Emergency Door Closing via Controller Signal Ignoring
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Solution Overview
Problem
Automatic door operators in swing door entrance systems fail to properly close the door during emergencies due to short circuits caused by heat, which can occur when smoke turns into fire, leading to prolonged opening of the door and failure to entrap the fire.
Innovation Solution
The automatic door operator includes a controller with a normal operating mode and an emergency mode, where in emergency mode, it ignores spurious indications of the activation sensor being maintained actuated, preventing the door from remaining open for an extended period, ensuring the door can close to entrap the fire when needed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If the activation sensor is maintained actuated during extended hold open period, then the door remains open for extended period, but in emergency mode this causes the door to fail closing due to short circuits from heat
Solution Approach 1:
The controller dynamically changes its response to the activation sensor based on the detected emergency condition. In normal operation, the controller extends the hold open period when the sensor remains actuated. In emergency mode, the controller ignores subsequent actuation signals after the initial hold open period, preventing the door from remaining open due to short circuits caused by heat from fire.
Solution Approach 2:
The system changes the operational parameters of the door operator based on emergency detection. The controller modifies the hold open period duration and the response to activation sensor signals when emergency conditions (smoke or fire) are detected, transitioning from a state that allows extended holding open to a state that ensures door closing despite sensor status.
2Object-affected harmful factors
If the door remains open during extended hold open period to facilitate evacuation, then passenger safety is improved, but fire entrapment capability deteriorates
Solution Approach 1:
The system performs preliminary action by detecting emergency conditions (smoke or fire) before the extended hold open period begins. When emergency is detected during the initial hold open period, the controller prepares for forced closing by ignoring subsequent activation sensor signals, ensuring the door will close promptly to entrap the fire after allowing initial evacuation.
Solution Approach 2:
The system converts the harmful effect of prolonged door opening (fire spread) into a beneficial outcome by using the emergency detection mechanism to trigger forced closing. The activation sensor that would normally extend hold open period is ignored in emergency mode, transforming the potential harm into beneficial fire entrapment while still allowing initial evacuation during the first hold open period.
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
This solution ensures the door operator remains functional during emergencies, allowing for safe evacuation while preventing the door from remaining open due to short circuits, thereby effectively managing fire entrapment.
Implementation Method 1
The automatic door operator causes opening of the swing door member by an electric motor which generates torque that is transferred to the swing door member via the linkage
Implementation Method 2
the automatic door operator may comprise a forced close arrangement which is adapted to provide mechanical energy from a preloaded spring via a transfer mechanism to the linkage, so as to cause forced closing of the door leaf
Data Source
AI summary
An automatic door operator (30) in adapted for use in an entrance system (1) that comprises a swing door member (10) being operable between a closed position (18) which prevents passage, and an open position (19) which admits passage. The automatic door operator (30) has an electric motor (34), an activation sensor (15) configured for manual actuation by a person wishing to pass through the entrance system, and a controller (31) having a normal operating mode and an emergency mode. In the normal operating mode, the controller is responsive to the activation sensor (15) and configured for, when the activation sensor (15) is actuated, controlling the motor (34) to generate torque for causing the door member (10) in the entrance system (1) to move from the closed position (18) to the open position (19), and to stay in the open position (19) during a configured hold open period (43).