Building Automation Occupancy Detection Using RF Signal Quality
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Solution Overview
Problem
Existing building automation systems, such as lighting systems, struggle with inaccurate user detection due to limitations in passive infrared (PIR) detectors and unpredictable radio frequency transmissions, leading to false positives and negatives.
Innovation Solution
A detection subsystem that utilizes changes in radio signal quality indicators combined with motion detection to generate control signals for building automation, adapting its criteria based on observed changes in signal quality and user presence, and employing learning algorithms to improve accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If PIR detectors are used for user detection, then the system is inexpensive and simple to use, but the detection accuracy deteriorates for stationary objects
Solution Approach 1:
The patent combines multiple detection methods (motion detection and radio signal quality monitoring) into a unified detection subsystem. This merging allows the system to overcome the limitations of individual methods by using their complementary strengths, thereby improving detection accuracy while maintaining system simplicity.
Solution Approach 2:
The detection subsystem is designed to perform multiple functions: it can detect motion using PIR detectors and simultaneously monitor radio signal quality indicators. This multi-functionality allows the system to accurately detect both moving and stationary objects by switching between or combining different detection modes.
2Reliability
If radio frequency transmissions from user devices are used for detection, then user presence can be detected, but the control reliability deteriorates due to unpredictable transmission characteristics
Solution Approach 1:
The system continuously monitors radio signal quality indicators and uses this feedback to adjust its detection criteria. By analyzing changes in signal quality over time and comparing them against learned patterns, the system can reliably distinguish between signal variations caused by user presence versus other environmental factors, thereby improving both detection accuracy and control reliability.
Solution Approach 2:
The detection subsystem dynamically adjusts its interpretation criteria based on observed changes in radio signal quality parameters. By changing the thresholds and criteria for detecting user presence based on current signal conditions, the system adapts to varying transmission characteristics while maintaining reliable and accurate detection.
3Measurement precision
If the detection subsystem uses strict criteria for user detection, then false positives are reduced, but false negatives increase
Solution Approach 1:
The detection subsystem dynamically adjusts its detection criteria based on the operational context and learned patterns. Rather than using fixed strict criteria, the system adapts its thresholds and interpretation rules based on observed signal quality changes and motion detection data, thereby maintaining high detection accuracy while minimizing false negatives through context-aware decision making.
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 approach enhances user detection reliability by reducing false positives and negatives, allowing the system to adapt to different environments and scenarios without requiring additional hardware, ensuring consistent and efficient operation.
Implementation Method 1
a motion detecting part configured to receive indications of moving objects detected within at least a part of said area
Implementation Method 2
how changes in the state of occupancy in a space, or in structural features in or close to the space, affect the attenuation of radio signals that carry messages between nodes of the building automation system
Data Source
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AI summary
An arrangement for controlling a building automation system comprises a detection subsystem that produces detection signals (302) indicative of detected users within an area. A control signal generator (303) generates control signals (304) for the building automation system in response to said detection signals (302). A motion detecting part (306) receives indications (307) of moving objects, and the detection subsystem (301) produces said detection signals (302) at least partly based thereon (307). A radio quality part (308) provides (309) a quality indicator (310) indicative of an observed quality of radio frequency transmissions between nodes. The detection subsystem (301) produces said detection signals (302) also at least partly based on observed changes in the quality indicator (310).