Driving assistance method and driving assistance device

Abstract

A driving assistance method performs a lane change of an own vehicle (1) based on autonomous travel control, in which a controller (20) executes a process of determining whether the own vehicle is traveling on a first lane on which a vehicle is limited in a case where a vehicle is limited on the first lane and a second lane that are contiguous to each other and are included in a road on which the own vehicle travels (S2); and a process of not performing a lane change from the first lane to the second lane based on autonomous travel control in a case where it is determined that the own vehicle is traveling on the first lane (S3).

Description

TECHNICAL FIELD

[0001] The present application relates to a driving assistance method and a driving assistance device. BACKGROUND

[0002] A vehicle control device described in Patent Document 1 sets a judgment condition for allowing a lane change of a host vehicle from a host lane to an adjacent lane in accordance with a category of the adjacent lane, and performs travel control or assistance control related to the lane change in a case where the judgment condition is satisfied.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT DOCUMENT

[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-144976

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] Among a plurality of lanes of the same road, a vehicle that can travel on a part of the lanes is sometimes restricted by a rule. In the following description, a lane on which a vehicle that can travel in accordance with the rule is restricted is expressed as a "specific lane", and a lane other than the specific lane is expressed as a "general lane".

[0008] In a case where it is not possible to determine whether or not it is possible to travel on a specific lane even if an automatic lane change function is provided, it is preferable not to perform an automatic lane change from a general lane to a specific lane. In this case, if a lane change from a specific lane to a general lane is performed, a passenger can think that the automatic lane change function is irrelevant to the specific lane, and misinterpret that a lane change from a general lane to a specific lane is also possible. SUMMARY

[0009] An object of the present application is to provide an automatic lane change function that complies with a rule of a vehicle that is restricted from traveling on a specific lane, and to make it easy for a passenger to recognize a case where an automatic lane change to a specific lane is restricted.

[0010] According to one embodiment of the present application, there is provided a driving assistance method that performs a lane change of a host vehicle based on an automatic lane change function. In the driving assistance method, a controller performs a process of determining whether or not the host vehicle is traveling on a first lane of a plurality of lanes of the same traffic direction that are adjacent to each other on a road on which the host vehicle is traveling, the first lane being a lane on which a vehicle is restricted, and a process of not performing a lane change from the first lane to a second lane based on the automatic lane change function in a case where it is determined that the host vehicle is traveling on the first lane.

[0011] EFFECT OF THE INVENTION

[0012] According to the present application, it is possible to provide an automatic lane change function that complies with the rule that a vehicle is restricted from traveling on a specific lane, and to make it easy for an occupant to recognize a case where a lane change to the specific lane is restricted.

[0013] The objects and advantages of the present application will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application, as claimed. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is a diagram showing an example of an outline structure of a vehicle on which a driving assistance device of an embodiment is mounted.

[0015] Figure 2 is a diagram showing a part of an input device of Figure 1 .

[0016] Figure 3 is a block diagram showing an example of a functional structure of a controller.

[0017] Figure 4 is a flowchart showing an example of a driving assistance method of an embodiment. DETAILED DESCRIPTION

[0018] (Structure)

[0019] Figure 1 is a diagram showing an example of an outline structure of a vehicle on which a driving assistance device of an embodiment is mounted. The driving assistance device 10 mounted on the host vehicle 1 is provided with a sensor 11, a position measurement device 12, a map database (map DB) 13, an in-vehicle device 14, a navigation system 15, a display device 16, a sound output device 17, an input device 18, a vehicle behavior control device 19, and a controller 20. These devices are connected to each other for mutual transmission and reception of information, for example, by a CAN (Controller Area Network) and other in-vehicle LANs.

[0020] The sensor 11 detects a traveling state of the host vehicle 1. For example, the sensor 11 includes a front camera that takes an image of a front of the host vehicle 1, a rear camera that takes an image of a rear of the host vehicle 1, a side camera that takes an image of a left and right side of the host vehicle 1, and the like. In addition, the sensor 11 includes a front radar that detects an obstacle in front of the host vehicle 1, a rear radar that detects an obstacle in rear of the host vehicle 1, a side radar that detects an obstacle present on the left and right side of the host vehicle 1, and the like. Furthermore, the sensor 11 includes a vehicle speed sensor that detects a vehicle speed of the host vehicle 1, and the like.

[0021] The position measurement device 12 is provided with a GPS unit, a gyro sensor, a vehicle speed sensor, and the like. The position measurement device 12 detects radio waves transmitted from a plurality of communication satellites by the GPS unit, and acquires position information of the host vehicle 1 periodically. In addition, the position measurement device 12 detects the current position of the host vehicle 1 based on the acquired position information of the host vehicle 1, angle change information acquired from the gyro sensor, and vehicle speed acquired from the vehicle speed sensor.

[0022] The map database 13 is a storage that stores three-dimensional high-precision map information including position information of various facilities and specific locations, and is accessible from the controller 20. The three-dimensional high-precision map information is map information in which detailed and high-precision position information of a curved road and the size (for example, curvature or curvature radius) of the curved road, a merging point of a road, a branching point, a toll gate, a position of reduction of the number of lanes, and the like are associated with map information. In addition, the three-dimensional high-precision map information is information as a unit of a lane (that is, lane information), and includes information of a lane node that represents a reference point on a lane reference line (for example, a center line in a lane), and information of a lane link that represents an interval form of a lane between lane nodes.

[0023] In addition, the map database 13 can also include lane category information regarding the lane category of each lane. The lane category information can be information that represents, as a lane category, for example, a specific lane in which a vehicle that can travel is limited due to a traffic rule, or a general lane other than the specific lane. The specific lane can be, for example, an HOV (High Occupancy Vehicle) lane or a carpool lane provided on a free lane in the United States. The specific lane and the general lane are examples of the "first lane" and the "second lane" described in the scope of the right request, respectively.

[0024] The in-vehicle device 14 is various devices mounted on the host vehicle 1, and acts by operation of an occupant (for example, a driver). As such in-vehicle devices, a steering wheel, an accelerator pedal, a brake pedal, a direction indicator, a wiper, a lamp, a horn, and other specific switches, and the like can be listed.

[0025] The navigation system 15 acquires the current position information of the host vehicle 1 from the position measuring device 12, and superimposes the position of the host vehicle 1 on the map information for navigation, and displays it on a display or the like. In addition, the navigation system 15, in the case where a destination is set, sets a route from the current position of the host vehicle 1 to the destination as a target travel route, and performs a navigation control that guides the target travel route to the occupant. In this navigation control, the navigation system 15 displays the target travel route on the map of the display, and informs the occupant of the target travel route by voice or the like. The target travel route set in the navigation system 15 is also used for the route travel assist control of the controller 20. The route travel assist control is a control that causes the host vehicle 1 to autonomously travel along the set target travel route to the destination.

[0026] The display device 16 includes various displays such as a display possessed by the navigation system 15, a display incorporated into a mirror in the vehicle, a display incorporated into an instrument panel, a head-up display that is mapped onto a windshield, and the like. The display device 16 informs the occupant of various pieces of prompt information in accordance with the control of the controller 20.

[0027] The sound output device 17 is a device that outputs audible information of a speaker possessed by the navigation system 15, a speaker of an audio device, a buzzer, or the like. The sound output device 17 informs the occupant of various pieces of prompt information in accordance with the control of the controller 20.

[0028] The input device 18 is, for example, a button switch that can be input by manual operation of the occupant, a touch panel that is arranged on a screen of a display, or a microphone that can be input by voice of the occupant, or the like. The occupant can input setting information for prompt information prompted by the display device 16 or the audio output device 17 by operating the input device 18.

[0029] Figure 2 FIG. 7 is a view that shows an example of the input device 18 of the present embodiment. The input device 18 can be, for example, a button switch group arranged in a spoke portion of a steering wheel. The input device 18 is used for setting on / off and the like of the autonomous travel control based on the controller 20. The input device 18 includes a main switch 181, a resume / acceleration switch 182, a set / coast switch 183, a cancel switch 184, an inter-vehicle adjustment switch 185, and a lane change assist switch 186.

[0030] The main switch 181 is a switch that turns on / off the autonomous travel control of the controller 20. The resume / accelerate switch 182 is a switch that sets to restart the autonomous travel control at the set speed before the autonomous travel control is turned off, or to increase the set speed. The set / coast switch 183 is a switch that starts the autonomous travel control. To start the autonomous travel control, the set / coast switch 183 is pressed after the autonomous travel control is turned on by the main switch 181. In addition, the set / coast switch 183 is a switch that decreases the set speed. The cancel switch 184 is a switch that cancels the autonomous travel control. The inter-vehicle adjustment switch 185 is a switch for setting the inter-vehicle distance from the preceding vehicle. The lane change assist switch 186 is a switch for indicating (confirming) the start of the lane change when the controller 20 confirms the start of the lane change to the occupant.

[0031] In addition, in addition to the button switch group shown in FIG. 1, a direction indicator lever of the direction indicator or a switch of another in-vehicle device 14 can be used as the input device 18. Figure 2

[0032] The vehicle behavior control device 19 controls the vehicle behavior of the host vehicle 1. For example, in a case where the host vehicle 1 is cruising at a set speed by the autonomous travel control, the vehicle behavior control device 19 controls the operation of the drive mechanism and the operation of the brake for achieving the acceleration / deceleration and the travel speed so that the host vehicle 1 becomes the set speed. In addition, in a case where the host vehicle 1 is following the preceding vehicle by the autonomous travel control, the vehicle behavior control device 19 also controls the operation of the drive mechanism and the operation of the brake. In addition, the operation control of the drive mechanism includes the operation of the internal combustion engine in an engine automobile, and the operation of the travel motor in an electric automobile system. In addition, in a hybrid automobile, the torque distribution of the internal combustion engine and the travel motor is included.

[0033] In addition, in a case where the lane keeping control, the lane change assist control, the overtaking assist control, or the route travel assist control described later is executed by the autonomous travel control, the vehicle behavior control device 19 executes the steering control of the host vehicle 1 by controlling the operation of the steering actuator in addition to the operation control of the drive mechanism and the brake.

[0034] The controller 20 is one or a plurality of electronic control units (ECUs) for controlling the travel of the host vehicle 1, and includes a processor 21, a storage device 22, and the like. The processor 21 can be, for example, a CPU or an MPU. The storage device 22 can have a semiconductor storage device, a magnetic storage device, an optical storage device, and the like. The storage device 22 can include a register, a cache memory, a memory such as a ROM and a RAM serving as a main storage device, and the like.

[0035] ​The functions of the controller 20 described below are realized, for example, by causing the processor 21 to execute a computer program stored in the storage 22.

[0036] The controller 20 realizes a travel information acquisition function of acquiring information relating to the travel state of the host vehicle 1, and executes autonomous travel control of autonomously controlling the travel speed and / or the steering of the host vehicle 1. The travel information acquisition function is a function of acquiring travel information relating to the travel state of the host vehicle 1. For example, the controller 20 can acquire image information of the outside of the vehicle taken by the front camera, the rear camera, and the side camera of the sensor 11 as the travel information. In addition, the controller 20 acquires detection results of the front radar, the rear radar, and the side radar as the travel information. Furthermore, the controller 20 also acquires vehicle speed information of the host vehicle 1 detected by the vehicle speed sensor of the sensor 11 as the travel information.

[0037] Furthermore, the controller 20 acquires current position information of the host vehicle 1 from the position measuring device 12 as the travel information. The controller 20 acquires a set destination and a target travel route to the destination from the navigation system 15 as the travel information. The controller 20 acquires map information such as position information of a curved road and the size (for example, the curvature or the curvature radius) of the curved road, a merging point, a branching point, a tollgate, a position of a reduction in the number of lanes, and lane information from the map database 13 as the travel information. The controller 20 acquires operation information of the in-vehicle device 14 by an occupant as the travel information from the in-vehicle device 14.

[0038] In the autonomous travel control, the controller 20 autonomously controls the travel of the host vehicle 1 without depending on the operation by the occupant. The autonomous travel control of the controller 20 includes autonomous speed control of autonomously controlling the travel speed of the host vehicle 1, and autonomous steering control of autonomously controlling the steering of the host vehicle 1.

[0039] (Autonomous Speed Control)

[0040] In the autonomous speed control, when a preceding vehicle is detected, the controller 20 follows the preceding vehicle while performing inter-vehicle control to maintain an inter-vehicle distance corresponding to the vehicle speed set by the occupant or the speed limit, with the upper limit of the vehicle speed set by the occupant or the speed limit. On the other hand, when no preceding vehicle is detected, the controller 20 performs constant speed travel at the vehicle speed set by the occupant or the speed limit. The former is also referred to as inter-vehicle control, and the latter is also referred to as constant speed control. The occupant can set the inter-vehicle distance in the inter-vehicle control by operating the inter-vehicle adjustment switch 185.

[0041] In a case where it is detected by the front radar or the like of the sensor 11 that there is no preceding vehicle in front of the lane in which the host vehicle 1 is traveling, the cruise control is executed. In the cruise control, the action of the driving mechanism such as the engine or the brake is controlled by the vehicle behavior control device 19 while feeding back the vehicle speed data of the feedback vehicle speed sensor, so as to maintain the set traveling speed.

[0042] In a case where it is detected by the front radar or the like of the sensor 11 that there is a preceding vehicle in front of the lane in which the host vehicle 1 is traveling, the inter-vehicle control is executed. In the inter-vehicle control, the action of the driving mechanism such as the engine or the brake is controlled by the vehicle behavior control device 19 while feeding back the inter-vehicle distance data detected by the front radar, so as to maintain the set inter-vehicle distance as an upper limit.

[0043] (Autonomous Steering Control)

[0044] In the autonomous steering control, the controller 20 controls the action of the steering actuator based on the traveling information acquired by the traveling information acquisition function, thereby executing the steering control of the host vehicle 1. The autonomous steering control includes the lane keeping control, the lane change assist control, the overtaking assist control, and the route traveling assist control.

[0045] In the lane keeping control, the controller 20 controls the steering actuator, for example, so as to travel near the center of the lane, thereby assisting the steering operation of the occupant.

[0046] In the lane change assist control, the controller 20 turns on the turn signal when the occupant operates the direction indicator lever, and determines whether or not a prescribed lane change start condition is satisfied based on various kinds of traveling information acquired by the traveling information acquisition function. The lane change operation is started in a case where the lane change start condition is satisfied. The operation of the direction indicator lever by the occupant in the lane change assist control is an example of the "instruction input of the lane change" described in the scope of the right request.

[0047] In the lane change operation, the controller 20 performs the lane change maneuver of laterally moving the host vehicle 1 to the adjacent lane (hereinafter sometimes referred to as "destination lane") of the lane change destination. The controller 20, when executing the lane change operation, prompts the occupant of information indicating that the lane change is being automatically performed by the display device 16. When the lane change maneuver is completed, the controller 20 turns off the turn signal, and starts to execute the lane keeping function on the lane after the lane change.

[0048] Hereinafter, the function of the controller 20 that executes the lane change assist control will be sometimes referred to as "lane change assist function".

[0049] In the overtaking assistance control, the controller 20 proposes to the occupant to implement a lane change to overtake a preceding vehicle based on autonomous travel control, in a case where a preceding vehicle exists in front of the lane in which the host vehicle 1 is traveling and predetermined overtaking proposal conditions are satisfied. Hereinafter, the proposal of the lane change to overtake the preceding vehicle will be sometimes expressed as "overtaking proposal".

[0050] The overtaking proposal is prompted in a case where the lane change assistance switch 186 of the occupant operation input device 18 is confirmed and predetermined overtaking proposal execution conditions are satisfied, and the controller 20 executes automatic lane change. In the automatic lane change, the controller 20 executes a lane change operation to move the host vehicle 1 to the target lane.

[0051] Further, when predetermined lane recovery proposal conditions are satisfied after the host vehicle 1 has overtaken the preceding vehicle, the controller 20 proposes to the occupant to implement a lane change to return to the original lane before overtaking by the preceding vehicle based on autonomous travel control through the display device 16. Hereinafter, the proposal of the lane change to return to the original lane after overtaking the preceding vehicle will be sometimes expressed as "lane recovery proposal". The lane recovery proposal is prompted in a case where the lane change assistance switch 186 of the occupant operation input device 18 is confirmed and predetermined lane recovery execution conditions are satisfied, and the controller 20 executes automatic lane change. In the automatic lane change, the controller 20 executes a lane change operation to move the host vehicle 1 to the original lane. Hereinafter, the function of the controller 20 that executes the overtaking assistance control will be sometimes expressed as "overtaking assistance function".

[0052] In the route travel assistance control, the controller 20 proposes to the occupant to implement a lane change for traveling along the target travel path by autonomous travel control when predetermined route travel execution conditions are satisfied immediately before a travel direction change point such as a branch point, a merging point, an exit, a tollgate, and the like on the target travel path set by the navigation system 15. Hereinafter, the proposal of the lane change for traveling along the target travel path will be sometimes expressed as "route travel proposal". The route travel proposal is prompted in a case where the lane change assistance switch 186 of the occupant operation input device 18 is confirmed and predetermined route travel execution conditions are satisfied, and the controller 20 executes automatic lane change. In the automatic lane change, the controller 20 executes a lane change operation to move the host vehicle 1 to the target lane. Hereinafter, the function of the controller 20 that executes the route travel assistance control will be sometimes expressed as "route travel assistance function".

[0053] These assistance functions (lane change assistance function, overtaking assistance function, route travel assistance function) that automatically change the lane of the host vehicle 1 by autonomous steering control are collectively referred to as "automatic lane change function".

[0054] As described above, a part of a plurality of lanes in the same travel direction on the same road is sometimes a specific lane (a lane in which a vehicle is restricted from traveling by a rule). Whether the lane in which the host vehicle 1 is traveling is a specific lane can be determined, for example, on the basis of a result of measurement of the current position of the host vehicle 1 by the positioning device 12 and lane classification information of the map database 13. It can also be determined by the camera of the sensor 11 detecting a road sign indicating that it is a specific lane.

[0055] However, sometimes the host vehicle 1 does not have a function of determining whether the permission condition for traveling on a specific lane is satisfied. For example, an HOV lane is a lane in which only a vehicle in which a prescribed number or more of passengers are riding can travel, and in order to determine whether it is possible to travel on an HOV lane, a function of detecting the number of passengers is required. Even if a function of determining whether the permission condition is satisfied is provided, it is not always possible to make an appropriate determination.

[0056] In a case where it is not possible to determine whether it is possible to travel on a specific lane, it is preferable not to perform automatic lane changing from a normal lane to a specific lane. Therefore, the controller 20 restricts lane changing from a normal lane to a specific lane on the basis of the automatic lane changing function.

[0057] Specifically, the controller 20 does not execute the overtaking assistance function and the route travel assistance function in a case where the target lane is a specific lane. For example, automatic lane changing from a normal lane to a specific lane on the basis of the overtaking assistance function and the route travel assistance function is prohibited.

[0058] However, in a case where the passenger has instructed lane changing from a normal lane to a specific lane by operating the direction indicator lever, automatic lane changing from a normal lane to a specific lane on the basis of the lane changing assistance function is executed. This is because such lane changing is performed in accordance with the passenger's intention, and it is preferable to respect the passenger's intention.

[0059] In a case where automatic lane changing from a normal lane to a specific lane is thus restricted, if lane changing from a specific lane to a normal lane is executed in the opposite direction, the passenger can think that the automatic lane changing function is not related to specific lanes and misinterpret that lane changing from a normal lane to a specific lane is not restricted.

[0060] Therefore, the controller 20 does not execute all of the automatic lane changing functions (in this example, the lane changing assistance function, the overtaking assistance function, and the route travel assistance function) provided in the host vehicle 1 in a case where the host vehicle 1 is traveling on a specific lane. Thus, the passenger easily recognizes a case where automatic lane changing to a specific lane is restricted.

[0061] Figure 3is a block diagram of an example of a functional configuration of the controller 20. The controller 20 includes: a specific lane recognition unit 30, a preceding vehicle recognition unit 31, a surrounding situation recognition unit 32, a lane change request judgment unit 33, a lane change possibility judgment unit 34, and a lane change state management unit 35.

[0062] The specific lane recognition unit 30 determines, for example, whether the lane in which the host vehicle 1 is currently traveling (hereinafter sometimes referred to as the "current lane") is a specific lane, and whether the current lane becomes a specific lane ahead of the travel route of the host vehicle 1, based on the measurement result of the current position of the host vehicle 1 by the positioning device 12 and the lane category information of the map database 13. Furthermore, the specific lane recognition unit 30 determines whether the adjacent lane of the current lane is a specific lane, and whether the adjacent lane becomes a specific lane ahead of the travel route of the host vehicle 1. The specific lane recognition unit 30 can also determine these conditions by the camera of the sensor 11 detecting a road sign indicating that it is a specific lane.

[0063] The preceding vehicle recognition unit 31 recognizes a preceding vehicle existing ahead of the lane in which the host vehicle 1 is traveling, based on the travel information, and detects the relative speed Vr of the preceding vehicle with respect to the host vehicle 1 (Vr = vehicle speed of the preceding vehicle - vehicle speed of the host vehicle).

[0064] The surrounding situation recognition unit 32 recognizes the situation (e.g., other vehicles or white lines) around the host vehicle 1 based on the travel information. For example, the surrounding situation recognition unit 32 recognizes the interval d between other vehicles on the target lane and the host vehicle 1 in the lane extension direction.

[0065] When the preceding vehicle recognition unit 31 recognizes a preceding vehicle, the lane change request judgment unit 33 determines whether the prescribed overtake proposal condition is satisfied. For example, the overtake proposal condition can include the following conditions:

[0066] • The overtake assist function is effective.

[0067] • The relative speed Vr of the preceding vehicle with respect to the host vehicle 1 is less than a threshold speed Vt.

[0068] • The interval d between other vehicles on the target lane and the host vehicle 1 is equal to or greater than an interval threshold Dp. For example, the interval d can be the inter-vehicle distance between other vehicles and the host vehicle 1 in the lane extension direction, or can be the inter-vehicle time.

[0069] • It is possible to change lanes to the target lane side (e.g., the lane division line does not prohibit lane changing, the curvature radius of the road is 250 m or more, etc.).

[0070] • The current lane is not a specific lane.

[0071] • The target lane is not a specific lane.

[0072] If the overtake proposal condition is satisfied, the lane change request determination part 33 outputs an overtake proposal request to the lane change state management part 35. That is, the lane change request determination part 33 does not output an overtake proposal request if the host vehicle 1 is traveling on the specific lane. In addition, an overtake proposal request is not output to change lanes from the ordinary lane to the specific lane.

[0073] After the overtake is completed based on the overtake assist control, the lane change request determination part 33 determines whether a prescribed lane recovery proposal condition is satisfied. For example, the lane recovery proposal condition can include the following conditions:

[0074] • The overtake assist function is effective.

[0075] • The distance d between the other vehicle on the destination lane and the host vehicle 1 is equal to or greater than the distance threshold Dp.

[0076] • It is possible to change lanes to the original lane before the overtake.

[0077] • The current lane is not the specific lane.

[0078] • The destination lane is not the specific lane.

[0079] If the lane recovery proposal condition is satisfied, the lane change request determination part 33 outputs a lane recovery proposal request to the lane change state management part 35. That is, the lane change request determination part 33 does not output a lane recovery proposal request if the host vehicle 1 is traveling on the specific lane. In addition, a lane recovery proposal request is not output to change lanes from the ordinary lane to the specific lane.

[0080] On the other hand, the lane change request determination part 33 determines whether a lane that the host vehicle 1 should currently be traveling on in order to travel along a target travel path set by the navigation system 15 (hereinafter sometimes referred to as a "target lane") is selected and a prescribed route travel proposal condition is satisfied. For example, the route travel proposal condition can include the following conditions:

[0081] • The route travel assist function is effective.

[0082] • The lane in which the host vehicle 1 is currently traveling and the target lane are different.

[0083] • The distance dr from the current position of the host vehicle 1 to the travel direction change location is equal to or less than the distance da and equal to or greater than the distance db. For example, the distance da can be (2300 m + 400 m x N), and the distance db can be (700 m + 400 m x N). The natural number N is the number of lane changes necessary for the host vehicle 1 to move from the lane in which it is currently traveling to the target lane.

[0084] • The target lane is not the specific lane.

[0085] • The current lane is not the specific lane.

[0086] • The target lane is not the specific lane.

[0087] When the route travel proposal condition is satisfied, the lane change request determination section 33 sets a point at which the route travel proposal is presented, i.e., a proposal point. When the host vehicle 1 reaches the proposal point, the lane change request determination section 33 outputs a route travel proposal request to the lane change state management section 35. That is, the lane change request determination section 33 does not output a route travel proposal request in a case where the host vehicle 1 is traveling on the specific lane. In addition, a route travel proposal request for changing lanes from the ordinary lane to the specific lane is not output.

[0088] When the lane change request determination section 33 outputs the overtaking proposal request, the lane change state management section 35 outputs overtaking information for presenting the overtaking proposal to the occupant through the display device 16 or the sound output device 17. When the lane change request determination section 33 outputs the lane recovery proposal request, the lane change state management section 35 outputs lane recovery information for presenting the lane recovery proposal to the occupant through the display device 16 or the sound output device 17. When the lane change request determination section 33 outputs the route travel proposal request, the lane change state management section 35 outputs route travel information for presenting the route travel proposal to the occupant through the display device 16 and the sound output device 17. Therefore, in a case where the host vehicle 1 is traveling on the specific lane, the lane change state management section 35 does not present the overtaking proposal, the lane recovery proposal, and the route travel proposal to the occupant. In addition, the overtaking proposal, the lane recovery proposal, and the route travel proposal for changing lanes from the ordinary lane to the specific lane are not presented.

[0089] For presentation of the overtaking proposal, when the occupant confirms the lane change assist switch 186 of the operation input device 18, the lane change state management section 35 illuminates the direction indicator. When the overtaking proposal is presented to the occupant, the can-or-not-lane-change determination section 34 determines whether a prescribed overtaking execution condition is satisfied. For example, the overtaking execution condition can include the following conditions:

[0090] • The overtaking assist function is effective.

[0091] • The relative speed Vr of the preceding vehicle with respect to the host vehicle 1 is less than a threshold speed Vt.

[0092] • The interval d between the other vehicle on the target lane and the host vehicle 1 in the lane extension direction is equal to or greater than an interval threshold Dp.

[0093] • The lane change to the target lane side is possible.

[0094] • The current lane is not the specific lane.

[0095] • The destination lane is not the specific lane.

[0096] When the occupant confirms the passing proposal and the passing execution condition is satisfied, the lane change state management portion 35 executes automatic lane change. In the automatic lane change, the lane change state management portion 35 starts a lane change operation to move the host vehicle 1 to the destination lane. Therefore, in a case where the host vehicle 1 is traveling on the specific lane, the lane change state management portion 35 does not execute automatic lane change. In addition, automatic lane change from the normal lane to the specific lane is not executed.

[0097] For the presentation of the lane recovery proposal, when the occupant's operation of the lane change assist switch 186 of the input device 18 is confirmed, the lane change state management portion 35 illuminates the turn signal. When the occupant is presented with the lane recovery proposal, the lane change permission determination portion 34 determines whether a prescribed lane recovery execution condition is satisfied. For example, the lane recovery execution condition can include the following conditions:

[0098] • The passing assist function is effective.

[0099] • The interval d between the other vehicle on the destination lane and the host vehicle 1 in the lane extension direction is equal to or greater than the interval threshold Dp.

[0100] • It is possible to make a lane change to the original lane side before the passing.

[0101] • The current lane is not the specific lane.

[0102] • The destination lane is not the specific lane.

[0103] When the occupant confirms the lane recovery proposal and the lane recovery execution condition is satisfied, the lane change state management portion 35 executes automatic lane change. In the automatic lane change, the lane change state management portion 35 starts a lane change operation to move the host vehicle 1 to the destination lane. Therefore, in a case where the host vehicle 1 is traveling on the specific lane, the lane change state management portion 35 does not execute lane change. In addition, automatic lane change from the normal lane to the specific lane is not executed.

[0104] For the presentation of the route travel proposal, when the occupant's operation of the lane change assist switch 186 of the input device 18 is confirmed, the lane change state management portion 35 illuminates the turn signal. When the occupant is presented with the route travel proposal, the lane change permission determination portion 34 determines whether a prescribed route travel execution condition is satisfied. For example, the route travel execution condition can include the following conditions:

[0105] • The route travel assist function is effective.

[0106] • The current lane in which the host vehicle 1 is currently traveling is different from the target lane.

[0107] • The distance dr from the current position of the host vehicle 1 to the travel direction change location is equal to or less than the distance da and equal to or more than the distance db.

[0108] • The interval d in the lane extension direction between the other vehicle on the target lane and the host vehicle 1 is equal to or more than the interval threshold value Dp.

[0109] • The lane change to the target lane side is possible.

[0110] • The current lane is not the specific lane.

[0111] • The target lane is not the specific lane.

[0112] When the occupant confirms the route travel proposal and the route travel execution condition is satisfied, the lane change state management section 35 executes the automatic lane change. In the automatic lane change, the lane change state management section 35 starts the lane change operation to move the host vehicle 1 to the target lane. Therefore, in the case where the host vehicle 1 is traveling on the specific lane, the lane change state management section 35 does not execute the automatic lane change. In addition, the automatic lane change from the normal lane to the specific lane is not executed.

[0113] On the other hand, in the lane change assist function, when the occupant operates the direction indicator lever, the lane change state management section 35 illuminates the direction indicator. The lane change possibility determination section 34 determines whether the prescribed lane change start condition is satisfied. In addition, the lane change start condition can also include, for example, the following conditions:

[0114] • The lane change assist function is effective.

[0115] • The interval d between the other vehicle on the target lane and the host vehicle 1 is equal to or more than the interval threshold value Dp.

[0116] • The lane change to the target lane side is possible.

[0117] • The current lane is not the specific lane.

[0118] If the lane change start condition is satisfied, the lane change state management section 35 executes the automatic lane change. In the automatic lane change, the lane change state management section 35 starts the lane change operation to move the host vehicle 1 to the target lane.

[0119] Therefore, the lane change state management section 35 executes the automatic lane change from the normal lane to the specific lane based on the lane change assist function as described above.

[0120] On the other hand, in a case where the host vehicle 1 is traveling on the specific lane, automatic lane change based on the lane change assist function is not executed.

[0121] Thus, for example, in a case where the host vehicle 1 attempts automatic lane change from the specific lane to the general lane, it is possible to suppress disturbance of the traffic flow on the specific lane. That is, since the vehicles that can travel on the specific lane are limited, in general, the specific lane is empty compared to the general lane, and the speed of the vehicles traveling on the specific lane is faster than the speed of the vehicles traveling on the general lane. Therefore, if the host vehicle 1 decelerates on the specific lane because it is difficult to perform automatic lane change from the specific lane to the congested general lane, it sometimes hinders the following vehicles. By not executing automatic lane change in a case where the host vehicle 1 is traveling on the specific lane, it is possible to suppress such a case of disturbance of the traffic flow on the specific lane.

[0122] The vehicle behavior control device 19 controls the operation of the steering actuator based on the instruction from the lane change state management section 35, thereby executing the steering control of the host vehicle 1.

[0123] (Action)

[0124] Figure 4 is a flowchart of an example of the driving assist method of the embodiment.

[0125] In step S1, the controller 20 identifies the adjacent lane of the current lane on which the host vehicle 1 is currently traveling and the category of the current lane.

[0126] In step S2, the controller 20 determines whether the current lane is a specific lane or the current lane becomes a specific lane ahead of the travel route of the host vehicle 1. In a case where the current lane is a specific lane or the current lane becomes a specific lane ahead of the travel route of the host vehicle 1 (step S2: YES), the process proceeds to step S3. In a case where the current lane is not a specific lane and the current lane does not become a specific lane ahead of the travel route of the host vehicle 1 (step S2: NO), the process proceeds to step S4.

[0127] In step S3, the controller 20 prohibits automatic lane change based on all of the automatic lane change functions (in this example, the lane change assist function, the overtaking assist function, and the route following assist function) mounted on the host vehicle 1. Then the process ends.

[0128] In step S4, the controller 20 determines whether the adjacent lane is a specific lane or whether the adjacent lane ahead of the travel route of the host vehicle 1 becomes a specific lane. In a case where the adjacent lane is a specific lane or the adjacent lane ahead of the travel route of the host vehicle 1 becomes a specific lane (step S4: YES), the process proceeds to step S5. In a case where the adjacent lane is not a specific lane and the adjacent lane ahead of the travel route of the host vehicle 1 does not become a specific lane (step S4: NO), the process ends. In this case, the automatic lane change of any one of the lane change assist function, the overtaking assist function, and the route travel assist function is not prohibited.

[0129] In step S5, the controller 20 prohibits the automatic lane change to the adjacent lane based on the overtaking assist function and the automatic lane change to the adjacent lane based on the route travel assist function. Then the process ends.

[0130] (EFFECTS OF THE EMBODIMENTS)

[0131] (1) The controller 20 performs the driving assist control of the lane change of the host vehicle 1 based on the automatic lane change function. The controller 20 performs the process of determining whether the host vehicle 1 is traveling on the first lane on which the vehicle is defined, in a case where the vehicle is defined on the first lane among a plurality of lanes in the same traffic direction, which are adjacent to each other, of the road on which the host vehicle 1 travels, and the process of not performing the lane change from the first lane to the second lane based on the automatic lane change function, in a case where it is determined that the host vehicle 1 is traveling on the first lane.

[0132] Thus, in providing the automatic lane change function that complies with the rule of limiting the vehicle that can travel on the first lane, the occupant can easily recognize the case where the automatic lane change to the first lane is limited.

[0133] (2) The controller 20 can receive the instruction input of the lane change from the occupant, and control the travel of the host vehicle 1 to perform the lane change from the second lane to the first lane, in a case where the instruction input of the lane change from the second lane to the first lane is received. The lane change from the first lane to the second lane based on the automatic lane change function can be prohibited, in a case where the instruction input of the lane change from the first lane to the second lane is received.

[0134] Thus, it is possible to respect the will of the occupant who performs the lane change to the first lane, and on the other hand, in a case where the host vehicle 1 attempts the automatic lane change from the first lane to the second lane, it is possible to suppress the disturbance of the traffic flow of the first lane.

[0135] (3) The automatic lane change function can also include a first automatic lane change function of changing lanes to an adjacent lane when the preceding vehicle of the host vehicle 1 is traveling at a lower speed than the host vehicle 1. The controller 20 does not execute the first automatic lane change function of changing lanes from the first lane to the second lane, and does not execute the first automatic lane change function of changing lanes from the second lane to the first lane.

[0136] The automatic lane change function can include a second automatic lane change function of changing lanes to an adjacent lane based on a pre-set target travel path. The controller 20 does not execute the second automatic lane change function of changing lanes from the first lane to the second lane, and does not execute the second automatic lane change function of changing lanes from the second lane to the first lane.

[0137] Thus, it is possible to provide an automatic lane change function that complies with the rule of restricting vehicles that can travel on the first lane, and to enable the occupant to easily recognize the case where the automatic lane change to the first lane is restricted.

[0138] (4) The controller 20 can not execute all of the automatic lane change functions mounted on the host vehicle 1 when it is determined that the vehicles traveling on the first lane on which the host vehicle 1 travels are restricted.

[0139] Thus, it is possible to enable the occupant to easily recognize the case where the automatic lane change to the first lane is restricted when providing an automatic lane change function that complies with the rule of restricting vehicles that can travel on the first lane.

[0140] All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the present application and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. Although specific examples of the present application have been described above, various modifications, alterations, and permutations can be made to the examples without departing from the spirit and scope of the present application.

[0141] Symbol Explanation

[0142] 1: host vehicle, 10: drive assist device, 11: sensor, 12: position measurement device, 13: map DB, 14: in-vehicle device, 15: navigation system, 16: display device, 17: sound output device, 18: input device, 19: vehicle behavior control device, 20: controller, 21: processor, 22: storage device.

Claims

1. A driving assistance method of performing a lane change of an own vehicle based on an automatic lane change function, characterized by, The controller executes the following process: In a case where vehicles are limited from traveling on the first lane among a plurality of lanes in the same traveling direction that are adjacent to each other on a road on which the host vehicle is traveling, the first lane and a second lane, the controller determines whether the host vehicle is traveling on the first lane on which the vehicles are limited from traveling, In a case where it is determined that the host vehicle is traveling on the first lane, the controller does not execute a process of changing lanes from the first lane to the second lane based on the automatic lane change function, as a control to automatically change lanes from the first lane to the second lane for the host vehicle, The automatic lane change function includes a first automatic lane change function of changing lanes to an adjacent lane in a case where a preceding vehicle of the host vehicle has a lower vehicle speed than the host vehicle, The controller does not execute the first automatic lane change function of changing lanes from the first lane to the second lane, and does not execute the first automatic lane change function of changing lanes from the second lane to the first lane.

2. The drive assist method according to claim 1, wherein The controller executes the following process: The controller receives an instruction input of changing lanes from an occupant, In a case where an instruction input of changing lanes from the second lane to the first lane is received, the controller controls traveling of the host vehicle to change lanes from the second lane to the first lane, In a case where an instruction input of changing lanes from the first lane to the second lane is received, the controller does not perform a lane change from the first lane to the second lane based on the automatic lane change function.

3. A driving assistance method of performing a lane change of an own vehicle based on an automatic lane change function, characterized by, The controller executes the following process: In a case where vehicles are limited from traveling on the first lane among a plurality of lanes in the same traveling direction that are adjacent to each other on a road on which the host vehicle is traveling, the first lane and a second lane, the controller determines whether the host vehicle is traveling on the first lane on which the vehicles are limited from traveling, In a case where it is determined that the host vehicle is traveling on the first lane, the controller does not execute a process of changing lanes from the first lane to the second lane based on the automatic lane change function, as a control to automatically change lanes from the first lane to the second lane for the host vehicle, The automatic lane change function includes a second automatic lane change function of changing lanes to an adjacent lane based on a target traveling path set in advance, The controller does not execute the second automatic lane change function of changing lanes from the first lane to the second lane, and does not execute the second automatic lane change function of changing lanes from the second lane to the first lane.

4. The drive assist method according to any one of claims 1 to 3, wherein The controller does not execute all of the automatic lane change functions mounted on the host vehicle in a case where it is determined that a vehicle is limited from traveling on the first lane on which the host vehicle is traveling.

5. A driving assistance device for performing lane changes of the vehicle based on an automatic lane change function, characterized in that, The controller executes the following process: in a case where vehicles are defined as being limited in a first lane of a plurality of lanes, i.e., the first lane and a second lane, of a road on which the host vehicle is traveling in the same traffic direction as each other, the process of determining whether the host vehicle is traveling on the first lane on which vehicles are defined as being limited, in a case where it is determined that the host vehicle is traveling on the first lane, the process of not performing a lane change from the first lane to the second lane based on the automatic lane change function, as control for causing the host vehicle to automatically change lanes from the first lane to the second lane, the automatic lane change function includes a first automatic lane change function of changing lanes to an adjacent lane in a case where a vehicle speed of a preceding vehicle of the host vehicle is slower than a vehicle speed of the host vehicle, the controller does not execute the first automatic lane change function of changing lanes from the first lane to the second lane, and does not execute the first automatic lane change function of changing lanes from the second lane to the first lane.

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