Vehicle control method and vehicle control device

Abstract

A controller (18) executes: a process (S5) for detecting another vehicle traveling on a second lane adjacent to a first lane on which the own vehicle travels; a process (S2) for determining, as a merging point, a terminal point of a section in which the vehicle can travel on the second lane; a process (S3) for calculating an arrival time, which is the time until the own vehicle reaches the merging point; a process (S6) for calculating an arrival margin time until the front-back-directional position of a front end of the own vehicle reaches the front-back-directional position of a rear end of another vehicle traveling on the second lane ahead of the own vehicle; and processes (S9-S13) in which deceleration control is performed in a case where the arrival margin time is greater than a prescribed range and acceleration control is performed in a case where the arrival margin time is less than the prescribed range, and in which a determination as to whether or not to perform acceleration / deceleration control relative to the other vehicle is suspended in a case where it is determined that the arrival time is not less than a prescribed threshold and the arrival margin time is within the prescribed range.

Description

Vehicle control method and vehicle control device

[0001] The present invention relates to a vehicle control method and a vehicle control device.

[0002] The following Patent Document 1 describes a driving assistance device that determines the driving lane by comprehensively considering each risk on the planned route before the vehicle traveling on the main road approaches a merging point.

[0003] JP 2016-17914 A

[0004] However, in situations where another vehicle traveling in a second lane adjacent to the first lane in which the host vehicle is traveling is forced to enter (merge) into the first lane (for example, when the second lane is a merging lane or when there is an obstacle such as construction ahead of the second lane), the host vehicle may not be able to freely select the lane in which to travel. In such cases, the entry of the other vehicle into the first lane in which the host vehicle is traveling may cause anxiety to the occupants of the host vehicle. An object of the present invention is to reduce the anxiety felt by the occupants of the host vehicle when another vehicle traveling in the second lane adjacent to the first lane in which the host vehicle is traveling enters the first lane.

[0005] In one aspect of the vehicle control method of the present invention, a controller is caused to perform the following steps: detect other vehicles traveling in a second lane adjacent to a first lane in which the vehicle is traveling; determine the end of a section of the second lane in which the vehicle can travel as a merging point; calculate an arrival time, which is the time it takes for the vehicle to reach the merging point; calculate an arrival margin time, which is the time it takes for the front end of the vehicle to reach the front end of the other vehicle traveling in the second lane in front of the vehicle; perform deceleration control if the arrival margin time is greater than a predetermined range, and perform acceleration control if the arrival margin time is less than the predetermined range; and, if it is determined that the arrival time is greater than a predetermined threshold and the arrival margin time is within the predetermined range, defer judgment on acceleration / deceleration control for the other vehicle.

[0006] According to the present invention, when another vehicle traveling in a second lane adjacent to the first lane in which the vehicle is traveling enters the first lane, it is possible to reduce the sense of anxiety felt by the occupants of the vehicle. The objects and advantages of the present invention are realized and achieved by using the elements and combinations thereof set forth in the claims. It should be understood that both the foregoing general description and the following detailed description are merely exemplary and explanatory and are not intended to limit the invention as defined by the claims.

[0007] 1 is a schematic configuration diagram of an example of a vehicle control device according to an embodiment; (a) and (b) are schematic explanatory diagrams of an example of a vehicle control method according to an embodiment; (a) and (b) are schematic diagrams of an example of a functional configuration of a controller; (a) and (b) are schematic diagrams of an example of setting a boundary region for determining whether to perform merging deceleration control or merging acceleration control; (a) to (c) are schematic diagrams of an example of a screen display presented during execution of the vehicle control method according to an embodiment; and (a) is a flowchart of an example of a vehicle control method according to an embodiment.

[0008] (Configuration) Fig. 1 is a schematic configuration diagram of an example of a vehicle control device according to an embodiment. The host vehicle Ce is equipped with a vehicle control device 10 that controls the traveling of the host vehicle Ce. The traveling control by the vehicle control device 10 includes autonomous driving control that automatically drives the host vehicle Ce without the involvement of the driver based on the traveling environment around the host vehicle Ce, and driving assistance control that assists the driver in driving the host vehicle Ce by controlling at least one of driving and braking of the host vehicle Ce. The driving assistance control may be, for example, automatic braking, preceding vehicle following control, constant speed traveling control, merging assistance control, etc.

[0009] The vehicle control device 10 includes an external sensor 11, a vehicle sensor 12, a positioning device 13, a map database (map DB) 14, a communication device 15, a human-machine interface (HMI) 16, an actuator 17, and a controller 18. The external sensor 11 includes a plurality of different types of object detection sensors mounted on the host vehicle Ce, such as a laser radar, a millimeter-wave radar, a camera, and a LIDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging), that detect objects around the host vehicle Ce. The vehicle sensor 12 is mounted on the host vehicle Ce and detects various information (vehicle signals) obtained from the host vehicle Ce. The vehicle sensors 12 include, for example, a vehicle speed sensor that detects the vehicle speed of the host vehicle Ce, a wheel speed sensor that detects the rotational speed of the tires of the host vehicle Ce, a three-axis acceleration sensor that detects the acceleration and deceleration in three axes of the host vehicle Ce, a steering angle sensor that detects the steering angle of the steering wheel, a steering angle sensor that detects the steering angle of the steered wheels, a gyro sensor that detects the angular velocity of the host vehicle Ce, a yaw rate sensor that detects the yaw rate, an accelerator sensor that detects the accelerator opening of the host vehicle, and a brake sensor that detects the amount of brake operation by the driver.

[0010] The positioning device 13 includes a Global Navigation System (GNSS) receiver and receives radio waves from multiple navigation satellites to measure the current position of the vehicle Ce. The GNSS receiver may be, for example, a Global Positioning System (GPS) receiver. The positioning device 13 may be, for example, an inertial navigation system. The map database 14 stores road map data. For example, the map database 14 may store high-precision map data (hereinafter simply referred to as "high-precision map") suitable as map information for autonomous driving. The map database 14 may also store map data for navigation (hereinafter simply referred to as "navigation map").

[0011] The communication device 15 provides a communication function between the vehicle control device 10 and an external device. The communication method used by the communication device 15 may be, for example, wireless communication via a public mobile communication network, satellite communication, etc. The HMI 16 is an interface device that exchanges information between the vehicle control device 10 and a user (e.g., a passenger such as a driver) of the vehicle Ce. For example, the HMI 16 may include a display device that can be seen by the user, and a speaker or buzzer that outputs an alarm sound, a notification sound, or audio information.

[0012] The actuator 17 operates the steering wheel, accelerator opening, and brake device of the host vehicle in response to control signals from the controller 18 to generate vehicle behavior of the host vehicle. The actuator 17 includes a steering actuator, an accelerator opening actuator, and a brake control actuator. The steering actuator controls the steering direction and steering amount of the steering of the host vehicle. The accelerator opening actuator controls the accelerator opening of the host vehicle. The brake control actuator controls the braking operation of the brake device of the host vehicle.

[0013] The controller 18 is an electronic control unit that controls the driving of the host vehicle Ce. The controller 18 includes a processor 18a and peripheral components such as a storage device 18b. The processor 18a may be, for example, a CPU or an MPU. The storage device 18b may include a semiconductor storage device, a magnetic storage device, an optical storage device, or the like. The storage device 18b may include memories such as a register, a cache memory, and a ROM and RAM used as a main storage device. The functions of the controller 18 described below are realized, for example, by the processor 18a executing a computer program stored in the storage device 18b. Note that the controller 18 may also be formed by dedicated hardware for executing the information processing described below. For example, the controller 18 may include a functional logic circuit configured in a general-purpose semiconductor integrated circuit. For example, the controller 18 may include a PLD such as an FPGA.

[0014] Next, an example of a vehicle control method by the controller 18 will be described. FIG. 2A is a schematic explanatory diagram of an example of the vehicle control method of the first embodiment. The first lane Ln1 is a lane on the main road, and the second lane Ln2 is a merging lane that merges into the first lane Ln1 of the main road at a merging section Sm. The merging section Sm starts merging at a start position Ps and ends merging at an end position Pe. Assume a driving scene in which a host vehicle Ce is traveling on the first lane Ln1 adjacent to the second lane Ln2, and a merging vehicle Cm on the second lane Ln2 is traveling ahead of the host vehicle Ce at a slower speed than the host vehicle Ce, and attempts to enter (merge) from the second lane Ln2 into the first lane Ln1, as shown by the dashed line 20. The merging vehicle Cm is an example of the "other vehicle" described in the claims.

[0015] The present invention is applicable not only to the merging section Sm but also to a wide range of situations in which a vehicle traveling on the second lane Ln2 is unable to continue traveling on the second lane Ln2 and enters the first lane Ln1. For example, as shown in Figure 2(b), the present invention is applicable to a case in which a merging vehicle Cm traveling on the second lane Ln2 on the main lane is unable to continue traveling on the second lane Ln2 and enters the first lane Ln1 because of an obstacle 21 (e.g., road construction) in front of the vehicle, or a case in which the second lane Ln2 merges into the first lane Ln1 as the number of lanes decreases.

[0016] When such a driving scenario occurs, the vehicle control device 10, in autonomous driving control or driving assistance control, determines whether to decelerate the host vehicle Ce to allow the merging vehicle Cm to enter in front of the host vehicle Ce or to accelerate the host vehicle Ce to allow the merging vehicle Cm to enter behind the host vehicle Ce, based on the relative positional relationship and relative speed between the host vehicle Ce and the merging vehicle Cm. At this time, there is a risk that the occupant of the host vehicle may feel uneasy when it is necessary to determine whether to allow the merging vehicle Cm to enter in front of or behind the host vehicle Ce. Possible examples of such uneasiness include anxiety caused by the vehicle control device 10 completing its determination and the occupant starting acceleration control or deceleration control before the occupant can make a decision.

[0017] Therefore, the vehicle control device 10 of the embodiment reserves the decision to accelerate or decelerate the host vehicle Ce near the boundary between whether to make it easier for the merging vehicle Cm to enter in front of or behind the host vehicle Ce. Specifically, the controller 18 performs the following processes: a process of detecting a merging vehicle Cm traveling on the second lane Ln2 adjacent to the first lane Ln1 on which the host vehicle Ce is traveling; a process of determining the end of the section of the second lane Ln2 in which the vehicle can travel as the merging point Pm; a process of calculating an arrival time Tg, which is the time it takes for the host vehicle Ce to reach the merging point Pm; a process of calculating an arrival margin time TR, which is the time it takes for the front end of the host vehicle Ce to reach the front end of the merging vehicle Cm; a process of performing deceleration control if the arrival margin time TR is greater than a predetermined range, and performing acceleration control if the arrival margin time TR is less than the predetermined range; and a judgment process of withholding the judgment on acceleration / deceleration control for the merging vehicle Cm if it is determined that the arrival time Tg is greater than a predetermined threshold value and the arrival margin time TR is within the predetermined range. For example, if it is determined that the arrival time Tg is equal to or greater than a predetermined threshold and the arrival margin time TR is within a predetermined range, the previously started deceleration control or acceleration control may be continued, or the host vehicle Ce may be decelerated at a deceleration rate that occurs when the driver releases his / her foot from the accelerator pedal. Note that the controller 18 may calculate the arrival margin time TR as, for example, the result of dividing the longitudinal distance D1 from the front end of the host vehicle Ce to the rear end of the merging vehicle Cm by the relative speed Vr between the host vehicle Ce and the merging vehicle Cm. In the following description, an example will be described in which the arrival margin time TR is the result of dividing the longitudinal distance D1 by the relative speed Vr. However, the present invention is not limited to this calculation method, and various calculation methods may be used to calculate the arrival margin time TR.

[0018] By suspending the decision on acceleration / deceleration control for the merging vehicle Cm in this manner, the decision of whether to enter in front of or behind the host vehicle Ce can be left to the merging vehicle Cm. As a result, anxiety caused by the vehicle control device 10's decision on whether to have the merging vehicle Cm enter in front of or behind the host vehicle Ce differing from the occupant's decision can be reduced, as can anxiety caused by the vehicle control device 10 completing its decision and starting acceleration or deceleration control before the occupant makes a decision. The merging point Pm may be selected as a point by which the merging vehicle Cm needs to enter the first lane Ln1 from the second lane Ln2 at the latest. For example, the merging point Pm may be a point near the end position Pe of the merging section Sm in FIG. 2( a) or a point immediately before the obstacle 21 in FIG. 2( b). The controller 18 may calculate the arrival time Tg by dividing the distance D2 from the host vehicle Ce to the merging point Pm by the current vehicle speed of the host vehicle Ce.

[0019] 3 is a block diagram of an example of the functional configuration of the controller 18. The controller 18 includes an object detection unit 30, a vehicle position estimation unit 31, a map acquisition unit 32, a detection integration unit 33, an object tracking unit 34, an in-map position calculation unit 35, an acceleration / deceleration control unit 36, and a vehicle control unit 37. The object detection unit 30 detects the positions, postures, sizes, speeds, etc. of objects around the vehicle Ce, such as vehicles, motorcycles, pedestrians, and obstacles, based on detection signals from the external sensors 11. The object detection unit 30 may acquire information about objects around the vehicle Ce from other vehicles or infrastructure via vehicle-to-vehicle communication or road-to-vehicle communication.

[0020] The host vehicle position estimation unit 31 measures the absolute position of the host vehicle Ce, i.e., the position, attitude, and speed of the host vehicle Ce relative to a predetermined reference point, based on odometry using measurement results from the positioning device 13 and detection results from the vehicle sensor 12. The map acquisition unit 32 acquires map information about roads around the host vehicle Ce from the map database 14. The map acquisition unit 32 may acquire map information about the structure of the road on which the host vehicle Ce is traveling, as well as map information about merging lanes Lm and merging sections Sm that merge onto the road on which the host vehicle Ce is traveling.

[0021] For example, the map acquisition unit 32 may acquire information regarding the start position Ps and end position Pe of the merging section Sm as map information regarding the merging section Sm. The map acquisition unit 32 may acquire map information from an external map data server. Furthermore, for example, the map acquisition unit 32 may acquire location information of obstacles (e.g., construction work) present on the lane. The detection integration unit 33 integrates multiple detection results obtained by the object detection unit 30 from multiple object detection sensors and outputs a single detection result for each object. Specifically, the detection integration unit 33 calculates the most reasonable object behavior that minimizes error from the object behavior obtained from each object detection sensor, taking into account the error characteristics of each object detection sensor. For example, sensor fusion technology may be used to comprehensively evaluate the detection results of multiple types of sensors to obtain more accurate detection results.

[0022] The object tracking unit 34 tracks the object detected by the object detection unit 30. Specifically, based on the detection results integrated by the detection integration unit 33, the object tracking unit 34 verifies (corresponds) the identity of the object between different times from the behavior of the object output at different times, and predicts the behavior of the object, such as its speed, based on the correspondence. The intra-map position calculation unit 35 estimates the position and attitude of the host vehicle Ce on the map from the absolute position of the host vehicle Ce obtained by the host vehicle position estimation unit 31 and the map information acquired by the map acquisition unit 32. The intra-map position calculation unit 35 also identifies the road on which the host vehicle Ce is traveling. Furthermore, it identifies the lane on which the host vehicle Ce is traveling.

[0023] The acceleration / deceleration control unit 36 ​​controls the acceleration or deceleration of the host vehicle Ce. The acceleration / deceleration control unit 36 ​​includes an arrival margin calculation unit 40, an arrival time calculation unit 41, and an acceleration / deceleration determination unit 42. The arrival margin calculation unit 40 calculates a relative distance D1 between the host vehicle Ce and the merging vehicle Cm based on the detection results of the merging vehicle Cm by the object detection unit 30 and the object tracking unit 34. For example, the arrival margin calculation unit 40 may calculate the longitudinal distance from the front end of the host vehicle Ce to the rear end of the merging vehicle Cm as the relative distance D1. The arrival margin calculation unit 40 also calculates a relative speed Vr=(Ve-Vm) between the host vehicle Ce and the merging vehicle Cm based on the vehicle speed Ve of the host vehicle Ce and the vehicle speed Vm of the merging vehicle Cm. The arrival margin calculation unit 40 divides the relative distance D1 by the relative speed Vr to calculate an arrival margin time TR=D1 / Vr. The arrival time calculation unit 41 determines the junction point Pm and calculates an arrival time Tg, which is the time required for the host vehicle Ce to reach the junction point Pm.

[0024] The acceleration / deceleration determination unit 42 determines, based on the arrival margin time TR, whether acceleration control of the host vehicle Ce is necessary to allow the merging vehicle Cm to easily enter behind the host vehicle Ce, and whether deceleration control of the host vehicle Ce is necessary to allow the merging vehicle Cm to easily enter ahead of the host vehicle Ce. In the following description, acceleration control of the host vehicle Ce to allow the merging vehicle Cm to easily enter behind the host vehicle Ce may be referred to as "merging acceleration control," and deceleration control of the host vehicle Ce to allow the merging vehicle Cm to easily enter ahead of the host vehicle Ce may be referred to as "merging deceleration control." The process of determining whether merging acceleration control or merging deceleration control is necessary may be simply referred to as "acceleration / deceleration determination process." The acceleration / deceleration determination process is an example of a "determination process" described in the claims.

[0025] For example, the acceleration / deceleration determination unit 42 may execute the acceleration / deceleration determination process when it determines that the arrival margin time TR is equal to or less than the first threshold value Tr1 and that the relative distance D1 is equal to or less than the threshold distance Dth. For example, the first threshold value Tr1 may be 6 seconds, and the threshold distance Dth may be 50 meters. On the other hand, when the arrival margin time TR is greater than the first threshold value Tr1 and the relative distance D1 is greater than the threshold distance Dth, it may determine that the merging vehicle Cm is sufficiently far from the host vehicle Ce, and the acceleration / deceleration determination process may not be executed. In this case, the merging acceleration control or the merging deceleration control is not executed.

[0026] In the acceleration / deceleration determination process, the acceleration / deceleration determination unit 42 sets a reference value Tr0 of the arrival margin time, which serves as a boundary for determining whether to perform merging deceleration control or merging acceleration control. The acceleration / deceleration determination unit 42 sets a range obtained by adding a positive and negative margin to the reference value Tr0 as a boundary region R1. The boundary region R1 is an example of the "predetermined range" described in the claims, and is set to a range smaller than the first threshold value Tr1. FIG. 4(a) is a schematic diagram of an example of how the boundary region R1 is set. FIG. 4(a) is a coordinate system in which the horizontal axis represents the relative distance D1 and the vertical axis represents the relative velocity V1, and each coordinate represents a combination of the relative distance D1 and the relative velocity V1. Therefore, each coordinate uniquely corresponds to a specific arrival margin time. The same is true for FIG. 4(b).

[0027] For example, the acceleration / deceleration determination unit 42 may set a line BU, which is obtained by shifting a line representing the reference value Tr0 of the time to reach in FIG. 4A by a predetermined margin in the direction in which the relative distance D1 increases, as the upper boundary, and a line BL, which is obtained by shifting the line by the same margin in the direction in which the relative distance D1 decreases, as the lower boundary, and set the range between the upper boundary BU and the lower boundary BL as the boundary region R1. The range with rough hatching indicates the boundary region R1. For example, the predetermined margin may be a predetermined constant. For example, the upper boundary BU may be formed by a set of points where the time to reach (D1 / V1) is equal to the sum (Tr0 + (C1 / Vr)) of the reference value Tr0 and the result (C1 / Vr) of dividing a constant C1 by the relative velocity Vr. The lower boundary BL may be formed by a set of points where the arrival margin time (D1 / V1) is equal to the difference (Tr0-(C1 / Vr)) obtained by subtracting the division result (C1 / Vr) from the reference value Tr0. In this case, the acceleration / deceleration determination unit 42 may set the upper limit value of the boundary region R1 (hereinafter referred to as the "second threshold Tr2") to the sum of the reference value Tr0 and the division result (C1 / Vr) (Tr2=Tr0+(C1 / Vr)). Furthermore, the lower limit value of the boundary region R1 (hereinafter referred to as the "third threshold Tr3") may be set to the difference between the reference value Tr0 and the division result (C1 / Vr) (Tr3=Tr0-(C1 / Vr)).

[0028] FIG. 4A is a schematic diagram of another example of setting the boundary region R1. For example, the acceleration / deceleration determination unit 42 may set an upper boundary BU and a lower boundary BL by changing the slope of the reference value Tr0, and then set the range between the upper boundary BU and the lower boundary BL as the boundary region R1. The range with grained hatching indicates the boundary region R1. Specifically, the second threshold value Tr2 = Tr0 + C2 may be set by adding a predetermined value C2 to the reference value Tr0, and the third threshold value Tr3 = Tr0 - C2 may be set by subtracting the predetermined value C2 from the reference value Tr0. For example, the predetermined value C2 may be a constant. The acceleration / deceleration determination unit 42 may set the reference value Tr0 according to the vehicle speed Ve of the host vehicle Ce. For example, a larger reference value Tr0 may be set when the vehicle speed Ve is high compared to when the vehicle speed Ve is low. For example, a larger reference value Tr0 may be set as the vehicle speed Ve increases.

[0029] The acceleration / deceleration determination unit 42 determines whether the arrival margin time TR is greater than the second threshold value Tr2. In FIGS. 4( a) and 4(b), a vertically hatched region R2 indicates the range in which the arrival margin time TR is greater than the second threshold value Tr2. If the arrival margin time TR is greater than the second threshold value Tr2, the acceleration / deceleration determination unit 42 determines that merging deceleration control should be performed and outputs a deceleration command signal to the vehicle control unit 37. For example, the second threshold value Tr2 may be 4 seconds. The vehicle control unit 37 drives the actuator 17 in accordance with the deceleration command signal to decelerate the host vehicle Ce. The acceleration / deceleration determination unit 42 determines whether the arrival margin time TR is less than the third threshold value Tr3. In FIGS. 4( a) and 4(b), a horizontally hatched region R3 indicates the range in which the arrival margin time TR is less than the third threshold value Tr3. If the arrival margin time TR is less than the third threshold value Tr3, the acceleration / deceleration determination unit 42 determines that merging acceleration control should be performed and outputs an acceleration command signal to the vehicle control unit 37. The third threshold value Tr3 may be set to 2 seconds, for example. The vehicle control unit 37 drives the actuator 17 in accordance with the acceleration command signal to accelerate the host vehicle Ce.

[0030] When the arrival margin time TR is less than or equal to the second threshold value Tr2 and greater than or equal to the third threshold value Tr3 (i.e., when the arrival margin time TR is within the boundary region R1), the acceleration / deceleration determination unit 42 suspends the execution of the merging deceleration control and the merging acceleration control. In this case, the acceleration / deceleration determination unit 42 may, for example, output a constant speed control command signal to the vehicle control unit 37. In accordance with the constant speed control command signal, the vehicle control unit 37 may drive the actuator 17 so that the host vehicle Ce travels at a constant speed. Alternatively, for example, the vehicle control unit 37 may output an accelerator opening signal to the vehicle control unit 37 that sets the accelerator opening to zero or reduces the accelerator opening (the host vehicle Ce may be decelerated at a deceleration similar to that occurring when the driver releases the accelerator pedal). The vehicle control unit 37 may, for example, cause the host vehicle 1 to travel regeneratively by setting the accelerator opening of the drive source of the host vehicle Ce to zero in accordance with the accelerator opening signal. Alternatively, the vehicle control unit 37 may reduce the driving force of the host vehicle 1 by reducing the accelerator opening in accordance with the accelerator opening signal.

[0031] 4( a) and 4(b), the hatched region R4 indicates a range in which the merging vehicle Cm is located behind the host vehicle Ce and the vehicle speed Vm of the merging vehicle Cm is higher than the vehicle speed Ve of the host vehicle Ce. When the merging vehicle Cm approaches the host vehicle Ce from behind in this manner, the merging vehicle Cm may change its decision to enter in front of or behind the host vehicle Ce midway. Therefore, when the merging vehicle Cm is located behind the host vehicle Ce within a predetermined distance and the vehicle speed Vm is higher than the vehicle speed Ve, the acceleration / deceleration determination unit 42 may suspend the execution of the merging deceleration control and the merging acceleration control and leave it to the merging vehicle Cm to decide whether to enter in front of or behind the host vehicle Ce. In this case, the acceleration / deceleration judgment unit 42 may output a constant speed control command signal to the vehicle control unit 37, or may output an accelerator opening signal to the vehicle control unit 37 to set the accelerator opening to 0 or reduce the accelerator opening.

[0032] The acceleration / deceleration determination unit 42 may execute the acceleration / deceleration determination process at multiple times. For example, the acceleration / deceleration determination unit 42 may execute a first acceleration / deceleration determination process when the arrival time Tg becomes less than a first predetermined value Tg1, and a second acceleration / deceleration determination process when the arrival time Tg becomes less than a second predetermined value Tg2 that is smaller than the first predetermined value Tg1. That is, the acceleration / deceleration determination unit 42 may execute the second acceleration / deceleration determination process after a predetermined period of time has elapsed since the first acceleration / deceleration determination process was executed. For example, the first predetermined value Tg1 may be 6 seconds, and the second predetermined value Tg2 may be 4 seconds. However, if the merging vehicle Cm cannot be detected even when the arrival time Tg becomes less than the first predetermined value Tg1 because the distance at which the external sensor 11 can detect the merging vehicle Cm has become shorter, the first acceleration / deceleration determination process may be executed when the arrival time Tg becomes less than the second predetermined value Tg2. In addition, the acceleration / deceleration judgment unit 42 may perform the first acceleration / deceleration judgment process after a predetermined time has elapsed since detecting the merging vehicle Cm (in other words, it may prohibit the execution of the acceleration / deceleration judgment process until a predetermined time has elapsed since detecting the merging vehicle Cm).

[0033] The acceleration / deceleration determination unit 42 determines whether the situation in which the merging vehicle Cm will enter the first lane Ln1 is confirmed when the arrival time Tg becomes less than a third predetermined value Tg3, which is smaller than the second predetermined value Tg2. The third predetermined value Tg3 is an example of a "predetermined threshold" as described in the claims. Here, "the situation is confirmed" means that a determination as to whether the merging vehicle Cm will be placed in front of or behind the host vehicle 1 has been completed, and that the merging deceleration control or the merging acceleration control has been completed, or that even if the merging deceleration control or the merging acceleration control is ongoing, it is expected to be completed by the time the host vehicle Ce reaches the merging point Pm. "The merging deceleration control or the merging acceleration control has been completed" means that the relative distance D1 between the host vehicle Ce and the merging vehicle Cm is equal to or greater than a threshold, and the relative distance D1 does not change or increases.

[0034] The acceleration / deceleration determination unit 42 executes predetermined collision avoidance control when the situation is not determined at the timing when the arrival time Tg becomes less than the third predetermined value Tg3. For example, when it is not determined whether the merging vehicle Cm will be in front of or behind the host vehicle 1 (i.e., when merging deceleration control or merging acceleration control is not reserved), the acceleration / deceleration determination unit 42 may execute deceleration control as collision avoidance control to make it easier for the merging vehicle Cm to enter in front of the host vehicle 1. Furthermore, as the collision avoidance control, for example, the acceleration / deceleration determination unit 42 may compare the arrival margin time TR with a fourth threshold value Tr4 (e.g., 3 seconds) that is smaller than the second threshold value Tr2 and larger than the third threshold value Tr3, and execute deceleration control if the arrival margin time TR is greater than the fourth threshold value Tr4, or execute acceleration control if the arrival margin time TR is equal to or smaller than the fourth threshold value Tr4. Furthermore, for example, when merging acceleration control is not completed, the acceleration may be increased as collision avoidance control, and when merging deceleration control is not completed, the deceleration may be increased as collision avoidance control. For example, the acceleration / deceleration judgment unit 42 may also perform the above-mentioned collision avoidance control without performing the acceleration / deceleration judgment process when it detects a merging vehicle Cm for the first time after the arrival time Tg becomes less than the second predetermined value Tg2.

[0035] The acceleration / deceleration determination unit 42 displays the determination result of the acceleration / deceleration determination process and the boundary region R1 on the display device of the HMI 16. Figure 5A is a schematic diagram of an example of a screen display when it is determined that merging deceleration control should be executed to facilitate the entry of the merging vehicle Cm ahead of the host vehicle Ce. For example, the screen display may include a host vehicle icon Ice and a merging vehicle icon Icm representing the longitudinal positions of the host vehicle Ce and the merging vehicle Cm, boundary lines LU and LL representing the longitudinal positions of the boundary region R1 corresponding to the second threshold value Tr2 and the third threshold value Tr3, respectively, an arrow mark M11 indicating that merging deceleration control should be executed, and an arrow mark M12 indicating that the merging vehicle Cm should be allowed to enter ahead of the host vehicle Ce. Figure 5B is a schematic diagram of an example of a screen display when it is determined that merging acceleration control should be executed to facilitate the entry of the merging vehicle Cm behind the host vehicle Ce. For example, the screen display may include the host vehicle icon Ice, the merging vehicle icon Icm, the boundary lines LU and LL, an arrow mark M21 indicating that merging acceleration control will be executed, and an arrow mark M22 indicating that the merging vehicle Cm will enter behind the host vehicle Ce. Figure 5(c) is a schematic diagram of an example of a screen display when the execution of merging deceleration control and merging acceleration control is suspended. The screen display includes the host vehicle icon Ice, the merging vehicle icon Icm, and the boundary lines LU and LL, but does not include the above-mentioned arrow marks M11, M12, M21, and M22.

[0036] (Operation) This is a flowchart of an example of a vehicle control method according to an embodiment. In step S1, the controller 18 sets the value of the determination history flag FLG to "0." A value of "0" for the determination history flag FLG indicates that the acceleration / deceleration determination process has not yet been executed, and a value of "1" for the determination history flag FLG indicates that the process has been executed at least once. In step S2, the arrival time calculation unit 41 determines the junction point Pm. In step S3, the arrival time calculation unit 41 calculates the arrival time Tg. In step S4, the acceleration / deceleration determination unit 42 determines whether the arrival time Tg is less than a first predetermined value Tg1. If the arrival time Tg is not less than the first predetermined value Tg1 (S4: N), the process returns to step S2. If the arrival time Tg is less than the first predetermined value Tg1 (S4: Y), the process proceeds to step S5.

[0037] In step S5, the acceleration / deceleration determination unit 42 determines whether a merging vehicle Cm has been detected. If a merging vehicle Cm has not been detected (S5: N), the process returns to step S2. If a merging vehicle Cm has been detected (S5: Y), the process proceeds to step S6. In step S6, the arrival margin time calculation unit 40 calculates the relative distance D1 and the arrival margin time TR. In step S7, the acceleration / deceleration determination unit 42 determines whether the arrival margin time TR is greater than the first threshold value Tr1 or whether the relative distance D1 is greater than the threshold distance Dth. If the arrival margin time TR is less than the first threshold value Tr1 and the relative distance D1 is less than the threshold distance Dth (S7: N), the process proceeds to step S8. If the arrival margin time TR is greater than the first threshold value Tr1 or the relative distance D1 is greater than the threshold distance Dth (S7: Y), the process ends without performing merging acceleration control or merging deceleration control.

[0038] In step S8, the acceleration / deceleration determination unit 42 determines whether the determination history flag FLG is "0" and the arrival margin time TR is less than the second threshold value Tr2. If the determination history flag FLG is "0" and the arrival margin time TR is less than the second threshold value Tr2 (S8: Y), that is, if a merging vehicle Cm is detected for the first time after the arrival time Tg becomes less than the second predetermined value Tg2, the process proceeds to step S18. In this case, the acceleration / deceleration determination process (S9 to S13) is not executed, and collision avoidance control is executed in step S18. The process then ends. If the determination history flag FLG is "1" or the arrival margin time TR is equal to or greater than the second threshold value Tr2, the process proceeds to step S9.

[0039] In step S9, the acceleration / deceleration determination unit 42 determines whether the arrival margin time TR is greater than the second threshold value Tr2. If the arrival margin time TR is less than the second threshold value Tr2 (S9: N), the process proceeds to step S11. If the arrival margin time TR is greater than the second threshold value Tr2 (S9: Y), the process proceeds to step S10. In step S10, the acceleration / deceleration determination unit 42 executes merging deceleration control. Thereafter, the process proceeds to step S14. In step S11, the acceleration / deceleration determination unit 42 determines whether the arrival margin time TR is less than the third threshold value Tr3. If the arrival margin time TR is less than the third threshold value Tr3 (S11: Y), the process proceeds to step S12. If the arrival margin time TR is greater than or equal to the third threshold value Tr3 (S11: N), the process proceeds to step S13. In step S12, the acceleration / deceleration determination unit 42 executes merging acceleration control. Thereafter, the process proceeds to step S14. In step S13, the acceleration / deceleration determination unit 42 suspends the execution of the merging deceleration control and the merging acceleration control, after which the process proceeds to step S14.

[0040] In step S14, the acceleration / deceleration determination unit 42 determines whether the arrival time Tg is less than the second predetermined value Tg2. If the arrival time Tg is not less than the second predetermined value Tg2 (S14: N), the process proceeds to step S15. In step S15, the controller 18 continues the current vehicle speed control. For example, if merging deceleration control or merging acceleration control is being performed, the controller 18 continues this control. If merging deceleration control or merging acceleration control is on hold, the controller 18 continues to hold the merging deceleration control or merging acceleration control. Then, the process returns to step S14.

[0041] If the arrival time Tg is less than the second predetermined value Tg2 (S14: Y), the process proceeds to step S16. In step S16, the acceleration / deceleration determination unit 42 determines whether the arrival time Tg is greater than the third predetermined value Tg3. If the arrival time Tg is greater than the third predetermined value Tg3 (S16: Y), the process proceeds to step S17. In step S17, the controller 18 sets the value of the determination history flag FLG to "1." Thereafter, the process returns to step S6. If the arrival time Tg is equal to or less than the third predetermined value Tg3 (S16: N), the process proceeds to step S18. In step S18, collision avoidance control is executed. Thereafter, the process ends.

[0042] (Effects of the embodiment) (1) The controller executes the following processes: a process for detecting other vehicles traveling in the second lane adjacent to the first lane in which the vehicle is traveling; a process for determining the end of the section in which the vehicle can travel in the second lane as a merging point; a process for calculating an arrival time, which is the time it takes for the vehicle to reach the merging point; a process for calculating an arrival margin time, which is the time it takes for the front end of the vehicle to reach the front end of the other vehicle traveling in front of the vehicle in the second lane in the longitudinal direction; a process for determining that deceleration control should be performed if the arrival margin time is greater than a predetermined range, and that acceleration control should be performed if the arrival margin time is less than the predetermined range; and a determination process for suspending the decision on acceleration / deceleration control for the other vehicle if it is determined that the arrival time is equal to or greater than a predetermined threshold and that the arrival margin time is within the predetermined range.

[0043] In this way, when there is sufficient time until the host vehicle reaches the merging point, the execution of deceleration control and acceleration control is suspended near the boundary where it is necessary to determine whether the other vehicle should enter in front of or behind the host vehicle. This leaves it up to the other vehicle to decide whether to enter in front of or behind the host vehicle. As a result, it is possible to reduce anxiety that may arise when the controller's decision on whether the other vehicle should enter in front of or behind the host vehicle differs from the occupant's decision, or when the controller makes a decision and starts acceleration control or deceleration control before the occupant makes a decision.

[0044] (2) The controller may set a lower limit of the predetermined range by subtracting a predetermined value from the predetermined margin of arrival time and set an upper limit of the predetermined range by adding a predetermined value to the predetermined margin of arrival time. The controller may set a lower limit of the predetermined range by dividing a predetermined value by the relative speed between the host vehicle and the other vehicle, subtracting the result from the predetermined margin of arrival time, and set an upper limit of the predetermined range by adding the result to the predetermined margin of arrival time. By performing deceleration control or acceleration control outside the predetermined range set in this way, it is possible to prevent occupants from feeling uneasy.

[0045] (3) The controller may set the predetermined range according to the vehicle speed of the host vehicle. This allows the predetermined range of the time to reach to be set appropriately. (4) The controller may start the determination process after a first predetermined time has elapsed since the detection of another vehicle. This provides time for the occupant to determine the situation, thereby reducing the occupant's discomfort. (5) After executing the determination process, the controller may re-execute the determination process after a second predetermined time has elapsed. This reduces the occupant's discomfort caused by frequent changes in control.

[0046] (6) The controller may perform either deceleration control or acceleration control when the arrival time is less than a predetermined threshold and the arrival margin time is within a predetermined range. This makes it possible to avoid excessive closeness between the host vehicle and another vehicle when the host vehicle approaches a merging point. (7) The controller may suspend execution of deceleration control and acceleration control when another vehicle is present behind the host vehicle within a predetermined distance and the other vehicle's speed is higher than the host vehicle's speed. When another vehicle approaches the host vehicle from behind, there is a possibility that the other vehicle will change its decision midway. Therefore, by prioritizing the decision of the other vehicle and waiting until the situation is determined, changes in the host vehicle's behavior are reduced and a prolonged state in which the host vehicle and another vehicle are traveling side by side is avoided.

[0047] (8) The controller may set the accelerator opening to zero or reduce it when the arrival time is equal to or greater than a predetermined threshold and the arrival margin time is within a predetermined range. This allows a temporary jerk to be generated while suppressing a speed decrease, thereby notifying the driver or passengers through the vehicle behavior that a decision is pending. When the speed of the host vehicle is low, there is a high probability that another vehicle will enter in front, so the driver or passengers can prepare to decelerate the host vehicle. (9) The controller may display the determination result of the determination process and the predetermined range on a display device. By showing the passengers the positional relationship between the host vehicle and another vehicle on which the controller's decision is based, the driver or passengers can increase their confidence in the determination result and the behavior change of the host vehicle.

[0048] All examples and conditional terms described herein are intended for educational purposes to aid the reader in understanding the present invention and the concepts provided by the inventor for the advancement of technology, and should be construed without limitation to the specifically described examples and conditions above, and the configuration of examples herein for illustrating the advantages and disadvantages of the present invention. Although the embodiments of the present invention have been described in detail, it should be understood that various changes, substitutions, and alterations can be made thereto without departing from the spirit and scope of the present invention.

[0049] Ce...own vehicle, Cm...merging vehicle, 10...vehicle control device, 11...external sensor, 12...vehicle sensor, 13...positioning device, 14...map database, 15...communication device, 16...human-machine interface, 17...actuator, 18...controller, 18a...processor, 18b...storage device, 30...object detection unit, 31...own vehicle position estimation unit, 32...map acquisition unit, 33...detection integration unit, 34...object tracking unit, 35...in-map position calculation unit, 36...acceleration / deceleration control unit, 37...vehicle control unit, 40...arrival margin time calculation unit, 41...arrival time calculation unit, 42...acceleration / deceleration determination unit

Claims

1. A process of detecting another vehicle traveling ahead in a second lane adjacent to a first lane in which the host vehicle is traveling; a process of determining an end of a section in which the other vehicle can travel on the second lane as a merging point; A process of calculating an arrival time, which is a time required for the host vehicle to arrive at the junction; calculating a margin of arrival time until the front end of the host vehicle reaches the front end of the other vehicle traveling in the second lane in front of the host vehicle in the longitudinal direction; a process of performing deceleration control when the arrival time is within a predetermined threshold range and the arrival margin time is greater than the predetermined range, and performing acceleration control when the arrival margin time is less than the predetermined range; a determination process for suspending a determination on acceleration / deceleration control for the other vehicle until the arrival time falls below the predetermined threshold range when it is determined that the arrival time is within the predetermined threshold range and that the arrival margin time is also within the predetermined range; A vehicle control method comprising causing a controller to execute the above.

2. 2. The vehicle control method according to claim 1, wherein the controller sets a lower limit of the predetermined range by subtracting a predetermined value from the predetermined time to arrival, and sets an upper limit of the predetermined range by adding the predetermined value to the predetermined time to arrival.

3. 2. The vehicle control method according to claim 1, wherein the controller sets a lower limit of the predetermined range by subtracting a result obtained by dividing a predetermined value by a relative speed between the host vehicle and the other vehicle from the predetermined time to arrival, and sets an upper limit of the predetermined range by adding the result of division to the predetermined time to arrival.

4. 4. The vehicle control method according to claim 1, wherein the controller sets the predetermined range in accordance with a speed of the host vehicle.

5. 4. The vehicle control method according to claim 1, wherein the controller starts the determination process after a first predetermined time has elapsed since the other vehicle was detected.

6. 4. The vehicle control method according to claim 1, wherein the controller executes the determination process again after a second predetermined time has elapsed after the execution of the determination process.

7. The vehicle control method according to any one of claims 1 to 3, characterized in that the controller performs either deceleration control or acceleration control when the arrival time is less than the predetermined threshold value and the arrival margin time is within the predetermined range.

8. The vehicle control method according to any one of claims 1 to 3, characterized in that the controller suspends execution of deceleration control and acceleration control when the other vehicle is present behind the host vehicle within a predetermined distance and the vehicle speed of the other vehicle is higher than the vehicle speed of the host vehicle.

9. The vehicle control method according to any one of claims 1 to 3, wherein the controller sets an accelerator opening to 0 or reduces the accelerator opening when the arrival time is equal to or greater than a predetermined threshold and the arrival margin time is within the predetermined range.

10. 4. The vehicle control method according to claim 1, wherein the controller displays the determination result of the determination process and the predetermined range on a display device.

11. A process of detecting another vehicle traveling ahead in a second lane adjacent to a first lane in which the host vehicle is traveling; a process of determining an end of a section in which the other vehicle can travel on the second lane as a merging point; A process of calculating an arrival time, which is a time required for the host vehicle to arrive at the junction; calculating a margin of arrival time until the front end of the host vehicle reaches the front end of the other vehicle traveling in the second lane in front of the host vehicle in the longitudinal direction; a process of performing deceleration control when the arrival time is within a predetermined threshold range and the arrival margin time is greater than the predetermined range, and performing acceleration control when the arrival margin time is less than the predetermined range; a determination process for suspending a determination on acceleration / deceleration control for the other vehicle until the arrival time falls below the predetermined threshold range when it is determined that the arrival time is within the predetermined threshold range and that the arrival margin time is also within the predetermined range; A vehicle control device comprising: a controller that executes the above.