Page 22 - The ROV Manual - A User Guide for Remotely Operated Vehicles 2nd edition

10 CHAPTER 1 The ROV Business
Table 1.4 Sensors and Data Transmission Requirements
Sensor Type Bandwidth Protocol
Telemetry Type
Single beam sonar 2D multibeam sonar 3D multibeam sonar UT metal thickness Standard-def. video High-def. video Radiation sensor Pipe tracker
Low
Medium to high High
Low
Medium Medium to high Low
Low
RS-232/422/485 Ethernet Ethernet RS-232/422/485 Composite Ethernet RS-232/422/485 RS-232/422/485
Copper or optical fiber Copper or optical fiber Optical fiber
Copper or optical fiber Copper or optical fiber Optical fiber
Copper or optical fiber Copper or optical fiber
Table 1.5 Tool Type Versus Vehicle Characteristics
Tool Type
Weight in- Water
Power
Minimum Vehicle Size
Single-function manipulator
Light duty 4-function manipulator
Heavy-duty 7-function hydraulic manipulator
Wire rope cutter
Hydraulic grinder Diamond wire saw
Low Medium High
Medium Medium Low
DC electrical
Low pressure/flow hydraulic
High-pressure/low-flow
hydraulic
High-pressure/low-flow hydraulic
Low-pressure/high-flow hydraulic High-pressure/high-flow hydraulic
OCROV MSROV WCROV
MSROV and WCROV MSROV and WCROV WCROV
With the advent of fiber optic communication capabilities on smaller mobile platforms, sensor throughput capabilities have taken on a new dimension for the ROV as a sensor delivery platform. While data over copper is still the prevalent setup for OCROVs (due to its inherent short-distance transmission requirements and low-cost structure), fiber optics is the predominant telemetry con- ductor for MSROVs and WCROVs. A short sample of sensors along with their data transmission requirements and likely telemetry type is provided in Table 1.4.
For tooling, the main difficulties are (i) the vehicle’s ability to carry the tool as payload (i.e., the size of the vehicle vis-a`-vis the tool itself) with a large enough vehicle-to-tool ratio so that the tool does not “wag the dog”—or provide so much drag that it renders the vehicle uncontrollable with the tool attached, (ii) the vehicle’s power delivery capability is sufficient to power the tool while maintaining station, and (iii) the vehicle’s ability to physically reach the work site. A short sample of tooling along with the typical payload and vehicle size requirements is provided in Table 1.5.