Program Description
Vehicle Health Management (VHM) is the capability to
efficiently perform checkout, testing and monitoring of
space transportation vehicles, subsystems and components
before, during and after operation. This includes the
ability to perform timely status determination, diagnostics
and prognostics. VHM must support fault-tolerant response
including system/subsystem reconfiguration to prevent
catastrophic failures. VHM must support the planning and
scheduling of post-operational maintenance. The primary
purpose for pursuing VHM is to increase safety and
reliability while simultaneously reducing costs. Such
improvements increase system availability, and permit launch
on demand and on schedule, thereby greatly improving the
competitiveness of the U.S. launch industry.
The scope of VHM includes the entire space transportation
system. It applies to vehicle ground and flight operations
conducted in manufacturing, refurbishment and test
facilities. VHM applies across the entire life cycle of the
vehicle, beginning in the earliest phases of design. It is
an active element in developmental testing and
certification, and matures with the vehicle in flight
operational use.
Towards this end, the NASA Glenn Research Center has
extensive experience in developing and implementing health
management systems for real-time and post-test/flight launch
vehicle analysis. Our projects and areas of interest
include:
- Sensor validation based on analytical redundancy for real-
time and post-test applications; analytical redundancy
relationships can be quantitative or qualitative.
- Real-time anomaly detection algorithms to augment current
redline systems. These algorithms make no assumptions
regarding failure modes.
- Real-time and post-test event detection algorithms. Given
the large amount of data that typically requires analysis,
it is not feasible to reason on each data sample. To
function efficiently and to minimize demands on system
engineers, automated analysis must be event driven. The
event detection algorithms automate the identification of
visual patterns within a signal or sensor trace.
- Automated Post-Test Diagnostics. Our generic framework
facilitates portability to a variety of applications. An
automated post-test diagnostic system dramatically reduces
the time and cost associated with data handling/analysis and
employs heuristic case-based and model-based reasoning.
- Tools and instrumentation to allow fast and accurate
component/system life usage determination as well as methods
to permit the realization of optimum system life through
damage-mitigating control.
- Real-time diagnostic systems for sparsely instrumented
system that include the analysis of dynamic data.
- Tools that automate the design of a health management system
concurrently with the space system design. Including update
of the VHM system as test data becomes available and
quantifiable comprehensive VHM verification and validation.
The papers below are available in PDF format and require Adobe’s Acrobat reader software. Download the Adobe plug-in at www.adobe.com.
