ENSCO, Inc. is a provider of engineering services, products, and advanced technologies for national security, transportation safety and asset management, information sciences, data management including information management systems for weather monitoring, aerospace and avionics, and R and D for private corporations and local, state, and federal agencies and governments, including the United States Department of Defense. The company was established by Dr. Paul W. Broome in 1969. ENSCO's corporate headquarters are physically located in Annandale CDP in unincorporated Fairfax County, Virginia, but its postal address is in Falls Church. Wikipedia.
Tang L.,Clemson University |
Tang L.,ENSCO |
Wang K.-C.,Clemson University |
Huang Y.,Clemson University
IEEE Transactions on Industrial Informatics
Wireless sensors on rotating mechanical structures have rich and fast changing multipath that cannot be easily predicted by conventional regression approaches in time for effective transmission coding or power control, resulting in deteriorated transmission quality. This study aims to study the speed-dependent packet error rate (PER) of wireless sensor radios on rotating mechanical structures. A series of rotating IEEE 802.15.4 sensor radio transmission experiments and vector network analyzer measurements have been conducted to derive and validate a predictive PER model for a fast rotating sensor radio channel based on channel impulse response measurements. The proposed predictive PER model, including power attenuation, bit error rate (BER) and PER sub-models, captures the channel property of rotating sensors based on the received signal strength and the radio receiving sensitivity. The PER model has accurately predicted the PER profile of sensors on a rotating machine tool spindle as well as a rotating plate of a prototype rotation system. The analysis provides an in-depth understanding of how multipath propagation causes the fast power variation and the resulting speed-dependent PER for wireless sensors on rotating mechanical structures. © 2005-2012 IEEE. Source
Ensco | Date: 2014-06-02
Systems and methods for performing distance and velocity measurements, such as by using carrier signals, are disclosed. A measurement system device may include a first antenna configured to receive a first signal from a transmitting device, the first signal having a carrier frequency, and a second antenna configured to receive the first signal from the transmitting device. The measurement system device may also include a processor configured to determine a first differential distance between the first antenna and the second antenna from the transmitting device and to determine a rate of change of the first differential distance. The processor may also be configured to estimate a geometry of the measurement system device relative to the transmitting device using the rate of change of the first differential distance.
Ensco | Date: 2014-06-02
Systems and methods for performing distance and velocity measurements, such as by using carrier signals, are disclosed. A measurement method may include transmitting a first signal from an originator device to a transponder device and determining a carrier phase of the first signal at the transponder device. The measurement method may also include transmitting a second signal from the transponder device to the originator device and determining a carrier phase of the second signal at the originator device. The measurement method may include estimating a relative distance between the originator device and the transponder device using the carrier phase of the first carrier signal, the carrier phase of the second carrier signal. The method may also include estimating the relative distance using a frequency difference. The method may include using an adjusted relative distance to determine a total distance between the originator device and the transponder device.
Ensco | Date: 2011-11-23
A bridge apparatus to transfer persons between a moving structure such as a vessel and a second structure such as an offshore installation, for example, to span gaps between work boats and fixed offshore installations such as wind turbines. The bridge comprises a platform supported by a line, the platform being moveable in a vertical direction by movement, of the line, wherein the line extends in a vertical direction from the platform to a capstan, and from the capstan to a counterweight. Thus the inboard end of the bridge can remain in generally the same vertical position in relation to the support structure of the vessel, moving with the vessel in the water, and the outboard end of the bridge apparatus can remain in generally the same vertical position relative to the wind turbine, and the relative vertical movement between the wind turbine and the vessel is compensated by the movement of the bridge, while the stepping on and stepping off points on the bridge remain generally still in relation to the vessel and the wind turbine.
Ensco | Date: 2011-11-25
Launch and recovery apparatus (