Elevator door motion modification

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 modification means settable to a plurality of different states for representing a corresponding plurality of selected modifications, and 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 equal to the desired door traverse time, motion command signals to said elevator door mechanism in response to the difference between said door velocity signal indication and a dictated door velocity signal calculated, 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, in response to signals representing desired rates of acceleration and deceleration, desired maximum velocity, acceleration and deceleration, a desired door position where deceleration is to begin, and a desired velocity where said desired decreasing rate of deceleration is to begin, for providing said desired door position signal in response to an initial position signal and a position increment signal, and for selectively providing said position increment signal indicative of a finite value or of a zero value, alternatively, in dependence on the state of said modification means.