Elevator Safety Circuit Diagnostic Testing Field

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Solution Overview

Problem

The increasing complexity of elevator safety circuits due to microprocessor control and data bus architecture leads to higher risks of connection errors and wiring errors, necessitating improved diagnostics to ensure early fault detection and minimize operational disruptions.

Innovation Solution

A method is introduced where a testing field is added to messages sent through the communications bus in the elevator safety circuit, allowing nodes to identify functional nonconformances such as connection or wiring errors, and incorrect polarity, with recorded references in memory for comparison and severity indication, enabling quick fault location and diagnosis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If microprocessor control and data bus architecture are used to design safety circuits, then the safety circuit can be designed with modern technology and components can be connected to the same data bus, but the risk of connection errors, wiring errors, and incorrect voltage connection increases

Engineering Contradiction:
Improvedata bus architectureVSAvoidconnection error risk
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies preliminary action by incorporating a testing field into messages before they are transmitted through the data bus. This testing field contains predetermined bit patterns that allow nodes to verify the integrity of received messages and detect connection errors, wiring errors, or incorrect voltage connections before they cause safety issues. The testing field is prepared in advance and embedded in the message structure, enabling proactive error detection rather than waiting for faults to manifest during normal operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback mechanisms where receiving nodes compare the received testing field against expected reference values and generate error signals when discrepancies are detected. This feedback loop allows the system to automatically detect and report connection errors, wiring errors, and voltage connection issues. The feedback is continuous and occurs at each node along the data bus, enabling rapid identification of fault locations and types.

Inventive Principle:
Principle #23Feedback

2Reliability

If devices and data buses are duplicated to achieve adequate safety level, then safety integrity level is improved, but the amount of components, circuits and wiring needed increases

Engineering Contradiction:
Improvesafety integrity levelVSAvoidamount of components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses copying by creating redundant copies of critical safety data and testing fields across multiple nodes and communication channels. Instead of duplicating entire physical systems, the invention copies essential information (safety parameters, testing patterns, node identifiers) through the data bus architecture. This information copying provides verification and cross-checking capabilities that enhance safety integrity while avoiding the exponential increase in physical components that would result from full system duplication.

Inventive Principle:
Principle #26Copying

3Reliability

If fault situations are identified and located as soon as possible in an early stage, then operational harm is minimized, but the complexity of diagnostic systems increases

Engineering Contradiction:
Improvefault detection capabilityVSAvoiddiagnostic system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the diagnostic function into discrete, modular components distributed across multiple nodes in the safety circuit. Each node independently processes testing fields, compares received data against reference values, and generates localized error signals. This segmentation allows fault detection to be performed in parallel at multiple points simultaneously, reducing overall diagnostic complexity compared to a centralized diagnostic system while improving fault identification speed and accuracy.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2646359B1Safety circuit of an elevator, and computer program for identifying a functional nonconformance of a safety circuit of an elevator
Publication Date: 2022.06.08 KONE OYJ
  • EP2646359B1 patent drawingFigure 1
  • EP2646359B1 patent drawingFigure 2
  • EP2646359B1 patent drawingFigure 3

AI summary

The invention concerns a safety circuit of an elevator and a method for identifying a functional noncorformance of a safety circuit of an elevator. In the method, a message (1) is formed in node A. A test field (2) is added to the message (1) in order to test the functionality of the safety circuit of the elevator. The message (1) containing the test field (2) is sent from the node A to the communication route (6) included in the safety circuit.