Cable Car Roller Speed Control for Oscillation Damping

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Cable transport installations face issues with pumping phenomena, which cause mechanical fatigue, potential collisions, and passenger discomfort due to oscillations in cable lines, making it challenging to predict and prevent these oscillations effectively.

Innovation Solution

A method for controlling cable transport installations by measuring the translation speed of the cable at intermediate supports and drive pulleys, comparing the differences, and adjusting the rotation speed of support rollers using a motor or braking mechanism to actively dampen oscillations, thereby directly addressing the longitudinal dynamic movement of the cable.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If empirical criteria are applied during design to avoid pumping, then the complexity of prediction models is reduced, but the ability to systematically prevent oscillations under varying operating conditions deteriorates

Engineering Contradiction:
Improveprediction model complexityVSAvoidsystem reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent implements dynamic control of support rollers that can actively adjust their rotation speed to counteract oscillations in real-time. The support rollers transition from static passive elements to dynamic active elements that respond to detected cable speed variations, enabling the system to adapt to changing operating conditions and reliably prevent pumping phenomena.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent employs a feedback control system where cable speed is continuously measured at intermediate supports and compared to reference values. Based on this feedback, the rotation speed of support rollers is automatically adjusted to counteract detected oscillations, creating a closed-loop control system that systematically prevents pumping rather than relying on static design criteria.

Inventive Principle:
Principle #23Feedback

2Extent of automation

If active oscillation control is implemented by modifying drive system parameters globally, then the system can respond to detected oscillations, but the control action is not direct or targeted on the local oscillation

Engineering Contradiction:
Improveautomatic oscillation detection and responseVSAvoiddirectness of control action
Core Design Contradiction:
Extent of automationVSEase of operation

Solution Approach 1:

The patent applies local quality by equipping individual support rollers at intermediate supports with independent motorization and control. Each support roller can be controlled locally based on measurements taken at its specific location, allowing targeted counteraction of oscillations at the source rather than applying global drive system modifications that affect the entire cable loop.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent segments the cable support system into independently controllable support rollers at intermediate supports. Each support roller operates as an independent control unit with its own motor and sensor, allowing localized oscillation control without affecting other parts of the system, thereby providing direct and targeted control action.

Inventive Principle:
Principle #1Segmentation

3Ease of manufacture

If support rollers are made free to rotate independently without control, then the mechanical simplicity is maintained, but the ability to actively dampen cable oscillations is lost

Engineering Contradiction:
Improvemechanical simplicity of support rollersVSAvoidcable oscillations and pumping
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the purely passive mechanical support roller system with an electromechanical system. Motors are integrated into the support rollers to provide active control capability, substituting the need for complex mechanical damping mechanisms with controlled electromagnetic drive systems that can precisely adjust rotation speed to counteract oscillations.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the operational parameters of support rollers from fixed free-rotation to controlled variable-speed rotation. By dynamically adjusting the rotation speed parameter of support rollers based on detected cable oscillations, the system actively dampens pumping phenomena while maintaining the basic roller structure, thus balancing manufacturing simplicity with oscillation control effectiveness.

Inventive Principle:
Principle #35Parameter changes

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 method provides direct control over cable oscillations, improving passenger comfort and safety by effectively reducing the amplitude of pumping oscillations and preventing mechanical fatigue, thus enhancing the reliability and acceptability of cable transport systems for various uses.

Implementation Method 1

generating a signal representing the translation speed of the mobile cable at an intermediate support of the line of the installation by measuring the free rotation speed of a support roller with which the cable is in adherent contact

Methodology Applied
Scientific EffectAdherent contact friction: Friction

Implementation Method 2

correcting by accelerating or braking the rotation speed of the support roller of the intermediate support by clutching a motor or braking device on its axis

Methodology Applied
Scientific EffectTorque application: Torque

Data Source

PatentEP4480778A1Method for controlling line oscillations of a cable car transport installation and device configured to carry out the method
Publication Date: 2024.12.25 BUREAU DES ETUD DE CABLES
  • EP4480778A1 patent drawingFigure 1~3
  • EP4480778A1 patent drawingFigure 4~5
  • EP4480778A1 patent drawingFigure 6~7

AI summary

Method of controlling (300) the line oscillations of a cable vehicle transport installation, the method comprising a step of generating a reference setpoint (33) from real-time measurements on the drive pulley and the supports of the intermediate supports, a closed-loop comparison step between the setpoint (33) and a measurement (39) of the control variable on which the control device (22) acts directly or indirectly, a step of correcting the setpoint (33) by a controller (36), and a step of modifying the rotational speed of at least one roller (21) in adherent contact with the cable (1), according to a control (37) combined with a threshold (VS) and by temporary coupling of a motor or brake block, in order to reduce speed and voltage disturbances and thus control the oscillations of the cable line.