Autonomous driving assistance device and computer program

1. An autonomous driving assistance device for generating assistance information to be used in autonomous driving assistance that is executed in a vehicle, comprising:

a processor programmed to:

set a target travel trajectory that is an aimed travel trajectory for a road on which the vehicle travels;

set as an exclusion range a range with a radius of an exclusion range distance about a trajectory generation start point, the exclusion range distance being a distance set based on the type of autonomous driving assistance that is executed in the vehicle;

set a control target point to a position that is located on the target travel trajectory and ahead of the trajectory generation start point in a direction in which the vehicle is traveling based on a type of autonomous driving assistance being executed in the vehicle, the control target point being set at a position that is located out of the exclusion range and closer to the trajectory generation start point; and

generate a control trajectory to be followed by the vehicle by using a trajectory from the trajectory generation start point to the control target point.

2. The autonomous driving assistance device according to claim 1 , wherein:

the trajectory generation start point is a predicted position of the vehicle after a predetermined time, the predicted position being obtained on an assumption that the vehicle follows a trajectory from a current position of the vehicle or the trajectory generation start point to the control target point.

3. The autonomous driving assistance device according to claim 1 , wherein the processor is programmed to:

generate as the control trajectory a trajectory connecting the trajectory generation start point, and a predicted position of the vehicle after a predetermined time, the predicted position being obtained on an assumption that the vehicle follows trajectories from a current position of the vehicle and the trajectory generation start point to the control target point.

4. The autonomous driving assistance device according to claim 1 , wherein:

the autonomous driving assistance that is executed in the vehicle includes lane keeping driving assistance for keeping the vehicle in a same lane and lane change assistance for moving the vehicle to a different lane; and

a larger exclusion range distance is set for the lane change assistance than for the lane keeping driving assistance.

5. The autonomous driving assistance device according to claim 1 , wherein the processor is programmed to:

set the target control point on a condition that a minimum radius of turn in the trajectory leading from the trajectory generation start point to the control target point is equal to or larger than a threshold.

6. The autonomous driving assistance device according to claim 1 , wherein the processor is programmed to:

when the type of autonomous driving assistance that is executed in the vehicle is switched from a first assistance to a second assistance, switch the exclusion range distance from a first distance corresponding to the first assistance to a second distance corresponding to the second assistance in a plurality of steps.

7. The autonomous driving assistance device according to claim 6 , wherein the processor is programmed to:

switch the exclusion range distance from the first distance to the second distance in the plurality of steps in a case where the first distance is larger than the second distance; and

switch the exclusion range distance from the first distance to the second distance in one step in a case where the first distance is smaller than the second distance.

8. The autonomous driving assistance device according to claim 1 , wherein the processor is programmed to:

gradually reduce the exclusion range distance in a case where a same autonomous driving assistance is continuously executed in the vehicle.

9. A computer-readable storage medium storing a computer-executable program for generating assistance information to be used in autonomous driving assistance that is executed by a computer in a vehicle, the program causing the computer to execute functions comprising:

setting a target travel trajectory that is an aimed travel trajectory for a road on which the vehicle travels;

setting as an exclusion range a range with a radius of an exclusion range distance about a trajectory generation start point, the exclusion range distance being a distance set based on the type of autonomous driving assistance that is executed in the vehicle;

setting a control target point to a position that is located on the target travel trajectory and ahead of the trajectory generation start point in a direction in which the vehicle is traveling based on a type of autonomous driving assistance being executed in the vehicle, the control target point being set at a position that is located out of the exclusion range and closer to the trajectory generation start point; and

generating a control trajectory to be followed by the vehicle by using a trajectory from the trajectory generation start point to the control target point.