Driving assistance device, driving assistance method, and storage medium
A driving assistance device includes a storage medium configured to store computer-readable instructions, and a processor that is connected to the storage medium, in which the processor executes the computer-readable instructions to determine to prompt a driver of a mobile object to avoid contact with an object detected by an object detection device whose detection range is at least on a traveling direction side of the mobile object according to steering, and a steering direction for avoiding contact with the object, and when it is determined to prompt the driver of the mobile object to avoid contact with the object according to steering, cause an actuator capable of outputting force to a steering operator to execute outputting, first, a force to reach a first target force in the same direction as the steering direction in a first period to maintain the state, and causing, then, a force output in a second period longer than the first period to reach zero.
1 . A driving assistance device comprising:
a storage medium configured to store computer-readable instructions; and
a processor that is connected to the storage medium, wherein the processor executes the computer-readable instructions to:
determine to prompt a driver of a mobile object to avoid, via steering, contact with an object detected by an object detection device whose detection range is at least on a traveling direction side of the mobile object, and determine a rotation direction of a steering wheel for avoiding contact with the object; and
in response to a determination to prompt the driver of the mobile object to avoid contact with the object via steering, cause an actuator capable of outputting force to the steering wheel to:
output a force to reach a target force in a same direction as the rotation direction in a first period to maintain a present state while vibrating the steering wheel, wherein the first period is a period of ¼ or less of a reciprocal of 5 hertz and ¼ or more of a reciprocal of 30 hertz, and the first period is in a resonance frequency range of an upper arm of a human, and
at an end of the first period, cause the force to reach zero in a second period longer than the first period, wherein the second period is a period of ¼ or more of a reciprocal of 4 hertz.
2 . The driving assistance device according to claim 1 , wherein
a steering device mounted on the mobile object is a mechanical connection of the steering operator and the steering wheel,
the force is a first force,
the target force is a first target force, and
the processor causes the actuator to:
output a second force to reach a second target force in a direction opposite to the steering direction in a third period longer than the first period to maintain a present state after causing the first force output by the actuator in the second period to reach zero, and
at an end of the third period, cause the second force output to reach zero in a fourth period.
3 . The driving assistance device according to claim 2 ,
wherein the processor makes an integrated value of the first force output by the actuator in the same direction as the steering direction equal to an integrated value of the second force output by the actuator in a direction opposite to the steering direction.
4 . The driving assistance device according to claim 2 , wherein the fourth period is equal or substantially equal to the first period.
5 . The driving assistance device according to claim 2 , wherein a first rate of change of outputting the second force to reach the second target force in the third period is less than a second rate of change of causing the first force to reach zero in the second period.
6 . A driving assistance method executed by a driving assistance device, comprising:
determining to prompt a driver of a mobile object to avoid, via steering, contact with an object detected by an object detection device having a detection range that is at least on a traveling direction side of the mobile object, and determining a rotation direction of a steering wheel for avoiding contact with the object; and
in response to the determining, causing an actuator capable of outputting a force to the steering wheel to execute:
outputting a force to reach a target force in a same direction as the rotation direction in a first period to maintain a present state while vibrating the steering wheel, wherein the first period is a period of ¼ or less of a reciprocal of 5 hertz and ¼ or more of a reciprocal of 30 hertz, and the first period is in a resonance frequency range of an upper arm of a human, and
at an end of the first period, causing the force to reach zero in a second period longer than the first period, wherein the second period is a period of ¼ or more of a reciprocal of 4 hertz.
7 . A computer-readable non-transitory storage medium that has stored a program, in which the program causes a processor to execute
determining to prompt a driver of a mobile object to avoid contact, by steering, with an object detected by an object detection device with a detection range that is at least on a traveling direction side of the mobile object, and determining a rotation direction of the steering wheel for avoiding contact with the object; and
in response to the determining, causing an actuator capable of outputting a force to the steering wheel to execute:
outputting a force to reach a target force in a same direction as the rotation direction in a first period to maintain a present state while vibrating the steering wheel, wherein the first period is a period of ¼ or less of a reciprocal of 5 hertz and ¼ or more of a reciprocal of 30 hertz, and the first period is in a resonance frequency range of an upper arm of a human, and
at an end of the first period, causing the force to reach zero in a second period longer than the first period, wherein the second period is a period of ¼ or more of a reciprocal of 4 hertz.