Drive assist apparatus for vehicle
A drive assist apparatus for a vehicle includes: a driving environment recognizer recognizing driving environment information on outside of the vehicle; a target vehicle-to-vehicle distance setter setting a target preceding vehicle distance to a preceding vehicle; and a driving controller performing driving control for maintaining a preceding vehicle distance at the target preceding vehicle distance. When a vehicle driving path is congested, the target vehicle-to-vehicle distance setter sets an extended target preceding vehicle distance and a target following vehicle distance. When the vehicle driving path is congested, the driving controller calculates a target acceleration for maintaining a following vehicle distance at the target following vehicle distance, determines whether to permit acceleration or deceleration, performs acceleration control when the target acceleration is an acceleration-side value and acceleration is permitted, and performs deceleration control when the target acceleration is a deceleration-side value and deceleration is permitted.
1 . A drive assist apparatus for a vehicle, the drive assist apparatus comprising:
one or more processors; and
one or more memories storing instructions causing the one or more processors to:
recognize driving environment information on an outside of the vehicle, the outside including an area ahead of the vehicle and an area behind the vehicle;
set a target preceding vehicle distance to a preceding vehicle when the preceding vehicle is recognized based on the driving environment information; and
perform driving control maintaining a preceding vehicle distance from the vehicle to the preceding vehicle at the target preceding vehicle distance, wherein
the one or more processors are further caused to, when a driving path of the vehicle is congested,
(i) set an extended target preceding vehicle distance by extending the target preceding vehicle distance by adding a set distance to the target preceding vehicle distance, and set a target following vehicle distance to a following vehicle, wherein the set distance is configured to prevent another vehicle from cutting in front of the vehicle and increases as a preceding vehicle speed increases, and the target following vehicle distance is configured to allow a driver driving the following vehicle to reduce a frequency of braking against the vehicle during the congestion,
(ii) calculate a target acceleration based on a difference between (a) a following vehicle distance from the vehicle to the following vehicle and (b) the target following vehicle distance, to maintain the following vehicle distance at the target following vehicle distance, wherein the target acceleration is set to accelerate the vehicle with a greater acceleration as the following vehicle distance becomes less than the target following vehicle distance, and to decelerate the vehicle with a greater deceleration as the following vehicle distance becomes greater than the target following vehicle distance,
(iii) determine whether to permit the vehicle to accelerate or decelerate based on a relative relationship between the preceding vehicle distance and the extended target preceding vehicle distance, wherein the determination prevents the vehicle from accelerating when the preceding vehicle distance is less than or equal to the extended target preceding vehicle distance and prevents the vehicle from decelerating when the preceding vehicle distance is greater than the extended target preceding vehicle distance,
(iv) perform acceleration control using the target acceleration when the target acceleration is a value on an acceleration side and the vehicle is permitted to accelerate,
(v) perform deceleration control using the target acceleration when the target acceleration is a value on a deceleration side and the vehicle is permitted to decelerate,
(vi) maintain the following vehicle distance at the target following vehicle distance while controlling the preceding vehicle distance within a range between the target preceding vehicle distance and the extended target preceding vehicle distance, and
(vii) when the vehicle is permitted to decelerate and the target acceleration is a value on the deceleration side, calculate a second target acceleration for maintaining the preceding vehicle distance at the target preceding vehicle distance, and select a smaller of the target acceleration and the second target acceleration as a final target acceleration for the deceleration control.
2 . The drive assist apparatus for the vehicle according to claim 1 , wherein the one or more processors are further caused to set a predetermined value as the target following vehicle distance, and correct the target following vehicle distance based on a relative relationship between the vehicle and the following vehicle.
3 . The drive assist apparatus for the vehicle according to claim 1 , wherein the one or more processors are further caused to reflect a relative speed between the vehicle and the preceding vehicle upon determining whether to permit the vehicle to accelerate or decelerate.
4 . The drive assist apparatus for the vehicle according to claim 1 , wherein the one or more processors are further caused to determine whether to permit the vehicle to accelerate or decelerate maintaining the following vehicle distance based on a relative relationship between the preceding vehicle distance and the extended target preceding vehicle distance, the following vehicle distance, and a relative speed of the preceding vehicle.
5 . The drive assist apparatus for the vehicle according to claim 1 , wherein the determination, based on a relative speed between the vehicle and the preceding vehicle, permits the vehicle to accelerate even when the preceding vehicle distance is less than or equal to the extended target preceding vehicle distance, and permits the vehicle to decelerate even when the preceding vehicle distance is greater than the extended target preceding vehicle distance.
6 . The drive assist apparatus for the vehicle according to claim 5 , wherein when the preceding vehicle distance is less than or equal to the extended target preceding vehicle distance, a region where acceleration is permitted becomes larger as the relative speed becomes greater, and when the preceding vehicle distance is greater than the extended target preceding vehicle distance, a region where deceleration is permitted becomes larger as the relative speed becomes greater on a negative side.
7 . The drive assist apparatus for the vehicle according to claim 1 , wherein when the preceding vehicle distance reaches the target preceding vehicle distance due to acceleration of the vehicle, the one or more processors are further caused to maintain the preceding vehicle distance at the target preceding vehicle distance without further acceleration.
8 . The drive assist apparatus for the vehicle according to claim 1 , wherein the one or more processors are further caused to correct the target acceleration to zero when the target acceleration is a value on the deceleration side and the vehicle is permitted to accelerate, and correct the target acceleration to zero when the target acceleration is a value on the acceleration side and the vehicle is permitted to decelerate.
9 . A drive assist apparatus for a vehicle, the drive assist apparatus comprising:
circuitry configured to
receive recognized driving environment information on an outside of the vehicle, the outside including an area ahead of the vehicle and an area behind the vehicle,
set a target preceding vehicle distance to a preceding vehicle when the preceding vehicle is recognized based on the driving environment information, and
perform driving control for maintaining a preceding vehicle distance from the vehicle to the preceding vehicle at the target preceding vehicle distance, wherein:
the circuitry is configured to, when a driving path of the vehicle is congested,
(i) set an extended target preceding vehicle distance by extending the target preceding vehicle distance by adding a set distance to the target preceding vehicle distance, and set a target following vehicle distance to a following vehicle, wherein the set distance is configured to prevent another vehicle from cutting in front of the vehicle and increases as a preceding vehicle speed increases, and the target following vehicle distance is configured to allow a driver driving the following vehicle to reduce a frequency of braking against the vehicle during the congestion,
(ii) calculate a target acceleration based on a difference between (a) a following vehicle distance from the vehicle to the following vehicle and (b) the target following vehicle distance, to maintain the following vehicle distance at the target following vehicle distance, wherein the target acceleration is set to accelerate the vehicle with a greater acceleration as the following vehicle distance becomes less than the target following vehicle distance, and to decelerate the vehicle with a greater deceleration as the following vehicle distance becomes greater than the target following vehicle distance,
(iii) determine whether to permit the vehicle to accelerate or decelerate based on a relative relationship between the preceding vehicle distance and the extended target preceding vehicle distance, wherein the determination prevents the vehicle from accelerating when the preceding vehicle distance is less than or equal to the extended target preceding vehicle distance and prevents the vehicle from decelerating when the preceding vehicle distance is greater than the extended target preceding vehicle distance,
(iv) perform acceleration control using the target acceleration when the target acceleration is a value on an acceleration side and the circuitry determines to permit the vehicle to accelerate,
(v) perform deceleration control using the target acceleration when the target acceleration is a value on a deceleration side and the circuitry determines to permit the vehicle to decelerate,
(vi) maintain the following vehicle distance at the target following vehicle distance while controlling the preceding vehicle distance within a range between the target preceding vehicle distance and the extended target preceding vehicle distance, and
(vii) when the vehicle is permitted to decelerate and the target acceleration is a value on the deceleration side, calculate a second target acceleration for maintaining the preceding vehicle distance at the target preceding vehicle distance, and select a smaller of the target acceleration and the second target acceleration as a final target acceleration for the deceleration control.
10 . The drive assist apparatus for the vehicle according to claim 9 , wherein the circuitry is further configured to determine whether to permit the vehicle to accelerate or decelerate maintaining the following vehicle distance based on a relative relationship between the preceding vehicle distance and the extended target preceding vehicle distance, the following vehicle distance, and a relative speed of the preceding vehicle.
11 . The drive assist apparatus for the vehicle according to claim 9 , wherein the circuitry is further configured to set a predetermined value as the target following vehicle distance, and correct the target following vehicle distance based on a relative relationship between the vehicle and the following vehicle.
12 . The drive assist apparatus for the vehicle according to claim 9 , wherein the circuitry is further configured to reflect a relative speed between the vehicle and the preceding vehicle upon determining whether to permit the vehicle to accelerate or decelerate.
13 . The drive assist apparatus for the vehicle according to claim 9 , wherein the determination, based on a relative speed between the vehicle and the preceding vehicle, permits the vehicle to accelerate even when the preceding vehicle distance is less than or equal to the extended target preceding vehicle distance, and permits the vehicle to decelerate even when the preceding vehicle distance is greater than the extended target preceding vehicle distance.
14 . The drive assist apparatus for the vehicle according to claim 13 , wherein when the preceding vehicle distance is less than or equal to the extended target preceding vehicle distance, a region where acceleration is permitted becomes larger as the relative speed becomes greater, and when the preceding vehicle distance is greater than the extended target preceding vehicle distance, a region where deceleration is permitted becomes larger as the relative speed becomes greater on a negative side.
15 . The drive assist apparatus for the vehicle according to claim 9 , wherein when the preceding vehicle distance reaches the target preceding vehicle distance due to acceleration of the vehicle, the circuitry is further configured to maintain the preceding vehicle distance at the target preceding vehicle distance without further acceleration.
16 . The drive assist apparatus for the vehicle according to claim 9 , wherein the circuitry is further configured to correct the target acceleration to zero when the target acceleration is a value on the deceleration side and the vehicle is permitted to accelerate, and correct the target acceleration to zero when the target acceleration is a value on the acceleration side and the vehicle is permitted to decelerate.