Elevator Landing Compensation Control for Bounce Suppression

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Solution Overview

Problem

Elevator systems experience disruptive oscillations and position changes due to load changes and stretching/contraction of load bearing members, particularly in high-rise buildings with few load bearing members, leading to passenger discomfort from bounce and vibration.

Innovation Solution

A dynamic compensation control system that uses motion state sensors and a Notch filter to adjust motor torque and maintain elevator position stability, employing high-bandwidth feedback control to minimize oscillations and vibrations by directly measuring car motion states and adjusting the filter based on hoistway dynamics and load changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If load bearing members are stretched or contracted due to load changes, then the elevator car can move vertically to accommodate passengers, but disruptive oscillations and bounce motion occur

Engineering Contradiction:
Improveelevator car position adjustmentVSAvoidelevator car vertical position stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The system uses motion state sensors to detect the actual motion state of the elevator car and feeds this information back to the controller. The controller then adjusts motor torque in real-time to counteract oscillations and maintain position stability, resolving the contradiction between position adaptability and stability.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically changes motor torque parameters based on detected motion states and load conditions. By adjusting torque in real-time, the system accommodates load changes while suppressing oscillations, resolving the position stability issue.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If high-bandwidth feedback control is implemented to reduce oscillations, then position stability and passenger comfort improve, but system complexity increases

Engineering Contradiction:
Improveelevator car position stabilityVSAvoidcontrol system complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The system uses the elevator car's own motion state sensors to detect and control its position. The self-contained feedback mechanism reduces the need for external complex control systems while maintaining high position stability.

Inventive Principle:
Principle #25Self-service

3Object-affected harmful factors

If dynamic compensation control is activated during landing operations, then bounce and vibrations are reduced, but control system complexity increases

Engineering Contradiction:
Improvebounce and vibrationVSAvoidcontrol system complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The system dynamically adjusts control parameters based on real-time motion state detection. The controller activates dynamic compensation only when needed (during landing operations with detected oscillations), reducing bounce and vibration without requiring permanently complex control mechanisms.

Inventive Principle:
Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system effectively reduces or eliminates bounce and vibrations, providing a high-bandwidth response to maintain elevator stability and passenger comfort by quickly reacting to load changes and adjusting the dynamic compensation filter to optimize performance.

Implementation Method 1

A dynamic compensation control system employs a Notch filter to adjust motor torque and maintain elevator position stability, employing high-bandwidth feedback control to minimize oscillations and vibrations

Methodology Applied
Scientific EffectNotch filter: Filter (electronic)

Implementation Method 2

The controller receives motion state information from motion state sensors and determines a motion state error related to a desired motion state of the elevator car

Methodology Applied
Scientific EffectMotion state sensing: Accelerometer

Implementation Method 3

The control output is a current to generate a motor torque at the elevator machine

Methodology Applied
Scientific EffectElectromagnetic torque generation: Electromagnetic Induction

Data Source

PatentEP3378820B1Dynamic compensation control for elevator systems
Publication Date: 2023.05.10 OTIS ELEVATOR CO
  • EP3378820B1 patent drawingFigure 1
  • EP3378820B1 patent drawingFigure 2~3
  • EP3378820B1 patent drawingFigure 4A~4B

AI summary

Methods and systems of controlling elevators including detecting a landing stop for an elevator car (103), measuring load information associated with the stop, controlling stopping of the elevator at the landing using a machine (111) based on at least one of the detected landing and the measured load information and performing dynamic compensation control of a motion state of the elevator with a computing system (115) and the elevator machine (111). The dynamic compensation control includes receiving motion state information related to at least one motion state of the elevator car at the computing system (115), receiving the landing and load information at the computing system (115), applying a filter to the received information and generating a first control signal, and producing a control output from the first control signal to control the elevator machine (111) to minimize oscillations, vibrations, excessive position deflections, and/or bounce of the elevator car (103) at the detected landing.