Review of Autonomous Undersea Vehicle (AUV) Developments 
Although small in size, the REMUS vehicle is configured to support a variety of sensor 
packages. The vehicle has a CTD (conductivity/temperature/depth) sensor and an optical 
backscatter sensor on board. Telemetry data provides time of day, depth, heading, and a 
geographic fix for the data. A longer version of REMUS with an acoustic doppler current profiler 
and GPS system is undergoing tests. Additional PC-104 slots and RS-232 ports are available 
for user-designed payloads. 
REMUS has three motors forward of the propeller. The REMUS propulsion assembly is 
optimized to provide 1.5 pounds of thrust at a forward speed of 4 knots. At this speed a 40- 
nautical-mile track can be completed in 10 hours. REMUS runs from a 24-volt power supply 
and draws approximately 32 watts while maneuvering through the ocean, enabling the vehicle to 
operate at 4 knots for 14 hours. 
The REMUS control computer is based on PC-104 technology, a small-scale computerized 
version of the common IBM-PC hardware. The CPU sits in a custom motherboard, on which 
are eight 12-bit analog to digital channels, input/output ports, power supplies, and other 
interface circuitry. Internally, REMUS runs a DOS program written in C++ that executes out of 
an autoexec.bat file. The vehicle user interface is designed to run on a laptop computer. 
REMUS possesses a sophisticated acoustical system with a digital signal processor. A 
receiving array of four hydrophones is located in the nose, and on the bottom is a hydrophone 
that can both transmit and receive. To determine its position, REMUS transmits a coded ping to 
a transponder and listens for a reply. The range and bearing of the reply allows REMUS to 
determine its location. REMUS can be programmed to interrogate a trail of transponders, 
approaching each transponder by minimizing range. When the range to a transponder is below 
a predetermined threshold, the vehicle then listens on a different channel for the next 
transponder and approaches it using the same technique. By setting the transponders once 
using GPS, a known trackline may be followed on mission after mission. This system has been 
used to autonomously dock the vehicle. 
Table 9. REMUS Specifications 
Length: 53 inches (1.3 meters) 
Beam: Approx. 5.5 feet 
Diameter: 7.5 inches (19.1 cm) 
Maximum Operating Depth: 492 feet (150 meters) 
Gross Weight: 68 Ibs. in the air, neutrally buoyant in water 
Dive Duration: 14 hours at 4 knots 
Propulsion: Three motors; one direct drive thruster and sprocket-driven rudder, two 
pitch motors, and one stem propeller 
Power requirements: 24-volt supply, 32 watts while maneuvering at 4 knots 
Power Source: Rechargeable lead acid batteries 
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