NASA SBIR 2004 Solicitation


PROPOSAL NUMBER: 04 X4.03-8276
SUBTOPIC TITLE: Inspection and Diagnostics
PROPOSAL TITLE: Distributed Impact Detection System

SMALL BUSINESS CONCERN (Name, E-mail, Mail Address, City/State/Zip, Phone)
Invocon, Inc.
19221 I-45 South, Suite 530
Conroe, TX 77385-8746

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
Mike Walcer
19221 IH 45 South; Suite 530
Conroe, TX 77385-8746

Automated impact detection and characterization on manned spacecraft has been an elusive goal due to the transitory nature of the detectable high-frequency signals. The proposed approach for this effort is to use large numbers of self-powered, miniaturized, "stick on" piezoelectric sensory nodes that are synchronized within a radio frequency network. Each node will continuously monitor an accelerometer or acoustic emission sensor element for an impact event, such as the foam impact that caused the Columbia tragedy or an MMOD impact. When a programmable threshold is exceeded, a low-latency signal acquisition circuit will capture the event as a digital waveform for post-processing and impact characterization. In addition, autonomous collaboration and synchronization between nodes of the network will provide for accurate location determination through amplitude and time-of-arrival analysis. The innovative signal conditioning circuit design is capable of operation in the micro-watt range on average while constantly maintaining the capability to process and acquire very high-frequency acoustic signals. Such performance can provide operating lifetimes of 20+ years on a single AA battery, or unlimited operation from scavenged power sources such as solar or thermal gradients.

This system could benefit many current and future NASA space flight and exploration programs, including the Shuttle, ISS, and Project Constellation programs, or a Moon or Mars habitat, where the risk of MMOD impacts causing critical damage to vehicles or life support systems exists. In addition to MMOD impacts, the basic design of the proposed system could be used for detection of leaks from pressurized vehicles and habitats through the produced airborne and surface-borne ultrasonic energy. The system would also enable the detection of crack propagation in structures through Acoustic Emission techniques while requiring minimal vehicle resources.

Potential Non-NASA applications include asset monitoring during shipment or transportation through the continuous monitoring and recording of shock events for both commercial and military equipment. Such a device could be placed in a shipping container and provide a history of any shock or high-g accelerations experienced including a timestamp and potentially location via GPS. Currently available commercial systems have very limited battery life and only provide an indication that an acceleration threshold has been exceeded with no way to characterize the event through signal analysis techniques.