Integral gain elevator door motion control

Elevator door apparatus, comprising:

• a motor driven elevator door mechanism;
• demand means for providing signals indicative of demands to open or close said elevator door;
• position means providing signals related to the position of said elevator door;
• and
• control means for controlling said door mechanism in response to said demand signals and said position signals;
• characterized by:
• said position means comprising a transducer for providing signals which vary as a function of the position of said door mechanism;
• and
• said control means comprising cyclically operative signal processing means for providing, in response to said transducer, signal indications of the position and velocity of said door, and, in response to said demand means, said modification means and said position and velocity signal indications, for providing, in each of a series of cycles throughout a period of time during each door traverse, a velocity error signal in response to the difference between said door velocity signal indication and a dictated door velocity signal provided in each cycle to equal the velocity which the door is desired to have during such cycle in accordance with a desired door traverse velocity profile, an integral gain signal as the product of an integral gain constant and said velocity error signal, an integral gain command signal as the summation of all such integral gain signals provided in all such cycles of such door traverse, and a proportional gain command signal as the product of a proportional gain constant and said velocity error signal, and a motion command signal to said elevator door mechanism in response to said integral gain command signal and said proportional gain command signal.