Electric control apparatus for damper device in suspension system of automotive vehicle

An electric control apparatus for a damper device in a suspension system of an automotive vehicle, comprising:

• first detection means for detecting absolute velocity of a sprung mass of the vehicle in vertical movement;
• second detection means for detecting relative velocity of the sprung mass to an unsprung mass of the vehicle in vertical movement;
• means for determining a target damping coefficient in a predetermined small value when the detected absolute velocity is different from the detected relative velocity in a movement direction and for increasing the target damping coefficient in accordance with an increase of a velocity ratio of the detected absolute velocity to the detected relative velocity when the detected absolute velocity coincides with the detected relative velocity in the movement direction;
• and
• setting means for setting a damping coefficient of the damper device to the target damping coefficient;
• wherein the electric control apparatus further comprises:
• third detection means for detecting a magnitude of vertical vibration of the sprung mass;
• and
• correction means for correcting a maximum value of the target damping coefficient to a predetermined small value when the detected magnitude of vertical vibration of the sprung mass is less than a predetermined value and for increasing the maximum value of the target damping coefficient in accordance with an increase of the detected magnitude of vertical vibration of the sprung mass more than the predetermined value.