Steering system

A steering system comprising:

• an electric motor configured to turn a steered wheel of a vehicle;
• a detector configured to detect a steering operation performed by a driver;
• and
• a controller configured to:
• control the electric motor by switching an autonomous steering mode in which the electric motor is controlled based on an autonomous steering command value, a manual steering mode in which the electric motor is controlled based on a manual steering command value corresponding to the steering operation performed by the driver, and a cooperative steering mode in which the electric motor is controlled based on a cooperative steering command value incorporating both the autonomous steering command value and the manual steering command value;
• control the electric motor in the cooperative steering mode when a manual steering request is transmitted:
• at a time point that is prior, by a first predetermined time, to occurrence of predicted switching from the autonomous steering mode to the manual steering mode, or
• when the vehicle arrives at a point located a first predetermined distance before a point where the predicted switching is to occur;
• and
• output an automatic stop request for generating an autonomous steering command value that causes the vehicle to move to and stop at a predetermined stop position, after the manual steering request is transmitted, and when the steering operation by the driver is not detected before:
• a time point that is prior, by a second predetermined time, to the occurrence of the predicted switching, or
• the vehicle arrives at a point that is located a second predetermined distance before the point where the predicted switching is to occur.