Elevator Control System Pit Inspection Safety Communication
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Solution Overview
Problem
Conventional elevator systems face challenges in efficiently integrating an additional pit inspection control station while meeting safety requirements, leading to increased cable wire lengths and potential safety issues due to the need for additional hardware and power amplifiers.
Innovation Solution
The elevator control system employs a dual communication path, where safety-relevant information is transmitted through a safety communication system, and non-safety relevant information, such as direction control, is communicated via a separate independent line, allowing the pit inspection control station to enable elevator car movement without requiring additional cables or power amplifiers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an additional pit inspection control station is integrated into the existing safety chain, then safety requirements are met, but the number of cable wires increases dramatically and power amplifiers are needed
Solution Approach 1:
The patent divides the communication into two separate segments: safety-relevant information is transmitted through the safety communication system (safety chain), while non-safety relevant information (such as direction control) is communicated through a separate independent line. This segmentation allows the pit inspection control station to be integrated without dramatically increasing cable wire requirements in the safety chain, as only essential safety signals need to be added there.
Solution Approach 2:
The patent introduces an intermediary communication approach where a separate independent line acts as a mediator for non-safety relevant information. This intermediary channel offloads communication tasks from the safety chain, preventing the safety communication system from becoming overloaded with non-critical signals and avoiding the need for additional power amplifiers in the safety path.
2Reliability
If additional hardware and power amplifiers are added to meet safety requirements, then safety integrity is maintained, but device complexity and cost increase
Solution Approach 1:
By segmenting the communication into safety-critical and non-safety-critical paths, the patent ensures that only essential safety signals traverse the safety chain, maintaining safety integrity without requiring additional hardware amplifiers. The separate independent line handles direction control and other non-safety functions, eliminating the need to upgrade the safety chain's power handling capacity.
Solution Approach 2:
The patent creates a parallel communication path (separate independent line) that copies the control station functionality for non-safety purposes, allowing the original safety chain to remain unchanged and avoid the need for additional hardware amplifiers while still providing complete control functionality.
3Device complexity
If safety and non-safety information are transmitted through the same communication path, then hardware requirements are reduced, but safety reliability decreases
Solution Approach 1:
The patent implements segmentation by creating distinct communication paths: the safety communication system exclusively handles safety-relevant information, while the separate independent line carries non-safety relevant information. This segmentation prevents safety signals from being overwhelmed or interfered with by non-safety traffic, maintaining safety reliability while using efficient hardware utilization.
Solution Approach 2:
The patent applies local quality by assigning different communication characteristics to different information types. The safety path is optimized for critical, low-volume safety signals with highest reliability requirements, while the separate independent line handles higher-volume non-safety traffic. This localized optimization ensures safety reliability without unnecessary hardware overhead.
Data Source
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AI summary
Disclosed is an elevator control system, comprising an elevator controller (18) configured to control an elevator car (12) such as to move along an elevator hoistway (14), and at least one control station configured to be operated by a person and to communicate with the elevator controller (18), such as to move the elevator car (12) along the hoistway (14), the at least one control station comprising a pit inspection control station (30) located in a pit (24) of the hoistway (14), the pit inspection control station (30) comprising at least one pit inspection control station safety switch (80, 86, 88, 90) being connected to the elevator controller (18) via a safety communication system, the at least one pit inspection control station safety switch (80, 86, 88, 90) being configured to enable movement of the elevator car (12) according to operation of the pit inspection control station (30), the pit inspection control station (30) further being connected to the elevator controller (18) via a further communication line (58) independent of the safety communication system, the further communication line (58) configured to communicate information with respect to an intended direction of movement of the elevator car (12).