Dynamic Measurement Cycle for CO2 Sensor Battery Life

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Solution Overview

Problem

Carbon dioxide sensors consuming more power than carbon monoxide sensors pose a challenge in maintaining long-term operation of combustion devices without battery replacement, necessitating large primary battery capacities to ensure continuous monitoring without reducing detection accuracy.

Innovation Solution

A carbon dioxide concentration determination circuit that includes a primary battery power source, carbon dioxide sensor, detection means, predicted concentration range determination, measurement cycle adjustment based on predicted concentrations, and alarm signal generation to ensure safety and extend battery life by varying measurement cycles according to predicted carbon dioxide levels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If carbon dioxide sensors are operated continuously at a short measurement interval to ensure detection accuracy, then detection reliability is improved, but primary battery life is significantly reduced

Engineering Contradiction:
Improvedetection reliabilityVSAvoidprimary battery life
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The measurement interval is made dynamic rather than fixed. The control unit adjusts the measurement interval based on predicted carbon dioxide concentration levels: shorter intervals when concentration is high (improving detection reliability) and longer intervals when concentration is low (extending battery life). This dynamic adaptation resolves the contradiction between continuous monitoring and battery conservation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system performs preliminary prediction of carbon dioxide concentration using past measurement data before actually conducting measurements. This preliminary action allows the system to anticipate when frequent measurements will be necessary and when they can be reduced, optimizing the balance between detection reliability and battery life before the contradiction actually manifests.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If the measurement interval is shortened to maintain detection accuracy during high carbon dioxide concentration periods, then detection precision is improved, but energy consumption increases

Engineering Contradiction:
Improvedetection precisionVSAvoidsensor energy consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The measurement interval dynamically adapts based on predicted carbon dioxide concentration. When prediction indicates high concentration approaching alarm thresholds, the system switches to short measurement intervals for precise detection. When prediction indicates low concentration, the system extends measurement intervals to reduce energy consumption, thus resolving the contradiction between measurement precision and energy usage.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the temporal parameter (measurement interval) based on the predicted state of carbon dioxide concentration. By modifying this parameter dynamically rather than keeping it constant, the system achieves high detection precision only when necessary, thereby reducing overall energy consumption while maintaining detection accuracy during critical periods.

Inventive Principle:
Principle #35Parameter changes

3Duration of action of stationary object

If a large primary battery capacity is used to support continuous operation of carbon dioxide sensors, then operational duration is extended, but device size and cost increase

Engineering Contradiction:
Improveoperational durationVSAvoidbattery capacity requirements
Core Design Contradiction:
Duration of action of stationary objectVSDevice complexity

Solution Approach 1:

By implementing dynamic measurement intervals based on predicted carbon dioxide concentration, the system extends operational duration without requiring oversized batteries. The adaptive strategy allows the same battery to support the device for over a year by reducing measurements during low-risk periods while maintaining short intervals during high-risk periods, avoiding the need for large battery capacity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The prediction mechanism performs preliminary assessment of carbon dioxide concentration trends before actual measurements are taken. This allows the system to proactively extend operational duration by avoiding unnecessary measurements, thereby reducing overall power consumption and extending battery life without increasing battery capacity or device complexity.

Inventive Principle:
Principle #10Preliminary 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

The circuit effectively extends primary battery life while maintaining detection accuracy by adjusting measurement cycles based on predicted carbon dioxide concentrations, ensuring safety without reducing battery longevity.

Implementation Method 1

a carbon dioxide sensor 7 that operates using the power source including the primary battery 9 as an operation power source

Methodology Applied
Scientific EffectInfrared absorption: Absorption (EM radiation)

Data Source

PatentEP2119965B1Circuit for judging concentration of carbon dioxide
Publication Date: 2014.12.03 TOYOTOMI CO LTD
  • EP2119965B1 patent drawingFigure 1
  • EP2119965B1 patent drawingFigure 2
  • EP2119965B1 patent drawingFigure 3

AI summary

A carbon dioxide concentration determination circuit is provided where a primary battery may be used as long as possible without reducing the detection accuracy of a carbon dioxide concentration. Carbon dioxide concentration detection means 15 for detecting the carbon dioxide concentration in a room based on an output of a carbon dioxide sensor 7, enabling the carbon dioxide sensor 7 to perform a detecting operation" at a predetermined measurement cycle is provided. Predicted concentration range determination means 17 determines by computation a concentration range within which a predicted carbon dioxide concentration falls, from two or more preset concentration ranges. The predicted carbon dioxide concentration is predicted to be detected at a subsequent time of measurement. Measurement cycle determination means 19 determines the measurement cycle such that the higher the upper limit concentration of the concentration range determined by the predicted concentration range determination means, the shorter becomes the measurement cycle where the carbon dioxide sensor may perform the detecting operation" High-concentration determination means 21 outputs a high-concentration determination signal when the measurement cycle becomes the shortest and the number of times that the carbon dioxide concentration has successively reached a predetermined high concentration reaches a preset number of times.