PIR Occupancy Estimation Using Motion Signals and ML Counting
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Solution Overview
Problem
Existing people counting technologies for indoor spaces, such as visible light cameras, thermal imaging, and millimeter wave detection systems, are expensive and are used sparingly, necessitating a cost-effective alternative for occupancy estimation.
Innovation Solution
A PIR occupancy estimation system using a standard low-cost PIR motion sensor combined with signal processing and machine learning techniques to estimate the number of occupants, including preprocessing, feature extraction, and post-processing stages to generate accurate occupancy counts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If expensive people counting technologies (visible light cameras, thermal imaging, LIDAR, millimeter wave detection systems) are used, then measurement precision and reliability of occupancy detection are improved, but device cost increases significantly
Solution Approach 1:
The patent replaces expensive, complex occupancy detection systems with inexpensive PIR motion sensors that can be widely deployed. The system uses multiple low-cost sensors instead of a single expensive sensor, achieving reliable occupancy estimation through quantity rather than individual sensor sophistication
Solution Approach 2:
The patent substitutes complex optical and electromagnetic detection systems (cameras, thermal imaging, LIDAR, millimeter wave) with simple thermal-based PIR sensors. The complexity is shifted from the sensor hardware to the signal processing and machine learning algorithms, replacing expensive hardware with cheaper hardware plus computational processing
2Ease of manufacture
If simple PIR motion sensors are used, then device cost is reduced, but measurement precision and ability to accurately count multiple occupants deteriorates
Solution Approach 1:
The patent divides the occupancy detection task into multiple independent PIR sensors positioned throughout the space, each detecting motion in its own zone. The system processes signals from multiple sensors and combines the information to estimate total occupancy, using spatial segmentation to overcome the limitations of individual simple sensors
Solution Approach 2:
The patent introduces machine learning algorithms and signal processing intermediaries that translate the simple binary motion detection output of PIR sensors into accurate occupancy estimates. The intermediary processing layer extracts meaningful occupancy information from the raw sensor signals, bridging the gap between simple sensors and accurate measurement
3Measurement precision
If multiple PIR sensors are deployed to improve occupancy estimation accuracy, then measurement precision improves, but device complexity and system complexity increase
Solution Approach 1:
The patent merges the outputs of multiple PIR sensors into a unified occupancy estimate through centralized signal processing and machine learning. Instead of having each sensor operate independently or requiring complex coordination, the system combines all sensor signals and uses algorithms to produce a single occupancy count, simplifying the overall system architecture despite using multiple sensors
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 a cost-effective solution for occupancy estimation by accurately counting occupants using low-cost PIR sensors, enhancing energy efficiency and comfort in HVAC systems.
Implementation Method 1
a PIR motion sensor with a field of view of an area where occupants are expected to be present, and the PIR motion sensor is adapted to output a PIR signal
Data Source
AI summary
An occupancy estimation system is provided. The occupancy estimation system is configured to estimate a number of occupants in a target space. The occupancy estimation system includes a PIR motion sensor and a control apparatus. The PIR motion sensor is with a field of view of an area where occupants are expected to be present, and the PIR motion sensor is adapted to output a PIR signal. The control apparatus is adapted to receive the PIR signal to compile an aggregate of the minor and major motion behaviors of the occupants in the field of view and generate an occupancy estimation count accordingly.