Lane change support device
The lane change support device is configured to estimate a lane speed of another vehicle traveling on a lane of a lane change destination, determine a minimum length of a space in a lane of a lane change destination necessary for lane change based on a lane speed of the other vehicle, estimate an actual length of a space in the lane of the lane change destination, and determine whether lane change is possible based on the minimum length and the actual length, and calculate a target relative speed of the own vehicle with respect to the other vehicle based on an allowable acceleration or deceleration speed of the own vehicle, and search for a space in a lane of a lane change destination necessary for lane change while controlling a vehicle speed of the own vehicle in such a manner that a relative speed becomes a target relative speed.
1 . A lane change support device comprising:
sensors configured to acquire information of an object target around an own vehicle, the sensors including a camera sensor and a radar sensor; and
a processor configured to
estimate an average vehicle speed of adjacent vehicles traveling in a target lane that is a destination of a lane change of the own vehicle based on the information acquired by the sensors,
determine a reference length of a space between the adjacent vehicles in the target lane that is necessary for the own vehicle to make the lane change based on the estimated average vehicle speed using a first map, the first map indicating a relationship between the average vehicle speed of the adjacent vehicles and the reference length,
estimate an actual length of the space between the adjacent vehicles in the target lane based on the information acquired by the sensors,
determine whether the actual length is less than the reference length,
set a magnitude of an allowable acceleration or deceleration of the own vehicle based on a traveling state of the own vehicle in a case where the actual length is less than the reference length, the traveling state including a distance from a current position of the own vehicle to a branch point on a road where the own vehicle is traveling, and the magnitude of the allowable acceleration or deceleration being increased as the distance from the current position of the own vehicle to the branch point decreases,
calculate a magnitude of a target relative speed of the own vehicle with respect to the average vehicle speed of the adjacent vehicles based on the magnitude of the allowable acceleration or deceleration using a second map, the second map indicating a relationship between the magnitude of the target relative speed and the magnitude of the allowable acceleration or deceleration,
search for a space in the target lane that is necessary for the own vehicle to make the lane change while controlling a vehicle speed of the own vehicle such that a relative speed of the own vehicle with respect to the average vehicle speed of the adjacent vehicles becomes the target relative speed, and
output an instruction signal to autonomously drive the own vehicle into the space identified by the search.
2 . The lane change support device according to claim 1 , wherein the processor is further configured to
determine whether the vehicle speed of the own vehicle is higher than the average vehicle speed of the adjacent vehicles,
determine whether the vehicle speed of the own vehicle is equal to or lower than a sum of the average vehicle speed of the adjacent vehicles and the target relative speed in a case where the vehicle speed of the own vehicle is higher than the average vehicle speed of the adjacent vehicles,
search for a space having a length equal to or larger than the reference length in the target lane while controlling the vehicle speed of the own vehicle such that the relative speed of the own vehicle with respect to the average vehicle speed of the adjacent vehicles becomes the target relative speed, in a case where the vehicle speed of the own vehicle is equal to or lower than the sum of the average vehicle speed of the adjacent vehicles and the target relative speed, and
output the instruction signal to autonomously drive the own vehicle into the space identified by the search.
3 . The lane change support device according to claim 1 , wherein the processor is further configured to
determine whether the vehicle speed of the own vehicle is higher than the average vehicle speed of the adjacent vehicles,
determine whether the vehicle speed of the own vehicle is higher than a sum of the average vehicle speed of the adjacent vehicles and the target relative speed in a case where the vehicle speed of the own vehicle is higher than the average vehicle speed of the adjacent vehicles,
determine a realizable relative speed of the own vehicle with respect to the average vehicle speed of the adjacent vehicles and determine a corrected reference length of a space in which the own vehicle is able to make the lane change based on the realizable relative speed, in a case where the vehicle speed of the own vehicle is higher than the sum of the average vehicle speed of the adjacent vehicles and the target relative speed,
search for a space having a length equal to or larger than the corrected reference length in the target lane while controlling the vehicle speed of the own vehicle such that the relative speed of the own vehicle with respect to the average vehicle speed of the adjacent vehicles becomes the realizable relative speed, and
output the instruction signal to autonomously drive the own vehicle into the space identified by the search.
4 . The lane change support device according to claim 1 , wherein the processor is further configured to
determine whether the vehicle speed of the own vehicle is equal to or lower than the average vehicle speed of the adjacent vehicles,
determine whether the vehicle speed of the own vehicle is equal to or higher than a difference between the average vehicle speed of the adjacent vehicles and the target relative speed in a case where the vehicle speed of the own vehicle is equal to or lower than the average vehicle speed of the adjacent vehicles,
search for a space having a length equal to or larger than the reference length in the target lane while controlling the vehicle speed of the own vehicle such that the relative speed of the own vehicle with respect to the average vehicle speed of the adjacent vehicles becomes the target relative speed, in a case where the vehicle speed of the own vehicle is equal to or higher than the difference between the average vehicle speed of the adjacent vehicles and the target relative speed, and
output the instruction signal to autonomously drive the own vehicle into the space identified by the search.
5 . The lane change support device according to claim 1 , wherein the processor is further configured to
determine whether the vehicle speed of the own vehicle is equal to or lower than the average vehicle speed of the adjacent vehicles,
determine whether the vehicle speed of the own vehicle is lower than a difference between the average vehicle speed of the adjacent vehicles and the target relative speed in a case where the vehicle speed of the own vehicle is equal to or lower than the average vehicle speed of the adjacent vehicles,
determine a realizable relative speed of the own vehicle with respect to the average vehicle speed of the adjacent vehicles and determine a corrected reference length of a space in which the own vehicle is able to make the lane change based on the realizable relative speed, in a case where the vehicle speed of the own vehicle is lower than the difference between the average vehicle speed of the adjacent vehicles and the target relative speed,
search for a space having a length equal to or larger than the corrected reference length in the target lane while controlling the vehicle speed of the own vehicle such that the relative speed of the own vehicle with respect to the average vehicle speed of the adjacent vehicles becomes the realizable relative speed, and
output the instruction signal to autonomously drive the own vehicle into the space identified by the search.
6 . The lane change support device according to claim 1 , wherein the adjacent vehicles include a preceding vehicle and a following vehicle that are traveling in the target lane adjacent to a lane where the own vehicle is traveling.
7 . The lane change support device according to claim 1 , wherein the processor is further configured to control the own vehicle to perform the lane change without executing the search for the space in a case where the actual length is equal to or greater than the reference length.
8 . The lane change support device according to claim 1 , wherein
the traveling state of the own vehicle further includes a traveling mode of the own vehicle, the traveling mode including a sport mode where steering responsiveness of the own vehicle is given priority over riding comfort and a comfort mode where riding comfort is given priority over the steering responsiveness, and
the processor is further configured to increase the magnitude of the allowable acceleration or deceleration when the traveling mode is the sport mode compared to when the traveling mode is the comfort mode.
9 . The lane change support device according to claim 1 , wherein the traveling state of the own vehicle further includes an origination of a lane change request, the origination of the lane change request being either a manual request made by a driver of the own vehicle operating a turn signal lever or an autonomous request output by a navigation system installed in the own vehicle, and
the processor is further configured to increase the magnitude of the allowable acceleration or deceleration when the lane change request is the manual request compared to when the lane change request is the autonomous request.
10 . The lane change support device according to claim 1 , wherein the first map indicates that the reference length increases as the average vehicle speed of the adjacent vehicles increases.
11 . The lane change support device according to claim 1 , wherein the second map indicates that the magnitude of the target relative speed increases as the magnitude of the allowable acceleration or deceleration increases.