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Epilogue
Published in R. Kurt Barnhart, Douglas M. Marshall, Eric J. Shappee, Introduction to Unmanned Aircraft Systems, 2021
The command and control (C2) components comprise the UAS subsystem that enables controllable and autonomous flight. An essential C2 element is human, and the term operator “in the loop” implies direct control of the vehicle through pilot intervention, and operator “on the loop” indicates that the operator is monitoring autonomous flight. Other components most generally comprising the C2 subsystem are the ground control station (GCS) and associated software and electronics, antennae, ground-based and airborne transceivers, the autopilot to enable autonomous flight, air data and GPS systems, MEMS gyros, accelerometers and magnetometers for navigation and vehicle control, the interconnecting circuits and data buses, and onboard intelligences for computing and data processing. Larger UASs may also include auto-takeoff and autolanding systems. Although UAS command and control may occur via other methods (e.g., light transmission or through the umbilical cable of a tethered vehicle), C2 is most commonly accomplished via two-way transmissions that communicate commands to the UAS through an uplink and telemetry from the aircraft to the GS through the downlink. The medium through which this communication is accomplished is the radio frequency (RF) portion of the electromagnetic spectrum.
Diving and ROV
Published in Sukumar Laik, Offshore Petroleum Drilling and Production, 2018
ROV carries as payload various instruments, which collect data and/or perform tasks for which the vehicle is deployed. The telemetry and power supply from the surface station is often sent through an umbilical cable. In some cases, onboard batteries provide power and the telemetry through an acoustic link.
Horizontal path-following control for deep-sea work-class ROVs based on a fuzzy logic system
Published in Ships and Offshore Structures, 2018
Xingxing Huo, Tong Ge, Xuyang Wang
The functions of the umbilical cable are to supply electricity to the ROV and to transfer data between the ROV and the tether management system (see Figure 3). The umbilical cable force is mainly generated by the relative motion between the umbilical cable and seawater. However, the relative motion between the large part of the umbilical cable and the seawater is relatively small, because the working depth of the deep-sea work-class ROV is large and the umbilical cable is very long. Therefore, the umbilical cable force is small and is mainly generated by a very small part of the umbilical cable near the ROV. It can be assumed that the magnitude of the force generated by the small part of the umbilical cable is proportional to the second-order relative velocity, the direction of the force is opposite to the relative velocity and the speed of the small part of the umbilical cable is approximate to the speed of the ROV. In addition, the moment about the vertical axis from the umbilical cable is zero, because the umbilical cable is linked to the vertical axis of the ROV. Hence, the simplified model of the umbilical cable can be written as where Kx and Ky are the coefficients of the cable disturbing forces.
Study on the subsea umbilical cable equivalent device’s hydraulic transmission characteristics
Published in Ships and Offshore Structures, 2021
Yufang Li, Honglin Zhao, Deguo Wang
As shown in Figure 1, the umbilical cable is connected to the upper production control module and the bottom production equipment (Bagley et al. 2013). The umbilical cable provides hydraulic power to the subsea manifold system and the valves of the subsea tree. It also provides the necessary chemical injection channels for oil production and storage equipment, transmits control signals for the upper module, and transmits sensor data for subsea production facilities (Komperød 2016).