Shared-Shaft Elevator Control Using Dynamic Car Authorization

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Solution Overview

Problem

Existing elevator systems with multiple cars in a shared shaft face risks of collisions due to inadequate collision prevention mechanisms, which can lead to passenger safety hazards.

Innovation Solution

An elevator safety system that includes an elevator control unit to monitor the shaft and dynamically determine authorized sections for each car based on position, movement direction, and speed, using linear motors to guide cars into safe paths, and stop them if unauthorized, with sensors for turning stations and locking devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple elevator cars are allowed to move in the same shaft, then productivity is improved, but the risk of collision increases

Engineering Contradiction:
Improveelevator transport capacityVSAvoidcollision prevention
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The shaft is divided into multiple shaft sections with authorized and unauth ized zones. The control unit dynamically assigns authorized shaft sections to each elevator car based on real-time position, movement direction, and speed, creating virtual segmentation that prevents collision while maintaining high productivity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The authorized shaft section boundaries are not fixed but dynamically adjusted based on real-time monitoring of elevator car positions, speeds, and movement directions. This dynamic authorization system allows flexible utilization of shaft space while maintaining safety margins

Inventive Principle:
Principle #15Dynamics

2Reliability

If dynamic authorization system is implemented, then collision protection is improved, but device complexity increases

Engineering Contradiction:
Improvecollision protectionVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The elevator control unit performs multiple functions: it monitors shaft conditions, determines authorized sections, communicates with all elevator cars, and enforces safety boundaries. This multi-functional approach consolidates complexity into a single centralized controller rather than distributing it across multiple components

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system continuously monitors elevator car positions, speeds, and movement directions, and uses this feedback to dynamically adjust authorized shaft sections. This closed-loop control ensures collision protection while adapting to changing operational conditions in real-time

Inventive Principle:
Principle #23Feedback

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

Reduces the risk of collisions by dynamically managing car movements, allowing safe operation with multiple cars in a shared shaft and enabling flexible shaft extensions during construction phases.

Implementation Method 1

provide an authorization to the at least two elevator cars to move, such as by a linear motor, in or into the authorized shaft section

Methodology Applied
Scientific EffectLinear motor: Linear Motor

Data Source

PatentEP3978412B1Elevator safety system, method for collision protection in an elevator system, and elevator system
Publication Date: 2025.12.31 KONE OYJ
  • EP3978412B1 patent drawingFigure 1
  • EP3978412B1 patent drawingFigure 2~3
  • EP3978412B1 patent drawingFigure 4~5

AI summary

An elevator safety system (110) comprising an elevator control unit (1000) configured to: monitor (610) an elevator shaft (13), receive (620) a position, a movement direction, and a speed of at least one elevator car (10) arranged into the elevator shaft (13), and determine dynamically (630) at least one authorized shaft section (21) based on the monitoring, and on the position, the movement direction, and the speed of at least one elevator car (10), and to provide (640) an authorization to the at least one elevator car (10) to move, such as by a linear motor, in or into the authorized shaft section (21) of the elevator shaft (13). The elevator safety system (110) further comprises at least one elevator car controller (30) configured to: provide the position, the movement direction, and the speed of the at least one elevator car to the elevator control unit (1000), and receive the authorization. The elevator control unit (1000) and the elevator car controller (30) are arranged to be in communication with each other.