  In addition, when the current driving mode is the second driving support mode and the driver turns off the automatic operation switch 31, the driving_ECU 22 sets the threshold value Pbth3 (where the setting threshold value Pbth3> the setting threshold value Pbth2) by the driver. When the brake operation with the larger brake depression amount is performed continuously for the set time or more, or the steering by the driver with the steering torque larger than the set threshold value Psth3 (however, the set threshold value Psth3> Psth2) continues for the set time or more. If it has been performed, it is determined that a transition to the manual operation mode is to be made.

  In addition, in the case where the current driving mode is the second driving support mode, the traveling_ECU 22 assumes that the automatic driving switch 31 is maintained in the on state, and when the system condition is not satisfied, It is determined that the mode should be shifted to the automatic evacuation mode.

  Here, in order to realize the above-described first and second driving support modes, the traveling_ECU 22 determines, for example, when the traveling environment recognizing unit 21d or the like recognizes the preceding vehicle ahead of the own vehicle traveling path, for example, A target traveling route is set based on the traveling locus of the preceding vehicle. When the traveling_ECU 22 does not recognize the preceding vehicle, the traveling_ECU 22 sets a target traveling route based on, for example, the own vehicle traveling route.

  In this case, for example, the traveling_ECU 22 needs to change the lane from the own vehicle traveling lane to the adjacent lane in order to avoid an obstacle such as a traffic section or a construction section or a falling object existing in front of the own vehicle traveling path. When such a case occurs, a lane change route for changing lanes is set as a transient target travel route.

  When setting such a lane changing route, the traveling_ECU 22 sets a target point, for example, at a point on an adjacent lane ahead of a predetermined distance according to the vehicle speed (for example, see FIG. 4). Then, the traveling_ECU 22 calculates, for example, a target movement amount and a target acceleration in the vehicle width direction for causing the host vehicle 100 to reach the target point over a set time for each predetermined time, and changes the lane based on these. Set the route for use.

  At that time, for example, as shown in FIG. 5, when the own vehicle 100 approaches the obstacle 102, the traveling_ECU 22 determines the obstacle or the like in order to avoid the contact between the own vehicle 100 and the obstacle 102. The lane change route is appropriately corrected according to the relative distance to the vehicle. That is, in the example illustrated in FIG. 5, the target point is corrected toward the host vehicle 100 from the target point illustrated in FIG. 4, and a lane changing route for causing the host vehicle 100 to reach the target point over a set time is set. I do. In this embodiment, the obstacle and the like include a preceding vehicle traveling at a relatively low speed.

  Then, the traveling_ECU 22 confirms that there is no parallel running vehicle or the like in the adjacent lane to which the lane is to be changed, and when there is no parallel running vehicle or the like, performs the lane change control including the operation control based on the lane changing route. Do.

  However, when performing the lane change control, the traveling_ECU 22 determines that the maximum steering speed, which is the maximum steering speed to be performed in the steering control for traveling the own vehicle along the lane change route, is equal to or greater than a preset threshold value. In some cases, the execution of the lane change control is prohibited.

  At this time, when the lane change involves urgency set in advance, the threshold is changed to a second threshold (threshold 2) higher than the first threshold (threshold 1) which is a reference value (see FIG. 7). ).

  Here, the threshold value 1 is, for example, an upper limit value of a steering speed for preventing a sudden yaw moment or the like and realizing a lane change without giving anxiety to a driver or an occupant. Are set to be smaller as the speed becomes faster. The threshold value 2 is, for example, an upper limit value of the steering speed allowed when performing emergency evacuation steering, and is set so as to be relatively larger than the threshold value 1 and to be smaller as the own vehicle speed V becomes faster. ing. Note that these thresholds 1 and 2 are set based on experiments, simulations, and the like.

  That is, when setting the route by the lane change control, the traveling_ECU 22 sets a limit on the steering speed so that the maximum steering speed of the steering to be performed in the steering control does not exceed the threshold value. In this case, when the traveling_ECU 22 determines that there is a high urgency to change lanes due to traffic congestion in front of the own vehicle traveling road or the presence of an obstacle such as a construction section or a falling object, the maximum steering is performed. The threshold value of the speed is changed to the threshold value 2 which is larger than the threshold value 1 which is the threshold value of the maximum steering speed when it is determined that the urgency is not high. Then, the traveling_ECU 22 suppresses or prohibits the execution of the lane change when the maximum steering speed exceeds the threshold 2 in setting the route by the lane change control.

  As described above, in the present embodiment, the traveling_ECU 22 implements each function as a target traveling route setting unit, a traveling control unit, a lane change route setting unit, a lane change control unit, and a lane change urgency determination unit. .

  The throttle actuator 26 is connected to the output side of the E / G_ECU 23. The throttle actuator 26 opens and closes a throttle valve of an electronic control throttle provided in a throttle body of the engine. The throttle actuator 26 opens and closes the throttle valve according to a drive signal from the E / G_ECU 23 to adjust an intake air flow rate. As a result, a desired engine output is generated.

  An electric power steering motor 27 is connected to the output side of the PS_ECU 24. The electric power steering motor 27 applies a steering torque to the steering mechanism by the rotational force of the motor. In automatic driving, the electric power steering motor 27 is controlled by a drive signal from the PS_ECU 24 to drive the vehicle in the current traveling lane. Is maintained, and lane change control for moving the vehicle to an adjacent lane (lane change control for overtaking control or the like) is executed.

  A brake actuator 28 is connected to an output side of the BK_ECU 25. The brake actuator 28 adjusts a brake hydraulic pressure supplied to a brake wheel cylinder provided on each wheel. When the brake actuator 28 is driven by a drive signal from the BK_ECU 25, the brake wheel cylinder , A braking force is generated, and the vehicle is forcibly decelerated.

  Next, the lane change execution determination control executed by the traveling_ECU 22 will be described with reference to the flowchart of the lane change execution determination routine shown in FIG. This routine is repeatedly executed at every set time during execution of the second driving support mode (automatic driving mode). When the routine starts, the traveling_ECU 22 firstly executes the locator unit 11 in step S101. And the traveling environment information of the own vehicle from the camera unit 21 and the like.

  In the following step S102, the traveling_ECU 22 determines whether or not the own vehicle needs to change lanes from the current own vehicle traveling lane to an adjacent lane. Here, the traveling_ECU 22 may determine whether a lane change is required to drive the own vehicle based on route map information from the current position to the destination, or an obstacle existing in front of the own vehicle traveling path. It is determined that it is necessary to change lanes when it is necessary to avoid a collision.

  If it is determined in step S102 that it is not necessary to change lanes, the traveling_ECU 22 exits the routine while maintaining the traveling control of the own vehicle according to the currently set target traveling route.

  On the other hand, when it is determined in step S102 that it is necessary to change lanes, the traveling_ECU 22 proceeds to step S103 and determines whether or not lane change from the current vehicle traveling lane should be permitted.

  This lane change permission determination is performed according to, for example, a flowchart of a lane change permission determination subroutine shown in FIG. 3. When the subroutine starts, the traveling_ECU 22 determines in step S201 that the locator unit 11 and the camera unit 21 Based on the traveling environment information, it is checked whether or not there is an adjacent lane that can be changed lane next to the own vehicle traveling lane.

  Then, in step S201, the traveling_ECU 22 proceeds to step S202 when determining that there is an adjacent lane that can change lanes, and proceeds to step S204 when determining that there is no adjacent lane that can change lanes.

  When the process proceeds from step S201 to step S202, the traveling_ECU 22 checks whether or not there is a parallel running vehicle that runs alongside the own vehicle on an adjacent lane in which the lane can be changed.

  If it is determined in step S202 that there is no parallel running vehicle, the traveling_ECU 22 proceeds to step S207.

  On the other hand, when it is determined in step S202 that there is a parallel running vehicle 101 (for example, see FIG. 4) that runs in parallel with the own vehicle 100, the traveling_ECU 22 proceeds to step S203 and moves the parallel running vehicle 101 ahead of the own vehicle 100. After the vehicle is instructed to decelerate to move relative to the vehicle 100, the process proceeds to step S204.

  When the process proceeds from step S201 or step S203 to step S204, the traveling_ECU 22 checks whether an obstacle exists within a set distance in front of the target traveling route of the own vehicle.

  Then, in step S204, when it is determined that there is no obstacle within a set distance ahead of the target traveling route of the host vehicle, the traveling_ECU 22 proceeds to step S216.

  On the other hand, if it is determined in step S204 that the obstacle 102 (see, for example, FIG. 4) exists within the set distance in front of the target travel route of the host vehicle 100, the traveling_ECU 22 proceeds to step S205, and proceeds to step S205. After issuing a deceleration instruction as needed, the process proceeds to step S206.

  When the process proceeds from step S205 to step S206, the traveling_ECU 22 determines in advance, for example, a collision prediction time TTC (Time To Collision) calculated by dividing the relative distance between the host vehicle 100 and the obstacle 102 ahead by the relative speed. It is checked whether it is equal to or less than the set threshold Tth.

  If it is determined in step S206 that the predicted collision time TTC is greater than the threshold value Tth, the traveling_ECU 22 proceeds to step S216.

  On the other hand, if it is determined in step S206 that the predicted collision time TTC is equal to or less than the threshold value Tth, the traveling_ECU 22 determines that if the host vehicle 100 continues traveling, there is a high possibility of colliding with the obstacle 102, and step S215 is performed. Proceed to.

  When the process proceeds from step S202 to step S207, the traveling_ECU 22 checks whether an obstacle exists within a set distance ahead of the current target traveling route (that is, the own vehicle traveling lane).

  When the traveling_ECU 22 determines in step S207 that there is no obstacle within the set distance ahead of the target traveling route, the process proceeds to step S208, and the obstacle exists within the set distance ahead of the target traveling route. If it is determined, the process proceeds to step S211.

  When the process proceeds from step S207 to step S208, the traveling_ECU 22 calculates a lane change route that is a transitional target traveling route for the vehicle to change lanes from the current vehicle traveling lane to the adjacent lane.

  Then, when the process proceeds to step S209, the traveling_ECU 22 does not have a high urgency to perform a lane change to avoid an obstacle or the like as a threshold for the maximum steering speed of the steering for the lane change to be performed according to the lane change route. Threshold 1 (reference value: see FIG. 7), which is the threshold when it is determined that the threshold value is determined. The threshold value 1 is, for example, a steering speed within a range in which a yaw moment or the like generated by steering does not affect the riding feeling, and within a range in which the own vehicle can safely change lanes. The steering speed is set.

  In the following step S210, the traveling_ECU 22 checks whether or not the maximum steering speed of the steering to be performed according to the lane changing route is less than the threshold value 1.

  Then, in step S210, the traveling_ECU 22 proceeds to step S217 when determining that the maximum steering speed is less than the threshold 1, and proceeds to step S216 when determining that the maximum steering speed is equal to or greater than the threshold 1.

  When the process proceeds from step S207 to step S211, the traveling_ECU 22 checks whether or not the minimum distance Lc required for changing lanes is less than the current distance Lb from the host vehicle to the obstacle. The minimum distance Lc is, for example, a distance set in advance based on a test vehicle simulation or the like so that the minimum distance Lc increases as the vehicle speed V increases.

  When it is determined in step S211 that the minimum distance Lc is less than the distance Lb to the obstacle, the traveling_ECU 22 proceeds to step S215, and determines that the minimum distance Lc is equal to or greater than the distance Lb to the obstacle. In this case, the process proceeds to step S212.

  When the process proceeds from step SS211 to step S212, the traveling_ECU 22 calculates a lane change path that is a transitional target traveling path for the vehicle to change lanes from the current vehicle traveling lane to the adjacent lane.

  Then, when proceeding to step S213, the traveling_ECU 22 sets a threshold value 2 (> threshold value 1: see FIG. 7) as a threshold value for the maximum steering speed of steering for lane change to be performed according to the lane changing route. That is, the traveling_ECU 22 sets a second threshold value that is a threshold value for the maximum steering speed when it is determined that the urgency for avoiding an obstacle ahead is high. For example, the threshold 2 is set to a steering speed within a range in which the own vehicle can safely change lanes, although the yaw moment generated by the steering may affect the riding feeling.

  In the following step S214, the traveling_ECU 22 checks whether or not the maximum steering speed of the steering to be performed according to the lane changing route is less than the threshold value 2.

  Then, in step S214, the traveling_ECU 22 proceeds to step S217 when determining that the maximum steering speed is less than the threshold 2, and proceeds to step S215 when determining that the maximum steering speed is equal to or more than the threshold 1.

  When the process proceeds from step S206, step S211, or step S214 to step S215, the traveling_ECU 22 determines that the driving mode is to be switched from the currently selected second driving support mode to the automatic evacuation mode. Exit the subroutine.

  Further, when the process proceeds from step S204, step S206, or step S210 to step S216, the traveling_ECU 22 determines that the lane change from the current vehicle traveling lane to the adjacent lane is prohibited, and then exits the subroutine. .

  When the process proceeds from step S210 or step S214 to step S217, the traveling_ECU 22 determines that the lane change from the current vehicle traveling lane to the adjacent lane is permitted, and then exits the subroutine.

  In the main routine of FIG. 2, when the process proceeds from step S103 to step S104, the traveling_ECU 22 checks whether the lane change permission determination has been made in the above-described lane change permission determination.

  Then, when it is determined in step S104 that the lane change is permitted, the traveling_ECU 22 proceeds to step S105, and follows the lane change route set in step S208 or step S212 from the current vehicle traveling lane. After executing the lane change control to the adjacent lane, the routine exits. Accordingly, for example, when there is an adjacent lane that can change lanes, it is determined that there is no obstacle or the like within a set distance ahead of the own vehicle traveling path, and the urgency of the lane change is not high. In the case where the maximum steering speed of the steering to be performed in the steering control for traveling the own vehicle along the calculated lane changing route is less than the threshold value 1, if the current vehicle traveling lane is adjacent, Lane change control to the lane is executed. Also, for example, when there is an adjacent lane that can change lanes, it is determined that the urgency of the lane change is high due to an obstacle or the like existing within a set distance ahead of the own vehicle traveling path. In the case where the maximum steering speed of the steering to be performed in the steering control for causing the own vehicle to travel along the calculated lane changing route is less than the threshold 2 that is larger than the threshold 1, the current own vehicle Lane change control from the traveling lane to the adjacent lane is executed.

  On the other hand, when it is determined in step S104 that the lane change is not permitted, the traveling_ECU 22 proceeds to step S106, and in the above-described lane change permission determination, a deceleration instruction for a parallel running vehicle or a forward obstacle is issued. Check if it is.

  If it is determined in step S106 that a deceleration instruction has been issued, the traveling_ECU 22 proceeds to step S107, executes deceleration control for a parallel running vehicle or a forward obstacle, and then exits the routine.

  On the other hand, if it is determined in step S106 that the deceleration instruction has not been issued, the traveling_ECU 22 proceeds to step S108, and switches the driving mode from the second driving support mode to the automatic evacuation mode in the above-described lane change permission determination. It is determined whether or not a determination has been made.

  If it is determined in step S108 that switching to the automatic evacuation mode has been performed, the traveling_ECU 22 proceeds to step S109, and switches the driving mode from the current second driving support mode to the automatic evacuation mode. After that, exit the routine. Accordingly, for example, when there is an adjacent lane that can change lanes, it is determined that there is no obstacle or the like within a set distance ahead of the own vehicle traveling path, and the urgency of the lane change is not high. In the case where the maximum steering speed of the steering to be performed in the steering control for traveling the own vehicle along the calculated lane changing route is equal to or greater than the threshold value 1, the current vehicle traveling lane is adjacent. The execution of the lane change control to the lane is suppressed or prohibited. Also, for example, when there is an adjacent lane that can change lanes, it is determined that the urgency of the lane change is high due to an obstacle or the like existing within a set distance ahead of the own vehicle traveling path. In the case where the maximum steering speed of the steering to be performed in the steering control for causing the own vehicle to travel along the calculated lane changing route is equal to or larger than the threshold 2 larger than the threshold 1, the current vehicle Execution of the lane change control from the traveling lane to the adjacent lane is suppressed or prohibited.

  When the steering torque or the brake depression amount by the driver that is equal to or greater than a predetermined value is detected, the traveling_ECU 22 can switch to the first driving support mode or the manual driving mode in order to reflect the driver's intention. .

  On the other hand, if it is determined in step S108 that the switching to the automatic evacuation mode has not been performed, the traveling_ECU 22 exits the routine as it is.

  According to such an embodiment, when the necessity of lane change is determined based on a preset condition during traveling in the second driving support mode, the vehicle is changed from the own vehicle traveling lane to the adjacent lane. When a lane change route is set to cause the vehicle to perform lane change control with steering control based on the lane change route, if the lane change involves urgency set in advance, the threshold is set to a threshold value 1 as a reference value. If the maximum steering speed of the steering to be performed based on the lane change route is equal to or higher than the set threshold, the threshold is set to a higher threshold 2 than the threshold, and the execution of the lane change control is suppressed or prohibited, thereby giving the occupant a sense of discomfort It is possible to make an appropriate lane change without any trouble.

  That is, for example, when the urgency to change lanes is low, such as when there is no obstacle or the like within a set distance ahead of the target traveling route, priority is given to the driver's riding feeling as a threshold for the maximum steering speed. By setting the threshold value 1, lane change in which the occurrence of a yaw moment or the like is suppressed can be realized.

  On the other hand, for example, when there is a high degree of urgency to change lanes, such as when a person with a disability exists within a set distance ahead of the target travel route, priority is given to changing lanes over riding feeling, By setting the threshold value 2 for the maximum steering speed to a threshold value higher than the threshold value 1, it is possible to expand an area in which lane change is permitted (ie, it is possible to suppress the shift to the automatic evacuation mode, etc.), and the occupant feels discomfort The lane change can be performed appropriately without giving the vehicle.

  Therefore, when urgency is required, it is possible to change lanes at the maximum steering speed less than the threshold value 1 because the parallel running vehicle 101 exists in the lane adjacent to the own vehicle traveling lane (for example, see FIG. 4). Even if the appropriate timing is missed, if the maximum steering speed is less than the threshold value 2, passing of the parallel running vehicle 101 (the parallel running vehicle after passing is indicated by reference numeral “101 ′” in FIG. 5). After waiting, the lane can be changed to the adjacent lane.

  FIG. 6A shows a time change of the steering wheel angle θ when it is assumed that the parallel running vehicle 101 does not exist and the lane change can be started at the timing shown in FIG. 4, for example. In this case, even if the steering speed (differential value (dθ / dt) of the steering wheel angle) is less than the threshold value 1, the lane change can be completed by the timing of crossing the obstacle 102.

  On the other hand, FIG. 6B shows a time change of the steering wheel angle θ when the lane change is started at the timing shown in FIG. 5, for example. In this case, as shown by the broken line in FIG. 6B, when the steering speed is limited by the threshold value 1, the lane change cannot be completed by the timing of crossing the obstacle 102, so that the lane change is abandoned. Inevitably, by changing the threshold value for the steering speed to the threshold value 2, the lane change can be completed by the timing (that is, the lane change can be executed without giving up).

  It should be noted that the present invention is not limited to the embodiments described above, and various modifications and changes are possible, and these are also within the technical scope of the present invention. For example, the case where the lane change involves urgency is not limited to the case where an obstacle exists in front of the target traveling route, and may include a case where a pedestrian jumps out.

DESCRIPTION OF SYMBOLS 1 ... Driving assistance apparatus 10 ... Car communication line 11 ... Locator unit (driving environment recognition means)
12 Locator calculation unit 12a Own vehicle position estimation unit 12b Map information acquisition unit 13 Front and rear acceleration sensor 14 Wheel speed sensor 15 Gyro sensor 16 GNSS receiver 18 High-precision road map database 21 Camera unit (traveling) Environmental recognition means)
21a… Main camera 21b… Sub camera 21d… Driving environment recognition units 211, 21r… Side rear camera 22… Driving_ECU (Target running route setting means, running control means, lane changing route setting means, lane change controlling means, Lane change urgency determination means)
23 ... E / G_ECU
23 ... PS_ECU
24… BK_ECU
26 ... throttle actuator 27 ... electric power steering motor 28 ... brake actuator 31 ... automatic operation switch 32 ... steering wheel touch sensor 33 ... steering torque sensor 34 ... brake sensor 100 ... own vehicle 101 ... parallel running vehicle 102 ... obstacle

Claims (2)

Driving environment recognition means for recognizing the driving environment of the vehicle;
Based on the traveling environment, target traveling route setting means for setting a target traveling route on the own vehicle traveling lane,
Traveling control means having an automatic driving mode for performing driving assistance control that does not require steering by the driver based on the target traveling path,
When the necessity of lane change is determined based on a preset condition during traveling in the automatic driving mode, a lane change route for changing the own vehicle lane from the own vehicle travel lane to an adjacent lane is set. Lane change route setting means,
A lane change control unit that performs lane change control with steering control based on the lane change path,
In setting a route by the lane changing route setting means, a configuration is provided in which a steering speed is limited so that a maximum steering speed does not exceed a threshold value,
Based on the information of the traveling environment recognition means, further comprising a lane change urgency determination means to determine that accompanied by an emergency of lane change when there is an obstacle within a set distance ahead of the target travel route,
The threshold value of the maximum steering speed when the urgency is determined to be high by the lane change urgency determination means is larger than the first threshold value that is the threshold value of the maximum steering speed when it is determined that the urgency is not high. While changing the threshold to 2.
A driving assistance system for a vehicle, wherein when the maximum steering speed exceeds the second threshold value when setting a route by the lane change route setting means, execution of a lane change is prohibited.   The vehicle driving support device according to claim 1, wherein the first threshold value and the second threshold value are variably set according to a vehicle speed of the host vehicle.

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