CONTROL METHOD OF MOTOR DRIVEN POWER STEERING SYSTEM

摘要

The present invention relates to a control method of a motor driven power steering system. The objective of the present invention is to provide a lock and stop control method of the improved motor driven power steering system to solve the problem of impact occurrence on a rough road, the phenomenon of over turning of the steering wheel in creep driving after full turn and a big impact sound occurring on a smooth road. To this end, the present invention includes a step of checking whether the car stops or not; a step of determining the value of the current according to the steering wheel torque value detected in steering operation when a car stops and start an MDPS motor by applying the determined current value to the MDPS motor in phase current; and a step of reducing the increasing steering angle as controlling the current applied to the MDPS motor after it enters the lock and stop mode as the value to match the steering angle detected in real time when the detected steering angle reaches the entering angle set as the value following the current applied to the motor at the lock and stop mode entering moment. The current value controlled at the lock and stop mode to match the entering angle or the steering angle detected in real time is already set as the value following the current applied to the motor in the way the current value becomes the different value according to the current applied to the motor at the moment of entering the lock and stop mode.