Power Line RF Presence Detection Without Room Sensors

Solution Overview

Problem

Existing presence detection systems require dedicated monitors in each room, which is inconvenient and costly, and they do not effectively utilize existing power lines to detect user presence, position, and identity.

Innovation Solution

The system uses existing power lines to detect user presence, position, and identity by monitoring voltage changes on the ground line when a user physically contacts a powered device, or by transmitting and receiving radio frequency signals, or by capacitive coupling between devices and users.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If dedicated monitors are installed in each room to detect user presence, then detection reliability is improved, but device complexity and cost increase

Engineering Contradiction:

Improvepresence detection reliabilityVSAvoidsystem complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies universality by enabling existing power lines to serve dual functions: delivering electrical power and detecting user presence through RF signal transmission and reflection. This eliminates the need for dedicated monitors in each room, reducing system complexity while maintaining detection capability through the existing power distribution infrastructure

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The power line presence detection system applies self-service by utilizing the existing power line infrastructure to perform detection functions without requiring additional dedicated monitoring equipment. The power lines themselves become the detection medium, reducing overall system complexity while maintaining reliability

Inventive Principle:

Principle #25Self-service

2Measurement precision

If dedicated monitors are installed in each room to detect user presence, then detection precision is improved, but cost increases

Engineering Contradiction:

Improveuser presence detection precisionVSAvoidsystem cost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent applies universality by enabling existing power lines to serve dual functions: delivering electrical power and detecting user presence through RF signal transmission and reflection. This eliminates the need for dedicated monitors in each room, reducing system complexity while maintaining detection capability through the existing power distribution infrastructure

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The power line presence detection system applies self-service by utilizing the existing power line infrastructure to perform detection functions without requiring additional dedicated monitoring equipment. The power lines themselves become the detection medium, reducing overall system complexity while maintaining reliability

Inventive Principle:

Principle #25Self-service

3Device complexity

If existing power lines are used to detect user presence through RF signals, then device complexity is reduced, but detection precision may worsen

Engineering Contradiction:

Improvesystem complexityVSAvoiduser presence detection precision

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent applies intermediary by using RF signals as a mediator to transmit presence detection information through the power line infrastructure. The RF signals bounce off objects and users in the room, carrying reflection information back to the detection device, enabling precise detection while utilizing the existing power line network

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system employs periodic action by continuously transmitting RF signals through the power lines at regular intervals and analyzing the reflections. This continuous periodic detection ensures accurate real-time presence detection while utilizing the existing power distribution infrastructure

Inventive Principle:

Principle #19Periodic action

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 approach allows for the detection of user presence, position, and identity without the need for dedicated monitors, making it more convenient and cost-effective, and enabling automation of tasks and refinement of speech processing techniques.

Implementation Method 1

transmitting and receiving radio frequency signals

Methodology Applied

Scientific EffectRadio frequency signal transmission: Electromagnetic Induction

Implementation Method 2

capacitive coupling between devices and users

Methodology Applied

Scientific EffectCapacitive coupling: Capacitance

Implementation Method 3

monitoring voltage changes on the ground line when a user physically contacts a powered device

Methodology Applied

Scientific EffectVoltage change detection: Conduction (electrical)

Data Source

PatentUS12298830B1Presence detection through radio frequency emissions from an electrical circuit

Publication Date: 2025.05.13 AMAZON TECH INC

AI summary

Described implementations utilize existing power lines at a location to detect and monitor the presence, position, and/or identity of users at the location. Rather than requiring dedicated monitors within each room or position within the location, the described implementations monitor a baseline voltage signal and/or an introduced voltage signal on the ground line of an existing power line of the location to determine the presence, position, and/or identity of a user at the location, either alone or in combination with other information.