Elevator Control for Building Sway Mitigation
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Solution Overview
Problem
Existing elevator systems face challenges in effectively addressing building sway conditions, particularly in high-rise and ultra-high-rise buildings, due to the high cost and limited information provided by sensor devices used to detect sway, which are not well-suited for variable and significant sway conditions.
Innovation Solution
A method and system that detect building sway using a MEMs accelerometer to determine characteristics such as frequencies and periods, and control the position and movement of the elevator car based on expected sway patterns, identifying critical zones and adjusting control strategies according to the detected sway characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional sensor devices are used to detect building sway, then the system can detect sway conditions, but the cost increases and the information provided is limited
Solution Approach 1:
The patent replaces traditional mechanical sensor devices with a MEMS accelerometer-based system. The MEMS accelerometer detects building sway through mechanical vibration detection, converting mechanical motion into electrical signals that can be processed to determine sway characteristics including frequency and amplitude, thereby reducing cost while maintaining measurement precision.
Solution Approach 2:
The patent changes the detection parameter from traditional sway detection methods to acceleration measurements. By measuring acceleration data from the MEMS accelerometer and analyzing the frequency spectrum of the acceleration signals, the system derives sway characteristics without requiring expensive traditional sensors, thus improving measurement capability while reducing device complexity.
2Loss of information
If traditional sensor devices are used to detect building sway, then the system can detect sway conditions, but the information provided is limited for high rise buildings
Solution Approach 1:
The patent implements a feedback mechanism where the MEMS accelerometer continuously monitors building sway, the controller processes the acceleration data to identify sway frequencies and characteristics, and adjusts elevator operation accordingly. This closed-loop feedback system provides comprehensive sway information and adapts to varying building conditions, overcoming the limitations of traditional sensors in high rise buildings.
Solution Approach 2:
The patent employs dynamic analysis of the acceleration signals to capture varying sway characteristics. By performing spectral analysis on the time-varying acceleration data, the system can identify different sway frequencies and patterns, providing complete information about the building's dynamic response to wind and other environmental factors, thereby improving adaptability to high rise building conditions.
3Strength
If the elevator system does not control position based on expected sway, then the system operation is simple, but damage to components may occur
Solution Approach 1:
The patent applies preliminary action by predicting expected sway based on detected building sway characteristics before the elevator reaches critical positions. The controller uses the acceleration data and sway frequency information to anticipate future sway conditions and adjusts elevator position proactively, preventing component damage before it occurs rather than reacting after damage has occurred.
Solution Approach 2:
The patent implements preliminary anti-action by applying counteracting forces to the elevator system before harmful sway effects can occur. The controller calculates the expected sway and applies compensating control actions to offset the anticipated lateral movement, thereby preventing damage to elevator components such as ropes and guides before the harmful sway can take effect.
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 provides more specific and effective control over the position and movement of the elevator, minimizing damage to components and maintaining desired system performance by accurately responding to building sway conditions.
Implementation Method 1
detecting the sway of the building (e.g., using a MEMs accelerometer)
Implementation Method 2
building sway conditions may introduce lateral movement of the roping of a traction-based elevator system
Data Source
AI summary
An illustrative example method of controlling an elevator situated in a hoistway of a building includes detecting sway of the building, determining characteristics of the detected sway including a plurality of frequencies and associated periods of the sway, determining an expected sway of an elongated member of the elevator system based on the determined characteristics, and controlling at least one of position and movement of an elevator car in the hoistway based on the expected sway.