Elevator Control Unit Safety Verification Method
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Solution Overview
Problem
Existing elevator systems lack a comprehensive method to ensure safe commissioning, which is critical for preventing unsafe operational states and ensuring the integrity of safety circuits during the initial setup and subsequent operation.
Innovation Solution
A method and apparatus that utilize a control unit with a bus system to verify, check, and secure safety-state detection means, ensuring the elevator system transitions from an unsecured to a secured state only after completing verification, functional capability checking, and safety function validation, thereby preventing unintentional modifications and ensuring safe operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If comprehensive safety verification and functional capability checking are performed during commissioning, then operational safety is improved, but commissioning time and complexity increase
Solution Approach 1:
The control unit performs safety verification and functional capability checking of safety-state detection means during the commissioning phase before normal operation begins. This preliminary action ensures all safety functions are validated in advance, preventing future operational failures while establishing a secure baseline state for subsequent operation.
Solution Approach 2:
The commissioning process is divided into distinct sequential steps: verification of safety-state detection means, checking of functional capability, and validation of safety functions. This segmentation allows systematic validation of each safety component independently, ensuring comprehensive coverage while maintaining organized documentation of completion status.
2Ease of operation
If the control unit remains in unsecured state during commissioning to allow configuration, then ease of operation is improved, but safety is worsened due to potential unintentional modifications
Solution Approach 1:
The control unit dynamically transitions between unsecured and secured states based on the commissioning phase. During commissioning, the control unit is in an unsecured state allowing configuration and modification. Upon completion of safety verification and functional capability checking, the control unit automatically transitions to a secured state, preventing further modifications and ensuring safety integrity for normal operation.
Solution Approach 2:
All necessary configurations and modifications are performed during the unsecured commissioning phase before the secured state is activated. This preliminary action ensures the control unit is fully configured for normal operation while preventing any unintended modifications after the secured state begins, thereby maintaining both ease of configuration and safety integrity.
3Reliability
If all safety-state detection means are verified and functionally checked before operation, then safety function reliability is improved, but device complexity increases
Solution Approach 1:
The control unit autonomously performs verification and functional capability checking of safety-state detection means without requiring external test equipment or complex manual procedures. The control unit uses its own resources and existing bus communication to validate each safety component, simplifying the commissioning process while ensuring comprehensive safety validation.
Solution Approach 2:
The control unit receives feedback signals from safety-state detection means during verification and functional capability checking. This feedback mechanism allows the control unit to automatically determine whether each safety function is operating correctly, enabling systematic validation while maintaining a relatively simple commissioning interface and procedure.
Data Source
AI summary
An elevator system includes a control unit, a bus, a plurality of bus-nodes connected via the bus with the control unit, and a plurality of safety-state detection devices connected with the control unit via the bus-nodes. A method of commissioning the elevator system includes the steps: A) verification by the control unit of the safety-state detection means that are connected to the bus; B) checking of the functional capability of the safety-state detection means that are connected; C) checking by the control unit of the safety functions of the elevator system based on a change in state of a safety-state detection means; and D) release of the elevator system for a normal operation only after positive execution by the control unit of the steps A) to C), wherein the release is accompanied by a change in state of the control unit from an unsecured state into a secured state.