Missile Propellant Life Monitoring via Companion Samples

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Solution Overview

Problem

Current methods for monitoring the service life of missiles are either costly and destructive or pose risks due to embedded sensors, and there is a need for a reliable, non-destructive, and cost-effective solution to assess the condition of propellant charges.

Innovation Solution

A system using accompanying samples with embedded stress and temperature sensors, which are thermally and environmentally equivalent to the propellant charges in rockets, to monitor critical parameters and calculate the remaining service life, along with environmental detection devices to record and analyze the aging conditions of missiles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If destructive testing is used to monitor propellant life, then measurement precision is improved, but device complexity and cost increase significantly

Engineering Contradiction:
Improvepropellant condition assessmentVSAvoidtesting system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses accompanying samples as simplified copies of the actual propellant charges. These samples contain embedded sensors that replicate the monitoring function without requiring complex destructive testing of the real propellant. The copy principle allows continuous monitoring through representative samples while preserving the integrity of the actual missile propellant.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

Sensors are embedded in the accompanying samples during manufacturing, before the propellant charge is fully cured and before deployment. This preliminary action allows the monitoring system to be in place and operational from the outset, continuously tracking environmental parameters and propellant condition without requiring later intervention or complex testing procedures.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If embedded sensors are placed in the propellant charge, then measurement precision is improved, but reliability deteriorates due to ignition risks

Engineering Contradiction:
Improvestress and temperature monitoringVSAvoidignition safety
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The monitoring system is segmented into two distinct parts: the actual missile propellant charge and the separate accompanying samples. The sensors are embedded only in the accompanying samples, not in the real propellant. This segmentation isolates the ignition risk to the samples while preserving the reliability of the actual missile system, yet still provides accurate monitoring data through the representative samples.

Inventive Principle:
Principle #1Segmentation

3Measurement precision

If environmental sensing devices are used with destructive testing, then measurement precision is improved, but loss of time increases due to frequent testing intervals

Engineering Contradiction:
Improveservice life assessmentVSAvoidtesting and analysis time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The accompanying samples with embedded sensors provide continuous monitoring of propellant condition and environmental parameters throughout storage and service life. This continuous action eliminates the need for periodic destructive testing intervals, as the sensors continuously record stress, temperature, and other critical parameters, providing real-time data without interrupting missile availability or requiring repeated removal and testing cycles.

Inventive Principle:
Principle #20Continuity of useful action

4Measurement precision

If multiple sensors are embedded in each rocket, then measurement precision is improved, but device complexity and cost increase

Engineering Contradiction:
Improvepropellant charge monitoringVSAvoidsensor system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Instead of embedding multiple complex sensor systems in each actual missile, the patent uses simplified accompanying samples as copies that contain the sensors. The samples replicate the essential monitoring function with fewer and simpler sensors, reducing device complexity and cost while still providing accurate propellant condition data through the representative sample measurements.

Inventive Principle:
Principle #26Copying

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 accurate, non-destructive monitoring of missile propellant charges, reducing costs and risks while providing reliable data on remaining service life, enabling better inventory management and extending operational life.

Implementation Method 1

They measure the mechanical stress normal to the sensor membrane and the local temperature

Methodology Applied
Scientific EffectStress measurement:

Implementation Method 2

They measure the mechanical stress normal to the sensor membrane and the local temperature

Methodology Applied
Scientific EffectTemperature measurement:

Implementation Method 3

the propellant is usually glued or attached to the inner wall of the housing and shrinks or expands more than the housing material with temperature

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 4

The chemical aging processes take place at different speeds, with the rate of oxidation increasing sharply with temperature

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 5

Exposed to the environment, it also ages within a housing due to chemical processes and mechanical loads, oxidation and moisture

Methodology Applied
Scientific EffectChemical aging:

Data Source

PatentEP2581594B1System for lifespan monitoring of missiles
Publication Date: 2019.10.02 BAYERN CHEM GES FUR FLUGCHEM ANTRIEBE MBH
  • EP2581594B1 patent drawingFigure 1~4
  • EP2581594B1 patent drawingFigure 5

AI summary

In a system for monitoring the service life of rockets, at least one companion sample (11) is produced from each batch of propellant in addition to the rockets (1). This companion sample is exposed to the same environmental conditions as the rockets (1). The companion sample (11) has a combustion chamber filled with a propellant (7) from the batch and corresponds to the combustion chamber of the rockets filled with a propellant from the batch. The propellant (7) of the companion sample (11) and the propellant (7) of the rockets (1) adhere to the combustion chamber wall. The propellant (7) of the companion sample (11) is provided with voltage sensors (12 to 15) on its surface adjacent to the combustion chamber wall, which are coupled to at least one data acquisition device (16).