| 摘要 |
An electronic vehicle door unlatch control reduces unwanted noise and actuator stress by varying unlatch actuator activation duration to provide the minimum duration required for door opening. A reversible actuator moves a detent between a fork bolt releasing position and a fork bolt retaining position; and an unlatch switch is activated by the fork bolt to signal whether the door is open or closed. A door opening signal activates the actuator to move the detent to the fork bolt releasing position and deactivate the actuator when the unlatch switch indicates the door is open or at the end of a first predetermined time period, whichever occurs first. The actuator is then activated in reverse to return the detent essentially to the fork bolt retaining position when the unlatch switch indicates the door is open, when the door opening signal is no longer received, or at the end of a second predetermined time period longer than the first predetermined time period, whichever occurs first. Usually, the detent will be activated to its fork bolt releasing position, the striker will escape the fork bolt and the detent will be returned to its fork bolt retaining position in a time of such short duration that actuator noise and stress will be minimized. Even if the door is frozen shut, however, the initial activation of the detent to its fork bolt releasing position will be limited in duration to the first predetermined time period; and the detent will stay in that position, with the actuator inactivated and therefore silent and unstressed, until the door opens, the operator stops trying to open it or the second predetermined time period times out.
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