Otis Elevator Company

Charles F Schoenmann

J Mark Deric

An elevator system having a microprocessor-based elevator door motion controller controls door motion by means of the difference between actual door velocity and a dictated door velocity, which is dictated in a variety of ways in dependence on conditions of the elevator. The disclosed invention comprises sensing a door reversal demand and causing the dictated velocity to be in accordance with a reverse acceleration factor determined as the square of the velocity of the door at the time the door reverse demand is made divided by twice the distance within which it is desired that the door shall stop after the reversal demand is made, before accelerating in the reverse direction, and providing a door-stopping boost or kick current to the elevator door motor in order to assist the door in stopping, the current being a derivative lag function of the velocity of the door at the time the reversal demand is sensed. An exemplary elevator system and door controller, and door control program logic flowcharts are disclosed to illustrate the environment of the invention as well as the preferred embodiment of the invention itself.

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Somers, CT, United States of America

Charles F Schoenmann