Automatic Door Sensor Dynamic Detection Area Adjustment
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Solution Overview
Problem
Automatic door sensor devices face erroneous detection issues when transitioning from an open to a closed position due to overlapping detection areas and swaying support members, leading to malfunction and failure in detecting objects.
Innovation Solution
An automatic door sensor device with a detection area changer that temporarily adjusts the detection area by switching between first and second moving object detection areas, allowing the detection area to overlap with the door track during normal operation but avoiding overlap when transitioning, and adjusting sensitivity thresholds to prevent erroneous detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the detection area of the microwave sensor is set to overlap with the doorway area for better object detection, then the detection capability is improved, but erroneous detection of the closing door as an object occurs
Solution Approach 1:
The patent applies dynamics by making the detection area changeable based on door state. The microwave sensor's detection area is dynamically adjusted: during door closing transition, the detection area is reduced to avoid detecting the door, while in normal operation, the detection area is expanded to overlap with the doorway area for better object detection. This resolves the contradiction by adapting the detection area to different operational contexts.
Solution Approach 2:
The patent changes the parameter of detection area size based on door state. By switching between a first detection area (smaller, non-overlapping) during door closing and a second detection area (larger, overlapping) during normal operation, the system achieves both reliable error prevention and accurate object detection without compromising either requirement.
2Reliability
If the detection area is reduced to prevent erroneous detection during door closing, then false alarms are prevented, but the ability to detect actual objects in the doorway area is compromised
Solution Approach 1:
The system dynamically switches between two detection area configurations based on door state. During door closing transition, a smaller first detection area is used to prevent erroneous detection. During normal operation, a larger second detection area that overlaps with the doorway is activated to ensure accurate object detection. This dynamic adaptation resolves the contradiction between reliability and measurement precision.
Solution Approach 2:
The detection area is periodically switched between two states: a restricted area during door closing transitions and an expanded area during normal operation. This periodic adjustment ensures that the system maintains high reliability during critical transitions while preserving excellent object detection capability during stable operation periods.
3Measurement precision
If the infrared sensor is configured to detect objects in the doorway area, then object detection is improved, but the sensor malfunctions when the transom sways during door closing
Solution Approach 1:
The patent merges the detection functions of the microwave sensor and infrared sensor, using their respective strengths. The microwave sensor provides reliable detection during door closing transitions when the infrared sensor is susceptible to transom sway interference. The infrared sensor handles normal object detection when conditions are stable. This combination allows the system to achieve high measurement precision while maintaining reliability across different operational states.
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
Prevents erroneous detection of the door transitioning from an open to a closed position as an object, ensuring reliable detection of actual objects while minimizing false alarms and maintaining detection accuracy.
Implementation Method 1
a microwave sensor that uses Doppler effect
Data Source
AI summary
There is provided an automatic door sensor device (1) capable of preventing a door (3) which is transitioning from an open position to a closed position from being erroneously detected as an object by temporarily changing a detection area (A, C2, C3). The automatic door sensor device (1) includes a doorway area sensor (7a) that detects the presence of an object in a doorway area (B) which includes at least a portion of an area defined by the path of a door (3), detectors (6, 7b) that detect the presence and/or the movement of an object in changeable detection areas (A, C2, C3), and a detection area changer (31) that changes the detection areas (A, C2, C3) when it is determined, by using the doorway area sensor (7a), that the door (3) is transitioning from an open position to a closed position.