Elevator Rope Sway Detection and Damping via Movable Mass
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Solution Overview
Problem
High-rise and mid-rise buildings experience undesirable rope sway in elevator systems due to earthquakes, high winds, and vertical air flow, leading to potential damage, noise, and vibration, which existing mitigation techniques have not adequately addressed.
Innovation Solution
The implementation of a movable mass system within the hoistway with elongated members coupled to a counterweight, equipped with strategically positioned dampers and sensors that detect contact to adjust elevator operation parameters in response to sway conditions, thereby mitigating rope sway and reducing vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If dampers are positioned to contact elongated members during sway, then rope sway is reduced, but device complexity increases
Solution Approach 1:
The hoistway is divided into multiple zones with dampers positioned at different locations along the elongated members. Each damper independently contacts its specific section, allowing localized sway mitigation without requiring a complex centralized system. This segmentation enables effective rope sway reduction while maintaining manageable device complexity.
Solution Approach 2:
The dampers serve as intermediary elements between the moving elongated members and the stationary hoistway structure. These intermediaries absorb and dissipate sway energy through controlled contact, protecting the rope system from excessive movement without requiring direct intervention in the rope's primary function.
2Measurement precision
If sensors and controllers are added to detect and respond to sway, then sway mitigation precision is improved, but device complexity increases
Solution Approach 1:
Sensors detect sway conditions and provide feedback signals to the controller, which then activates dampers or adjusts elevator operations in response. This feedback loop enables precise sway detection and coordinated mitigation, improving measurement precision while using a relatively simple control architecture that monitors and responds to sway events.
Solution Approach 2:
The system uses the sway-induced contact between dampers and elongated members to automatically trigger detection and response actions. The physical contact itself generates the detection signal, and the controller automatically adjusts operations without requiring complex external monitoring or manual intervention.
3Object-affected harmful factors
If elevator operation is adjusted in response to sway detection, then ride comfort is improved, but productivity decreases
Solution Approach 1:
Instead of stopping elevator operations completely during sway events, the system applies partial mitigation by adjusting speed, acceleration, or floor selection on a case-by-case basis. This partial action reduces harmful vibrations and noise while maintaining sufficient productivity by allowing limited operation to continue during mild sway conditions.
Solution Approach 2:
The controller modifies operational parameters such as speed, acceleration, and stopping points in response to detected sway conditions. By dynamically changing these parameters rather than halting operations entirely, the system reduces vibration and noise impacts while preserving elevator productivity through adaptive operation.
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
Effectively minimizes rope sway and associated vibrations, reducing damage and noise, while allowing for tailored responses to varying sway conditions through controlled elevator operations.
Implementation Method 1
At least one damper is positioned to selectively contact at least one of the elongated members if sway occurs
Data Source
AI summary
An exemplary elevator system includes a first mass that is moveable within a hoistway. A second mass is moveable within the hoistway. A plurality of elongated members couple the first mass to the second mass. At least one damper is positioned to selectively contact at least one of the elongated members if sway occurs. A sensor is associated with the damper. The sensor detects contact between the damper and the at least one of the elongated members. A controller adjusts at least one aspect of elevator system operation responsive to the detected contact.