Unmanned Systems Technology 009 | Ocean Aero Submaran S10 | Simulation and testing | Farnborough report | 3W-110xi b2 TS HFE FI | USVs | Data storage | Eurosatory/UGS 2016 report

26 While the S10 in its current configuration has a fixed keel, later versions or larger developments of the design could use the folding keel, particularly those versions intended for more extensive underwater operations. The deployment actuator, an electrical ram in the S10, is connected to the hull structure at one end and a crank at the other that deploys and retracts the sail, pivoting on an axle whose outer ends are mounted in support blocks fixed to the hull structure. For wing control and positioning, the S10 uses an electrically driven wing and flap control system. In this version, control of the wing sail’s angle of incidence (AOI) and the angle of the camber change flap rely on oil-compensated stepper motors driving the gearbox with concentric worm gears connected to the elliptical pulley system to rotate the flap. One stepper motor drives the gearbox to turn the main wing while the other stepper motor drives the flap. By synchronising the rate of rotation of each stepper motor you can move the wing and flap as one. In the folding keel design, the actuator housing is attached to a spacer block that extends aft and bifurcates into a fork, forming a slot that accommodates the yoke attached to the keel assembly when it is in its retracted position. The aft end of the fork attaches to the upper portion of the keel yoke via a horizontal pivot pin forward of and above a second pivot that connects the lower end of the yoke and the upper end of the keel board. An extension mounted between the fork legs extends forwards and upwards, and includes a mounting face that extends parallel to the wing’s main axis. Two brackets mounted to an extension of the fork come out at 90° to it and meet a base plate that lies parallel to this mounting face. Mounted low and aft on this base plate, the wing’s two-stage gearbox lies parallel to the hydraulic motor and two-position clutch assembly. The main wing is mounted on the gearbox output shaft. A transverse tube on the upper aft portion of the base plate contains the axle that forms the main pivot for both the wing and keel assemblies. The axle and its supporting structure also transfer the aerodynamic, hydrodynamic and other forces that act on the wing and the keel into the hull. The keel assembly works very much like a four-bar linkage. At the bottom, the keel board is joined to the bulb through a horizontal pivot close to the hydrodynamic centre of the bulb, which is broad and rounded at its forward end and tapers to a point aft. A centreline slot in the forward upper portion of the bulb accommodates the keel board when the mechanism folds up. The keel bulb is also connected to the hull by a forward stay foil, the aft end of which is connected to the bulb by a horizontal pivot pin. This pin is free to slide along a track underneath the bulb from the middle to near the front as the keel deploys, and back as it folds up. The forward end of this stay foil pivots on a pin in the bow. A second centreline slot under the forward end of the bulb allows for the scissor motion of the stay within that part of the bulb as it folds and unfolds. Motor, clutch and worm drives In the hydraulic wing drive systems design, control of the wing sail’s AOI and the angle of the camber change flap rely on the hydraulic motor, the gearbox and the two-position hydraulic clutch. In one position, the clutch enables the gearbox to turn the wing and flap together, while in the other position it holds the wing fixed while moving the flap via a system of cables and pulleys. While the electric version in the S10 uses separate stepper motors to actuate the wing and flap, Ocean Aero’s hydraulic configuration combines a single motor and a clutch, which makes it easier to use in a folding configuration. Also, changes in the wing’s AOI are more frequent than flap angle adjustments, so it is more efficient to gear them together and drive them with a single motor. This arrangement also simplifies control, as two motors don’t have to be run at exactly the same speed to change the wing’s AOI while keeping the flap angle constant with respect to the wing. This configuration is primarily designed for deeper operations down to 200 m. A pump driven by an electric motor August/September 2016 | Unmanned Systems Technology Dossier | Ocean Aero Submaran S10 A vehicle that can be easily handled by two people for launch and recovery was a key factor in sizing the S10