Closed-Loop Elevator Monitoring via Motor Torque Estimation

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Solution Overview

Problem

Existing closed-loop elevator installations face challenges in monitoring parameters such as cable tension and aging, leading to potential belt slippage and noise issues, requiring frequent manual checks and interventions.

Innovation Solution

A method that estimates parameters like cable tension and adhesion using motor torque values, allowing for remote monitoring and automated tension control without dedicated sensors, reducing the need for regular technician visits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If manual tension measurement and adjustment is performed regularly, then belt slippage risk is reduced, but maintenance complexity and time consumption increase

Engineering Contradiction:
Improvebelt grip reliabilityVSAvoidmaintenance time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system enables self-monitoring of belt tension by continuously measuring motor torque and automatically comparing it against reference values. The elevator installation monitors its own belt condition without external intervention, triggering alerts only when tension deviations exceed thresholds, thereby eliminating the need for regular manual maintenance while ensuring reliable belt grip.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system implements continuous feedback by measuring motor torque, comparing it with reference torque values stored in memory, and generating alerts when deviations indicate belt tension problems. This closed-loop monitoring provides real-time information about belt condition, allowing timely intervention only when necessary, thus reducing overall maintenance time while maintaining reliability.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If dedicated sensors are installed for monitoring parameters, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improveparameter monitoring precisionVSAvoidsensor installation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system uses motor torque as an intermediary parameter to indirectly measure belt tension and other installation parameters. Instead of installing dedicated sensors on the belt or mechanical components, the system leverages the existing motor torque sensor to derive information about belt tension, adhesion, and aging through mathematical relationships, thereby achieving precise monitoring without adding device complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The motor torque measurement serves multiple functions simultaneously: it monitors belt tension, detects belt aging, evaluates adhesion conditions, and tracks cabin load variations. This multi-functional approach allows a single measurement parameter to provide comprehensive monitoring of the elevator installation, eliminating the need for multiple dedicated sensors and reducing overall system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

This approach enhances the reliability and simplicity of monitoring, minimizing human interventions and unnecessary replacements, while maintaining precise measurements of load and element condition.

Implementation Method 1

receive a measured value of a parameter representative of a motor torque applied by the drive motor

Methodology Applied
Scientific EffectTorque measurement: Torque

Implementation Method 2

If the belt is relatively loose, there is a risk of the belt slipping on a drive pulley

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 3

cable tension is likely to change over time

Methodology Applied
Scientific EffectTension: Tension

Data Source

PatentEP3303203B1Monitoring of closed-loop elevator equipment
Publication Date: 2023.09.20 SODIMAS
  • EP3303203B1 patent drawingFigure 1~3
  • EP3303203B1 patent drawingFigure 2
  • EP3303203B1 patent drawingFigure 4~7

AI summary

The invention relates to a method for monitoring elevator equipment. Said elevator equipment includes a car and/or counterweight, two pulleys that are to be installed on the respective ends of an elevator shaft, a linear element passing through the pulleys and on which the car and/or counterweight is mounted, and a drive motor for moving said linear element. The elevator equipment is arranged so that said at least one linear element forms a closed loop with the pulleys and the car and/or counterweight mounted on the linear element. The method includes: (a) receiving (204) a measured value of a parameter representing a drive torque (C'') applied by the motor, (b) estimating (202, 205) at least one value (Q) of a parameter related to the elevator equipment on the basis of the value received in step (a) of the parameter representing the drive torque, and (c) transmitting a signal, produced on the basis of the value estimated in step (b), to a user interface or device for controlling the elevator equipment.