Elevator Hoistway Car Separation Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In high-rise buildings, multiple elevator cars traveling in the same direction within a hoistway often require precise control to maintain a sufficient separation distance to avoid interference and ensure safe operation, while minimizing the number of hoistways and improving passenger service efficiency.
Innovation Solution
A controller dynamically determines and maintains a separation distance between leading and trailing elevator cars by calculating the shortest and normal stopping distances, ensuring the trailing car can stop at least a threshold distance away from the leading car's emergency stopping position, even during sudden stops, by continuously monitoring and adjusting the speed and motion profiles of both cars.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple elevator cars are operated in the same hoistway to reduce the number of hoistways, then productivity is improved, but the risk of interference between cars increases
Solution Approach 1:
The controller proactively determines and maintains appropriate separation distances between elevator cars before interference can occur. By calculating stopping distances and maintaining buffer zones in advance, the system prevents potential collisions while allowing multiple cars to operate efficiently in the same hoistway
Solution Approach 2:
The controller continuously monitors the positions and motion states of multiple elevator cars, dynamically adjusting separation distances based on real-time feedback. This closed-loop control ensures that cars maintain safe distances while maximizing transportation productivity
2Reliability
If separation distance between elevator cars is increased to ensure safety, then reliability is improved, but the efficiency of space utilization deteriorates
Solution Approach 1:
The separation distance between elevator cars is made dynamic rather than fixed. The controller continuously adjusts the separation distance based on real-time conditions such as car positions, speeds, and stopping requirements, allowing minimum safe distances to be maintained only when necessary while maximizing hoistway utilization during safe operating conditions
Solution Approach 2:
The system changes the separation distance parameter dynamically based on operational conditions. By calculating shortest and normal stopping distances and adjusting separation accordingly, the system maintains safety while optimizing space utilization in the hoistway
3Productivity
If elevator cars travel at higher speeds to improve transportation efficiency, then productivity is improved, but the stopping distance increases making separation control more difficult
Solution Approach 1:
The controller determines stopping distances in advance based on predicted travel conditions and maintains separation distances that account for these pre-calculated values. This preliminary calculation allows high-speed operation while ensuring adequate stopping space is always available
Solution Approach 2:
The system continuously monitors actual stopping distances and adjusts separation requirements based on real-time feedback about car performance and conditions, allowing optimization of both speed and stopping distance
Data Source
AI summary
A separation distance is maintained between a leading elevator car (14) and a trailing elevator car (12) traveling in the same direction in an elevator hoistway (16). A shortest stopping distance (dssl) of the leading elevator car (14) and a normal stopping distance (dnst) of the trailing elevator car (12) are determined. The separation distance (dsep) is controlled such that a difference between the normal stopping distance (dnst) of the trailing elevator car (12) and the shortest stopping distance (dssl) of the leading elevator car (14) is greater than or equal to a threshold distance (dthresh).