JP6986239B2 - Vehicle driving control device - Google Patents

Description

The present invention relates to a vehicle travel control device, and more particularly to a vehicle travel control device having an adaptive cruise control (ACC) function and a lane change function.

Adaptive cruise control (ACC), which controls constant-speed travel when there is no preceding vehicle and controls following the preceding vehicle when there is a preceding vehicle, has been put into practical use. For example, in Patent Document 1, "the actual acceleration when the own vehicle changes course to the adjacent travel lane during the follow-up travel control and then shifts to the constant speed travel control is determined after the preceding vehicle leaves the front of the own vehicle. The target vehicle speed is set so that it is larger than the actual acceleration when shifting to high-speed driving control. " In this case, the follow-up driving control in the original lane is removed by changing the lane, and the constant speed driving control in the changed lane is shifted, and the lane change depends on the driver's operation.

Japanese Unexamined Patent Publication No. 2009-149255

By the way, even on a highway where the type of vehicle and the legal speed are regulated, changing lanes when vehicles with different speeds coexist may cause contact with other vehicles and disruption of traffic flow. It could be. Therefore, it is being considered to automatically change lanes in conjunction with ACC, but in that case, change lanes in the shortest possible time and short distance within the vehicle behavior range that does not cause discomfort to the driver or passengers. Is desirable to complete.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicle travel control device capable of shortening the time required for changing lanes during follow-up travel control.

In order to solve the above problems, the present invention is a traveling control device for a vehicle provided with a surrounding recognition means for recognizing an own lane, an adjacent lane, and another vehicle traveling in each lane.
When the surrounding recognition means does not recognize the preceding other vehicle traveling in the own lane, constant speed running control is performed according to the target vehicle speed, and when the surrounding recognition means recognizes the preceding other vehicle traveling in the own lane, the first The ACC function that performs follow-up driving control to follow the preceding other vehicle according to the target inter-vehicle time of 1.
When the lane change function on / off switch is turned on by the driver, it is possible to change lanes by making a lane change judgment based on the presence or absence of other vehicles that are estimated to be close to the front and rear safe distance of the adjacent lane. When it is determined, the first target vehicle-to-vehicle time is changed to a shorter second target vehicle-to-vehicle time, and the vehicle-to-vehicle distance with the preceding other vehicle is shortened to a distance corresponding to the second target vehicle-to-vehicle time. to display the lane change ready, and car line change preparation function,
The automotive line changing function on / off switch is turned on, and, by the automobile line change preparation function, in a state in which the lane change ready is displayed, said adjacent lane in the same direction of turn signal operation by the driver When this is done, if the lane change can be continued, the vehicle driving control device is provided with a lane change function that automatically steers the lane change to the adjacent lane after blinking the blinker for a predetermined time. It is in.

According to the vehicle travel control device according to the present invention, the target vehicle-to-vehicle time (second target vehicle-to-vehicle time) in the follow-up travel control when the lane is changed is shorter than the target vehicle-to-vehicle time when the lane is not changed. By doing so, the time (inter-vehicle distance) between the vehicle and the preceding vehicle is shortened before the lane change is implemented, so the time and distance required for the lane change can be shortened, and the impact on the traffic flow is minimized. Can be limited.

Moreover, since it is not necessary to increase the acceleration or the target speed, the behavior of the vehicle does not change, and the driver and passengers do not feel uncomfortable. Further, even if the target speed of the constant speed running control is already set to the upper limit value, the time required for changing the lane and the required distance can be shortened, and the required speed is required more than when the target speed setting or the acceleration setting is increased. The effect of shortening the time and required distance is great.

It is a schematic diagram which shows the traveling control system of a vehicle. It is a schematic plan view which shows the outside world sensor group of a vehicle. It is a block diagram which shows the traveling control system of a vehicle. It is a flowchart which shows the traveling control which concerns on embodiment of this invention. It is a top view which shows the front-vehicle distance (a) and the rear-vehicle distance (b). It is the time chart of the comparative example (a) and each Example (b)-(c).

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In FIG. 1, in the vehicle 1 provided with the driving control system according to the present invention, in addition to general automobile components such as an engine and a vehicle body, the vehicle side performs recognition, judgment, and operation that have been conventionally performed by a driver. In addition, an outside world sensor 21 for detecting the vehicle surrounding environment, an inside world sensor 22 for detecting vehicle information, a controller / actuator group for speed control and steering control, an ACC controller 14 for constant speed driving / following driving control, and , The automatic driving controller 10 for carrying out a vehicle line change (route follow-up control) is provided.

Controller / actuator group for speed control and steering control, EPS (electric power steering) controller 31 for steering control, engine controller 32 for acceleration / deceleration control, ESP (registered trademark; stability control system) / ABS ( Anti-lock braking system) Includes controller 33.

The outside world sensor 21 is an automatic driving controller that uses the white line 5 on the road defining the own lane 51 and the adjacent lane 52, the existence of other vehicles, obstacles, people, etc. around the own vehicle and the relative distance as image data or point group data. It consists of a plurality of detection means for inputting to 10.

For example, as shown in FIG. 2, the vehicle 1 has a millimeter wave radar (211) and a camera (212) as front detection means 211 and 212, and LIDAR (laser image detection) as front side detection means 213 and rear side detection means 214. / Distance measurement), equipped with a camera (back camera) as a rear detection means 215, covering 360 degrees around the own vehicle, and the position and distance of vehicles and obstacles within the safe distance in the front, rear, left and right directions of the own vehicle, and the position of the white line. It is possible to detect it.

The internal world sensor 22 is composed of a plurality of detection means such as a vehicle speed sensor, a yaw rate sensor, and an acceleration sensor that measure physical quantities indicating the motion state of the vehicle, and as shown in FIG. 3, each measured value is an automatic driving controller 10. Is input to, and is calculated and processed together with the input from the outside world sensor 21.

The automatic driving controller 10 includes an environment / state estimation unit 11, a route generation unit 12, and a vehicle control unit 13. The environment / state estimation unit 11 acquires the absolute position of the own vehicle by using the positioning means 24 such as GPS, and obtains the white line position, the other vehicle position and the speed of the own lane 51 and the adjacent lane 52 detected by the outside world sensor 21. presume. The route generation unit 12 refers to the map information 23, and is detected by the own vehicle position estimated by the environment / state estimation unit 11, the white line position of the adjacent lane 52, the position and speed of another vehicle, and the internal sensor 22. Based on the motion state of the own vehicle, the target route 50 from the own vehicle position to the arrival target point in the lane change is generated. The vehicle control unit 13 calculates a target vehicle speed and a target steering angle based on the target route 50, transmits a vehicle speed command to the ACC controller 14, and transmits a steering angle command for following the route to the EPS controller 31.

The vehicle speed is also input to the EPS controller 31 and the ACC controller 14. Since the steering torque changes depending on the vehicle speed, the EPS controller 31 transmits a torque command to the steering mechanism 41 with reference to the steering angle-steering torque map for each vehicle speed. By controlling the engine 42, the brake 43, and the steering mechanism 41 by the engine controller 32, the ESP / ABS controller 33, and the EPS controller 31, the vertical and horizontal motion of the vehicle 1 is controlled.

(Overview of lane change function)
Next, an outline of the lane change function will be described assuming a lane change for overtaking a preceding vehicle on a highway having two or more lanes on each side with a median strip.

The automatic driving controller 10 has external information (lane, own vehicle position, other vehicle position and speed traveling in the own vehicle lane and adjacent lane) acquired by the external world sensor 21, and internal world acquired by the internal world sensor 22. Based on the information (vehicle speed, yaw rate, acceleration), the target route and target vehicle speed for changing lanes are generated. Then, it is determined whether or not a safe lane change is possible based on the distance to another vehicle and the relative speed based on the generated target route and target vehicle speed, and if it is determined that the lane can be changed, "the lane can be changed". Set a "flag".

Only when the lane change function is activated and the "lane changeable flag" is set and the driver has the intention to change lanes (winker operation, etc.), the automatic driving controller 10 automatically follows the target route. The lane change is executed by steering.

At this time, the automatic driving controller 10 is generated by the vehicle motion due to the vehicle position and the motion characteristics of the vehicle, that is, the front wheel steering angle δ generated when the steering torque T is applied to the steering mechanism 41 while traveling at the vehicle speed V. From the relationship between the yaw rate and the lateral acceleration, the speed, attitude, and lateral displacement of the vehicle after Δt seconds are estimated, a steering angle command is given to the EPS controller 31 so that the lateral displacement becomes yt after Δt seconds, and the speed Vt after Δt seconds. A speed command is given to the ACC controller 14 so as to be.

At the end of the lane change, the vehicle position is in the center of the adjacent lane 52 (xc ± α, yc ± β; α and β are margins of error), and the distance between the vehicle and the overtaking vehicle is the vehicle speed and the vehicle speed behind. It is judged by being larger than the rear safety distance determined by. The rear safety distance will be described later.

(Relationship between ACC, EPS, ESP / ABS, engine control and lane change function)
The lane change function is mainly carried out by combining vertical control (speed control) by the ACC controller 14 and horizontal control (steering control) by the EPS controller 31. As a matter of course, the ACC controller 14, the EPS controller 31, the engine controller 32, and the ESP / ABS controller 33 operate independently of the automatic steering, but the automatic driving controller 10 operates while the lane change function is operating. It can also be operated by inputting a command from.

Upon receiving the steering angle command from the automatic driving controller 10, the EPS controller 31 issues a torque command to the actuator (EPS motor) with reference to the vehicle speed-steering angle-steering torque map, and the front wheel targeted by the steering mechanism 41. Gives the rudder angle. Further, the ACC controller 14 that receives the speed command from the automatic driving controller 10 issues a deceleration command for brake control or an acceleration / deceleration command for engine control according to the vehicle speed acquired from the internal sensor 22.

Upon receiving the deceleration command from the ACC controller 14, the ESP / ABS controller 33 issues a hydraulic pressure command to the actuator and controls the braking force of the brake 43 to control the vehicle speed. Further, the engine controller 32 that receives the acceleration / deceleration command from the ACC controller 14 gives a torque command to the engine 42 by controlling the actuator output (throttle opening), and controls the vehicle speed by controlling the driving force. ..

The ACC function functions by combining hardware and software such as a millimeter wave radar 211 as an external sensor 21, an ACC controller 14, an engine controller 32, and an ESP / ABS controller 33.

That is, if there is no preceding vehicle, the vehicle runs at a constant speed at the target vehicle speed (cruise control set speed), and if it catches up with the preceding vehicle (when the preceding vehicle speed is less than or equal to the target vehicle speed), it is set according to the preceding vehicle speed. It follows the preceding vehicle while maintaining the inter-vehicle distance according to the time gap (inter-vehicle time = inter-vehicle distance / own vehicle speed).

When the preceding vehicle deviates from the detection range of the millimeter-wave radar 211 due to the departure of the preceding vehicle from the lane or the change of the lane of the own vehicle, the vehicle accelerates to the target vehicle speed at the set acceleration and runs at a constant speed while maintaining the target vehicle speed. The same applies when the direction of the vehicle is changed by automatic steering when the vehicle line is changed and the preceding vehicle is out of the detection range of the millimeter wave radar 211, and the vehicle accelerates to the target vehicle speed at the set acceleration.

By the way, when changing lanes in conjunction with the ACC function, in consideration of the influence on traffic flow, etc., in the shortest possible time and short distance within the vehicle behavior range that does not cause discomfort to the driver or passengers. Although it has already been mentioned that it should be completed, the target speed has already been set to the upper limit of the speed limit because the shortening of the travel time to the adjacent lane and the shortening of the time from overtaking the preceding vehicle to securing the rear safe distance are due to the increase in the target speed. If so, it cannot be implemented.

Therefore, in the present invention, the time required for changing lanes and the required distance are shortened by shortening the target inter-vehicle time for follow-up traveling without changing the target speed and acceleration settings. Specifically, multiple target vehicle-to-vehicle times for follow-up driving in ACC are prepared, including cases where the lane change function is used / not used, and the minimum target vehicle-to-vehicle time is applied when the lane change function is activated. To.

(Improved lane change flow Example 1)
Hereinafter, the lane change linked to the ACC function will be described with reference to FIG.

(1) Activation of ACC and preparation for activation of lane change function When the driver turns on the lane change function on / off switch (step 100), ACC operation determination is performed (step 101), and the vehicle is not activated. In the case of, ACC is activated and the fact that ACC is being activated is displayed in the instrument panel (step 104). If the ACC is already operating, the automatic driving controller 10, the ACC controller 14, the EPS controller 31, the engine controller 32, the ESP / ABS controller 33, the outside sensor 21, the inside sensor 22, which are necessary for executing the lane change. Then, a system check of the actuators is performed (step 102).

(2) Determining whether or not to activate the lane change function After the system check, the automatic driving controller 10 determines whether or not to activate the lane change function (step 103). If, for some reason, each controller, sensor, or actuator does not operate normally and becomes NG, the lane change function cannot be activated is displayed in the instrument panel, and the driver is notified by voice or the like. Notify that the line change function cannot be activated (step 105).

(3) Activation of the lane change function If the determination as to whether or not the activation is possible is OK, the lane change function is activated (step 110). While the lane change function is activated, the automatic driving controller 10 constantly performs (i) recognition of the surrounding environment and (ii) generation of the lane change route / vehicle speed target described in the next section.

(4) Surrounding environment recognition and generation of vehicle speed target for lane change route (i) Surrounding environment recognition The environment / state estimation unit 11 of the automatic driving controller 10 obtains itself from point group data and image data obtained from the outside world sensor 21. From the relative coordinates of the white line of the own lane to the vehicle, the relative coordinates / relative speed of the other vehicle, and the absolute coordinates of the own vehicle acquired by the GPS positioning means 24 with reference to the map information 23, the own vehicle position (x, (y coordinate) is estimated.
(Ii) Generation of lane change route / vehicle speed target In the route generation unit 12 of the automatic driving controller 10, the own vehicle position on the lane 51 estimated by the surrounding environment recognition process of the environment / state estimation unit 11 and the adjacent lane 52. Based on the white line position and the vehicle speed acquired by the internal sensor 22, the own vehicle position (xt, yt) and the target vehicle speed (Vt) assuming that the vehicle travels in the center of the adjacent lane after Δt seconds are calculated.

(5) Judgment of whether or not to change the lane Next, the calculated target route 50 / vehicle speed, the relative position / speed of the preceding other vehicle detected by the outside world sensor 21, the forward safety distance (X _FOC ) determined by the own vehicle speed, and _Whether or not to change lanes is determined from the rear safety distance (X ROC) determined by the speed of the own vehicle and the speed of other vehicles behind.

The front (or front side) safety distance can be obtained by the following equation 1. The concept of the distance between vehicles ahead is shown in FIG. 5 (a).
(Equation 1) X _FOC = X _BD = V _VUT ² / (2 ・ a _VUT )
However,
X _BD : Braking distance (m), V _VUT : Own vehicle speed (km / h),
a _VUT : Own vehicle deceleration (m / s ² )

The rear (or posterior) safety distance can be calculated by the following equation 2. The concept of the distance between vehicles behind is shown in Attachment 5 (b).
(Equation 2) X _ROC = X _RT + X _BB + X _BD + X _ST
here,
X _RT = (V _RO- V _VUT ) ・ RT
X _BB = {V _RO ^2- (V _RO- (a _RO / 2) / BB) ² } / a _RO- V _VUT / BB
X _BD = {(V _RO ^2- V _VUT ² ) / 2 ・ a _RO }-{(V _RD- V _VUT ) / a _RO } ・ V _VUT
X _ST = V _VUT・ ST
However,
X _RT : Rear vehicle reaction distance (m), X _BB : Braking start distance (m)
X _BD : Braking distance (m), X _ST : Safe inter-vehicle distance after braking (m),
V _VUT : own vehicle speed (km / h), V _RO : rear vehicle speed (km / h),
a _RO : Rear vehicle deceleration (m / s ² ),
RT: Reaction time (sec), BB: Braking start-up time (sec), ST: Safe inter-vehicle time (sec)

It is presumed that the vehicle will change lanes according to the target route 50 calculated as described above, overtake other vehicles in front, and approach within the front safe distance or the rear safe distance until the distance between the vehicles behind is equal to or greater than the safe distance behind. The presence or absence of a vehicle is determined (step 112), and if it is estimated that there is no vehicle, it is determined that the lane can be changed, and the "lane changeable flag" is set (step 113).

The arithmetic processing leading to the above determination is continued while the lane change function is activated, and the lane change flag is updated at any time according to the surrounding environment. On the other hand, if the judgment of whether or not to change lanes is NG, "Cannot change lanes" is displayed in the instrument panel, etc., and the driver is notified by voice or the like that the lanes cannot be changed ( Step 173).

(6) Change of ACC time gap When it is determined that the lane can be changed as described above, the driver is notified by voice or the like that the time gap of the ACC setting is changed (step 120), and the time gap becomes the first. The target vehicle-to-vehicle time (time gap 1) of 1 is changed to a second target vehicle-to-vehicle time (time gap 2) shorter than that (step 121).

At the same time as the time gap setting is changed, the changed time gap setting is sent from the vehicle control unit 13 of the automatic driving controller 10 to the ACC controller 14, and the vehicle is accelerated by the acceleration / deceleration command from the ACC controller 14, and the second The inter-vehicle distance with the preceding other vehicle is shortened to the inter-vehicle distance according to the target inter-vehicle time (time gap 2). The acceleration at this time may be the same as the initial setting value, but by changing to a larger setting value within the settable range, it is possible to shorten the time for reducing the inter-vehicle distance.

ACC setting items include cruise control set speed (target speed) for constant speed driving control, time gap (target vehicle-to-vehicle time τ = inter-vehicle distance / vehicle speed) for follow-up driving control, and initial values for each. Is set. The time gap can be set in multiple stages. For example, when the initial value is set to the first target vehicle-to-vehicle time (time gap 1), the second target vehicle-to-vehicle time (time gap 2) shorter than that is set. In addition to the case where the second target vehicle-to-vehicle time (time gap 2) is applied when it is determined in advance that the lane can be changed, the third target vehicle-to-vehicle time (time gap 2), which is shorter than the second target vehicle-to-vehicle time (time gap 2), is applied. The target vehicle-to-vehicle time (time gap 3) is specified in advance in combination with the second target vehicle-to-vehicle time (time gap 2), and the third target vehicle-to-vehicle time (time gap 3) is applied in step 133 described later. You can also do it. This configuration will be described in Example 2.

(7) Ready to change lane (READY) display When the flow from the activation of the lane change function to the change of the ACC time gap is completed as described above, it is assumed that the lane change is ready in the instrument panel. "Ready to change lane (READY)" is displayed (step 122). The driver confirms that the lane can be changed by displaying "Ready to change lane (READY)" during the follow-up driving. If the vehicle is traveling in the center lane of a road having three or more lanes on each side, it is possible to provide a "Ready to change lane (READY)" display corresponding to each of the left and right lanes to indicate which adjacent lane can be changed to the left or right.

(8) Driver's intention to change lane (winker operation)
With the display of "Ready to change lane (READY)" as described above, the driver operates the blinker to start the lane change (step 130). This winker operation is a trigger operation for starting a lane change, and at the same time, as described above, if a "lane change ready (READY)" display is provided corresponding to each of the left and right sides, either the left or right side is adjacent. It is an indication of the intention to change to a lane.

After the winker operation, the blinker does not blink immediately, and it is determined whether or not the blinker can blink (step 131). According to the blinker blinking determination, the blinker blinks when the driver is in the ready to change lane (READY) state and the driver operates the trigger (step 132). In this embodiment, step 133 is not taken into consideration, and the second target vehicle-to-vehicle time (time gap 2) is maintained until the start of automatic steering.

(9) Execution of lane change Automatic steering is started 3 seconds after the blinker starts blinking (step 140). At the same time, "Changing lane" is displayed in the instrument panel, and the driver is notified that the lane is being changed by voice or the like (step 141). Along with the start of automatic steering, the vehicle is accelerated by the acceleration / deceleration command from the ACC controller 14, and the vehicle runs at the ACC target vehicle speed (cruise control set speed) in the changed lane and overtakes the preceding other vehicle. The lane change possibility determination is always continued even during the lane change (step 142), and if it is determined that the lane change is possible, the lane change end determination is performed (step 143).

If it is determined that the lane change cannot be continued during the lane change (before the lane change), a notice of transfer of authority is issued to the driver (step 170), automatic steering is stopped, and the vehicle in the instrument panel is displayed. The line changing display is turned off (steps 171, 172). In this case, the lane changeable flag is lowered, and a display and notification that the lane cannot be changed are given (step 173). Further, when it is determined that the lane change cannot be continued at the initial stage of the lane change, instead of stopping the automatic steering, it is possible to return to the own lane by automatic steering and return to the follow-up driving control.

(10) Judgment of end of lane change The judgment of the end of lane change is made based on the position of the own vehicle (horizontal position) and the distance between vehicles behind (vertical position), and the position of the own vehicle is approximately in the center of the target lane. Moreover, when it is determined that the lane change is completed because the distance between the vehicle and the overtaken vehicle is larger than the rear safety distance, the "car lane changing" display in the instrument panel is turned off (step 144).

(11) Stopping the lane change function If the driver does not turn off the lane change function on / off switch even after the lane change is completed, the lane change function is in the activated state and the surrounding environment is recognized. The generation of the lane change route / vehicle speed target and the determination of whether or not the lane can be changed are continuously performed, but when the driver turns off the lane change function on / off switch (step 145), the vehicle The line change ready (READY) display is turned off (step 146), the surrounding environment recognition, the generation of the lane change route / vehicle speed target, and the lane change possibility determination are stopped (step 150). At the same time, a notification of change in the ACC time gap is issued (step 151), the ACC time gap is changed to the first target inter-vehicle time (time gap 1) (step 152), and the lane change function is stopped (step 160). ).

(Improved lane change flow Example 2)
In the first embodiment described above, when a second target vehicle-to-vehicle time (time gap 2) shorter than the first target vehicle-to-vehicle time (time gap 1) is specified in advance and it is determined that the lane can be changed, the second target The case where the inter-vehicle time (time gap 2) is applied has been described, but the second target inter-vehicle time (time gap 2) and the shorter third target inter-vehicle time (time gap 3) are specified in combination. It is also possible to further shorten the inter-vehicle time by applying the third target inter-vehicle time (time gap 3) while the blinker is blinking before the lane change is executed. Hereinafter, the lane change flow (Example 2) to which the third target inter-vehicle time (time gap 3) is applied will be described with reference to FIG.

Even when the target inter-vehicle time (time gaps 2 and 3) in the second and third stages are specified, (3) activation of the lane change function of the first embodiment (step 110) to (6) ACC time gap The flow from the change (step 121) to (7) lane change ready (READY) display (step 122) is common, and when it is determined that the lane can be changed, the first target vehicle-to-vehicle time (time gap) The distance from 1) is changed to the second target vehicle-to-vehicle time (time gap 2), which is shorter than that, and the vehicle-to-vehicle distance is according to the second target vehicle-to-vehicle time (time gap 2) by the lane change ready (READY) display (step 122). Although the distance is shortened, in the second embodiment, it is shorter than the second target inter-vehicle time (time gap 2) after (8) the driver's intention to change the lane (winker operation / step 130). It is further changed to the third target vehicle-to-vehicle time (time gap 3), and the vehicle-to-vehicle distance is further shortened according to the third target vehicle-to-vehicle time (time gap 3).

That is, when the driver operates the winker while "Ready to change lane (READY)" is displayed (step 130), the blinker blinking determination is performed (step 131), and the lane change is ready (READY). When there is a trigger operation by the driver, the blinker blinks (step 132), and at the same time, the ACC time gap changes from the second target vehicle-to-vehicle time (time gap 2) to the third target vehicle-to-vehicle time (time gap 3). The vehicle is accelerated by the acceleration / deceleration command from the ACC controller 14 while the blinker is blinking (step 133), and the distance between the vehicle and the preceding vehicle is increased to the distance according to the third target vehicle-to-vehicle time (time gap 3). It is controlled to be shortened.

Automatic steering is started 3 seconds after the blinker starts blinking (step 140). During this time, unless the third target vehicle-to-vehicle time (time gap 3) is reached, acceleration will continue, and in the changed lane, the vehicle will be accelerated until it reaches the ACC target vehicle speed (cruise control set speed), overtaking other vehicles in front. .. When the driver is notified that the lane is being changed at the same time as the start of automatic steering (step 141), the lane change possibility determination is continued even during the lane change (step 142), and it is determined that the lane can be changed. The lane change end determination is performed (step 143), and the flow thereafter is the same as in the first embodiment.

As described above, in the second embodiment, the acceleration is started while the blinker is blinking, so that the distance between the vehicle and the preceding vehicle is shortened before the automatic steering is started, and the vehicle overtakes the preceding vehicle to secure the rear safety distance. The required mileage is shortened, and the ACC target vehicle speed (cruise control set speed) can be reached promptly after the automatic steering is executed, which is advantageous in shortening the time required for changing the lane.

Also in the second embodiment, as in the first embodiment, if the driver does not turn off the lane change function on / off switch after the lane change is completed, the lane change function is in the activated state and the surroundings. Although environmental awareness, generation of lane change routes / vehicle speed targets, and lane change availability judgments are being continued, the ACC time gap has returned to the second target vehicle-to-vehicle time (time gap 2). The second target inter-vehicle time (time gap 2) is maintained until it is determined that the lane can be changed. On the other hand, when the driver turns off the lane change function, step 146 and subsequent steps are executed in the same manner as in the first embodiment.

(Effect of shortening the required time by improving the lane change)
In order to verify the effect of shortening the required time by changing the vehicle line of the traveling control according to the present invention, the ACC target vehicle speed (cruise control set speed) is 100 km / h (27.8 m / s) and the acceleration is 0.6 (m / m / s). s ² ) The vehicle whose initial time gap is set to 3.6 seconds catches up with the preceding vehicle traveling at 80 km / h (22.2 m / s) and changes lanes from the state of following the vehicle. Assuming that the lane is changed by the function, the comparative example in which the ACC time gap is maintained at the initial value (τ1) until the lane change, and the second and third target inter-vehicle time (τ2, τ3) shorter than that. For Examples 1 and 2 changed to, the simulation was performed by calculating the time (distance) required to reach the inter-vehicle distance that can secure the rear safe distance as the lane change required time (distance). The results are shown in the term chart of FIG. In the figure, the upper row shows the vehicle speed V (km / h), and the lower row shows the inter-vehicle distance x (m), which have a relationship of x = Vτ · 1000/3600.

In the comparative example of FIG. 6A, the vehicle catches up with the preceding vehicle and decelerates to 80 km / h to follow the vehicle, and the ACC time gap is maintained at the initial value τ1 = 3.6 seconds after the lane changeable flag. There is a trigger T (winker operation) by the driver in this state, and after 1.5 seconds of idle running, the blinker blinks W, after 3 seconds of blinking, the lane change starts S, and acceleration starts at the same time (acceleration 0.6 m). / ^s 2), the inter-vehicle distance to the preceding vehicle begins to be reduced from the initial value x1 = 79.9m, it is accelerated up to 100km / h after 9.3 seconds. After that, it took 15 seconds to finish the lane change E at the rear safe distance (23.3 m, displayed in the minus direction in the figure) overtaking the preceding vehicle. In this comparative example, the time required to change lanes starting from the trigger T was 28.8 seconds, and the required distance was 749.7 m.

FIG. 6B corresponds to the first embodiment, and the ACC time gap is changed to τ2 = 2.0 seconds immediately after the lane changeable flag, so that the driver triggers T (winker operation). At that point, the inter-vehicle distance has been shortened to x2 = 44.4m, and the lane change starts S after 1.5 seconds of idle driving and 3 seconds of blinker blinking W, and acceleration starts at the same time, and 100km after 9.3 seconds. Immediately after the speed was increased to / h, the vehicle overtook the preceding vehicle, and after 8.6 seconds, the lane change was completed E at the rear safe distance (23.3 m), and the time required to change the lane starting from the trigger T was 22. In 0.4 seconds, the required distance was shortened to 573.3m.

FIG. 6 (c) corresponds to the second embodiment, in which the ACC time gap is changed from the initial value τ1 = 3.6 seconds to τ2 = 2.0 seconds immediately after the lane changeable flag, and is triggered by the driver. The point that the inter-vehicle distance is shortened to x2 = 44.4 m at the time of T (winker operation) is the same as in Example 1, but after 1.5 seconds of idle running, the winker blinks W and the ACC time gap is τ3. The difference is that the speed is further changed to 1.0 second, at which point acceleration starts. After 3 seconds of blinker blinking W, the lane change starts S (at this point, the inter-vehicle distance x3 = 22.2 m corresponding to the time gap τ3 is not shortened), and 6.3 seconds later, the speed is increased to 100 km / h. After passing the preceding vehicle and 8.6 seconds later, the lane change was completed E at the rear safe distance (23.3m), the time required for the lane change starting from the trigger T was 19.2 seconds, and the required distance was 494. It was 3m.

As is clear from the above simulation results, in the first embodiment, the ACC time gap is changed to the second target inter-vehicle time (τ2) shorter than the initial value (τ1) when the lane change function is activated, and before the lane change. Since the inter-vehicle time is shortened, the target speed and acceleration settings are the same as in the comparative example, but the time required for changing lanes is shortened by 20% or more. Moreover, the fact that the target speed and acceleration settings are the same as in the comparative example means that the vehicle behavior when changing lanes is also the same as in the comparative example.

Further, in the second embodiment, the ACC time gap is changed to the second target inter-vehicle time (τ2) when the lane change function is activated, the inter-vehicle time is shortened, and the ACC time gap is set at the same time as the blinker blinks. The time required to change lanes has been reduced by 33% or more by further changing to the third target inter-vehicle time (τ3) and shortening the inter-vehicle time even while the blinker is blinking. Needless to say, also in the second embodiment, the setting of the target speed and the acceleration is the same as in the comparative example, and the vehicle behavior when changing lanes is also the same as in the comparative example.

Further, in the first and second embodiments, the target speed and the acceleration are set in the same manner as in the comparative example, but the acceleration setting at the time of activating the lane change function or accelerating before and after the lane change is larger than the ACC set acceleration. It is expected that the required time will be further shortened by adding the operation to be performed.

Although some embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications and modifications can be made based on the technical idea of the present invention. I will add.

1 Vehicle (own vehicle)
2 Vehicles (preceding other vehicles)
3 Vehicles (following other vehicles)
5 White line 10 Automatic driving controller 11 Environment / state estimation unit 12 Route generation unit 13 Vehicle control unit 14 ACC controller 21 External sensor 22 Internal sensor 31 EPS controller 32 Engine controller 33 ESP / ABS controller 41 Steering mechanism 42 Engine 43 Brake 50 Target Routes 51 and 52 lanes

Claims (4)

A vehicle travel control device equipped with a peripheral recognition means for recognizing one's own lane, an adjacent lane, and another vehicle traveling in each lane.
When the surrounding recognition means does not recognize the preceding other vehicle traveling in the own lane, constant speed running control is performed according to the target vehicle speed, and when the surrounding recognition means recognizes the preceding other vehicle traveling in the own lane, the first The ACC function that performs follow-up driving control to follow the preceding other vehicle according to the target inter-vehicle time of 1.
When the lane change function on / off switch is turned on by the driver, it is possible to change lanes by making a lane change judgment based on the presence or absence of other vehicles that are estimated to be close to the front and rear safe distance of the adjacent lane. When it is determined, the first target vehicle-to-vehicle time is changed to a shorter second target vehicle-to-vehicle time, and the vehicle-to-vehicle distance with the preceding other vehicle is shortened to a distance corresponding to the second target vehicle-to-vehicle time. to display the lane change ready, and car line change preparation function,
The automotive line changing function on / off switch is turned on, and, by the automobile line change preparation function, in a state in which the lane change ready is displayed, said adjacent lane in the same direction of turn signal operation by the driver When this is done, if the lane change can be continued, the vehicle driving control device is provided with a lane change function that automatically steers the lane change to the adjacent lane after blinking the blinker for a predetermined time. .. The vehicle according to claim 1, wherein when the lane change function on / off switch is turned on, the operation of the ACC function is determined, and when the ACC function is not activated, the ACC function is activated. Travel control device. The second target vehicle-to-vehicle time is changed to a shorter third target vehicle-to-vehicle time while the blinker is blinking for the predetermined time, and the vehicle-to-vehicle distance corresponding to the third target vehicle-to-vehicle time is preceded before the lane change is executed. The vehicle travel control device according to claim 1 or 2, wherein the lane change function is configured so as to further shorten the distance between the vehicle and another vehicle. When the lane change function on / off switch is turned on by the driver, the lane change function and the lane change preparation function are in the activated state unless the driver subsequently turns the lane change function on / off, and the lane can be changed. If it is determined, the second being of the applied target inter-vehicle time, the inter-vehicle distance to the preceding vehicle until the vehicle distance according to the target inter-vehicle time of the second is shortened, is configured so that is maintained, wherein Item 6. The vehicle traveling control device according to any one of Items 1 to 3.

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