Control device of automotive power pivot door

In an automotive power pivot door including a hinge device that permits a door to pivot upward and downward between full-open and full-close positions about an upper end thereof relative to a vehicle body, a gas stay that can hold the door at the full-open position when it is in a normal condition, a reversible electric motor that drives the door to pivot upward and downward when energized and an electromagnetic clutch that is interposed between the motor and the door to selectively establish and break a torque transmission path from the motor to the door,

• a system for detecting an abnormal condition of the gas stay, the system including a control unit which is configured to carry out:
• de-energizing the motor and disengaging the clutch when the door is lifted up to the full-open position;
• detecting a moved distance by which the door moves down from the full-open position within a predetermined time (t1) that elapses from the time on which the clutch is disengaged;
• engaging the clutch when the moved distance is equal to or longer than a first predetermined distance (L1);
• disengaging the clutch again when a second predetermined time (t2) passes from the time on which the clutch is engaged;
• counting a frequency by which the clutch takes the engaged condition;
• and
• judging that the gas stay is in an abnormal condition when the counted frequency indicates a predetermined frequency.

An apparatus for controlling a door, comprising:

• a reversible electric motor that drives the door in open and close directions;
• an electromagnetic clutch interposed between the motor and the door to selectively establish and break a torque transmission path from the motor to the door;
• a holder that holds the door at a full-open position;
• and
• a control unit that is configured to perform the following:
• de-energizing the motor and disengaging the clutch when the door is in the full-open position;
• detecting a distance that the door moves from the full-open position within a first predetermined time (t1) from the time the clutch is disengaged;
• engaging the clutch when the distance is equal to or larger than a first predetermined distance (L1);
• disengaging the clutch again when engagement of the clutch exceed a second predetermined time (t2);
• and
• determining whether the holder has failed based on a number of times the clutch has engaged.