19 June 2001




B. Bourgeois
Naval Research Laboratory
Stennis Space Center, MS 39529-5004



This memorandum report details the specifications for the upgrade of the ORCA control system that was implemented during the OCT96-MAR97 period. The upgrade to the control system provided the following:

" Supportable versions of software and hardware components.
" Elimination of ORCA control system circuit cards.
" Replacement of electric throttle with supportable hydraulic throttle.
" Installation of low-cost magnetic compass for vessel heading data.
" Automated waypoint following capability.
" Vessel depth feedback to the OSCC (ORCA Sensor Control Computer) via the SPC (Ship Positioning Computer) port.
" Access to control system gains and parameters.
" Upgraded comm link to asynchronous radios with 5 ports.
" Eliminated dependence of PC-SCC (Ship Control Computer, PC version) on discontinued video card.
" Documented radio interface data protocols.
" Copy of proprietary sub-side source code for vessel control system.
" Conversion of the host-ship portion of the control system to a unix system providing:- Government ownership of the software.


- GUI interfaces with popup windows. This results in a more capable operator interface and a reduction in hardware interface components.
- Gauges for analog parameter readouts.
- History feature, allowing 'replay' of system parameters.
- Ethernet only connection between the SCC and OSCC.
- Allows OSCC to provide backup control of the ORCA.
- Smart bellypack and navtray that utilize stateless switches and microcontrollers with serial port communication to the SCC.
- Allows pilot control over the coverage map, video camera, and acoustic obstacle detection system.


" Remote control mode that allows an external computer to control vessel heading, speed and depth.
" Integration of the Tasman GPS unit for vessel positioning.
" Upgrade of Robertson Gyrocompass to enable NMEA output. Inclusion of gyrocompass heading as a control system input.
" Addition of temperature sensors in the electronics bay.

Sponsored by the Oceanographer of the Navy.

Published as a Memorandum Report, December, 1997.
Naval Research Laboratory Contribution Number NRL/MR/7442 97-8075.
NRL Memorandum Report