Patent ID: 7434666

Claim:
A condition monitoring method for measuring the stopping accuracy of an elevator car, the method comprising the steps of: defining a door zone for each floor; mounting a door zone detector on the elevator car; moving the elevator car towards a destination floor; measuring acceleration values of the elevator car during its travel towards the destination floor by means of an acceleration sensor attached to the elevator car; calculating the distance of the stopped elevator from the edge of the door zone on the basis of the measured acceleration values; calculating a computational final velocity of the elevator car on the basis of the measured acceleration values, said acceleration values being measured during the time span from the departure of the elevator car to its stopping back in position; calculating an average acceleration by utilizing the computational final velocity; calculating corrected acceleration values by utilizing an average acceleration error; and calculating the distance of the stopping position of the elevator car to the edge of the door zone on the basis of the corrected acceleration values.