Driving assistance device, driving assistance method, and storage medium

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.

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.