Elevator Controller Switch State Verification

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Solution Overview

Problem

Current elevator systems require time-consuming and labor-intensive safety protocols for ensuring that switches are functional before entering the hoistway for maintenance, which can lead to unsafe operations if not executed correctly, particularly due to the reliance on technician diligence and the potential for faulty switches.

Innovation Solution

An elevator system with a controller that monitors and requires a change of state from each hoistway door switch, inspection switch, and emergency stop switch before allowing inspection mode operation, ensuring all switches are functional before enabling movement, thereby preventing unsafe operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional safety protocols requiring individual switch testing are used, then safety is improved, but time consumption and operational complexity increase

Engineering Contradiction:
ImprovesafetyVSAvoidtime consumption
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system performs self-verification by automatically monitoring switch states and detecting changes without requiring external manual testing. The controller continuously monitors the switches and autonomously determines whether safety conditions are met, eliminating the need for technicians to manually test each switch before maintenance.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system implements continuous feedback by monitoring switch states and automatically detecting when a switch state has changed. This feedback mechanism allows the controller to verify switch functionality in real-time and automatically determine when safety conditions are satisfied, replacing manual verification processes.

Inventive Principle:
Principle #23Feedback

2Reliability

If manual verification of each switch is required, then reliability is improved, but ease of operation deteriorates

Engineering Contradiction:
Improveswitch functionality verificationVSAvoidease of maintenance access
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The system automatically monitors and verifies switch functionality without requiring technician intervention. The controller continuously checks switch states and autonomously determines whether all switches are functional, eliminating the manual verification burden from technicians while maintaining high reliability.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system performs preliminary verification by continuously monitoring switch states before maintenance begins. The controller is already tracking switch functionality, so when maintenance is requested, the verification is essentially already complete or can be instantly assessed, eliminating the need for separate manual testing steps.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If continuous monitoring of all switches is implemented, then safety is improved, but device complexity increases

Engineering Contradiction:
Improvesafety monitoringVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The existing elevator controller is made multi-functional by adding switch monitoring capabilities to its existing control functions. Rather than adding a separate dedicated monitoring system, the controller performs both elevator operation control and safety switch monitoring, reducing overall system complexity while maintaining continuous safety oversight.

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

Solution Approach 2:

The switch monitoring function is merged with the existing elevator control system. The controller integrates multiple functions (elevator operation, switch monitoring, state detection, and safety determination) into a single unified system, reducing the number of separate components and simplifying the overall device architecture.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3725722B1Elevator systems
Publication Date: 2024.07.17 OTIS ELEVATOR CO
  • EP3725722B1 patent drawingFigure 1
  • EP3725722B1 patent drawingFigure 2
  • EP3725722B1 patent drawingFigure 3

AI summary

An elevator system 2 is provided which comprises: a hoistway 6 accessible by at least one hoistway door 10a, 10b, 10c; at least one elevator car 4 located in the hoistway 6; a hoistway door switch 12a, 12b, 12c associated with the at least one hoistway door 10a, 10b, 10c; at least one inspection switch 16; at least one emergency stop switch 18; and an elevator controller 24. The elevator controller 24 is configured to monitor the hoistway door switch 12a, 12b, 12c, the inspection switch 16 and the emergency stop switch 18 and to prevent inspection mode operation of the elevator car 4 until at least one change of state is detected of each of the hoistway door switch 12a, 12b, 12c, the inspection switch 16 and the emergency stop switch 18.