Control System Performance of an Unmanned Wind-propelled Catamaran

Recent experimental testing of an unmanned autonomous marine surface vehicle has demonstrated several key advances in control system performance for a wind propelled platform. The HWT X-1 is a winged catamaran based on a modi…ed conventional sailing vessel intended for use as a surveillance and sensor platform in either littoral or unprotected waters. Using GPS and an o¤the-shelf commercial Attitude and Heading Reference System (AHRS) as the primary sensors, in integrated control architecture has been implemented that has demonstrated closed loop control about a …gure-8 course while under wind propulsion. A speed regulation control system maintains a minimum speed on course using a combination of electric drive motors and wind propulsion, reducing power on the drive motors as the wing-sail accelerates the vehicle. Trajectory control is accomplished with line acquisition and line tracking controllers. The line acquisition control uses a line-of-sight guidance law, and acquires the line within 100m. The line tracking controller demonstrated an ensemble mean of 1.0m and a standard deviation of 0.7m for sheltered waters, and mean of 1.6m and a standard deviation of 1.2m for open waters. Copyright c 2007 IFAC