Otis Elevator Company

Uwe Schonauer

Peter L Herkel

Helmut L Schroder-Brumloop

Stefan Spannhake

Christoph M Ernecke

Robert Oesterle

A system is provided for damping vertical oscillations of an elevator car stopped at an elevator landing. The system includes an elevator traction sheave that receives a torque, a sensor that provides a sensor signal indicative of the torque, a controller that provides a control signal based on the sensor signal, and a motor that applies the torque to the sheave. Oscillations in the torque correspond to the vertical oscillations of the car stopped at the landing during a first (e.g., position control) mode of operation. The motor drives the sensor signal towards a baseline value in response to receiving the control signal during a second (e.g., constant torque control) mode of operation in order to reduce the vertical oscillations of the car.

Actively damping vertical oscillations of an elevator car

A position detecting device for detecting the position of an object () movable along a predetermined path of movement, comprising a signal transmission medium () extending along the path of movement, a signal generator () movable together with said movable object (), by means of which a signal can be coupled into the signal transmission medium (), at least one signal receiver () at an extraction location in an end portion of said path of movement, a signal propagation time measuring means () adapted to determine the signal propagation time between coupling location and extraction location (), wherein the signal generator () is designed to deliver a periodically repeating signal pulse sequence (FIG.) in which the time intervals between consecutive signal pulses are different for each pair of consecutive signal pulses each, the period duration of the repetitive signal pulse sequence is greater than the maximum signal propagation time with maximum interval between coupling location and extraction location, and the time intervals between consecutive signal pulses are shorter than the maximum signal propagation time.

Arrhythmic pulse sequence for sonic distance measurement

A laser disposed on an elevator car is scanned at a uniform rate; one or more pairs of sensors disposed on opposite sides of the hoistway determine the time for the laser to scan from one sensor to the other, from which the vertical distance between the elevator car and a sensor pair is determined, thereby to derive hoistway position, elevator speed and acceleration.

Measuring elevator position with scanning laser beam

Each torque-producing phase current of a multi-phase motor is passed through a filter which includes an R/C shunt to ground and a series, current-compensated choke. Each choke has a winding in series with each phase so that the net current generated by phase currents in the windings is zero, and therefore the net flux generated by phase currents in the highly permeable core of the choke is zero at all times. However, there is significant inductive reactance created by the non-counterbalanced motor leakage currents, which prevent leakage currents from circulating through the motor. Thus, torque-producing motor currents can accurately be measured for feedback, without pollution from leakage currents. LEM current transducers allow use of small, proportional currents in the measuring and suppress inter-phase coupling.

Current compensated choke filter for multi-phase motor drives

A sonic position sensing system for measuring the position of an object, such as an elevator, includes transmitting a sonic signal along a conductor by a transmitter; receiving said sonic signal at a first receiver, located a first distance along said conductor from said transmitter; receiving said sonic signal at a second receiver located a second distance from said transmitter and on an opposite side of said transmitter from said first receiver; calculating a first distance between said transmitter and said first receiver; calculating a second distance between said transmitter and said second receiver; and calculating a total measured distance between said first receiver and said second receiver as the sum of said first distance and said second distance as the sum of said first distances and said second distance. The first or second distances may be scaled by the total measured distance to compensate for temperature effects. The position may also be corrected for velocity and/or acceleration of the object.

Sonic position measurement system

A method for detecting if an elevator door is blocked comprises the steps of: initiating a movement of the elevator door; starting a timer count upon the initiation of the movement of the door; determining if the timer count has expired before a door position reference switch is actuated; and determining that the elevator door is blocked if the timer count has expired before the door position reference switch is actuated.

Growing community of inventors

Berlin, Germany

Uwe Schonauer