Elevator Pit Sensor Self-Check for Tamper-Safe Car Shutdown
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Solution Overview
Problem
Existing elevator systems lack effective safety measures to prevent injury to maintenance personnel entering the elevator pit and do not adequately address sensor assembly malfunctions or tampering, which can lead to unsafe conditions.
Innovation Solution
An elevator system equipped with a sensor assembly that detects a person in the pit and initiates the safety chain to disable the elevator car, accompanied by a test device to verify sensor functionality and detect tampering, using sensors like LIDAR, millimeter wave RADAR, or RGBD cameras, and mechanisms to introduce a known background for testing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sensor assembly is installed to detect persons in the pit, then safety of maintenance personnel is improved, but device complexity increases due to additional monitoring components
Solution Approach 1:
The sensor assembly is designed to perform multiple functions: detecting persons in the pit, testing its own operational status, and identifying tampering attempts. This multi-functionality reduces the need for separate safety systems, thereby improving reliability while limiting the increase in device complexity.
Solution Approach 2:
The sensor assembly includes self-test capabilities where it automatically tests its own operational status by detecting known backgrounds (such as the pit environment or test objects). This self-service approach ensures continuous safety monitoring without requiring external intervention, improving reliability while adding minimal complexity.
2Reliability
If self-test capability is integrated into the sensor assembly, then detection of sensor malfunction is improved, but device complexity increases
Solution Approach 1:
The sensor assembly performs self-tests by automatically detecting known backgrounds (such as the pit environment or introduced test objects) and evaluating whether detected objects match expected parameters. This self-service mechanism detects malfunctions without external testing equipment, improving reliability while adding minimal complexity.
Solution Approach 2:
The self-test system uses feedback mechanisms where the sensor assembly compares detected objects against expected backgrounds and triggers alerts or safety chain activation when deviations are detected. This feedback loop ensures continuous monitoring of sensor functionality without requiring complex external testing infrastructure.
3Reliability
If the sensor assembly monitors for tampering, then safety against intentional interference is improved, but device complexity increases due to additional monitoring requirements
Solution Approach 1:
The sensor assembly is designed to simultaneously detect persons, test its own functionality, and identify tampering attempts using the same hardware components. This multi-functionality approach improves safety against intentional interference without requiring separate tampering detection systems, thereby limiting the increase in device complexity.
Solution Approach 2:
The tampering detection system uses feedback mechanisms where the sensor assembly continuously monitors for unexpected objects or changes in the detection region and compares them against expected backgrounds. When tampering is detected, the system triggers safety chain activation or alerts, providing robust anti-tampering protection through intelligent analysis rather than additional hardware.
4Speed
If automatic safety chain activation is implemented upon person detection, then response time is improved, but device complexity increases due to automated control mechanisms
Solution Approach 1:
The sensor assembly automatically activates the safety chain upon detecting a person in the pit without requiring external intervention or manual activation. This self-service approach ensures immediate response to potential hazards, improving response time while using existing safety chain infrastructure to limit the increase in device complexity.
Solution Approach 2:
The system uses feedback mechanisms where the sensor assembly continuously monitors the detection region and automatically triggers safety chain activation when a person is detected. This automated feedback loop ensures rapid response to hazards while using intelligent control algorithms rather than complex mechanical systems to manage the automation.
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
Ensures the safety of maintenance personnel by preventing elevator movement during pit entry and reliably detects sensor malfunctions and tampering, thereby enhancing safety and operational integrity.
Implementation Method 1
The sensor includes at least one of a LIDAR sensor, a millimeter wave RADAR sensor and an RGBD camera
Implementation Method 2
The sensor includes at least one of a LIDAR sensor, a millimeter wave RADAR sensor and an RGBD camera
Implementation Method 3
The sensor includes at least one of a LIDAR sensor, a millimeter wave RADAR sensor and an RGBD camera
Data Source
Figure 1
Figure 2A~2B
Figure 3
AI summary
An elevator system includes a hoistway, an elevator car configured to travel in the hoistway, and a pit located at a bottom of the hoistway. A safety chain is configured to enable or disable motion of the elevator car, and a sensor assembly is configured to initiate opening the safety chain to disable motion of the elevator car upon detection of a person in a detection region of the sensor assembly in the hoistway. A test device is configured to test operation of the sensor assembly to detect malfunctioning and/or tampering of operation of the sensor assembly.