International Submarine Engineering has developed two types of remotely operated vehicles under the sponsorship of the Canadian Hydrographic Service, Department of Fisheries and Oceans, Bedford Institute of Oceanography. The ARCS (Autonomous Remotely Controlled Submersible) is designed for seabed surveys under the Arctic ice cap. It is characterized by a high degree of autonomous operation and on-board intelligence. It is presently undergoing final development testing in preparation for under-ice trials in the Canadian arctic. The DOLPHIN (Deep Ocean Logging Platform with Hydrographic Instrumentation for Navigation) is designed for surveys of the continental shelf. A prototype vehicle was completed in 1983 and has undergone extensive sea trials. An upgraded version is now nearing completion.
Early work on the ARCS has been reviewed by Jackson and Ferguson (1984), C Thomas (1985a), and R. Thomas (1985), and on the DOLPHIN by Jackson and Ferguson (1983), Gilbert (1984), and C. Thomas (1985b).
Table 1 compares the general characteristics of the two vehicles. The missions performed by the ARCS are fundamentally limited by the requirement of a self-contained power source, in this case batteries. The diesel-powered DOLPHIN is aimed at missions of approximately the same length, but the new version under development will be capable of refueling in the water. Both vehicles are capable of carrying a variety of instruments and payloads.
TABLE 1 General characteristics of DOLPHIN and ARCS(available in full paper)
The ARCS is 17 ft long (extendable to 21 ft with an extra battery/payload section), and 27 in in diameter. The short version weights 3000lb, and can operate at depths of up to 1000 ft at 5 knots. Figure 1 illustrates the general arrangement of the vehicle subsystems. They are, from fore to aft:
Nose section (flooded)
8 Mesotech 980 obstacle avoidance sonars, 107-123 kHz, each with an effective beam-width of 15-20 degrees;
Oceano RM101 long baseline transmitter-receiver, 11-14 kHz;
International Submarine Technology acoustic telemetry receiver, 7.5-10 kHz, 15-17.5kHz.
Forward electronics section (1 atm.)
main control computers
acoustic telemetry electronics
digital tape recorded
obstacle avoidance sonar electronics
long baseline electronics
forward planes controllers and mountings (2)
Batteries (1 atm.)
Optional second battery or payload (1 atm.)
Aft electronics section (1 atm.)
thruster motor controllers
doppler sonar electronics
aft plane controllers (4)
Robertson SKR-80 subsea gyrocompass
Aft flooded section
acoustic telemetry transmitter
Mesotech 808 digital echo-sounder, 192-208kHz
Paroscientific 2400-AS-002 digital pressure transducer
Ametek MRQ 4015D dual axis Doppler sonar, 296-304kHz
Thruster motor section (oil filled)
brushless DC motors (2)
aft plane mounts (4)
The ARCS mission requirements call for a high degree of autonomous capability and fault tolerance.
Fig. 1 ARCS: general layout (available in full paper)