Elevator Car Rescue Control Using Load-Based Run Selection
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Solution Overview
Problem
Conventional elevator rescue operations require high power consumption from batteries, leading to large and costly rescue drive devices, which are not feasible for high-volume elevators.
Innovation Solution
A method and system that selects between two rescue runs based on elevator car load, using a battery-operated rescue drive device to supply power to the hoisting machine and brakes, with a first run for balanced loads and a second run for unbalanced loads, minimizing power usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If a battery-operated rescue drive device is used to provide power during supply outage, then automatic rescue operation is enabled, but power consumption from the battery becomes excessive
Solution Approach 1:
The system utilizes the elevator car's own weight imbalance to generate motion during rescue operation. When the car is unbalanced, gravity automatically moves the car without requiring external power, making the system self-service and eliminating the need for a large battery-powered drive device.
Solution Approach 2:
The invention converts the harmful effect of weight imbalance (which causes uncontrolled movement) into a beneficial force that drives the elevator car during rescue operation. The unbalanced load becomes the driving force that moves the car to the landing without requiring additional power.
2Ease of operation
If a manual brake lever is used to open hoisting machinery brakes, then labor-intensive operation is required, but the solution only works for unbalanced elevator car load
Solution Approach 1:
The system automatically detects whether the elevator car is balanced or unbalanced and selects the appropriate rescue run mode accordingly. This self-service capability eliminates the need for manual intervention and ensures the system works for both balanced and unbalanced loads.
Solution Approach 2:
The invention dynamically adapts the rescue operation mode based on the real-time load condition. The control system switches between first rescue run (for balanced loads requiring power assistance) and second rescue run (for unbalanced loads using gravity), making the system versatile for all load conditions.
3Adaptability or versatility
If a tirak hoist is added to move the elevator car in case of balanced load, then the solution becomes more versatile, but the operation becomes even more complex and slow
Solution Approach 1:
The existing hoisting machine and brake system are made multi-functional by enabling them to operate in two different rescue modes. The same hardware handles both balanced and unbalanced loads through different control strategies, eliminating the need for additional specialized equipment like tirak hoist.
Solution Approach 2:
The control system acts as an intermediary that manages the rescue operation based on load detection. It automatically determines the appropriate rescue run mode and controls the brake and motor accordingly, replacing the need for manual operation and additional mechanical devices.
4Reliability
If the electric motor draws high power to prevent elevator car movement during starting phase, then ride comfort is maintained, but the battery capacity requirements increase
Solution Approach 1:
The system allows the elevator car to move naturally under gravity when unbalanced, requiring minimal or no power from the battery. The motor only provides small amounts of power for control and synchronization, rather than drawing high power to prevent movement, thus reducing battery capacity requirements while maintaining safety.
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
Enables the use of smaller, less powerful, and cheaper rescue drive devices by optimizing power consumption during elevator rescue operations, ensuring smooth and safe movement to the landing.
Implementation Method 1
supplying electrical power from a battery of the rescue drive device to an electric motor of the hoisting machine
Implementation Method 2
supplying electrical power from a battery of the rescue drive device to hoisting machinery brakes
Implementation Method 3
allowing drifting of the elevator car to a landing by means of gravity
Data Source
AI summary
In a system and method for an automatic rescue operation of an elevator car in an elevator system, the elevator system includes a hoisting machine and a battery-operated rescue drive device configured to provide power signals to the hoisting machine and/or hoisting machinery brakes. A load sensor is configured to gather elevator car load information, and the rescue drive device is configured to select, based on the elevator car load information, a first rescue run or a second rescue run.