TRANSPORTATION SYSTEM WITH DECELERATING CONTROL

摘要

TRANSPORTATION SYSTEM WITH DECELERATING CONTROL A solid state static converter changes a first current frequency to a second current frequency such as, for example, A.C. to D.C., D.C. to A.C., or A.C. of one frequency to A.C. of another frequency such as in a cycloconverter or the like, and operates a motor driving a traction sheave to control the movement of an elevator car in response to an error signal derived by the selective summation of a speed signal from a tachometer and a pair of vehicle speed command signals. One command signal is a function of the commanded velocity versus time and operatively controls the system during acceleration, constant velocity and a portion of deceleration. The other command signal is a function of the commanded velocity versus time as modified by the sensed position of the car and solely operatively controls the system during a portion of deceleration to stop the vehicle at a selected landing. The modified decelerating vehicle speed command signal is provided by an integrating circuit receiving stepped inputs as a function of a preconditioning input and the command signal input from a feedback circuit and modified in accordance with the sensed position of the vehicle to provide a vehicle command signal having a predetermined plurality of slopes.