Infrared Detector Cooler Predictive Maintenance by Refrigerating Time Drift

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Solution Overview

Problem

Conventional detector coolers in optronics systems are fragile, heterogeneous, and costly, with maintenance limited to detecting breakdowns after they occur, leading to unavailability and high maintenance costs, and there is a need for a system that can anticipate malfunctions without increasing bulk.

Innovation Solution

Implementing a predictive maintenance system that monitors the state of health of the cooler-detector by measuring the drift in refrigerating time, using a processing card to calculate the trend of refrigerating time based on 'on-off' cycles and storing aggregated data to predict potential breakdowns, allowing for self-adaptive behavior and minimal memory usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If predictive maintenance monitoring is implemented to detect breakdowns early, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improvedetector cooler reliabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The detector cooler system performs self-diagnosis by automatically monitoring its own refrigerating time and comparing it against stored reference values. The system autonomously detects deviations indicating potential failures without requiring external monitoring equipment, thereby improving reliability while avoiding additional system complexity.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system implements feedback by continuously measuring the actual refrigerating time, comparing it with reference values stored in memory, and using this comparison to predict potential failures. This closed-loop feedback mechanism enables early detection of degradation trends without adding complex external monitoring infrastructure.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If detailed temperature measurements and TMF data are stored for analysis, then measurement precision is improved, but the volume of storage required increases

Engineering Contradiction:
Improverefrigerating time measurement precisionVSAvoidmemory volume
Core Design Contradiction:
Measurement precisionVSVolume of stationary object

Solution Approach 1:

The system extracts and stores only the essential reference refrigerating time values in memory, rather than storing complete temperature measurement datasets. This selective extraction approach maintains the precision needed for TMF calculation while dramatically reducing the storage volume required for maintenance monitoring.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system performs partial data retention by storing only the critical reference TMF values needed for comparison, rather than preserving all raw temperature data. This partial action approach provides sufficient measurement precision for failure prediction while minimizing memory consumption.

Inventive Principle:
Principle #16Partial or excessive 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 enables early detection of potential breakdowns, reduces maintenance costs, enhances operational performance, and increases autonomy by minimizing energy consumption while providing better control over the detector cooler.

Implementation Method 1

a cooling machine 3 which uses, for example, helium and supplies the cryostat 2 with the refrigeration needed to bring its temperature (usually lower its temperature) from an ambient temperature to the operating temperature

Methodology Applied
Scientific EffectRefrigeration: Cryogenics

Implementation Method 2

a sensor 8 for measuring the temperature Td of the detector supplied by a sensor 8

Methodology Applied
Scientific EffectTemperature sensing: Thermography

Implementation Method 3

an IR detector 1 placed in a vacuum chamber (cryostat 2) which maintains the temperature of this chamber at an operating temperature of the detector

Methodology Applied
Scientific EffectVacuum insulation: Vacuum

Data Source

PatentUS8857196B2Optronic infrared system with predictive maintenance in terms of the number of cycles before breakdown
Publication Date: 2014.10.14 THALES SA
  • US8857196B2 patent drawing
  • US8857196B2 patent drawing
  • US8857196B2 patent drawing

AI summary

The invention relates to an optronics system equipped with: a detector cooler having a cooling machine, a cryostat, an IR detector placed in the cryostat, and a sensor for measuring the temperature TD of the detector; and a processing card which includes means for servocontrolling the cooling machine according to the temperature TD. The system includes a sensor for sensing the system's internal temperature TS, and the processing card includes means for calculating: the refrigerating time (TMF) based on the temperatures TD and TS, on each “on-off” cycle of the detector cooler, the trend of the drift in the refrigerating time TMF, as a function of the number of “on-off” cycles of the detector cooler, a number of “on-off” cycles of the detector cooler before breakdown as a function of said trend of the drift of the TMF, and means for storing data used in said calculations; these data are aggregated data and not the measurements of temperatures TD and TS, nor said TMFs, in order to limit the size of the storage means.