Driving assistance device, vehicle, driving assistance method, and storage medium

1. A driving assistance device in a vehicle, the driving assistance device comprising

a control unit configured to perform a lane change from a traveling lane in which the vehicle travels to a branch lane branching from the traveling lane, by driving assistance capable of automatically performing the lane change on an initiative of a system,

wherein the control unit

notifies, by way of a display or a voice output device, of an end of the driving assistance in the branch lane before the vehicle enters the branch lane at a notification position a predetermined distance before a reference position at which the branching of the branch lane starts,

acquires a travel distance in the branch lane, an elapsed time in the branch lane, and information indicating passage of an end position of the branch lane detected based on map information or external environment recognition information, after the lane change is completed by crossing a division line of the traveling lane, and

ends the driving assistance in the branch lane in a case where the travel distance exceeds a predetermined threshold distance, in a case where the elapsed time exceeds a predetermined threshold time, or in a case of passing through the end position of the branch lane detected based on the map information or the external environment recognition information.

2. The driving assistance device according to claim 1 , wherein the control unit determines whether or not it is necessary to perform the lane change to the branch lane in order to arrive at a destination set based on map information, and determines the branch lane to which the lane change is to be performed when determining that it is necessary to perform the lane change.

3. The driving assistance device according to claim 2 , wherein the control unit notifies, by way of a display or a voice output device, of the lane change to the branch lane, at a notification position a predetermined distance before a reference position at which the branching of the branch lane starts.

4. The driving assistance device according to claim 1 , wherein the control unit comprises:

a function of automatically performing the lane change on the initiative of the system,

a driver-initiated lane change function of automatically performing the lane change for each instruction input by a driver, and

a function in which the system of the vehicle monitors states of lanes on left and right of the vehicle, notifies the driver of the lane to which the lane change is possible, and performs the lane change based on an operation of the driver.

5. The driving assistance device according to claim 4 , wherein the control unit provides the function of automatically performing the lane change on the initiative of the system in a case where an approval instruction is input by the driver via an input device and map information matches image information captured by an imaging device.

6. The driving assistance device according to claim 5 , wherein the control unit provides the driver-initiated lane change function in a case where the approval instruction is not input or in a case where the map information does not match the image information.

7. The driving assistance device according to claim 1 , wherein the control unit starts the lane change from a change start position a predetermined distance before a reference position at which the branching of the branch lane starts.

8. The driving assistance device according to claim 7 , wherein

the control unit estimates a time from the start of the lane change to completion of entry of the vehicle into the branch lane based on map information and a vehicle speed of the vehicle, and

sets the change start position to enable at least time in which the estimated time is set in advance to be secured.

9. The driving assistance device according to claim 8 , wherein the control unit starts blinking a blinker of the vehicle from a blinking start position that is a position at a predetermined distance before the reference position at which branching of the branch lane starts and before the change start position at which the lane change is started.

10. The driving assistance device according to claim 9 , wherein

the control unit estimates a time from the start of the blinking of the blinker of the vehicle to the start of the lane change based on the map information and the vehicle speed of the vehicle, and

sets the blinking start position for starting the blinking of the blinker of the vehicle to enable at least time in which the estimated time is set in advance to be secured.

11. The driving assistance device according to claim 1 , wherein the end position is a termination position of the branch lane, and is a position of an end portion of a traffic island provided near the end position.

12. The driving assistance device according to claim 1 , wherein the driving assistance includes

a first function of controlling acceleration and deceleration of the vehicle within a predetermined vehicle speed while maintaining an inter-vehicle distance from a preceding vehicle, a second function of maintaining the vehicle inside a lane, and a third function of changing the traveling lane of the vehicle to an adjacent lane, and

at least one of the first function, the second function, and the third function ends with the end of the driving assistance.

13. A vehicle having a driving assistance function, the vehicle comprising the driving assistance device according to claim 1 .

14. A driving assistance method for a driving assistance device in a vehicle, the driving assistance method comprising:

performing a lane change from a traveling lane in which the vehicle travels to a branch lane branching from the traveling lane, by driving assistance capable of automatically performing the lane change on an initiative of a system;

notifying, by way of a display or a voice output device, of an end of the driving assistance in the branch lane before the vehicle enters the branch lane at a notification position a predetermined distance before a reference position at which the branching of the branch lane starts;

acquiring a travel distance in the branch lane, an elapsed time in the branch lane, and information indicating passage of an end position of the branch lane detected based on map information or external environment recognition information, after the lane change is completed by crossing a division line of the traveling lane; and

ending the driving assistance in the branch lane in a case where the travel distance exceeds a predetermined threshold distance, in a case where the elapsed time exceeds a predetermined threshold time, or in a case of passing through the end position of the branch lane detected based on the map information or the external environment recognition information.

15. A non-transitory computer readable storage medium storing a program for causing a computer to execute the driving assistance method according to claim 14 .

16. A driving assistance device in a vehicle, the driving assistance device comprising:

a control unit configured to perform a lane change from a traveling lane in which the vehicle travels to a branch lane branching from the traveling lane, by driving assistance capable of automatically performing the lane change on an initiative of a system,

wherein the control unit

acquires a travel distance in the branch lane, an elapsed time in the branch lane, and information indicating passage of an end position of the branch lane detected based on map information or external environment recognition information, after the lane change is completed by crossing a division line of the traveling lane,

ends the driving assistance in the branch lane in a case where the travel distance exceeds a predetermined threshold distance, in a case where the elapsed time exceeds a predetermined threshold time, or in a case of passing through the end position of the branch lane detected based on the map information or the external environment recognition information,

wherein the control unit has, as lane change assistance, a plurality of lane change functions including:

a function of automatically performing the lane change on the initiative of the system;

a driver-initiated lane change function of automatically performing the lane change for each instruction input by a driver; and

a function in which the system of the vehicle monitors states of lanes on left and right of the vehicle, notifies the driver of the lane to which the lane change is possible, and performs the lane change based on an operation of the driver.

17. A driving assistance method for a driving assistance device in a vehicle, the driving assistance method comprising:

performing a lane change from a traveling lane in which the vehicle travels to a branch lane branching from the traveling lane, by driving assistance capable of automatically performing the lane change on an initiative of a system;

acquiring a travel distance in the branch lane, an elapsed time in the branch lane, and information indicating passage of an end position of the branch lane detected based on map information or external environment recognition information, after the lane change is completed by crossing a division line of the traveling lane; and

ending the driving assistance in the branch lane in a case where the travel distance exceeds a predetermined threshold distance, in a case where the elapsed time exceeds a predetermined threshold time, or in a case of passing through the end position of the branch lane detected based on the map information or the external environment recognition information,

wherein the lane change is performed based on, as lane change assistance, a plurality of lane change functions including:

a function of automatically performing the lane change on the initiative of the system;

a driver-initiated lane change function of automatically performing the lane change for each instruction input by a driver; and

a function in which the system of the vehicle monitors states of lanes on left and right of the vehicle, notifies the driver of the lane to which the lane change is possible, and performs the lane change based on an operation of the driver.