Embedded Wireless Corrosion Monitoring for Condition Based Maintenance

Corrosion of aircraft and rotorcraft costs the DoD billions of dollars annually and is the largest maintenance cost driver for the Navy and Marine Corps.  Localized corrosion such as pitting, crevice, exfoliation, and environment assisted cracking is difficult to detect and degrades structural integrity.  Currently, corrosion control is based on costly schedule based maintenance and inspection practices.  To enable more efficient condition based maintenance, Luna is developing a wireless corrosion monitoring system with embedded diagnostics and prognostics.

On-aircraft corrosion monitoring provides a means of identifying only those aircraft and components that are in need of maintenance.  The corrosion monitoring system, using inputs from various environmental and corrosivity sensors, tracks component usage, environmental exposure, and specific material damage modes as a function of time.  Corrosion diagnostic models are based on direct measurements of exposure conditions and cumulative environmental severity.  By assuming usage scenarios, these models can be used as prognostic indicators for forecasting appropriate inspection and maintenance intervals.  By tracking an aircrafts cumulative environmental severity, while monitoring real time corrosion rates of surrogate alloys, an intelligent, embedded system can provide accurate, reliable, structural health diagnostics and prognostics for advanced condition based maintenance activities.

The development of a robust monitoring system for aircraft structural corrosion presents multiple challenges that include sensor system design, and corrosion model development and validation in accelerated tests and service environments.  Appropriate sensors must be integrated within a compact, robust package that can be easily retrofit and that requires minimal operator attention.  Luna is meeting the need for aircraft corrosion monitoring by developing an ultra low power, wireless sensor suite with embedded processing that is compatible with energy harvesting technology to achieve very long service life.  The results of Luna’s efforts in corrosion sensor development, wireless sensor suite design, and accelerated corrosion testing will be presented.