Abstract: A system for producing a velocity pattern for a vehicle such as an elevator car which must be brought smoothly to a stop accurately aligned with a desired one of a number of stations. The distance between the vehicle and the station at which a stop is required (target distance) is expressed in digital form, and is processed electronically to produce a velocity pattern which results in constant deceleration of the vehicle during the entire approach except for an initial build-up to, and a final tapering off from, the constant deceleration. A single adjustment for deceleration rate automatically adjusts the slowdown distance to the correct value to suit the selected deceleration rate. The calculation is done repetitively at high speed to minimize any lag between the diminishing target distance and the corresponding velocity pattern. Further adjustments permit control of the final tapering off from constant deceleration, with the slowdown distance automatically adjusted to suit these adjustments also.

Abstract: An elevator control system using vertically elongated single-turn loops of wire movable with the car past a vertical column of stationary coils of wire, one at each floor, which are de-energized one at a time repetitively at high speed. The sudden collapse of magnetic flux from a coil induces a pulse into the loops if the car is adjacent. Each loop has one or more twists so that the polarities of the induced pulses vary in a predictable manner over the vertical length of the loops. When pulses are induced in the loops, the unique combination of positive and negative pulses defines the quantized distance between the car floor and the building floor whose coil caused the pulses. The quantized distance between the car floor and any desired target floor in the building is computed repetitively by adding the pertinent floor heights, as stored in a memory, to the reading obtained from the loops.