Control apparatus and method of rear-wheel steering system

A control apparatus of a rear-wheel steering (RWS) system, comprising:

• a plurality of sensors configured to detect a vehicle status;
• and
• a processor configured to:
• check the vehicle status in response to signals input from the plurality of sensors and determine a control mode for the RWS system, the control mode being one of reverse-phase control, in-phase control, and neutral control;
• and
• in an event of a sharp steering situation, change the control mode for the RWS system and perform controlling the RWS system;
• wherein the processor is configured to:
• calculate a target understeer ratio based on an estimated value of a side-slip angle and a vehicle speed;
• determine the control mode based on comparing the target understeer ratio and a vehicle understeer ratio;
• perform the reverse-phase control in response to the target understeer ratio being lower than the vehicle understeer ratio;
• perform the in-phase control in response to the target understeer ratio being higher than the vehicle understeer ratio;
• and
• perform the neutral control in response to the target understeer ratio being equal to the vehicle understeer ratio.

A control method of a rear-wheel steering (RWS) system, comprising:

• detecting, using a plurality of sensors, a vehicle status;
• based on the vehicle status detected using signals input from the plurality of sensors, determining a control mode for the RWS system, the control mode being one of reverse-phase control, in-phase control, and neutral control;
• and
• in an event of a sharp steering situation, responding to the sharp steering situation by changing the control mode for the RWS system among reverse-phase control, in-phase control, and neutral control and performing controlling the RWS system accordingly.