Cooperative control apparatus of motor driven power steering apparatus for smart parking assistant system
The present invention relates to a cooperative control apparatus of a motor driven power steering apparatus for a smart parking assistant system (SPAS). The cooperative control apparatus may relieve excessive response of the motor driven power steering apparatus even through an excessive required steering angle is inputted from the SPAS, prevent damage of the motor driven power steering apparatus by controlling the motor driven power steering apparatus through a motor angular speed, reduce vibration, and improve steering performance with high control precision regardless of external disturbance.
1. A cooperative control apparatus of a motor driven power steering apparatus for a smart parking assistant system (SPAS), comprising:
a position control unit configured to calculate a target steering angular speed at which a vehicle is to be automatically steered through a wheel steering angle inputted from a steering angle sensor and a required steering angle inputted from the SPAS;
a limit value setting unit configured to determine whether or not the required steering angle directly inputted from the SPAS is an excessive required value and decide an excessive target limit setting value for reducing the target steering angular speed, wherein the required steering angle is calculated by the SPAS;
a target angular speed setting unit configured to calculate a final target steering angular speed through the target steering angular speed calculated by the position control unit and the excessive target limit setting value set by the limit value setting unit, and convert the final target steering angular speed into a final target motor angular speed through a converter which converts the final target steering angular speed into the final target motor angular speed by applying a reduction ratio to the final target steering angular speed; and
a motor angular speed control unit configured to calculate an angular speed control value for controlling a motor through the final target motor angular speed inputted from the target angular speed setting unit and the motor angular speed inputted from the motor angular sensor, and output the calculated angular speed control value to the motor driven power steering apparatus.
2. The cooperative control apparatus of claim 1 , wherein the limit value setting unit calculates a required steering angle acceleration according to an input cycle of the required steering angle inputted from the SPAS, compares the required steering angle acceleration with a preset excessive required limit setting value, and decides an excessive target limit setting value for reducing the target steering angular speed.