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www.sea-technology.com November 2016 / st 11 munications and support electronics for the autopilot. The second major system was the software package that would implement all parts of the autopilot system, including the user interface and control algorithms. L-3 MAPPS's Dr. Xavier Cyril, director of product engineering and ser- vices, and Dr. Francois Belanger, project lead on en- gineering activities, along with their team, developed and delivered the new Victoria-class autopilot system for testing by NRC. For the National Research Council, what began as an advisory role quickly expanded with the opportunity to validate the new technology through a comprehensive numerical and physical model testing program. A suc- cessful collaborative partnership among NRC, the Royal Canadian Navy, Defence Research and Development Canada Atlantic and L-3 MAPPS was soon realized. Autopilot System The new submarine autopilot has two areas of con- trol. First, it can control and maintain a set depth; sec- ond, it can control and maintain a given heading. The newly developed autopilot system uses various onboard navigation sensors to determine the course, heading and depth on a continuous basis. It uses these sensor readings to determine what the boat is doing in three dimensions, and the au- topilot will determine what the submarine should be doing, comparing these measurements. Any difference is considered an error, and using a soft- ware algorithm, it is able to calculate what course and depth corrections are required. Once the cal- culation is completed, electronic commands are sent to control the rudder and/or hydroplanes to move the boat back to the course, heading and depth required. The new system uses a modern, touch-screen- based operator interface, presenting the operator with similar information to the legacy system. This is an intuitive display designed according to the hu- man factor aspects built into the legacy system. A major benefit to the new system is that it provides the operator the ability to make small depth and course cor- rections. An out-of-trim estimator displays the ballast and trim condition of the submarine. In the old system, the trim and ballast condition had to be mentally estimated by the operator by monitoring the plane deflec- tion angles on the control console. Testing NRC's project team began a program of physical model tests to evaluate the per- formance of the new autopilot system dur- ing surface operations in February 2014. The primary objective was to quantify seakeeping capabilities and limitations for surface operations in a variety of seaways, at various speeds, headings and operation- al scenarios. The secondary objective was to collect appropriate data for the devel- opment of guidelines to support submarine special opera- tions forces exercises in shallow water/littoral conditions. The testing also served as a primary source of quality data for the validation of numerical simulation software codes. To achieve these objectives, NRC developed special- ized evaluation tools, the first based on Defence Research and Development Canada Atlantic's submarine simulation software, DSSP; the second on a 4.7-m-long free-running submersible model of the Victoria-class submarine, tested at a scale of 1:15. The model testing of the new system was conducted in NRC's towing tank in its world-class facilities in St. John's, Newfoundland and Labrador. At 200 m long, 7 m deep (Top to Bottom) Testing the new Victoria-class autopilot system in NRC's towing tank facility in St. John's. The Victoria-class submarine model constructed by NRC experts in St. John's. The submarine model ready for testing in NRC's towing tank, St. John's. The submarine model submerged in NRC's towing tank, St. John's.