Distributed Impact Detection System, Phase II

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, acoustic emission sensor, or PZT element for an impact event, such as the foam impact that caused the Columbia tragedy or a micro-meteor 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 ultrasonic acoustic signals. Additionally, the system will provide a general purpose hardware platform on which integrated structural health monitoring algorithms and sensing techniques can be implemented. Such performance can provide operating lifetimes of 10+ years on a single AA battery, or unlimited operation from scavenged power sources. More »