Elevator Safety Control Device for Shaft Personnel Detection
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Solution Overview
Problem
Existing elevator systems fail to ensure safety for personnel in headroom and pit spaces, as individuals may be harmed due to inadequate safety space dimensions and elevator car movement speeds, despite regulatory specifications, and existing safety systems may not adequately prevent harm in these scenarios.
Innovation Solution
A safety control device and method that detects the presence of a person in specified areas of the elevator shaft, triggering a safety procedure to switch from normal drive control to safety drive control, reducing the elevator car's speed or preventing movement to prevent harm, using sensors like light curtains, pressure detectors, or ultrasonic sensors to initiate safety measures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the elevator car operates at normal drive speed to maintain productivity, then productivity is improved, but safety of personnel in headroom and pit spaces deteriorates
Solution Approach 1:
The sensor detects the presence of a person in the headroom or pit space before the elevator car arrives, triggering a preliminary safety response. The controller pre-reduces the drive speed or prevents movement before the car reaches the hazardous area, ensuring safety is established in advance rather than reacting after danger occurs.
Solution Approach 2:
The sensor continuously monitors the headroom and pit spaces for person presence and provides feedback to the controller. Based on this feedback, the controller dynamically adjusts the elevator car's drive speed or movement authorization, creating a closed-loop safety system that responds to real-time conditions.
2Reliability
If the elevator car speed is reduced to improve safety, then safety of personnel is improved, but productivity deteriorates
Solution Approach 1:
The elevator car's drive speed is made dynamic rather than static. The controller continuously adjusts the speed based on real-time sensor feedback about person presence in hazardous areas. When no person is detected, normal speed is maintained for productivity; when a person is detected, speed is reduced for safety, creating an adaptive system that optimizes both safety and productivity.
Solution Approach 2:
The drive speed parameter is changed based on detection conditions. The controller modifies the speed parameter from normal operational values to reduced safety values or zero (preventing movement) when a person is detected in the headroom or pit space, thereby adapting system behavior to current safety requirements.
3Ease of manufacture
If permanent headroom and pit safety spaces are designed with minimum dimensions per regulations, then ease of manufacture is improved, but safety of personnel deteriorates
Solution Approach 1:
A sensor system acts as an intermediary between the elevator car and personnel in the headroom/pit space. Rather than relying solely on physical space dimensions for safety, the sensor detects person presence and triggers protective actions (speed reduction or movement prevention), providing an additional layer of safety that compensates for the limited safety space dimensions.
Solution Approach 2:
The passive mechanical safety approach (relying on minimum safety space dimensions) is supplemented or replaced with an active electronic detection and control system. Sensors and controllers monitor and respond to person presence, substituting the need for larger safety spaces with intelligent detection and response mechanisms.
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
Enhances safety by reducing the risk of injury to personnel in elevator shaft areas by adjusting elevator car speed and movement controls based on detected presence, ensuring safer operations within defined safety spaces.
Implementation Method 1
A sensor is provided which allows to detect whether a person is present in a headroom or a pit safety space
Data Source
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AI summary
A safety control device applicable to an elevator system including an elevator car 10 driven in an elevator shaft 20 by means of a drive device 50, said safety control device comprising at least one sensor 70, 71 configured to detect, in the elevator shaft, a presence of an object in at least one specified area 21, 22 of the elevator shaft, and a controller 60 configured to receive and process a signal of the at least one sensor indicating a detection result, and to conduct, when the detection result indicates the presence of an object in the at least one specified area of the elevator shaft, a safety procedure in which a switch from a normal drive control of the drive unit to a safety drive control is executed in which a target value set for the speed of the elevator car is decreased.