Infrared Radar Sensor Fusion for Occupancy Detection
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Solution Overview
Problem
Traditional occupancy counting devices in buildings are high in cost, consume considerable energy, have accuracy and range limitations, and often fail to accurately verify human presence due to reliance on single technologies like PIR sensors, laser beam-break sensors, or cameras.
Innovation Solution
A presence detection system combining an infrared detector with a radar detector and a computer processor executing a sensor fusion algorithm for enhanced accuracy, using a focal plane array for radiant energy sensing and radar for presence confirmation, including vital sign detection and localization, to accurately count and classify human presence while minimizing energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional occupancy counting devices (PIR sensors, laser beam-break sensors, cameras) are used, then occupancy detection is achieved, but cost is high, energy consumption is considerable, accuracy is low, and range limitations exist
Solution Approach 1:
The patent combines infrared detection and radar detection into a unified occupancy sensing system. The infrared detector captures thermal signatures while the radar detector captures motion and vital sign information, and their results are fused to achieve accurate occupancy detection that overcomes the limitations of either sensor type alone.
Solution Approach 2:
The radar detector serves multiple functions: it detects occupancy presence, measures vital signs (heartbeat and respiration), and provides localization information. This multi-functionality reduces the need for separate detection systems and improves overall system efficiency.
2Measurement precision
If traditional occupancy counting devices are used, then occupancy detection is achieved, but energy consumption is considerable
Solution Approach 1:
The system employs periodic detection cycles where the infrared detector performs initial occupancy screening, and the radar detector is activated only when occupancy is detected or suspected. This periodic operation rather than continuous operation significantly reduces energy consumption while maintaining detection accuracy.
Solution Approach 2:
The infrared detector serves as a preliminary filter that identifies when radar detection is necessary. By using the low-power infrared sensor to trigger the higher-power radar sensor only when needed, the system achieves accurate occupancy detection with minimized overall energy consumption.
3Measurement precision
If single technology devices (PIR, laser, camera) are used, then occupancy detection is achieved, but accuracy in verifying human presence is low
Solution Approach 1:
The system merges infrared thermal signature detection with radar motion and vital sign detection. The infrared detector identifies warm bodies while the radar detector confirms human presence through characteristic motion patterns and vital signs, creating a reliable verification system that reduces false positives.
Solution Approach 2:
The system uses feedback from the infrared detector to trigger radar detection, and then uses radar vital sign detection results to confirm human presence. This multi-stage feedback process continuously verifies occupancy status and improves detection reliability by cross-validating signals from both sensor types.
4Length of stationary object
If traditional occupancy counting devices are used, then occupancy detection is achieved, but range limitations exist
Solution Approach 1:
The system combines infrared detection effective at closer ranges with radar detection effective at longer ranges. The infrared detector provides accurate thermal signature detection within its effective range, while the radar detector extends the overall system range and provides complementary motion-based detection that remains accurate at greater distances.
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 system provides accurate, low-cost, and energy-efficient occupancy counting with reduced false alarms and range limitations, confirming human presence through vital sign detection, and adapting to changing detection requirements, suitable for building management systems.
Implementation Method 1
an infrared detector; a radar detector; and a computer processor configured to receive respective signals from the infrared and radar detectors
Implementation Method 2
a radar detector includes at least one antenna and a switching module configured to steer the at least one antenna for presence detection
Implementation Method 3
the radar detector is configured to perform one of an initial presence detection and a presence confirmation, and the infrared detector is configured to perform the other of the initial presence detection and the presence confirmation
Implementation Method 4
the infrared detector includes a focal plane array including a plurality of radiant energy sensors configured to convert radiant energy into an electrical signal
Data Source
AI summary
A presence detection system includes an infrared detector and a radar detector. A computer processor of the system is configured to receive respective signals from the infrared and radar detectors and process the signals via execution of an algorithm.