Vehicle Control Device, Vehicle Control Method, and Steering System

A vehicle control method performed by a controller of a vehicle, the vehicle including:

• a braking device that generates braking force on each wheel of the vehicle;
• and
• a steer-by-wire steering system that includes a steering operation input member and a steering device including a steering actuator that applies steering force to steered road wheels of the vehicle, the steer-by-wire steering system being configured to control a steering angle of the steered road wheels independently of an operation amount of the steering operation input member,
• the controller being configured to output a control signal to the steering actuator based on the operation amount of the steering operation input member,
• the vehicle control method comprising:
• obtaining an abnormality detection signal indicating whether the vehicle has an abnormality that causes abnormal behavior of the vehicle when the braking force is generated by the braking device;
• when occurrence of the abnormality is detected based on the abnormality detection signal, calculating predicted behavior, which is behavior of the vehicle predicted to occur when the braking device is activated, and
• outputting the control signal to the steering actuator to generate the steering force in a direction to suppress the predicted behavior so that the vehicle behaves in accordance with the operation amount of the steering operation input member when the braking device is activated.

A steer-by-wire steering system comprising:

• a steering operation input member attachable to a vehicle;
• a steering device including a steering actuator that applies steering force to steered road wheels of the vehicle;
• and
• a controller that outputs a control signal to the steering actuator based on an operation amount of the steering operation input member, wherein
• the steer-by-wire steering system is configured to control a steering angle of the steered road wheels independently of the operation amount of the steering operation input member;
• and
• the controller
• obtains an abnormality detection signal indicating whether the vehicle has an abnormality that causes abnormal behavior of the vehicle when braking force is generated by a braking device of the vehicle on each wheel of the vehicle,
• when occurrence of the abnormality is detected based on the abnormality detection signal, calculates predicted behavior, which is behavior of the vehicle predicted to occur when the braking device is activated, and
• outputs the control signal to the steering actuator to generate the steering force in a direction to suppress the predicted behavior so that the vehicle behaves in accordance with the operation amount of the steering operation input member when the braking device is activated.