Sound-based prognostics for a combustion air inducer

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Solution Overview

Problem

Existing HVAC systems lack self-diagnostic capabilities, leading to extended downtime due to manual inspection inefficiencies and potential misdiagnosis, as they cannot detect faults within the system without technician intervention.

Innovation Solution

A sound-based HVAC diagnostic system that uses microphones to capture audio signals from HVAC components, analyzing these signals against an audio signature library to identify faults and output recommendations for servicing, enabling the system to self-diagnose and provide necessary information for technicians.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If manual inspection is used for HVAC system diagnosis, then technician expertise can identify issues, but extended downtime occurs due to multiple trips and potential misdiagnosis

Engineering Contradiction:
Improvediagnosis accuracyVSAvoidsystem downtime
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The HVAC system performs self-diagnosis by automatically capturing audio signals from its own components, analyzing these signals against a library of audio signatures, and generating diagnostic reports without requiring technician intervention. This self-service capability eliminates the need for multiple technician trips and reduces system downtime while maintaining high diagnosis accuracy through automated pattern recognition.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system performs preliminary diagnostic actions by continuously monitoring audio signals and identifying faults before they escalate into major failures. The audio analysis system proactively detects abnormal patterns and generates service recommendations in advance, allowing technicians to prepare appropriately and reducing the time required for actual repairs.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If general error alerts are provided without self-diagnosis, then system operation can continue, but multiple technician visits are required increasing downtime

Engineering Contradiction:
Improveservice efficiencyVSAvoidtechnician downtime
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The system replaces manual mechanical inspection with automated acoustic analysis. Microphones capture audio signals that are processed by algorithms comparing them against a database of known fault signatures. This substitution of mechanical technician inspection with automated acoustic detection dramatically improves service efficiency by providing precise diagnostic information before the technician arrives, eliminating unnecessary trips and preparation time.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If no audio analysis is performed, then system complexity remains low, but fault detection precision is insufficient requiring manual inspection

Engineering Contradiction:
Improvefault detection precisionVSAvoiddiagnostic system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system introduces an audio signature library as an intermediary between the raw audio signals and the diagnostic decision-making process. The library contains pre-characterized acoustic patterns for various faults, serving as a reference database that enhances fault detection precision. This intermediary layer allows the system to achieve high measurement precision through pattern matching without requiring excessively complex real-time analysis algorithms, thus managing device complexity effectively.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 reduces downtime by allowing the HVAC system to accurately diagnose issues and provide necessary information for repairs, ensuring correct servicing without multiple technician visits and minimizing misdiagnosis.

Implementation Method 1

acoustic signature of the combustion air inducer

Methodology Applied
Scientific EffectAcoustic wave: Sound

Data Source

PatentUS12105057B2Sound-based prognostics for a combustion air inducer
Publication Date: 2024.10.01 LENNOX IND INC
  • US12105057B2 patent drawing
  • US12105057B2 patent drawing
  • US12105057B2 patent drawing

AI summary

A device is configured to operate a Heating, Ventilation, and Air Conditioning (HVAC) system. The device is further configured to determine that the speed of a combustion air inducer has exceeded a speed threshold value. The device is further configured to receive an audio signal from a microphone while operating the HVAC system, to identify an audio signature for the combustion air inducer from an audio signature library, and to determine the audio signature for the combustion air inducer is present within the audio signal. The device is further configured to determine a fault type based on the determination that the audio signature for the combustion air inducer is present within the audio signal.