Patent ID: 6854565

Claim:
A method for monitoring the condition of the door mechanism of an elevator and determining need for maintenance, said door mechanism comprising a door actuating system, door panels and a door operator, the method comprising the steps of: measuring the signals of the control system of a door in good condition and generating a set of characteristics descriptive of the operation of the door from them; measuring the signals of the door control system; dividing the operation during the opening and closing movements of the door into stages according to which parts of the door are functioning at each stage; from the measured signals, generating a set of characteristics descriptive of the operation of the door; comparing the set of characteristics thus generated to the set of characteristics for a normal operating condition stored in memory; based on the comparison of the two sets of characteristics, performing a diagnosis to determine where and how the operation of the door and its components deviates from normal operation and determining a degree of deviation such that both failures of operation and non-optimal operation prior to failures can be determined; and utilizing the result of the diagnosis to establish the need for servicing and a servicing time.