Infrared Door Sensor Timing Adjustment for Interference Reduction
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Solution Overview
Problem
Existing infrared (IR) sensor systems for automatic door systems face challenges such as interference from moving doors, limited coverage area, and complexity in transmitter and detector beam paths, which affect their energy efficiency, noise susceptibility, and flexibility in detection area size and shape.
Innovation Solution
The proposed IR sensor system includes a door sensor with emitters and receptors configured to emit and receive IR light beams, with a controller that adjusts the timing of emitting and listening phases to reduce interference from adjacent sensors. This system allows for individual control of emitters and receptors, enabling more precise detection and pattern adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If active IR sensors emit infrared light continuously to detect objects, then detection capability is improved, but energy consumption increases
Solution Approach 1:
The patent implements periodic emission of infrared light pulses rather than continuous emission. The controller transmits infrared light in periodic pulses and measures reflected light during designated time windows, reducing energy consumption while maintaining detection capability through the periodic on-off cycling of the emitter.
Solution Approach 2:
The patent maintains continuous detection capability by ensuring that at least one sensor in each pair is actively receiving reflected infrared light during the entire measurement cycle. The emitter and receiver operate in a coordinated continuous manner where the emitter pulses and the receiver continuously monitors, ensuring uninterrupted detection functionality.
2Area of stationary object
If multiple door sensors are deployed adjacent to each other to cover larger areas, then detection coverage is improved, but interference between sensors increases
Solution Approach 1:
The patent divides the detection system into pairs of adjacent door sensors, where each pair operates semi-independently. The controller in each sensor pair coordinates the emission and reception timing to distinguish between signals from different pairs, segmenting the overall detection area into manageable zones that reduce mutual interference.
Solution Approach 2:
The controller in each door sensor receives feedback about the operational state of adjacent sensors and adjusts the timing of emission and reception accordingly. This feedback mechanism allows the system to dynamically coordinate between adjacent sensors to minimize interference while maintaining comprehensive coverage.
3Device complexity
If door sensors operate independently without coordination, then system simplicity is maintained, but detection accuracy decreases due to interference
Solution Approach 1:
The controller performs preliminary timing adjustments by determining optimal emission and reception time windows before actual detection occurs. Each sensor pair pre-coordinates its operational timeline with adjacent sensors to avoid interference, establishing a structured timing protocol that ensures accurate detection without complex real-time coordination.
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
The IR sensor system operates with enhanced energy efficiency, reduced noise and interference, and increased flexibility in detection area size and shape, while providing intelligent adjustments to the IR curtain during door opening and closing.
Implementation Method 1
one or more emitters configured to emit an emission beam comprising IR light during an emitting phase
Implementation Method 2
one or more receptors configured to receive a reception beam comprising the IR light reflected off of a surface during a listening phase
Implementation Method 3
an interference beam from an adjacent door sensor
Data Source
AI summary
A door sensor may include one or more emitters configured to emit an emission beam comprising IR light during an emitting phase. The door sensor may further include one or more receptors configured to receive a reception beam comprising the IR light reflected off of a surface during a listening phase and an interference beam from an adjacent door sensor. The door sensor may further include a controller operatively coupled to a memory storing computer-readable instructions that, when executed by the controller, cause the controller to: determine one or more of the frequency and phase of the interference beam; determine whether the door sensor should be primary or secondary to the adjacent door sensor; and adjust a timing of one or more of the emitting phase and the listening phase to reduce interference from the adjacent door sensor.