Elevator Hoistway Access Detection and Override Control
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Solution Overview
Problem
Existing elevator systems lack enhanced safety features to prevent accidental movement during maintenance or repair procedures, where individuals are present within the hoistway, as current detection and override systems are not sufficiently robust to ensure safe operation.
Innovation Solution
A sensor-based safety system that includes a controller communicating with sensors and override devices to prevent elevator car movement unless an individual provides authorization, combined with lighting controls to prompt override signals, ensuring safe operation by preventing movement unless explicit authorization is given.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sensors and override devices are installed to detect individual presence in the hoistway, then safety during maintenance procedures is improved, but device complexity increases
Solution Approach 1:
The safety system is divided into separate functional modules: sensors for detecting individual presence, override devices for authorization, and a controller for processing signals. This segmentation allows each component to be independently optimized and maintained, reducing overall system complexity while maintaining high safety standards
Solution Approach 2:
The system performs preliminary detection of individual presence in the hoistway before allowing elevator car movement. The sensor detects presence in advance, and the override device requires preliminary authorization, preventing unsafe movement before it can occur
2Reliability
If the controller prevents movement when an individual is detected in the hoistway, then safety is improved, but productivity decreases
Solution Approach 1:
The system dynamically adjusts elevator car movement based on real-time detection of individual presence in the hoistway. When no individual is detected, normal operation proceeds without restriction. When an individual is detected, the system transitions to a restricted mode requiring override authorization, balancing safety with operational efficiency
Solution Approach 2:
The system changes the operational parameter of elevator car movement from unrestricted to restricted based on the parameter of individual presence detection. This conditional parameter change allows the system to maintain high productivity during normal operation while ensuring safety when individuals are present
3Loss of information
If lighting is altered to prompt override signals, then communication with individuals in the hoistway is improved, but use of energy increases
Solution Approach 1:
The lighting system operates periodically rather than continuously, altering appearance or intensity only when needed to prompt override signals. This periodic action reduces energy consumption while maintaining effective communication with individuals in the hoistway during critical moments
Data Source
AI summary
An elevator system (20) includes a sensor (30, 36) for detecting the presence of an individual within a hoistway (24). A controller (32) prevents movement of an elevator car (22) whenever an individual is in the hoistway (24). A pit override device (34) provides an override signal to the controller (32) permitting movement of the elevator car (22) if someone is in a pit (26). A car top override device (38) selectively provides an override signal to the controller (32) permitting movement of the car. A disclosed example includes controlling at least one light (40) within the hoistway (24) in conjunction with movement or attempted movement of the elevator car (22).