Multi-Unit Air Conditioning Occupancy Detection Using Time-Sum Logic
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Solution Overview
Problem
Existing air conditioning systems with multiple indoor units and motion detectors often falsely determine occupancy due to passing individuals, leading to unnecessary power consumption when resuming air conditioning operations.
Innovation Solution
An air conditioning system with a controller that suspends operations when the room is vacant and resumes based on a detection time period sum from motion detectors, preventing false determinations and reducing power usage by stopping fans and compressors during suspension.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the motion detector detects presence of a person, then the air conditioning operation is resumed, but false determination occurs when a person simply passes through the room
Solution Approach 1:
The system accumulates detection time periods from multiple motion detectors before triggering air conditioning operation. This preliminary accumulation action filters out transient detections from passing individuals while ensuring reliable operation resumption when actual occupants are present.
Solution Approach 2:
The system combines detection results from multiple motion detectors installed at different indoor units. By merging detection time periods from multiple sources, the system achieves more reliable occupancy determination that distinguishes between passing individuals and actual occupants.
2Reliability
If the air conditioning operation is resumed upon detection, then the room occupancy is addressed, but power is wasted when the detection is false
Solution Approach 1:
The system performs preliminary verification by accumulating detection time periods from multiple motion detectors before resuming air conditioning operation. This preliminary check prevents false operation resumption and subsequent power waste while ensuring reliable operation when actual occupants are present.
3Area of stationary object
If multiple indoor units are used with motion detectors, then detection coverage is improved, but false determination probability increases
Solution Approach 1:
The system merges detection time periods from multiple motion detectors installed at different indoor units. By combining results from multiple detectors and requiring accumulated time threshold, the system maintains wide detection coverage while improving reliability through cross-validation of detections.
Solution Approach 2:
The system accumulates detection time periods from multiple motion detectors as a preliminary verification step before triggering air conditioning operation. This preliminary accumulation process filters out transient false detections while maintaining comprehensive detection coverage across the room.
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 effectively limits false occupancy determinations and reduces power consumption by ensuring accurate detection of room usage, preventing wasteful energy use and confirming units have stopped operating when unoccupied.
Implementation Method 1
Each of the motion detectors (50) detects presence or absence of a person in the room (10), based on an amount of infrared radiation
Data Source
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AI summary
False determination in the presence or absence of a person in a in a room is limited. An air conditioner (20) suspends an air conditioning operation if a room (10) is vacant. If at least one of motion detectors (50), each provided to one of the indoor units (40), starts to detect the presence of a person during suspension of the air conditioning operation, an indoor controller (45) of an indoor unit (40a) sums, for each of the motion detectors (50), time periods in which the presence of the person is detected to obtain a detection time period sum. If any one of detection time period sums, each for one of the motion detectors (50), reaches a reference value (T2) within a predetermined time period (T3), the outdoor controller (37) causes the air conditioner (20) to resume the air conditioning operation.