Motion Sensor Array Occupancy Detection
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Solution Overview
Problem
Existing motion sensor systems, such as those using passive infrared (PIR) sensors, often incorrectly determine a space as unoccupied, leading to premature activation or deactivation of building systems like lighting and HVAC, even when people are still present, due to their reliance on fixed time durations and lack of accurate occupancy detection.
Innovation Solution
An array of motion sensors connected to a processor that characterizes sensor data as state vectors, applies a compaction process to disregard random motion, and identifies a gate sensor to determine occupancy characteristics by analyzing consecutive state vectors, ensuring accurate detection of space occupancy and the number of people through feature vectors and machine learning algorithms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a fixed time duration is used to determine occupancy, then the system is simple to implement, but the occupancy detection accuracy deteriorates
Solution Approach 1:
The patent divides the occupancy detection problem into multiple time intervals (first duration and second duration) and uses different detection criteria for each interval. The system segments the detection process to achieve both simplicity in implementation and accuracy in occupancy determination by analyzing sensor data at different temporal stages.
Solution Approach 2:
The patent transitions from a static fixed-time duration approach to a dynamic detection system that adapts its evaluation criteria based on the temporal pattern of sensor activations. The system dynamically adjusts its occupancy determination based on whether motion is detected in the first duration versus the second duration, improving accuracy while maintaining operational simplicity.
2Extent of automation
If motion sensors are used to detect occupancy, then the system can automatically control lighting and HVAC, but false alarms occur when people are stationary
Solution Approach 1:
The patent applies preliminary action by first detecting motion in an initial time interval (first duration) before making occupancy determinations. This preliminary detection phase filters out false alarms by requiring motion to be detected before the system commits to an occupancy state, thereby improving reliability while maintaining automation.
Solution Approach 2:
The system uses feedback from continuous sensor monitoring to refine its occupancy determinations. By comparing sensor data across multiple time intervals and adjusting its determination based on ongoing detection results, the system maintains reliable occupancy detection while preserving automatic control capabilities.
3Loss of energy
If the system turns off lights after a predetermined time, then energy efficiency improves, but comfort deteriorates when occupants remain stationary
Solution Approach 1:
The patent applies dynamics by making the lighting control adaptive rather than static. The system dynamically adjusts lighting based on the temporal pattern of motion detection - extending the lighting duration when motion is detected in the second time interval, thereby maintaining comfort while managing energy consumption through intelligent control.
Solution Approach 2:
The system uses feedback from continuous occupancy monitoring to control lighting. By ongoing sensor data and adjusting lighting status based on whether occupants remain stationary or move, the system balances energy efficiency with occupant comfort, turning lights off only when truly unoccupied.
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 provides accurate and reliable occupancy detection, preventing premature system changes and ensuring that spaces remain appropriately lit and heated even when occupants are stationary for extended periods, thereby improving energy efficiency and comfort.
Implementation Method 1
Passive infrared (PIR) motion sensors are often used for occupancy sensing
Data Source
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AI summary
Aspects of the present disclosure include arrays of motion sensors that may be used to monitor a space to determine occupancy characteristics of the space, such as whether or not the space is occupied and the number of people located within the space. The array of motion sensors may be operatively connected to one or more building system components, such as lighting and HVAC equipment and can be used for adjusting an operating condition of the building system component based on whether a space is occupied.