JP7047627B2 - Travel control device and travel control method - Google Patents

Description

The present invention relates to a vehicle travel control device and a travel control method.

Patent Document 1 discloses a vehicle tracking control device. This vehicle follow-up control device identifies the vehicle in front, which is the vehicle in front of the vehicle, and determines whether or not there is a direction instruction in the direction indicator of the vehicle in front in the follow-up control for the vehicle in front. judge. In addition, if it is determined that there is a direction instruction, if there is a situation that hinders the change of lane of the preceding vehicle, for example, if there is a vehicle in the adjacent lane that runs in parallel with the preceding vehicle, or if there is a vehicle in the adjacent lane running in parallel with the preceding vehicle, the own vehicle runs in parallel. If there is a vehicle with a high speed, the follow-up control is continued, while if there is no situation that hinders the lane change of the preceding vehicle, the follow-up control is canceled.

Japanese Unexamined Patent Publication No. 2013-173383

In the method of Patent Document 1, when the vehicle follow-up control device determines that the follow-up control of the preceding vehicle is canceled from the direction instruction information of the direction indicator of the preceding vehicle, the vehicle itself is present despite the existence of the preceding vehicle. When the vehicle suddenly approaches the vehicle in front and, for example, the departure of the vehicle in front from the driving lane of the vehicle is delayed, the driver may feel uncomfortable or the vehicle may be suddenly braked. In addition, if the vehicle follow-up control device does not release the follow-up control of the preceding vehicle, for example, when the preceding vehicle decelerates when changing lanes, the own vehicle also decelerates, which may cause unnecessary acceleration / deceleration. rice field.

According to one embodiment of the present invention, a vehicle travel control device is provided. This travel control device includes a front vehicle identification unit (40) that identifies a front vehicle (200) that is a preceding vehicle traveling in front of the own vehicle (100), and a front vehicle behavior detection unit that detects the behavior of the front vehicle. According to the follow-up control unit (21) that executes the follow-up control that follows the front vehicle specified by the front vehicle identification unit with a predetermined inter-vehicle distance, and the detected behavior of the front vehicle. The vehicle includes a departure determination unit (20) for determining whether or not the vehicle in front is likely to leave the lane in which the vehicle is traveling. When the withdrawal determination unit determines that the preceding vehicle is in the withdrawal state, the follow-up control unit sets the inter-vehicle distance in the follow-up control when the front vehicle is not in the withdrawal state. The follow-up control is performed by changing to a second inter-vehicle distance shorter than the inter-vehicle distance of the vehicle, and the follow-up control unit determines the second inter-vehicle distance with respect to the first inter-vehicle distance according to the speed of the own vehicle. Determine the ratio . According to this embodiment, when the departure determination unit determines that the vehicle in front is in the withdrawal state, the follow-up control unit sets the inter-vehicle distance in the follow-up control to the second inter-vehicle distance shorter than the first inter-vehicle distance. Since it is changed, the own vehicle does not come close to the vehicle in front as compared with the case where the follow-up control is not performed. Further, when the vehicle in front decelerates and leaves the lane, the distance between the vehicle and the vehicle in front can be maintained at the second distance shorter than the distance between the first vehicle even if the deceleration is slower than the deceleration of the vehicle in front. That is, it is not necessary to decelerate the own vehicle according to the preceding vehicle, and the own vehicle can be decelerated more slowly than the preceding vehicle. Further, since the speed of the own vehicle when the front vehicle leaves is faster than that in the case of decelerating according to the preceding vehicle, the acceleration for returning the own vehicle to the original speed may be small. That is, fluctuations in acceleration and speed of the own vehicle can be suppressed to a small level. That is, it is possible to prevent unnecessary deceleration / acceleration. As a result, the driver feeling can be improved and the fuel efficiency can be improved.

It is explanatory drawing which shows the schematic structure of the travel control device. It is explanatory drawing which shows the structure of each detection part and the traveling control device. It is explanatory drawing which shows the detection range of the preceding vehicle and other vehicles. It is a flowchart of the follow-up control executed by the travel control device. It is explanatory drawing which shows the correction process of the target inter-vehicle distance executed by the travel control device. It is explanatory drawing which compares the comparative example and the front vehicle recognition state and the control state of this embodiment. This is an example of a situation in which the correction process of the target inter-vehicle distance is executed. This is another example of a situation in which the target vehicle-to-vehicle distance correction process is executed. This is another example of a situation in which the target vehicle-to-vehicle distance correction process is executed. It is explanatory drawing which shows the acceleration, the speed, and the target inter-vehicle distance of the own vehicle when the preceding vehicle decelerates and leaves. It is explanatory drawing which shows the acceleration, the speed, and the target inter-vehicle distance of the own vehicle when the preceding vehicle leaves without decelerating.

The schematic configuration of the own vehicle 10 will be described with reference to FIG. In the following description, the own vehicle 10 capable of automatic driving will be described as an example, but the contents described can also be applied to the driving support of the own vehicle 10. The own vehicle 10 includes a travel control device 100, a drive system 130, a steering system 140, a braking system 160, rear wheels 170 and 171 and front wheels 172 and 173, various detection units 180, and a communication unit 190. It is equipped with a route guidance device 195.

The travel control device 100 acquires various information necessary for driving the own vehicle 10 by using various detection units 180, a communication unit 190, and a route guidance device 195, and controls the operation of the own vehicle 10. The own vehicle 10 may be an automatically driven vehicle or a non-automatically driven vehicle. When the own vehicle 10 is not automatically driven, the travel control device 100 assists the driver in driving.

The drive system 130 includes a drive ECU 132, a drive device 134, a differential gear 136, and a drive shaft 138. The drive ECU 132 controls the drive device 134 in response to an instruction from the travel control device 100. The drive device 134 is, for example, an electric motor or an internal combustion engine. The drive device 134 may include both an electric motor and an internal combustion engine. The output of the drive device 134 is transmitted to the rear wheels 170 and 171 via the differential gear 136 and the drive shaft 138. When an electric motor is used as the drive device 134, the drive device 134 may also be used as a generator that regenerates the kinetic energy of the own vehicle 10 into electric power. In the present embodiment, the drive device 134 drives the rear wheels 170 and 171. However, the front wheels 172 and 173 may be driven, and both the rear wheels 170 and 171 and the front wheels 172 and 173 may be driven.

The steering system 140 includes a steering ECU 142, a steering wheel 144, an encoder 146, a steering device 148, a steering motor 150, and a steering gear 152. In the automatic driving, the steering ECU receives an instruction from the traveling control device 100 and controls the steering device 148. An encoder 146 is connected to the steering device 148, and the encoder 146 detects the rotation angle of the steering wheel 144 when the driver operates the steering wheel 144. In the case of automatic driving, the steering device 148 drives the steering motor 150 according to an instruction from the steering ECU, and in the case of non-automatic driving, the steering motor 150 is driven according to the rotation angle of the steering wheel 144, and the driver. Assists the operation of. The steering motor 150 controls the steering angles (angles with respect to the straight direction) of the front wheels 172 and 173 via the steering gear 152. The steering gear 152 is composed of, for example, a rack and a pinion. The steering gears 152 may impart turning radius to the steering angles of the right and left front wheels 172 and 173, if necessary.

The braking system 160 includes a braking ECU 162, a hydraulic pump 164, a brake hose 166, a brake caliper 168, and a brake disc 169. The braking ECU 162 drives and controls the hydraulic pump 164 in response to an instruction from the travel control device 100. When the driver steps on the brake pedal (not shown) and receives a braking instruction from the braking ECU 162, the hydraulic pump 164 sends hydraulic pressure to the brake caliper 168 via the brake hose 166. When the hydraulic pressure is sent, the brake caliper 168 brakes the own vehicle 10 by pressing a brake pad (not shown) against the brake disc 169. In the present embodiment, a disc brake that presses the brake pad against the brake disc 169 has been described as an example, but a drum brake may also be used. When the drive device 134 includes an electric motor, the travel control device 100 may brake the drive ECU 130 by instructing the drive ECU 130 to regenerate from the electric motor.

The various detection units 180 acquire information necessary for traveling of the own vehicle 10. The various detection units 180 will be described later. The communication unit 190 uses vehicle-to-vehicle communication such as V2V (Vehicle-to-Vehicle) and road-vehicle communication such as V2I (Vehicle-to-roadside-Infrastructure) to allow another vehicle or own vehicle 10 to travel. Get information about the road. The route guidance device 195 has map information, for example, receives a signal from a satellite of GNSS (Global Navigation Satellite System), identifies the position of the own vehicle 10, and determines the route to the destination of the own vehicle 10. invite. The route guidance device 195 receives signals from GNSS satellites, for example, radio waves from radio beacons installed on roads, radio waves from mobile base stations, and radio waves from Wi-Fi base stations, and uses these. The position of the own vehicle 10 may be specified. The map information may include the number of lanes of the road, the width of the lane, the direction of traffic in the lane, and the regulation information of the road.

The various detection units 180 and the travel control device 100 will be described with reference to FIG. The own vehicle 10 includes a camera 182, a radar 184, a vehicle speed detection unit 186, and a steering direction detection unit 188 as various detection units 180.

The camera 182 photographs the front of the own vehicle 10. In the present embodiment, a monocular camera or a twin-lens camera can be used as the camera 182. The camera 182 may be a monochrome camera or a color camera. Further, the camera 182 may be a camera including a wide-angle lens or a zoom lens. Further, a plurality of cameras 182 may cover a wide angle. Further, a rotating device for changing the shooting direction of the camera 182 may be provided.

The radar 184 radiates an electromagnetic wave or a laser in front of the own vehicle 10, receives the reflected wave, and detects the state in front of the own vehicle 10. As the radar 184, for example, a millimeter wave radar using millimeter waves, an infrared radar using infrared rays, and a LiDAR (Light Detection and Ranking) radar using light having a shorter wavelength than infrared rays can be used. The radar 184 may be configured to include a plurality of radars among them.

The vehicle speed detection unit 186 detects and acquires the speed of the own vehicle 10. The speed of the own vehicle 10 can be detected by using, for example, the rotational speed of the differential gear 136 or the drive shaft 138. The steering direction detection unit 188 detects and acquires the direction of the front wheels 173 and 174. The orientation of the front wheels 173 and 174 can be detected using the rack position of the steering gear 152.

The travel control device 100 includes a front vehicle identification unit 104, a lane detection unit 106, a front vehicle behavior detection unit 108, a departure determination unit 116, a follow-up control unit 118, an auto cruise control unit 120, and a travel mode switching unit. 122 and. The travel control device 100 is a computer including a CPU 102, a RAM, a ROM, an input / output port (I / O), and the like. By the operation of the CPU 102, the front vehicle identification unit 104, the lane detection unit 106, and the front vehicle behavior detection are performed. The functions of the unit 108, the departure determination unit 116, the follow-up control unit 118, the auto cruise control unit 120, and the traveling mode switching unit 122 are realized. The RAM, ROM, and input / output port (I / O) are not shown. Further, illustration and description of functions and configurations not related to follow-up control and auto-cruise control will be omitted.

The front vehicle identification unit 104 uses the above-mentioned camera 182 and radar 184 to detect the front vehicle 20 in front of the own vehicle 10 and specify the existence and position of the front vehicle 20 as shown in FIG. As shown in FIG. 3, the front vehicle specifying unit 104 provides a reliability index (expressed as a percentage) according to the distance from the own vehicle 10, and the front vehicle 20 existing in a region equal to or higher than a predetermined index will be described later. It is the target of the front vehicle behavior detection unit 108, the departure determination unit 116, and the follow-up control unit 118. The front vehicle identification unit 104 can also acquire the relative speed Rv of the front vehicle 20 by using the relative transition of the position of the front vehicle 20.

The lane detection unit 106 detects the lane boundary lines S1, S2, and S3 in front of the own vehicle 10 by using the above-mentioned camera 182 as shown in FIG.

The front vehicle behavior detection unit 108 detects the behavior of the front vehicle 20, particularly the lateral behavior. The front vehicle behavior detection unit 108 includes a direction instruction detection unit 110, a front vehicle lateral speed acquisition unit 112, and a front vehicle travel information acquisition unit 114. The direction instruction detection unit 110 detects whether or not the direction indicator of the front vehicle is blinking from the image of the front vehicle 20 acquired by using the camera 182. The front vehicle lateral speed acquisition unit 112 acquires the lateral speed of the front vehicle 20 by using the transition of the position of the front vehicle 20 acquired by using the camera 182 or the radar 184. The front vehicle travel information acquisition unit 114 acquires travel information of the front vehicle, for example, speed and steering direction, by using vehicle-to-vehicle communication such as V2V (Vehicle-to-Vehicular). The front vehicle behavior detection unit 108 does not need to include all of the direction instruction detection unit 110, the front vehicle lateral speed acquisition unit 112, and the front vehicle travel information acquisition unit 114, but at least one of them may be provided.

The departure determination unit 116 can use the behavior of the front vehicle 20 detected or acquired by the front vehicle behavior detection unit 108 to determine whether the front vehicle 20 is leaving the lane in which the own vehicle 10 is traveling or to leave. Judge whether or not the sex is large.

The follow-up control unit 118 executes follow-up control. Here, the follow-up control is a control in which the own vehicle 10 is made to follow the preceding vehicle at a speed equal to or lower than a preset speed and at a distance from the preceding vehicle 20. The auto-cruise control unit 120 controls the auto-cruise of the own vehicle 10. Auto-cruise means that the vehicle 10 is driven at a speed equal to or lower than a preset speed and does not deviate from the lane. The travel mode switching unit 122 switches between follow-up control, auto-cruise control, and normal control. In the present embodiment, the normal control means a control that is neither a follow-up control nor an auto-cruise control. When the vehicle in front 20 approaches the vehicle in front 20 during the auto cruise, or when the vehicle in front 20 interrupts the lane in which the vehicle 10 travels, the travel mode switching unit 122 switches from the auto cruise control to the follow-up control. Further, when the front vehicle 20 is separated from the own vehicle 10 or the front vehicle 20 is separated from the lane in which the own vehicle 10 is traveling during the follow-up control of the front vehicle 20, the traveling mode switching unit 122 may be used. Switch from follow-up control to auto-cruise control. The traveling mode switching unit 122 switches to follow-up control or auto-cruise control when the auto-cruise switch 125 is on, and switches to normal control when the auto-cruise switch 125 is off. The auto cruise switch 125 is turned on and off by, for example, the driver.

The control performed by each part of the travel control device 100 will be described with reference to a flowchart. The process shown in FIG. 4 is repeatedly executed while the driver turns on the auto cruise switch 125. In step S100 of FIG. 4, the front vehicle specifying unit 104 determines, for example, whether or not the front vehicle 20 exists in a region having a reliability index of 50% or more. If the preceding vehicle 20 does not exist, the process shifts to step S110, and the auto-cruise control unit 120 causes the own vehicle 10 to auto-cruise. On the other hand, if there is a vehicle in front, the process proceeds to step S120, and the follow-up control unit 118 executes control that the own vehicle 10 follows the vehicle in front 20. If the front vehicle 20 is present in the region of the reliability index of 40%, the front vehicle specifying unit 104 does not determine that the front vehicle 20 is present in the region of the reliability index of 50% or more. However, the front vehicle 20 exists in the lane adjacent to the lane in which the own vehicle 10 travels, the front vehicle 20 blinks the direction indicator on the lane side of the own vehicle 10, and the blinking lane boundary line is displayed. When stepping on, the front vehicle identification unit 104 may increase the reliability index by, for example, 10% to 50%, and determine whether or not the front vehicle 20 exists in a region having a reliability index of 50% or more. .. This is because the vehicle 20 in front may interrupt the lane in which the vehicle is traveling.

In step S120, the follow-up control unit 118 controls the traveling of the own vehicle 10 so as to follow the preceding vehicle 20. At this time, the follow-up control unit 118 is used for driving so that the speed of the own vehicle 10 is equal to or less than the preset vehicle speed and the distance between the own vehicle 10 and the preceding vehicle 20 is maintained at least the target inter-vehicle distance. The drive system 130 is controlled by the ECU 132, and the braking system 160 is controlled by the braking ECU 162. The target inter-vehicle distance at this time is called the "first inter-vehicle distance". Here, the first inter-vehicle distance may be a fixed value or may be determined according to the speed of the own vehicle 10. Further, the follow-up control unit 118 increases the first inter-vehicle distance as the speed of the own vehicle 10 increases, and may be a fixed value when the speed of the own vehicle 10 is equal to or higher than a predetermined speed. In the present embodiment, the follow-up control unit 118 uses the target vehicle-to-vehicle distance, but the target vehicle-to-vehicle time may be used instead of the target vehicle-to-vehicle distance. Here, the inter-vehicle time is the time from when the preceding vehicle 20 passes a certain point to when the own vehicle 10 passes the point. That is, controlling using the target inter-vehicle time means controlling by the time from when the preceding vehicle 20 passes a certain point to when the own vehicle 10 passes the point. In addition, the follow-up control unit 118 has a steering system for the steering ECU 142 so as not to go out of the lane in which the own vehicle 10 is traveling, in addition to keeping the distance between the vehicle and the preceding vehicle 20 greater than the target vehicle distance. The 140 may be controlled or the driver may be assisted.

In step S130, the departure determination unit 116 determines that the front vehicle 20 may leave the own vehicle 10 from the front. If there is a high possibility that the front vehicle 20 will leave the front of the own vehicle 10, the process shifts to step S140, and if the possibility that the front vehicle 20 will leave the front of the own vehicle 10 is small, the process proceeds to step S140. The process proceeds to step S190. As described above, the departure determination unit 116 determines whether the possibility of the front vehicle 20 leaving is high or small by using the behavior of the front vehicle 20 acquired from the front vehicle behavior detection unit 108. Even if the departure determination unit 116 determines that the vehicle in front 20 is likely to leave, there is a vehicle in front of the vehicle 20 in front of the vehicle 20, and the relative speed Rv between the vehicle 10 and the vehicle in front is high. In the negative case, that is, when the vehicle is approaching before the previous vehicle, it is not necessary to determine that there is a high possibility of leaving the vehicle. This is because even if the front vehicle 20 leaves, there is a possibility that the vehicle in front of the vehicle will be replaced and become the vehicle in front. Even if the blinking of the direction indicator of the front vehicle 20 is confirmed, it is not necessary to determine that there is a high possibility that the vehicle in front 20 will leave the vehicle if a certain period of time has passed without changing the lane. This is because the driver of the vehicle in front 20 may erroneously blink the turn signal.

In step S140, the front vehicle specifying unit 104 determines whether or not the front vehicle 20 has left the front of the own vehicle 10. For example, when the front vehicle 20 moves to a region where the reliability index is less than 50%, it may be determined that the front vehicle 20 has left the front of the own vehicle 10. At this time, if the front vehicle 20 is stepping on the lane boundary line indicated by the turn signal, the front vehicle identification unit 104 may lower the reliability index to determine the departure of the front vehicle 20. For example, when the vehicle in front 20 is in the same lane as the vehicle 10 and is in the region of the confidence index of 50%, but the turn signal is blinking and the vehicle is stepping on the lane boundary on the blinking side. The reliability index may be lowered by, for example, 10% to 40%, and it may be determined that the front vehicle 20 has left the front of the own vehicle 10.

In step S150, the follow-up control unit 118 calculates the relative speed Rv and the relative distance Rd between the own vehicle 10 and the preceding vehicle 20.

In step S160, the follow-up control unit 118 determines whether or not the relative speed Rv between the own vehicle 10 and the preceding vehicle 20 is less than a predetermined threshold value V. When the relative speed Rv between the own vehicle 10 and the preceding vehicle 20 is less than the threshold value V, the process shifts to step S190, and when the relative speed Rv is equal to or higher than the threshold value V, the process shifts to step S170.

In step S170, the follow-up control unit 118 causes the follow-up control unit 118 to determine whether or not the relative distance Rd between the own vehicle 10 and the preceding vehicle 20 is less than a predetermined threshold value W. When the relative distance Rd between the own vehicle 10 and the preceding vehicle 20 is less than the threshold value W, the process proceeds to step S190, and when the relative distance Rd is equal to or more than the threshold value W, the process proceeds to step S180.

In step S180, the follow-up control unit 118 changes the target inter-vehicle distance to a small second inter-vehicle distance shorter than the first inter-vehicle distance, as shown in FIG. The second inter-vehicle distance is, for example, about half or one-third of the first inter-vehicle distance. The follow-up control unit 118 may determine the magnitude of the second inter-vehicle distance and the reduction rate of the second inter-vehicle distance with respect to the first inter-vehicle distance according to the speed of the own vehicle 10. Further, the follow-up control unit 118 may shorten the inter-vehicle time instead of reducing the target inter-vehicle distance.

In step S190, as shown in FIG. 5, the follow-up control unit 118 maintains the target vehicle-to-vehicle distance from the preceding vehicle 20 so as to be at least the first inter-vehicle distance.

The follow-up control unit 118 includes a map for setting the first inter-vehicle distance and the second inter-vehicle distance according to the speed of the own vehicle 10 and the relative speed Rv between the own vehicle 10 and the preceding vehicle 20. Step S180. , A map may be used to set or correct the inter-vehicle distance in S190.

A comparative example, a recognition state of the front vehicle 20 of the present embodiment, and control of the own vehicle 10 with respect to the recognition state will be described with reference to FIG. Comparative Examples 1 and 2 and the present embodiment differ in the following points. Comparative Example 1 does not determine the possibility that the front vehicle 20 will leave the front of the own vehicle 10. That is, there are only two states: a state 1 in which the front vehicle specifying unit 104 recognizes and specifies the front vehicle 20, and a state 2 in which the front vehicle specifying unit 104 does not recognize and specifies the front vehicle 20. On the other hand, in the present embodiment and Comparative Example 2, it is determined that the front vehicle 20 may leave the front of the own vehicle 10. That is, the state 1, in which the front vehicle specifying unit 104 recognizes and identifies the front vehicle 20, but the departure determination unit 116 does not determine when the front vehicle 20 leaves the front of the own vehicle 10, the front vehicle specifying unit 104 A state in which the front vehicle 20 is not recognized and not specified 2. The front vehicle identification unit 104 recognizes and specifies the front vehicle 20, but when the front vehicle 20 leaves the front of the own vehicle 10, the departure determination unit 116 determines. There are three ways of doing state 3. The difference between Comparative Example 2 and this embodiment will be described later.

In both the present embodiment and Comparative Examples 1 and 2, the control of the own vehicle 10 in the state 1 and the state 2 is the same, respectively. That is, in the state 1, in both the present embodiment and Comparative Examples 1 and 2, the follow-up control unit 118 sets the speed of the own vehicle 10 to the set vehicle speed or less, and the target inter-vehicle distance between the own vehicle 10 and the preceding vehicle 20. Is not shortened, and the control that follows the preceding vehicle 20 is executed. Further, in the state 2, the auto cruise control unit 120 causes the own vehicle 10 to travel independently at a predetermined vehicle speed.

In the case of the state 3, the present embodiment and Comparative Example 2 are different as follows. In Comparative Example 2, in the case of the state 3, the follow-up of the preceding vehicle 20 is canceled, and the auto-cruise control unit 120 causes the own vehicle 10 to travel independently at a predetermined set vehicle speed. On the other hand, in the present embodiment, in the case of the state 3, the follow-up control unit 118 changes the target inter-vehicle distance between the own vehicle 10 and the preceding vehicle 20 from the first inter-vehicle distance to the second inter-vehicle distance. Then, the control to follow the vehicle in front 20 is executed.

Hereinafter, the behavior of the own vehicle 10 will be described with reference to the drawings. First, a case where the preceding vehicle 20 changes lanes from the overtaking lane of the expressway to the traveling lane will be described. As shown in FIG. 7, the front vehicle 20 changes lanes to the traveling lane while blinking the turn signal. In the case of Comparative Example 1, the front vehicle specifying unit 104 recognizes the vehicle in front 20, and the tracking control unit 118 executes tracking control so that the distance between the vehicle and the vehicle in front 20 is equal to or greater than the first vehicle distance. .. In the case of Comparative Example 2, when the front vehicle 20 blinks the direction indicator, the follow-up control unit 118 cancels the follow-up of the front vehicle 20. As a result, the auto-cruise control unit 120 causes the own vehicle 10 to independently perform auto-cruise running at a set vehicle speed. Therefore, the own vehicle 10 suddenly approaches the preceding vehicle 20. On the other hand, in the present embodiment, when the departure determination unit 116 determines that the front vehicle 20 leaves, the follow-up control unit 118 sets the target vehicle-to-vehicle distance from the front vehicle 20 from the first vehicle-to-vehicle distance. Change to the distance between vehicles of 2. As a result, the own vehicle 10 is closer to the front vehicle 20 than the comparative example 1, although it is not as close as the comparative example 2. When the own vehicle 10 is closer to the preceding vehicle 20 than the second inter-vehicle distance, the travel control device 100 instructs the braking ECU 162 to brake the own vehicle 10. When the front vehicle 20 completes the lane change to the traveling lane and the front vehicle identification unit 104 cannot detect the front vehicle 20, the auto-cruise control unit 120 sets the own vehicle 10 at a preset vehicle speed. To auto-cruise. The same applies to the case where the own vehicle 10 and the preceding vehicle 20 travel in the traveling lane and the preceding vehicle 20 moves to the overtaking lane.

Next, a case where the front vehicle 20 changes lanes from the expressway to the exit route will be described. As shown in FIG. 8, the front vehicle 20 decelerates while blinking the turn signal and changes lanes to the exit route. In the case of Comparative Example 1, the follow-up control is executed so that the inter-vehicle distance between the follow-up control unit 118 and the front vehicle 20 is longer than the first inter-vehicle distance as the vehicle decelerates. Therefore, the braking ECU 162 is instructed to brake, and the own vehicle 10 is decelerated. In the case of Comparative Example 2, when the front vehicle 20 blinks the direction indicator, the auto-cruise control unit 120 causes the own vehicle 10 to independently perform auto-cruise running at the set vehicle speed in order to cancel the follow-up of the front vehicle 20. .. Therefore, the own vehicle 10 suddenly approaches the preceding vehicle 20. On the other hand, in the present embodiment, when the departure determination unit 116 determines that the front vehicle 20 leaves, the follow-up control unit 118 sets the target vehicle-to-vehicle distance from the front vehicle 20 from the first vehicle-to-vehicle distance. Change to the distance between vehicles of 2. As a result, the own vehicle 10 is closer to the front vehicle 20 than the comparative example 1, although it is not as close as the comparative example 2. If the preceding vehicle 20 does not decelerate when changing lanes from the expressway to the exit road, it is the same as the case described with reference to FIG. 7. When the own vehicle 10 is closer to the preceding vehicle 20 than the second inter-vehicle distance, the travel control device 100 instructs the braking ECU 162 to brake the own vehicle 10. When the front vehicle 20 completes the lane change to the exit route and the front vehicle identification unit 104 cannot detect the front vehicle 20, the auto-cruise control unit 120 sets the own vehicle 10 at a preset vehicle speed. To auto-cruise.

Next, a case where the front vehicle 20 turns left at an intersection on a general road instead of an expressway will be described. A general road refers to a road other than an expressway. The expressway means a national expressway or a motorway. As shown in FIG. 9, the front vehicle 20 describes a case where the vehicle decelerates and turns left while blinking the turn signal. In the case of Comparative Example 1, the follow-up control unit 118 brakes the braking ECU 162 with respect to the braking ECU 162 in order to maintain the distance between the vehicle and the vehicle in front 20 so as to be larger than the distance between the first vehicle and the vehicle 20 as the vehicle in front decelerates. Is instructed to decelerate the own vehicle 10. In Comparative Example 2, when the front vehicle 20 blinks the direction indicator, the auto-cruise control unit 120 causes the own vehicle 10 to independently perform an auto-cruise run at a set vehicle speed in order to cancel the follow-up of the front vehicle 20. Therefore, the own vehicle 10 suddenly approaches the preceding vehicle 20. On the other hand, in the present embodiment, the follow-up control unit 118 changes the target vehicle-to-vehicle distance from the first vehicle-to-vehicle distance to the second vehicle-to-vehicle distance when it is determined that the preceding vehicle 20 is likely to leave. .. As a result, the own vehicle 10 is closer to the front vehicle 20 than the comparative example 1, although it is not as close as the comparative example 2. The front vehicle 20 will stop if there is a crossing person at the left turn. In such a case, when the own vehicle 10 is closer to the preceding vehicle 20 than the second inter-vehicle distance, the travel control device 100 of the own vehicle 10 refers to the own vehicle 10 with respect to the braking ECU 162. Instruct braking to stop. When the front vehicle 20 completes the left turn and no longer exists from the front of the own vehicle 10, the auto-cruise control unit 120 automatically cruises the own vehicle 10 at a preset vehicle speed.

Hereinafter, comparative example 1 in which the target vehicle-to-vehicle distance is maintained so as to be longer than the first vehicle-to-vehicle distance with respect to the acceleration and vehicle speed of the own vehicle 10 when the preceding vehicle 20 decelerates and leaves, and the target vehicle-to-vehicle distance is set to the second vehicle-to-vehicle distance. Compare with this embodiment which changes to a distance. As is clear from the graph shown in FIG. 10, the fluctuation of the acceleration is smaller and the fluctuation of the velocity is smaller in the present embodiment than in Comparative Example 1. That is, in Comparative Example 1, when the front vehicle 20 decelerates, the own vehicle 10 also decelerates in accordance with the deceleration, and when the front vehicle 20 leaves the front of the own vehicle 10, the vehicle accelerates to the set speed. On the other hand, in the present embodiment, when the front vehicle 20 decelerates, the target vehicle-to-vehicle distance is changed from the first vehicle-to-vehicle distance to the second vehicle-to-vehicle distance. Therefore, the deceleration of the own vehicle 10 from the first inter-vehicle distance to the second inter-vehicle distance may be slower than the deceleration of the preceding vehicle 20. Further, the speed of the own vehicle 10 from the first inter-vehicle distance to the second inter-vehicle distance is faster in the present embodiment than in Comparative Example 1. After that, when the front vehicle 20 leaves the front of the own vehicle 10, the vehicle accelerates to the set speed. At this time, in the present embodiment, since the speed of the own vehicle 10 before acceleration is faster than that in Comparative Example 1, the acceleration may be slow to the set speed. As described above, the present embodiment can suppress the fluctuation of the acceleration and the speed of the own vehicle 10 to be smaller than that of the comparative example 1. That is, this embodiment does not require unnecessary deceleration / acceleration as compared with Comparative Example 1. As a result, the present embodiment can improve the driver feeling and the fuel efficiency as compared with the comparative example.

Next, with respect to the acceleration and vehicle speed of the own vehicle 10 when the preceding vehicle 20 leaves without decelerating, Comparative Example 1 in which the target vehicle-to-vehicle distance is maintained so as to be greater than or equal to the first vehicle-to-vehicle distance, and Comparative Example 1 in which the target vehicle-to-vehicle distance is set to the second. This is compared with the present embodiment in which the distance between vehicles is changed to. It is assumed that the speed of the front vehicle 20 is slower than the speed of the auto cruise of the own vehicle 10. In this case, as shown in FIG. 11, the follow-up control unit 118 changes the target vehicle-to-vehicle distance from the first vehicle-to-vehicle distance to the second vehicle-to-vehicle distance from the time when it is determined that the preceding vehicle 20 is likely to leave. Accelerate the own vehicle 10 and increase the speed. Therefore, it is not necessary to suddenly accelerate to the set speed after the departure of the preceding vehicle 20 is completed. Therefore, according to the present embodiment, the changes in acceleration and speed can be made more gradual than in Comparative Example 1, so that the driver feeling can be improved. In addition, fuel efficiency can be improved.

As described above, according to the present embodiment, when the departure determination unit 116 determines that the possibility that the front vehicle 20 is separated from the lane in which the own vehicle 10 is traveling has increased, the follow-up control unit 118 follows the front vehicle 20. Instead of canceling, the second vehicle-to-vehicle distance, which is shorter than the first-vehicle distance, is opened to follow the vehicle in front 20, so there is no need for unnecessary deceleration / acceleration, and the driver feels better. Not only can it be improved, but fuel efficiency can also be improved. Further, since the follow-up of the front vehicle 20 is not canceled, the own vehicle 10 does not suddenly approach the front vehicle 20.

By shortening the target vehicle-to-vehicle distance, the follow-up control unit 118 may shorten the vehicle-to-vehicle distance from the preceding vehicle 20 from the first vehicle-to-vehicle distance to the second vehicle-to-vehicle distance, or may shorten the target vehicle-to-vehicle time. .. Further, the follow-up control unit 118 may determine the first inter-vehicle distance and the second inter-vehicle distance according to the speed of the own vehicle 10. Further, the follow-up control unit 118 may determine the ratio of the second inter-vehicle distance to the first inter-vehicle distance according to the speed of the own vehicle 10.

The front vehicle behavior detection unit 108 includes a direction instruction detection unit 110 that detects the behavior of the front vehicle 20 by using the blinking of the direction indicator of the front vehicle 20, and the departure determination unit 116 uses the behavior of the front vehicle 20 to detect the behavior of the front vehicle 20. You may determine the possibility that 20 will leave. This is because when the front vehicle 20 turns on the turn signal, the front vehicle 20 is likely to change lanes or turn left or right, so that the possibility that the front vehicle 20 will leave is increased.

The front vehicle behavior detection unit 108 includes a front vehicle lateral detection unit 112 that detects the behavior of the front vehicle 20 by using the lateral speed of the front vehicle 20, and the departure determination unit 116 uses the behavior to detect the front vehicle. You may determine the possibility that the car 20 will leave. Even when the front vehicle 20 changes lanes or turns left or right without turning on the turn signal, it is possible to determine the possibility that the front vehicle 20 will leave.

The front vehicle behavior detection unit 108 includes a front vehicle travel information acquisition unit that acquires the movement and behavior of the front vehicle 20 acquired by vehicle-to-vehicle communication, and the departure determination unit 116 uses the movement and behavior of the front vehicle 20 to acquire the front vehicle travel information. The possibility of withdrawal may be determined. Even if it is difficult to detect the movement of the front vehicle 20 with a camera or the like, it is possible to determine the possibility that the front vehicle 20 will leave. Further, when the destination and the route of the front vehicle 20 can be acquired by vehicle-to-vehicle communication, the movement of the front vehicle 20 can be easily predicted.

The present invention can be realized as the following forms.

(1) According to one embodiment of the present invention, a vehicle travel control device is provided. This travel control device includes a front vehicle identification unit (40) that identifies a front vehicle (200) that is a preceding vehicle traveling in front of the own vehicle (100), and a front vehicle behavior detection unit that detects the behavior of the front vehicle. According to the follow-up control unit (21) that executes the follow-up control that follows the front vehicle specified by the front vehicle identification unit with a predetermined inter-vehicle distance, and the detected behavior of the front vehicle. The vehicle includes a departure determination unit (20) for determining whether or not the vehicle in front is likely to leave the lane in which the vehicle is traveling. When the withdrawal determination unit determines that the vehicle in front is in the withdrawal state, the follow-up control unit sets the inter-vehicle distance in the follow-up control when the vehicle in front is not in the withdrawal state. The follow-up control is performed by changing to a second inter-vehicle distance shorter than the inter-vehicle distance of. According to this embodiment, when the departure determination unit determines that the vehicle in front is in the withdrawal state, the follow-up control unit sets the inter-vehicle distance in the follow-up control to the second inter-vehicle distance shorter than the first inter-vehicle distance. Since it is changed, the own vehicle does not come close to the vehicle in front as compared with the case where the follow-up control is not performed. Further, when the vehicle in front decelerates and leaves the lane, the distance between the vehicle and the vehicle in front can be maintained at the second distance shorter than the distance between the first vehicle even if the deceleration is slower than the deceleration of the vehicle in front. That is, it is not necessary to decelerate the own vehicle according to the preceding vehicle, and the own vehicle can be decelerated more slowly than the preceding vehicle. Further, since the speed of the own vehicle when the front vehicle leaves is faster than that in the case of decelerating according to the preceding vehicle, the acceleration for returning the own vehicle to the original speed may be small. That is, fluctuations in acceleration and speed of the own vehicle can be suppressed to a small level. That is, it is possible to prevent unnecessary deceleration / acceleration. As a result, the driver feeling can be improved and the fuel efficiency can be improved.

(2) In the above embodiment, the vehicle speed detection unit (186) for acquiring the speed of the own vehicle is further provided, and the follow-up control unit has the first inter-vehicle distance and the second vehicle according to the speed of the own vehicle. You may modify the inter-vehicle distance. Since the braking distance differs depending on the speed of the own vehicle, it is preferable to determine the first inter-vehicle distance and the second inter-vehicle distance according to the speed of the own vehicle.

(3) In the above embodiment, the follow-up control unit may determine the ratio of the second inter-vehicle distance to the first inter-vehicle distance according to the speed of the own vehicle. Since the braking distance differs depending on the speed of the own vehicle, it is preferable to determine the ratio of the second inter-vehicle distance to the first inter-vehicle distance according to the speed of the own vehicle.

(4) In the above embodiment, the front vehicle behavior detection unit includes a direction instruction detection unit (50) for detecting the blinking of the front vehicle direction indicator, and the departure determination unit blinks the direction indicator. It may be used to determine the possibility that the preceding vehicle will leave. When the vehicle in front turns on the turn signal, there is a high possibility that the vehicle in front will change lanes or turn left or right. According to this embodiment, it is possible to easily determine whether or not the vehicle in front is likely to leave by using the blinking of the turn signal.

(5) In the above embodiment, the front vehicle behavior detection unit includes a front vehicle lateral speed acquisition unit (112) that acquires the lateral speed of the front vehicle, and the departure determination unit is the side of the front vehicle. The speed in the direction may be used to determine the possibility that the vehicle in front will leave. According to this form, even when the vehicle in front changes lanes or turns left or right without turning on the turn signal, it can be easily determined whether or not the vehicle in front is likely to leave.

(6) In the above embodiment, the front vehicle behavior detection unit includes a front vehicle traveling information acquisition unit (114) that acquires the movement of the front vehicle by vehicle-to-vehicle communication with the front vehicle, and the departure determination unit is a withdrawal determination unit. The movement of the front vehicle acquired by the vehicle-to-vehicle communication may be used to determine the possibility that the front vehicle will leave. According to this form, even if it is difficult to detect the movement of the vehicle in front with a camera or the like, it is possible to determine the possibility that the vehicle in front will leave.

(7) In the above embodiment, the auto-cruise control unit (120) is provided, and when the front vehicle identification unit cannot detect the vehicle in front, the auto-cruise control unit travels independently at a preset vehicle speed. May be executed. According to this form, it is possible to control the traveling when the vehicle in front is not followed.

The present invention can be realized in various forms, and can be realized by, for example, a vehicle travel control device, a vehicle travel control method, or the like.

10 Own vehicle 20 Front vehicle 100 Travel control device 102 CPU 104 Front vehicle identification unit 106 Lane detection unit 108 Front vehicle behavior detection unit 110 Directional instruction detection unit 112 Front vehicle lateral speed acquisition unit 114 Front vehicle travel information acquisition unit 116 Departure judgment Part 118 Follow-up control part 120 Auto cruise control part 122 Driving mode switching part 125 Driving mode switching switch 130 Drive system 132 Drive ECU 134 Drive device 136 Differential gear 138 Drive shaft 140 Steering system 142 Steering ECU 144 Handle 146 Encoder 148 Steering device 150 Steering motor 152 Steering gear 160 Braking system 162 Braking ECU 164 Hydraulic pump 166 Brake hose 168 Brake caliper 169 Brake disc 170 Rear wheel 171 Rear wheel 172 Front wheel 173 Front wheel 180 Various detectors 182 Camera 184 Radar 186 Vehicle speed detection Detection unit 190 Communication unit 195 Route guidance device S1 lane boundary line S2 lane boundary line S3 lane boundary line Rv relative speed Rd relative distance

Claims (7)

It is a travel control device (100) and
A front vehicle identification unit (104) that identifies a front vehicle (20) that is a preceding vehicle traveling in front of the own vehicle (10), and a front vehicle identification unit (104).
The front vehicle behavior detection unit (108) that detects the behavior of the front vehicle,
A follow-up control unit (118) that executes follow-up control that follows the front vehicle specified by the front vehicle identification unit with a predetermined inter-vehicle distance.
A withdrawal determination unit (116) for determining whether or not the vehicle in front is likely to leave the lane in which the vehicle is traveling according to the detected behavior of the vehicle in front.
Equipped with
When the withdrawal determination unit determines that the vehicle in front is in the withdrawal state, the follow-up control unit sets the inter-vehicle distance in the follow-up control when the vehicle in front is not in the withdrawal state. The follow-up control is performed by changing to a second inter-vehicle distance shorter than the inter-vehicle distance of
The follow-up control unit determines the ratio of the second inter-vehicle distance to the first inter-vehicle distance according to the speed of the own vehicle .
Travel control device. The travel control device according to claim 1, further
A vehicle speed detection unit (186) for acquiring the speed of the own vehicle is provided.
The follow-up control unit corrects the first inter-vehicle distance and the second inter-vehicle distance according to the speed of the own vehicle.
Travel control device. The traveling control device according to claim 1 or 2 .
The front vehicle behavior detection unit includes a direction instruction detection unit (110) that detects blinking of the direction indicator of the front vehicle.
The departure determination unit determines the possibility that the vehicle in front will leave by using the blinking of the direction indicator.
Travel control device. The traveling control device according to claim 1 or 2 .
The front vehicle behavior detection unit includes a front vehicle lateral speed acquisition unit (112) that acquires the lateral speed of the front vehicle.
The departure determination unit determines the possibility that the front vehicle will leave by using the lateral speed of the front vehicle.
Travel control device. The traveling control device according to claim 1 or 2 .
The front vehicle behavior detection unit includes a front vehicle traveling information acquisition unit (114) that acquires the movement of the front vehicle by vehicle-to-vehicle communication with the front vehicle.
The departure determination unit determines the possibility that the front vehicle will leave by using the movement of the front vehicle acquired by the vehicle-to-vehicle communication.
Travel control device. The travel control device according to any one of claims 1 to 5 .
Equipped with an auto cruise control unit (120)
When the preceding vehicle identification unit cannot detect the vehicle in front, the auto-cruise control unit executes independent traveling at a preset vehicle speed.
Travel control device. It is a driving control method
Identify the preceding vehicle (20), which is the preceding vehicle traveling in front of the own vehicle (10),
A follow-up control that follows the vehicle in front is executed with a predetermined inter-vehicle distance.
Detecting the behavior of the vehicle in front,
According to the detected behavior of the preceding vehicle, it is determined whether or not the preceding vehicle is in a withdrawal situation in which the preceding vehicle is likely to leave the lane in which the own vehicle is traveling.
When it is determined that the preceding vehicle is in the withdrawal state, the inter-vehicle distance in the follow-up control is the second inter-vehicle distance shorter than the first inter-vehicle distance set when the preceding vehicle is not in the withdrawal state. The follow-up control is performed by changing to
The ratio of the second inter-vehicle distance to the first inter-vehicle distance is determined according to the speed of the own vehicle .
Driving control method.

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