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Wireless Data-Acquisition System for Testing Rocket EnginesA prototype wireless data-acquisition system has been developed as a potential replacement for a wired data-acquisition system heretofore used in testing rocket engines. The traditional use of wires to connect sensors, signal-conditioning circuits, and data acquisition circuitry is time-consuming and prone to error, especially when, as is often the case, many sensors are used in a test. The system includes one master and multiple slave nodes. The master node communicates with a computer via an Ethernet connection. The slave nodes are powered by rechargeable batteries and are packaged in weatherproof enclosures. The master unit and each of the slave units are equipped with a time-modulated ultra-wide-band (TMUWB) radio transceiver, which spreads its RF energy over several gigahertz by transmitting extremely low-power and super-narrow pulses. In this prototype system, each slave node can be connected to as many as six sensors: two sensors can be connected directly to analog-to-digital converters (ADCs) in the slave node and four sensors can be connected indirectly to the ADCs via signal conditioners. The maximum sampling rate for streaming data from any given sensor is about 5 kHz. The bandwidth of one channel of the TM-UWB radio communication system is sufficient to accommodate streaming of data from five slave nodes when they are fully loaded with data collected through all possible sensor connections. TM-UWB radios have a much higher spatial capacity than traditional sinusoidal wave-based radios. Hence, this TM-UWB wireless data-acquisition can be scaled to cover denser sensor setups for rocket engine test stands. Another advantage of TM-UWB radios is that it will not interfere with existing wireless transmission. The maximum radio-communication range between the master node and a slave node for this prototype system is about 50 ft (15 m) when the master and slave transceivers are equipped with small dipole antennas. The range can be increased by changing to larger antennas and/or greater transmission power. The battery life of a slave node ranges from about six hours during operation at full capacity to as long as three days when the system is in a "sleep" mode used to conserve battery charge during times between setup and rocket-engine testing. Batteries can be added to prolong operational lifetimes. The radio transceiver dominates the power consumption.
Document ID
20090041687
Acquisition Source
Stennis Space Center
Document Type
Other - NASA Tech Brief
External Source(s)
http://www.techbriefs.com/component/content/article/1346
Authors
Lin, Chujen (NASA Stennis Space Center Stennis Space Center, MS, United States)
Lonske, Ben (NASA Stennis Space Center Stennis Space Center, MS, United States)
Hou, Yalin (NASA Stennis Space Center Stennis Space Center, MS, United States)
Xu, Yingjiu (NASA Stennis Space Center Stennis Space Center, MS, United States)
Gang, Mei (Intelligent Automation Corp. United States)
Date Acquired
August 24, 2013
Publication Date
March 1, 2007
Publication Information
Publication: NASA Tech Briefs, March 2007
Subject Category
Man/System Technology And Life Support
Report/Patent Number
SSC-00231
Distribution Limits
Public
Copyright
Public Use Permitted.

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IDRelationTitle20090041667Collected WorksNASA Tech Briefs, March 2007
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