Autonomous driving assistance method and device

An autonomous driving assistance device installable to a vehicle, comprising:

• a manual driving control section configured to control the vehicle in accordance with manual driving by a driver of the vehicle;
• an autonomous driving control section configured to control autonomous driving of the vehicle using a detection result of a first sensor which detects a travelling state of the vehicle or a surrounding condition of the vehicle, the first sensor including a first yaw rate sensor used for stabilization control of the vehicle and a second yaw rate sensor used for position detection of the vehicle;
• a malfunction state detection section configured to detect whether there is a malfunction in the first sensor;
• and
• a travelling condition determining section configured to determine a travelling condition of the vehicle, wherein
• in response to it being detected that there is a malfunction in the first sensor during control of the autonomous driving of the vehicle, the autonomous driving control section is configured to execute emergency autonomous driving until a predetermined condition is satisfied while changing, based on the determined travelling condition, a driving manner of the emergency autonomous driving as compared with a driving manner of the autonomous driving executed before no malfunctions are detected in the first sensor,
• after the emergency autonomous driving is terminated, the autonomous driving assistance device being configured to selectively execute one of:
• causing the autonomous driving control section to stop the vehicle;
• and
• causing the manual driving control section to control the manual driving, and
• the autonomous driving control section is configured to:
• in response to a malfunction being detected in either one of the first yaw rate sensor and the second yaw rate sensor, control the emergency autonomous driving using the other one of the first and second yaw rate sensors;
• estimate a vehicle attitude using the other one of the first and second yaw rate sensors and a steering angle sensor installed to the vehicle, and determine whether the estimated vehicle attitude is stable;
• in response to determining that the estimated vehicle attitude is stable, continue a permitting state of braking of the vehicle for avoiding a collision with a forward vehicle that is travelling ahead of the vehicle;
• and
• in response to determining that the estimated vehicle attitude is not stable, change from the permitting state to a prohibiting state of braking of the vehicle.