Driving assistance device, driving assistance method, and storage medium

A driving assistance method comprising:

• by a computer, performing at least one of
• referring to an output of a detection device configured to detect presence of objects in front of a vehicle, and
• in response to a degree of approach between the vehicle and a target object among the objects satisfying a first condition, performing braking control to instruct a brake device of the vehicle to stop the vehicle or instructing a steering device of the vehicle to avoid contact with the target object by steering;
• performing a first preliminary operation in response to the degree of approach between the target object and the vehicle satisfying a second condition;
• performing a second preliminary operation in response to the degree of approach between the target object and the vehicle satisfying a third condition and it is determined that there is no space in which the vehicle can proceed after performing avoidance steering in any of travel paths to sides of the target object at a time in response to the third condition being satisfied,
• the first condition being a condition that is satisfied in response to the degree of approach is being higher than the second condition,
• the second condition being a condition that is satisfied in response to the degree of approach is being higher than the third condition;
• and
• changing a control mode of the braking control in response to a situation where the first preliminary operation or the second preliminary operation that is being executed becoming unable to continue occurs.

A non-transitory computer-readable storage medium that stores a program to be executed by a computer to perform at least:

• perform at least one of
• referring to an output of a detection device configured to detect presence of objects in front of a vehicle, and
• in response to a degree of approach between the vehicle and a target object among the objects satisfying a first condition, performing braking control to instruct a brake device of the vehicle to stop the vehicle or instructing a steering device of the vehicle to avoid contact with the target object by steering;
• perform a first preliminary operation in response to the degree of approach between the target object and the vehicle satisfying a second condition;
• perform a second preliminary operation in response to the degree of approach between the target object and the vehicle satisfying a third condition and it is determined that there is no space in which the vehicle can proceed after performing avoidance steering in any of travel paths to sides of the target object at a time in response to the third condition is being satisfied,
• the first condition being a condition that is satisfied in response to the degree of approach being higher than the second condition,
• the second condition being a condition that is satisfied in response to the degree of approach being higher than the third condition;
• and
• change a control mode of the braking control in response to a situation where the first preliminary operation or the second preliminary operation that is being executed becoming unable to continue occurs.