Door operation control apparatus

DETAILED DESCRIPTION The present invention seeks to overcome or at least ameliorate these problems by providing an improved door controller which can "learn" the characteristics of a particular door.
According to a first aspect, the present invention provides a door controller including: a mechanism for driving a door curtain between open and closed positions in response to received door operation command signals, door position encoder for providing signals indicative of the position of the door curtain relative to the door opening; timing mechanism for providing timing signals for said controller; processing mechanism responsive to said encoder and said timing mechanism for producing a representation of a door travel speed characteristic; memory device coupled to said processing mechanism for storing said representation of a door travel speed characteristic.
According to a second aspect, the present invention provides a door controller according to said first aspect wherein said processing mechanism is adapted to compare the door travel speed characteristic for each run of the door with the previously stored characteristic and being responsive to the difference in said characteristics exceeding a predetermined margin to indicate an obstruction condition.
Preferably, said mechanism for driving the door curtain is further responsive to detection of an obstruction condition to reverse the direction of travel of the door curtain for a predetermined period and then stop travel of said door curtain.
According to a third aspect, the present invention provides a door controller including: a mechanism for driving a door curtain between open and close position in response to received door operation command signals, door position encoder for providing signals indicative of the door curtain relative to the door opening, first memory device coupled to said door position encoder for storing signals representative of a desired closed position of the door curtain, second memory device coupled to said door position encoder for storing signals representative of a desired open position of said door curtain, said mechanism for driving the door curtain being responsive to said signals stored in said first and second memory devices to limit door curtain travel to between these stored positions