Vehicle control method and vehicle control device

Abstract

A vehicle control device (10) is provided with a controller (100) that controls a lane change of a host vehicle (1) from a first lane to a second lane adjacent to the first lane. A second lane monitoring unit (102) of the controller (100) starts a space detection process for detecting, from the second lane, a space necessary for the lane change. When no space is detected in the space detection process, a lateral movement control unit (104) of the controller (100) executes lateral movement control for changing the position of the host vehicle (1) in a lateral direction within the first lane. If a space is detected in the space detection process during the execution of the lateral movement control, a lane change execution unit (103) executes the lane change to the second lane.

Description

Vehicle control method and vehicle control device

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

[0002] There are known technologies for controlling lane changes of a vehicle. For example, Patent Literature 1 describes a vehicle control system that, when controlling a lane change from a first lane to a second lane, changes the position of a zone on the first lane where the vehicle is scheduled to start changing lanes to a position further back than the currently set position if it is predicted that a preceding vehicle traveling in the second lane will start decelerating.

[0003] Japanese Patent Application Laid-Open No. 2022-175913

[0004] In the vehicle control system described in Patent Document 1, the position of the zone where lane change control is scheduled to begin is changed to a rear position, so the host vehicle can change lanes to the second lane while maintaining a sufficient distance from the leading vehicle. However, in the vehicle control system described in Patent Document 1, if there is another vehicle (rear vehicle) behind the leading vehicle in the second lane and the host vehicle attempts to change lanes into the space between the leading vehicle and the rear vehicle, the distance between the rear vehicle and the host vehicle becomes short, which may prevent the host vehicle from changing lanes smoothly.

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicle control method and a vehicle control device that enable smooth lane changes.

[0006] In order to achieve the above object, a vehicle control method according to the present invention uses a processor to control a lane change of a host vehicle from a first lane to a second lane adjacent to the first lane. The processor starts a space detection process to detect a space required for a lane change from the second lane. If no space is detected in the space detection process, the processor executes lateral movement control to change the lateral position of the host vehicle within the first lane. If a space is detected in the space detection process while the lateral movement control is being executed, the processor changes lanes to the second lane.

[0007] According to the present invention, when the space required for a lane change is not detected, lateral movement control is executed to attempt to secure the space, thereby enabling a smooth lane change.

[0008] 1 is a block diagram showing an example of a functional configuration of a vehicle control device according to a first embodiment; FIG. 2 is a diagram showing an example of a hardware configuration of the vehicle control device according to the first embodiment; FIG. 3 is a diagram for explaining a monitoring range of a second lane monitoring unit; FIG. 4 is a diagram for explaining the operation of lateral movement control of a single approach pattern; FIG. 5 is a flowchart of lane change control processing according to the first embodiment; FIG. 6 is a diagram for explaining a rejection response of a vehicle (part 1); FIG. 7 is a diagram for explaining a rejection response of a vehicle (part 3); FIG. 8 is a diagram for explaining a rejection response of a vehicle (part 4); FIG. 9 is a diagram for explaining a rejection response of a vehicle (part 5); 10 is a diagram showing an example of ranking data according to Modification 1. FIG. 11 is a flowchart of lane change control processing according to Modification 1. FIG.

[0009] A vehicle control method and a vehicle control device according to an embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or equivalent parts are designated by the same reference numerals.

[0010] (First embodiment) A vehicle control device 10 according to an embodiment of the present invention is a device that controls the traveling of a host vehicle 1. The vehicle control device 10 realizes autonomous driving of the host vehicle 1 by controlling various components of the host vehicle 1. In this embodiment, the vehicle control device 10 is assumed to control level 4 autonomous driving, but other levels may be used. The vehicle control device 10 according to an embodiment of the present invention is characterized in that, when a lane change is required and there is not enough space in the lane to which the host vehicle 1 is to change lanes, the vehicle control device 10 executes lateral movement control, which will be described later, to attempt to secure space. For this reason, the following description will mainly focus on lane change control among the various controls of the host vehicle 1 performed by the vehicle control device 10. In addition, in the following description, the lane in which the host vehicle 1 is traveling will be referred to as the first lane, and the lane adjacent to the first lane into which the host vehicle 1 is to change lanes will be referred to as the second lane.

[0011] Next, the configuration of the vehicle control device 10 will be described. Fig. 1 is a diagram showing an example of the functional configuration of the vehicle control device 10. The vehicle control device 10 according to this embodiment is mounted on the host vehicle 1. In addition to the vehicle control device 10, the host vehicle 1 also includes an actuator 20 that operates each part of the host vehicle 1. In addition to the above, the host vehicle 1 also includes a turn signal, an engine, a body, a chassis, a drive train, a steering wheel, electrical parts, brakes, etc., but the general configuration of these components is not shown and will not be described here.

[0012] The vehicle control device 10 includes a controller 100 that controls the overall operation of the vehicle control device 10, a communication device 200, a position information acquisition unit 300 that acquires position information of the vehicle 1, a map database 400 that stores map information (map data) including information on roads on which the vehicle 1 is traveling, and a sensor 500 that detects the surroundings of the vehicle 1. Note that the communication device 200, the position information acquisition unit 300, the map database 400, and the sensor 500 may be configured to be shared with other systems or devices such as a navigation system.

[0013] The communication device 200 is, for example, a device such as a DCM (Data Communication Module), and is communicably connected to an external server, system, etc. wirelessly under the control of the controller 100. For example, the communication device 200 periodically communicates with a VICS (registered trademark) (Vehicle Information and Communication System) to acquire traffic information on the driving route of the vehicle 1 and the planned driving route, and outputs the traffic information to the controller 100. This traffic information includes accident information, congestion information, etc.

[0014] The position information acquisition unit 300 is any device, such as a GNSS (Global Navigation Satellite System) receiver, that can acquire the position of the vehicle 1. The GNSS receiver receives orbit information and time information from a plurality of positioning satellites, and outputs position information indicating the position of the vehicle 1 calculated based on the received signals to the controller 100.

[0015] The map database 400 is a database that stores map information (map data) including road information and intersection information. By referencing the map data stored in the map database 400, the vehicle control device 10 can recognize intersections, expressway exits, and the like ahead. The map data stored in the map database 400 also includes toll information for toll roads, etc.

[0016] The sensor 500 detects objects such as other vehicles around the host vehicle 1. The sensor 500 is, for example, a camera, a light detection and ranging (LiDAR), a radio detection and ranging (RADAR), a laser range finder (LRFw), or a sound navigation and ranging (SONAR). The sensor 500 outputs a sensor signal indicating the detection result to the controller 100. For example, the controller 100 detects the space required for the host vehicle 1 to change lanes from the second lane based on the input from the sensor 500.

[0017] The controller 100 is a control device that controls the operation (described later) of the vehicle control device 10. An example of the hardware configuration of the controller 100 is shown in Fig. 2. In the example of Fig. 2, the controller 100 includes a processor 1011, a memory 1012, a storage 1013, and a communication interface 1014, which are connected to each other via a bus 1010.

[0018] The processor 1011 includes, for example, one or more CPUs (Central Processing Units) and their peripheral circuits, and executes various types of arithmetic processing. The processor 1011 loads a control program stored in the storage 1013 into the memory 1012 and executes it. The processor 1011 may further include arithmetic circuits such as a logical arithmetic unit and a numerical arithmetic unit.

[0019] The memory 1012 includes, for example, a volatile semiconductor memory such as a RAM (Random Access Memory), and functions as a work memory for the processor 1011. The memory 1012 also temporarily stores the control program read by the processor 1011 from the storage 1013 and various data used in the processor 1011's arithmetic processing.

[0020] The storage 1013 includes a nonvolatile semiconductor memory such as an EEPROM (Electrically Erasable and Programmable Read Only Memory), a flash memory, etc. The storage 1013 stores the control program executed by the processor 1011 and various data used in the calculation processing of the processor 1011. For example, the storage 1013 stores, as examples of the various data, threshold data for detecting a space for changing lanes, data specifying a time limit for executing lateral movement control (described later), and the like.

[0021] The communication interface 1014 includes an interface circuit for connecting the controller 100 to an in-vehicle network that complies with standards such as CAN (Controller Area Network). The communication interface 1014 receives signals from the communication device 200, the map database 400, the position information acquisition unit 300, the sensor 500, and other in-vehicle components, and passes the signals to the processor 1011.

[0022] Furthermore, the communication interface 1014 transmits the vehicle control signal generated by the processor 1011 to the actuator 20 that operates the host vehicle 1. The actuator 20 is a mechanical element for driving the host vehicle 1, and includes a brake actuator, a steering motor, a drive unit (at least one of an engine and a motor), etc. The actuator 20 is controlled by the vehicle control signal received from the communication interface 1014, thereby realizing automatic driving of the host vehicle 1.

[0023] For example, the processor 1011 executes a control program stored in the storage 1013, causing the controller 100 to realize the functions shown in Fig. 1. That is, the controller 100 realizes the functions of a lane change necessity determination unit 101, a second lane monitoring unit 102, a lane change execution unit 103, and a lateral movement control unit 104. Note that these units are functional components mainly related to control when the host vehicle 1 changes lanes, and other functional components of the controller 100 are omitted from Fig. 1.

[0024] The lane change necessity determination unit 101 determines whether the host vehicle 1 needs to change lanes based on surrounding conditions, the driver's intention, and the like. For example, when the host vehicle 1 is traveling in the right lane (first lane) of a two-lane road by automated driving and plans to turn left at an intersection ahead, the lane change necessity determination unit 101 determines that the host vehicle 1 needs to change lanes to the adjacent lane to the left (second lane). For example, when traffic information received via the communication device 200 indicates that the host vehicle 1's traveling lane (first lane) is impassable due to construction, the lane change necessity determination unit 101 determines that the host vehicle 1 needs to change lanes to the adjacent lane (second lane). For example, when the left turn signal is flashing due to the driver's operation, the lane change necessity determination unit 101 determines that the host vehicle 1 needs to change lanes to the adjacent lane to the left (second lane).

[0025] When the lane change necessity determination unit 101 determines that it is necessary to change lanes to the second lane, the second lane monitoring unit 102 monitors a preset monitoring area Z1 around the host vehicle 1 in the second lane shown in FIG. 3 based on the output of the sensor 500, and determines whether or not there is a space in the monitoring area Z1 that is equal to or larger than a threshold value required for a lane change. Note that the detection range of the sensor 500 in the second lane may be the monitoring area Z1. The threshold value for space detection may be a preset fixed distance, or may be a distance that is set each time based on the speed of the host vehicle 1, the distance to an intersection or an expressway exit ahead, etc.

[0026] Furthermore, the second lane monitoring unit 102 monitors a monitoring area Z1 around the host vehicle 1 in the second lane based on the output of the sensor 500, and when there is a vehicle traveling in the monitoring area Z1, determines whether the vehicle is exhibiting a refusal to allow the host vehicle 1 to change lanes. Specifically, the second lane monitoring unit 102 determines that the vehicle is exhibiting a refusal to change lanes when the vehicle traveling in the second lane changes its lateral position in the second lane by a threshold value or more, accelerates, decelerates (suddenly decelerates) by a threshold value or more, or the like.

[0027] When the second lane monitoring unit 102 determines that there is space in the second lane, the lane change execution unit 103 sends a specific control signal to the actuator 20 to control the speed and direction of the vehicle 1, thereby causing the vehicle 1 to change lanes toward the space.

[0028] When the second lane monitoring unit 102 determines that there is no space in the second lane required for a lane change, the lateral movement control unit 104 executes lateral movement control to change the lateral position of the host vehicle 1 in the first lane for a predetermined time limit by transmitting a specific control signal to the actuator 20 to control the speed and direction of the host vehicle 1. Furthermore, when the required space in the second lane is not detected even after the time limit has elapsed, or when the second lane monitoring unit 102 detects a refusal response from a vehicle traveling in the second lane, the lateral movement control unit 104 terminates the lateral movement control and returns the position of the host vehicle 1 to the center of the first lane.

[0029] Here, the lateral movement control executed by the lateral movement control unit 104 will be specifically described. FIG. 4 shows the change in the lateral position of the host vehicle 1 in the first lane when the host vehicle 1 executes the lateral movement control. In FIG. 4, the lane immediately to the left of the first lane is the second lane to which the host vehicle 1 is to change lanes. When the lateral movement control is started at the lateral movement control start time t1, the host vehicle 1 traveling in the center of the first lane moves to the left, i.e., the second lane, up to the limit distance P1 at which the host vehicle 1 does not deviate from the first lane, and then maintains that position until the lateral movement control end time t2, which is the time limit, and travels in the first lane. This causes the host vehicle 1 to approach the second lane as close as possible, which is different from normal driving. This notifies the drivers of nearby vehicles traveling in the second lane of the urgency of the lane change and encourages them to perform driving operations to ensure the space necessary for the lane change. After the lateral movement control end time t2, the time limit has elapsed, so the lateral movement control ends and the position of the vehicle 1 is returned to the center of lane 1. Note that the lateral movement control shown in Figure 4 is a control pattern in which the position of the vehicle 1 changes so as to approach the second lane once, and therefore in the following description it is also referred to as lane change control of a one-time approach pattern.

[0030] Next, the operation of the vehicle control device 10 configured as described above will be described in detail with reference to Fig. 5. Fig. 5 is a flowchart of lane change control processing executed by the vehicle control device 10 of the host vehicle 1. The lane change control processing shown in this flowchart is started when the lane change necessity determination unit 101 determines that the host vehicle 1 needs to change lanes to the adjacent second lane while the host vehicle 1 is traveling in the first lane by autonomous driving. Note that apart from this processing, other vehicle control processing such as collision avoidance processing is also executed in parallel.

[0031] First, the second lane monitoring unit 102 monitors a monitoring area Z1 around the host vehicle 1 in the second lane based on the output of the sensor 500, and starts a space detection process to detect a space equal to or larger than the threshold required for a lane change from the monitoring area Z1 (step S101). This space detection process is executed in parallel with other processes until the lane change control process is completed. Note that the space detection process also detects vehicles traveling in the second lane.

[0032] If a space is detected by the space detection process (step S102; Yes), the lane change execution unit 103 causes the host vehicle 1 to change lanes toward the detected space (step S103), and the lane change control process then ends.

[0033] On the other hand, if no space is detected in the space detection process (step S102; No), the lateral movement control unit 104 starts lateral movement control of a one-time approach pattern that changes the lateral position of the vehicle 1 within the first lane as shown in Figure 4 (step S104).

[0034] After the lateral movement control is started, if a space is detected by the space detection process (step S105; Yes), the lane change execution unit 103 controls the vehicle 1 to change lanes toward the detected space.

[0035] On the other hand, if no space is detected from the second lane even after lateral movement control is started (step S105; No), the second lane monitoring unit 102 determines whether vehicles within the monitoring area Z1 around the vehicle 1 on the second lane are showing a refusal to allow the vehicle 1 to change lanes (step S106).

[0036] Here, the rejection reaction will be specifically explained using the drawings. For example, Fig. 6A shows the situation around the host vehicle 1 when it is determined that a lane change to the second lane is necessary. As shown in this figure, two vehicles 2 and 3 are traveling in a monitoring area Z1 around the host vehicle 1 in the second lane, and the distance between the vehicles 2 and 3 is narrow, so there is not enough space to change lanes. Therefore, lateral movement control is executed, and the host vehicle 1 changes its position so as to approach the second lane.

[0037] In response to the movement of the host vehicle 1 shown in Figure 6A, if the rear vehicle 3 changes its lateral position in the second lane by more than a threshold value so as to move away from the host vehicle 1 as shown in Figure 6B, or if it changes its lateral position in the second lane by more than a threshold value so as to move closer to the host vehicle 1 as shown in Figure 6C, the second lane monitoring unit 102 determines that the vehicle 3 is exhibiting a rejection reaction.

[0038] Furthermore, in response to the movement of the host vehicle 1 shown in Figure 6A, if the vehicle 3 behind accelerates as shown in Figure 6D, further shortening the distance between the vehicle 1 and the vehicle 2 in front, or if the vehicle suddenly decelerates by more than a threshold value, for example by braking suddenly as shown in Figure 6E, the second lane monitoring unit 102 determines that the vehicle 3 is exhibiting a rejection reaction.

[0039] 5, if it is determined that the host vehicle 1 has a refusal reaction (step S106; Yes), it will be difficult for the host vehicle 1 to obtain the space necessary for changing lanes even if the lateral movement control is continued, and therefore the lateral movement control unit 104 ends the lateral movement control and controls the host vehicle 1 to travel in the center of the first lane (step S107).Then, the lane change control process ends.

[0040] Furthermore, even if no rejection reaction is observed (step S106; No), if the time limit has elapsed since the start of the lateral movement control (step S108; Yes), the lateral movement control unit 104 similarly terminates the lateral movement control and controls the vehicle to travel in the center of the first lane (step S107). The lane change control process then terminates. On the other hand, if the time limit has not elapsed (step S108; No), the process returns to step S105, and the lateral movement control continues.

[0041] As described above, in the vehicle control device 10 according to this embodiment, when a lane change from the first lane to the second lane is required, the second lane monitoring unit 102 initiates a space detection process to detect a space required for the lane change from the second lane. If no space is detected in the space detection process, the lateral movement control unit 104 executes lateral movement control to change the lateral position of the host vehicle 1 within the first lane. This lateral movement control causes the host vehicle 1 to behave differently from normal driving, thereby informing the drivers of nearby vehicles traveling in the second lane of the urgency of the need to change lanes and urging them to perform a driving operation to ensure the space required for the lane change. This makes it possible to achieve a smooth lane change with the required space secured.

[0042] Furthermore, in the vehicle control device 10 according to this embodiment, if a refusal to allow a lane change is detected from a vehicle traveling in the second lane, the lateral movement control is terminated, thereby preventing a situation in which lateral movement control is executed unnecessarily in a situation in which it is not possible to secure space for a lane change, causing the vehicle 1 to behave unnaturally for a long period of time.

[0043] (Variations of the First Embodiment) In the first embodiment, the lateral movement control unit 104 executed the lateral movement control of the one-time approach pattern, which changes the lateral position of the host vehicle 1 in the first lane so as to approach the second lane once as shown in Fig. 4, but the control pattern of the lateral movement control executed by the lateral movement control unit 104 is not limited to this. Lateral movement control other than the one-time approach pattern will be described using Figs. 7A to 7E. Note that Figs. 7A to 7E all assume lateral movement control when changing lanes to the second lane, which is adjacent to the first lane on the left.

[0044] 7A, the lateral movement control unit 104 may execute lateral movement control to change the position of the vehicle 1 so that the vehicle approaches the second lane on the left side twice within a time limit. In the following description, this lateral movement control is also referred to as lane change control with a two-time approach pattern.

[0045] 7B , the lateral movement control unit 104 may execute lateral movement control in which the host vehicle 1 oscillates so as to repeatedly approach and leave the second lane within a predetermined period T1 without going beyond the first lane. In the following description, this lateral movement control is also referred to as lane change control with an oscillation pattern.

[0046] 7C , the lateral movement control unit 104 may execute lateral movement control in which the host vehicle 1 moves to the left so as to approach the second lane, and then oscillates left and right at a predetermined period T2. In the following description, this lateral movement control is also referred to as lane change control with an approaching oscillating pattern.

[0047] For example, as shown in Fig. 7D, the lateral movement control unit 104 may execute lateral movement control that changes the position of the vehicle 1 so as to move away from lane 2, contrary to the above-described one-time approach pattern (Fig. 3). In the following description, this lateral movement control is also referred to as lane change control of a departure pattern.

[0048] For example, as shown in Fig. 7E, the lateral movement control unit 104 may execute lateral movement control to change the position of the host vehicle 1 so that the host vehicle 1 approaches the second lane in stages. In the following description, this lateral movement control is also referred to as lane change control with a staged approach pattern. Note that, although Fig. 7E shows the host vehicle 1 approaching the second lane in two stages, the host vehicle 1 may approach the second lane in more stages.

[0049] The lane change control of each control pattern shown in Figures 7A to 7E results in more complex behavior of the vehicle 1 than the lane change control of the single approach pattern described above, and is therefore expected to be more easily noticed by the driver of a vehicle traveling in the second lane, thereby improving the possibility of securing space and changing lanes.

[0050] Second Embodiment Next, a second embodiment will be described. There are two types of lane changes: a highly urgent lane change that needs to be executed reliably, and a less urgent lane change that has little impact if not executed. The second embodiment is characterized by executing lateral movement control that takes into account the urgency of such lane changes.

[0051] 8 is a diagram showing an example of the functional configuration of a vehicle control device 11 according to the second embodiment. Compared to the vehicle control device 10 according to the first embodiment, the vehicle control device 11 according to the second embodiment newly includes an urgency calculation unit 105 and a control pattern determination unit 106. Note that the hardware configuration of the vehicle control device 11 according to the second embodiment is substantially the same as the hardware configuration of the vehicle control device 10 according to the first embodiment shown in FIG. 2, and therefore a description thereof will be omitted.

[0052] The urgency calculation unit 105 calculates an urgency indicating the degree of urgency of the lane change that the lane change necessity determination unit 101 has determined to be necessary. In this embodiment, the initial setting value of the urgency is set to 0, and the urgency calculation unit 105 calculates the urgency by adding 1 to the urgency each time the conditions shown in Fig. 9 are satisfied. Since six conditions are listed in Fig. 9, the urgency calculation unit 105 can calculate the urgency on a seven-level scale from 0 to 7.

[0053] For example, the urgency calculation unit 105 determines whether the increase in cost associated with a route change resulting from not changing lanes is equal to or greater than a predetermined threshold, based on map data stored in the map database 400. If it determines that the increase in cost is equal to or greater than the threshold, the urgency calculation unit 105 adds 1 to the urgency of the lane change. The increase in cost here refers to the increase in monetary costs, such as fuel costs and tolls, associated with the route change, the increase in time costs to reach the target value, and the like. Note that the urgency calculation unit 105 may set the urgency more precisely depending on the increase in cost.

[0054] For example, the urgency calculation unit 105 determines whether the congestion level when traveling on a route without lane changes increases by a threshold or more compared to the congestion level when traveling on a route with lane changes, based on congestion information included in traffic information acquired via the communication device 200, map data stored in the map database 400, etc. If it is determined that the congestion level increases by the threshold or more, the urgency calculation unit 105 increments the urgency by 1. Note that the urgency calculation unit 105 may set the urgency level more precisely depending on the increase in the congestion level.

[0055] For example, the urgency calculation unit 105 determines whether the vehicle 1 has previously failed to change lanes at the same location based on the output of the position information acquisition unit 300, the autonomous driving driving log data, etc. If it is determined that the vehicle 1 has previously failed to change lanes, the urgency calculation unit 105 adds 1 to the urgency. Note that the urgency calculation unit 105 may set the urgency more precisely depending on the number of failures, etc.

[0056] For example, if the urgency calculation unit 105 cannot detect the space necessary for changing lanes from the second lane for a predetermined time after starting the lateral movement control, the urgency calculation unit 105 adds 1 to the urgency. Note that the urgency calculation unit 105 may set the urgency more precisely depending on the time during which the space cannot be detected from the second lane.

[0057] For example, the urgency calculation unit 105 estimates the success rate of the current lane change from the circumstances around the vehicle 1, and if the estimated success rate is equal to or lower than a threshold, adds 1 to the urgency rate. The success rate of the lane change may be estimated based on the vehicle type, deceleration, inter-vehicle distance, remaining time until the time limit, etc. of the vehicle traveling in the second lane, which are acquired based on the output of the sensor 500. Note that the urgency calculation unit 105 may set the urgency rate more precisely depending on the success rate of the lane change.

[0058] For example, when an emergency vehicle is approaching from behind in the first lane in which the host vehicle 1 is traveling, the urgency calculation unit 105 adds 1 to the urgency. In this case, the urgency calculation unit 105 may set the urgency to the maximum value regardless of whether other conditions are met.

[0059] The method for calculating the urgency of a lane change is not limited to the above. For example, the urgency may be calculated based on whether or not more conditions than those shown in FIG. 9 are met.

[0060] 8 , the control pattern determination unit 106 determines a control pattern for lateral movement control based on the urgency of the lane change calculated by the urgency calculation unit 105. Specifically, the control pattern determination unit 106 determines a control pattern that is considered to have a higher probability of succeeding in changing lanes as the urgency increases.

[0061] The lateral movement control unit 104 executes lateral movement control based on the control pattern determined by the control pattern determination unit 106 .

[0062] Next, the operation of the lane change control process executed by the vehicle control device 11 will be described using the flowchart in Fig. 10. The lane change control process executed by the vehicle control device 11 is substantially the same as the lane change control process of the first embodiment (Fig. 5) except for the addition of steps S201 to S206, so only the added parts will be described in detail, and the description of the other parts will be simplified or omitted as appropriate.

[0063] When the space detection process is started (step S101) and the space required for the lane change is not detected from the second lane (step S102; No), the urgency calculation unit 105 calculates the urgency of the current lane change (step S201). As described above, the urgency is calculated by adding up the urgency each time the conditions shown in FIG. 9 are satisfied.

[0064] If the calculated urgency level is 1 or less (step S202; Yes), the control pattern determination unit 106 determines the control pattern of the lateral movement control to be the one-time approach pattern shown in Fig. 4 (step S203). The one-time approach pattern is the same as the control pattern of the lateral movement control executed in the lane change control process of the first embodiment.

[0065] On the other hand, if the calculated urgency is greater than 1 (step S202; No) and less than 2 (step S204; Yes), the control pattern determination unit 106 determines the control pattern for lateral movement control to be the two-approach pattern shown in Figure 7A (step S205).

[0066] On the other hand, if the calculated urgency level is greater than 2 (step S204; No), the control pattern determination unit 106 determines the control pattern for lateral movement control to be the swing pattern shown in FIG. 7B (step S206).

[0067] After the control pattern is determined in any one of steps S203, S205, and S206, the lateral movement control unit 104 starts lateral movement control based on the determined control pattern (step S104). The subsequent steps are the same as the lane change control process in the first embodiment, and therefore will not be described further.

[0068] As described above, in the vehicle control device 11 according to the present embodiment, in the lane change control process, lateral movement control is executed using a control pattern determined based on the urgency of the lane change. Specifically, when the urgency of the lane change is high, lateral movement control using a swing pattern is executed, in which the host vehicle 1 moves significantly left and right in the first lane, which is likely to attract the attention of the driver of the vehicle traveling in the second lane and is expected to result in a driving operation to secure space, thereby improving the possibility of successfully changing lanes. On the other hand, when the urgency of the lane change is low, lateral mobility control using a single approach pattern is executed, in which the host vehicle 1 does not move significantly in the first lane, which makes it possible to prevent a situation in which unnatural movements cause anxiety to the drivers of other vehicles.

[0069] In the lane change control process described above, the control pattern for lateral movement control is determined to be one of the single approach pattern, double approach pattern, and swing pattern based on the degree of urgency. However, this is merely an example, and the control pattern to be determined based on the degree of urgency can be determined arbitrarily. For example, the control pattern may be determined more precisely based on the degree of urgency.

[0070] (Variation 1) For example, the control pattern of the lateral movement control to be executed in the lane change control process of each embodiment may be determined based on the results of lateral movement control executed so far, including for vehicles other than the subject vehicle 1. Specifically, a large amount of result data indicating the results of the lateral movement control executed so far is stored in an external cloud server (not shown). This result data includes information indicating the control pattern of the executed lateral movement control, the region and date and time in which the lateral movement control was executed, whether the lane change was successful after the lateral movement control, and the like. In addition, the cloud server periodically tallys up the accumulated result data and stores ranking data, such as that shown in FIG. 11 , indicating the top three lateral movement control patterns most effective for successful lane changes for each region.

[0071] In the lane change control process (FIG. 5) of the first embodiment, the controller 100 may refer to the ranking data acquired from the cloud server via the communication device 200 and start the lateral movement control of the control pattern that is most effective in the region where the vehicle 1 is currently located in step S104.

[0072] In addition, in the case of the lane change control processing of the second embodiment, the process may be modified as shown in Figure 12, and if the urgency is 1 or less, the control pattern with the third highest effectiveness in the region where the vehicle 1 is currently located is selected (step S2031), if the urgency is greater than 1 but less than 2, the control pattern with the second highest effectiveness is selected (step S2051), and if the urgency is greater than 2, the control pattern with the first highest effectiveness is selected (step S2061).

[0073] In this way, it becomes possible to execute lateral movement control with a highly effective control pattern based on the results of lateral movement control that has actually been performed. Note that the control pattern of lateral movement control to be executed may be determined based on ranking data by time of day, season, etc., rather than the ranking data by region as shown in Figure 11. Furthermore, without referring to such ranking data, the result data of lateral movement control may be analyzed by artificial intelligence, and the most effective control pattern of lateral movement control may be executed.

[0074] (Other Modifications) The hardware configurations and flowcharts shown in the above-described embodiments and modifications are merely examples, and can be modified or applied as desired.

[0075] In addition, in the above embodiment, an example was described in which each function is realized by the processor 1011 executing a control program, but the vehicle control device 10 may also be configured using dedicated hardware that realizes each function.

[0076] Furthermore, the vehicle control device 10 may be configured to realize each function by storing and distributing a control program for executing the operations of the above-described embodiments on a computer-readable recording medium such as a CD-ROM (Compact Disc Read-Only Memory), a DVD (Digital Versatile Disc), an MO (Magneto Optical Disc), or a memory card, and installing the program on a computer. When each function is realized by sharing the work between an OS (Operating System) and an application, or by cooperation between the OS and an application, only the parts other than the OS may be stored on the recording medium.

[0077] The present invention allows various embodiments and modifications without departing from the broad spirit and scope of the present invention. Furthermore, the above-described embodiments are intended to explain the present invention and do not limit the scope of the present invention. In other words, the scope of the present invention is defined by the claims, not by the embodiments. Various modifications made within the scope of the claims and the meaning of the disclosure equivalent thereto are considered to be within the scope of the present invention.

[0078] 1 Vehicle, 2, 3 Vehicle, 10, 1 Vehicle control device, 20 Actuator, 100 Controller, 200 Communication device, 300 Position information acquisition unit, 400 Map database, 500 Sensor, 101 Lane change necessity determination unit, 102 Second lane monitoring unit, 103 Lane change execution unit, 104 Lateral movement control unit, 105 Urgency calculation unit, 106 Control pattern determination unit, 1010 Bus, 1011 Processor, 1012 Memory, 1013 Storage, 1014 Communication interface, t1 Lateral movement control start time, t2 Lateral movement control end time, Z1 Monitoring area, P1 Limit distance, T1, T2 Period.

Claims

1. A vehicle control method that uses a processor to control a lane change of a host vehicle from a first lane to a second lane adjacent to the first lane, wherein the processor: initiates a space detection process to detect a space required for the lane change from the second lane; if the space is not detected by the space detection process, executes lateral movement control to change the lateral position of the host vehicle within the first lane; and if the space is detected by the space detection process while the lateral movement control is being executed, changes lanes to the second lane.

2. The vehicle control method according to claim 1, wherein the processor executes the lateral movement control with a control pattern that changes the position of the host vehicle so as to repeatedly approach and leave the second lane.

3. The vehicle control method according to claim 1, wherein the processor executes the lateral movement control with a control pattern that changes the position of the host vehicle so as to gradually approach the second lane.

4. The vehicle control method according to claim 1, wherein the processor executes the lateral movement control with a control pattern that changes the position of the host vehicle so as to move away from the second lane.

5. The vehicle control method described in claim 1, wherein the processor executes the lateral movement control of a control pattern in which the position of the vehicle is changed so as to approach the second lane, and then the position of the vehicle is changed so as to repeatedly approach and leave the second lane.

6. A vehicle control method according to any one of claims 1 to 5, wherein the processor determines a control pattern for the lateral movement control depending on the urgency of the lane change.

7. The vehicle control method according to claim 6, wherein the processor sets the urgency based on a time during which the space cannot be detected in the space detection process.

8. The vehicle control method according to claim 6 or 7, wherein the processor sets the urgency level based on an amount of increase in cost in the event of a failed lane change.

9. A vehicle control method as claimed in any one of claims 6 to 8, wherein the processor estimates the success rate of changing lanes to the second lane from the conditions around the vehicle, and sets the urgency level based on the estimated success rate.

10. A vehicle control method according to any one of claims 6 to 9, wherein the processor sets the urgency level based on whether the vehicle has previously failed to change lanes at the same point.

11. A vehicle control method according to any one of claims 1 to 10, wherein the processor determines a control pattern for the lateral movement control to be executed based on results of the lateral movement control executed so far, including for vehicles other than the subject vehicle.

12. A vehicle control method as claimed in any one of claims 1 to 11, wherein the processor terminates the lateral movement control when it detects a refusal to allow a lane change from a vehicle traveling in the second lane.

13. A vehicle control device comprising: a processor that controls lane changes of a host vehicle from a first lane to a second lane adjacent to the first lane; and a sensor that detects the surroundings of the host vehicle, wherein the processor: starts a space detection process that detects a space required for the lane change from the second lane based on the output of the sensor; if the space is not detected by the space detection process, executes lateral movement control that changes the lateral position of the host vehicle within the first lane; and if the space is detected by the space detection process while the lateral movement control is being executed, changes lanes to the second lane.

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