REAR WHEEL STEERING CONTROL METHOD

PURPOSE:To improve the behavioral response of a car by using a transfer function that increases the ratio of a rear wheel angle to a front wheel steering angle or the lead characteristics of phase differences keeping pace with the rise of a front wheel frequency and decreases after the maximal value is exceeded. CONSTITUTION:A controller 19 obtains a desired rear wheel steering angle from the front wheel steering angle sensed by a sensor 21 based on a function that corresponds to the required behavioral characteristics of a car and inputs it to a power amplifier 20. The power amplifier 20 compares the rear wheel steering angle sensed by a sensor 23 and the desired rear wheel steering angle and operates a servo valve 15 in the direction where both are matched. In addition, a preset transfer function that increases the ratio of the rear wheel steering angle to the front wheel steering angle or the lead characteristics of a phase angle keeping pace with the rise of a front wheel steering frequency and decreases after the maximal value is exceeded is used in the steering stability area of the corresponding front wheel steering frequency.