Driving assistance system, storage medium storing driving assistance program, and driving assistance method

A non-transitory computer readable storage medium storing a driving assistance program stored in a storage medium for assisting a collision avoidance between a host vehicle and an object during operation of the host vehicle, the driving assistance program comprising instructions for causing a processor to:

• determine a driving trajectory of the host vehicle during an avoidance control period in which the host vehicle is controlled for the collision avoidance;
• and
• respectively control a steering angle and a braking force applied to wheels of the host vehicle according to the driving trajectory,
• wherein
• the determination of the driving trajectory includes:
• selecting, from among a single control mode in which a turning posture of the host vehicle during the avoidance control period is controlled by a single adjustment of the steering angle, and a coordinated control mode in which the turning posture during the avoidance control period is controlled by a coordination of the steering angle and the braking force, a control mode that matches a response characteristic estimated for the host vehicle during the avoidance control period;
• determining, in the single control mode, the driving trajectory so as to specify a required yaw rate necessary to control the turning posture by the single adjustment of the steering angle;
• determining, in the coordinated control mode, the driving trajectory so as to specify the required yaw rate necessary to control the turning posture by the coordination of the steering angle and the braking force;
• and
• specifying, in the coordinated control mode, the required yaw rate necessary to control the turning posture by coordinating a left-right distribution of the braking force with the steering angle.

A driving assistance method executed by a processor for assisting a collision avoidance between a host vehicle and an object during operation of the host vehicle, the driving assistance method comprising:

• determining a driving trajectory of the host vehicle during an avoidance control period in which the host vehicle is controlled for the collision avoidance;
• and
• respectively controlling a steering angle and a braking force applied to wheels of the host vehicle according to the driving trajectory,
• wherein the determination of the driving trajectory includes:
• selecting, from among a single control mode in which a turning posture of the host vehicle during the avoidance control period is controlled by a single adjustment of the steering angle, and a coordinated control mode in which the turning posture during the avoidance control period is controlled by a coordination of the steering angle and the braking force, a control mode that matches a response characteristic estimated for the host vehicle during the avoidance control period;
• determining, in the single control mode, the driving trajectory so as to specify a required yaw rate necessary to control the turning posture by the single adjustment of the steering angle;
• determining, in the coordinated control mode, the driving trajectory so as to specify the required yaw rate necessary to control the turning posture by the coordination of the steering angle and the braking force;
• and
• specifying, in the coordinated control mode, the required yaw rate necessary to control the turning posture by coordinating a left-right distribution of the braking force with the steering angle.

A driving assistance system comprising:

• a processor,
• wherein
• the driving assistance system is configured to assist in a collision avoidance between a host vehicle and an object during operation of the host vehicle,
• the processor is configured to:
• determine a driving trajectory of the host vehicle during an avoidance control period in which the host vehicle is controlled for the collision avoidance;
• and
• respectively control a steering angle and a braking force applied to wheels of the host vehicle according to the driving trajectory,
• the determination of the driving trajectory includes:
• selecting, from among a single control mode in which a turning posture of the host vehicle during the avoidance control period is controlled by a single adjustment of the steering angle and a coordinated control mode in which the turning posture during the avoidance control period is controlled by a coordination of the steering angle and the braking force, a control mode that matches a response characteristic estimated for the host vehicle during the avoidance control period;
• determining, in the single control mode, the driving trajectory so as to specify a required yaw rate necessary to control the turning posture by the single adjustment of the steering angle;
• determining, in the coordinated control mode, the driving trajectory so as to specify the required yaw rate necessary to control the turning posture by the coordination of the steering angle and the braking force;
• and
• adjusting, in the coordinated control mode, a phase of the required yaw rate so as to be advanced relative to a phase of the required yaw rate in the single control mode.

A driving assistance system comprising:

• a processor,
• wherein
• the driving assistance system is configured to assist in a collision avoidance between a host vehicle and an object during operation of the host vehicle,
• the processor is configured to:
• determine a driving trajectory of the host vehicle during an avoidance control period in which the host vehicle is controlled for the collision avoidance;
• and
• respectively control a steering angle and a braking force applied to wheels of the host vehicle according to the driving trajectory,
• the determination of the driving trajectory includes:
• selecting, from among a single control mode in which a turning posture of the host vehicle during the avoidance control period is controlled by a single adjustment of the steering angle and a coordinated control mode in which the turning posture during the avoidance control period is controlled by a coordination of the steering angle and the braking force, a control mode that matches a response characteristic estimated for the host vehicle during the avoidance control period;
• determining, in the single control mode, the driving trajectory so as to specify a required yaw rate necessary to control the turning posture by the single adjustment of the steering angle;
• determining, in the coordinated control mode, the driving trajectory so as to specify the required yaw rate necessary to control the turning posture by the coordination of the steering angle and the braking force;
• and
• increasing, in the coordinated control mode, magnitude of a yaw angle acceleration, which is a gradient of the required yaw rate, relative to magnitude of a yaw angle acceleration in the single control mode.