Networked Sensor Fusion for Presence Detection

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Solution Overview

Problem

Current person-presence-detection systems in home and building automation often fail to accurately detect individuals during quiet activities and require user interaction, leading to incorrect presence recognition and user annoyance.

Innovation Solution

A network of devices with various sensors (e.g., pushbutton sensors, motion detectors, brightness sensors, microphones, cameras) communicates with a central processing unit to continuously monitor and combine data signals, enabling accurate presence detection and tracking within a building, and allowing for automated control of systems like lighting and heating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If motion detectors are used to detect person presence, then presence detection is enabled, but detection accuracy deteriorates during quiet activities

Engineering Contradiction:
Improvepresence detection accuracyVSAvoiddetection precision during quiet activities
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent combines multiple detection devices (motion detectors, brightness sensors, microphones, cameras, temperature sensors) into a networked system that collectively detects person presence. This merging of multiple sensing modalities compensates for the limitations of individual motion detectors during quiet activities, maintaining both reliability and measurement precision.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The network devices serve multiple functions: motion detectors detect movement, brightness sensors detect ambient light changes, microphones detect sound, cameras detect visual presence, and temperature sensors detect thermal changes. This multi-functionality ensures accurate presence detection across various activity levels, from active movement to quiet states.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If run-on time is extended to reduce false negatives, then presence recognition improves for quiet activities, but false positives increase

Engineering Contradiction:
Improvepresence recognition reliabilityVSAvoidabsence detection accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The networked devices continuously monitor multiple parameters (motion, brightness, sound, temperature) and provide feedback to the control unit. This multi-parameter feedback system allows the system to distinguish between genuine absence and temporary quiet periods, reducing both false negatives and false positives by evaluating multiple concurrent signals rather than relying on extended run-on time alone.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2717517B1Network for detecting the presence of persons with a plurality of house installation/building system devices
Publication Date: 2018.01.31 ABB AG(DE)
  • EP2717517B1 patent drawingFigure 1
  • EP2717517B1 patent drawingFigure 2
  • EP2717517B1 patent drawingFigure 3

AI summary

The network (1) has communication paths (14) provided between apparatuses of a house installation system and a CPU (15) for transmission of data signals, where the CPU is provided with an operation unit (16) and a drive unit (18). The apparatuses generate the signals immediately after an action i.e. running action, is made by a person, and send the signals to the CPU that documents information about presence of the person at a location at specific time. The CPU replicates information about access of the person to rooms and an exit of a building based on combination of the received signals. The CPU is designed as a smart phone, a tablet personal computer, a car navigation apparatus or an internet connected computer, and the apparatuses are designed as a room temperature controller (3A), a surface-mounted motion sensor (3B), a brightness sensor/twilight switch (3C), microphone (3D) and/or a camera (3E). The drive unit is designed as an actuator.