The ORCA IV Vehicle

Overview

This years sub follows a design philosophy of incremental improvement of previous year's designs. The vehicle has kept the same physical design as the previous two years, as well as the sonar altimeter and pressure sensor. The magnetic compass and doppler velocity log have been upgraded in performance capabilities, and an entirely new digital light sensor has been added.

Hull Design

The ORCA IV hull is nearly identical to its predecessors in that it's designed for maximum stability and ease of upgradability. The ORCA IV is split into three main modules fore-and-aft. The central portion contains two water tight tubes which house the main electronics and power assemblies. The horizontal thrusters are also attached to the side of the center module. The bow and stern compartments are flooded and contain vertical thrusters, the environmental sensor package and and mission-specific equipment.

The vehicle has been very carefully designed to have a great upright stability. The batteries, since they are extremely heavy, are placed as low as possible in the hull, giving the sub very good static stability. The bow and stern sections swing outward away from the center module, allowing for easy access to the electronics assemblage.

Sensors and Electronics

The ORCA IV contains some new sensors this year to facilitate an overall increase in sub performance. New sensors include a Sontech Argonaut doppler velocity log, a Honeywell HMR3000 magnetic compass and custom built digital light sensor. The submarine uses a combination of the doppler velocity log, compass, pressure sensor and a homemade inertial measurement unit to build a picture of itself in relation to the world.

The vehicle is controlled by a software suite running on a pentium-class processor, built into a PC-104 hardware stack, running the Linux operating system. The control system for the submarine can be remotely accessed by a 900 MHz radio modem at short underwater distances, or by an ethernet cable fashioned into a tether.

Additional Information

Additional and more detailed information about ORCA IV can be found in the Articles and Press section of this site.