Elevator Car Positioning via Vibration Damper Gain Adjustment

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Solution Overview

Problem

Conventional elevator re-leveling methods in high-rise buildings face challenges due to decreased roping stiffness and time delays, leading to stability issues and reduced resonant frequency, which limit control logic gains and performance.

Innovation Solution

The implementation of a vibration damper system that adjusts motor control gains during re-leveling, using friction members to resist vertical movement and dampen vibrations, allowing for increased motor torque gains and improved re-leveling performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional re-leveling control logic is used in high-rise buildings, then the system is simple and easy to implement, but the roping stiffness decreases and resonant frequency drops leading to stability issues and poor performance

Engineering Contradiction:
Improvere-leveling performanceVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

A vibration damper is introduced as an intermediary mechanical component between the elevator car and the guide rail. This damper provides physical vibration suppression and stiffness support, allowing the control system to use higher gains without causing instability. The damper acts as a mediator that handles the mechanical vibration issues, enabling the control logic to achieve better performance without becoming overly complex.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system dynamically adjusts control parameters (gains) based on the activation state of the vibration damper. When the damper is activated, the control logic switches to a second set of gains that are optimized for the dampened condition, allowing higher gains to be used safely. This parameter change enables the system to overcome the limitations of reduced roping stiffness without requiring a complete redesign of the control architecture.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If higher control gains are used to improve re-leveling speed and precision, then re-leveling performance improves, but system stability deteriorates due to reduced roping stiffness and resonant frequency

Engineering Contradiction:
Improvere-leveling speedVSAvoidsystem stability
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The vibration damper serves as a physical intermediary that suppresses resonant vibrations and provides additional stiffness to the system. This mechanical intervention allows the control system to safely employ higher gains for faster re-leveling without compromising stability. The damper absorbs the destabilizing vibrations that would otherwise amplify with higher gains.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The control system dynamically adapts its gains based on the vibration damper's activation state. When the damper is active, the system transitions to using higher gains optimized for rapid correction. This dynamic parameter adjustment allows the system to achieve high productivity when needed while maintaining stability through the dampened mechanical support.

Inventive Principle:
Principle #15Dynamics

3Manufacturing precision

If higher control gains are used to improve re-leveling precision, then positioning accuracy improves, but vibration and resonance increase

Engineering Contradiction:
Improvepositioning accuracyVSAvoidvibration
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The vibration damper is positioned as a mechanical intermediary that directly counteracts resonant vibrations and bounce. By providing this physical damping mechanism, the system can apply higher control gains to achieve greater positioning accuracy without the harmful vibrations that would normally result from such aggressive control action.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system converts the potential harm of high-frequency vibrations into a benefit by using the vibration damper to selectively suppress only the harmful resonant frequencies. This allows the control system to use high gains for precise positioning while the damper filters out the unwanted vibrations, effectively turning the aggressive control action into a beneficial precision tool without the negative side effects.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 vibration damper system enhances re-leveling performance by minimizing resonant frequency excitation and enabling higher control gains, resulting in faster and more precise positioning of the elevator car, even in high-rise buildings with extended roping arrangements.

Implementation Method 1

A vibration damper is provided in an elevator system. The vibration damper includes a friction member configured to frictionally engage a guide rail of the elevator system when the vibration damper is in a deployed position.

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2370339B1Elevator car positioning using a vibration damper
Publication Date: 2015.08.05 OTIS ELEVATOR CO
  • EP2370339B1 patent drawingFigure 1
  • EP2370339B1 patent drawingFigure 2~3
  • EP2370339B1 patent drawingFigure 4~5

AI summary

An exemplary method of controlling elevator car position includes determining that an elevator car requires re-leveling and determining whether a vibration damper is activated. A gain for controlling operation of a motor responsible for moving the elevator car for the re-leveling is adjusted if the vibration damper is activated.