A method and a system for controlling the winding/unwinding of a rope portion onto/from a rotary drum, comprises the step of making available a rope which is at least partially wound onto a rotary drum, wherein the rope is guided from the rotary drum along a defined path as far as a hauling point, wherein a traction force acts on the rope beyond the hauling point. The method comprises unwinding or winding the rope by executing a rotation of the rotary drum, such that a defined rope portion is moved along the defined path; and determining the length of the defined rope portion in the region of the defined path. The method comprises determining an angle difference corresponding to the rotation of the rotary drum; and controlling the rotary drum for further winding/unwinding taking into account the length and the angle difference. A calibration in the region of the defined path during the use of the rotary drum provides a control for the rotary drum.

A method and a system for controlling the winding/unwinding of a rope portion onto/from a rotary drum, comprises the step of making available a rope which is at least partially wound onto a rotary drum, wherein the rope is guided from the rotary drum along a defined path as far as a hauling point, wherein a traction force acts on the rope beyond the hauling point. The method comprises unwinding or winding the rope by executing a rotation of the rotary drum, such that a defined rope portion is moved along the defined path; and determining the length of the defined rope portion in the region of the defined path. The method comprises determining an angle difference corresponding to the rotation of the rotary drum; and controlling the rotary drum for further winding/unwinding taking into account the length and the angle difference. A calibration in the region of the defined path during the use of the rotary drum provides a control for the rotary drum.

An asymmetric aircraft and an aircraft that can operate from small ships and be stored in high density with three aircraft or more in one helicopter hangar without needing a landing gear or wing fold. These aircraft slide into and out of the hangar on dollies like circuit boards in a computer and are launched and recovered using a large towed parafoil.

A propulsion system for a boat comprises a plurality of aerofoils connected to a main mast. At least one of the aerofoils is a displaceable aerofoil adapted to be displaced along the main mast between an open position and a closed position. When the displaceable aerofoil is in its open position the aerofoils together form a sail of open sail area. When the displaceable aerofoil is in its closed position at least some of the aerofoils overlap to form a sail of closed sail area, the closed sail area being less than the open sail area. The propulsion system can include a displacement mechanism to displace the displaceable aerofoil between its open and closed positions; at least one of the aerofoils having a solar panel thereon; and/or a stub mast extending along and free to rotate about a stub axis and; connected to the main mast by a stub pivot.

A propulsion system for a boat comprises a plurality of aerofoils connected to a main mast. At least one of the aerofoils is a displaceable aerofoil adapted to be displaced along the main mast between an open position and a closed position. When the displaceable aerofoil is in its open position the aerofoils together form a sail of open sail area. When the displaceable aerofoil is in its closed position at least some of the aerofoils overlap to form a sail of closed sail area, the closed sail area being less than the open sail area. The propulsion system can include a displacement mechanism to displace the displaceable aerofoil between its open and closed positions; at least one of the aerofoils having a solar panel thereon; and/or a stub mast extending along and free to rotate about a stub axis and; connected to the main mast by a stub pivot.

Embodiments described herein relate generally to a sailing vessel that can substantially obviate the heeling problem experienced by classical sailboats. During navigation, the sailing vessel is driven forward by an aerodynamic force exerted by wind on the sail, and balanced by a hydrodynamic force exerted by water on a float on the stern of the sailing vessel, the aerodynamic force and the hydrodynamic force being parallel or substantially parallel to a longitudinal axis of the sailing vessel.

Embodiments described herein relate generally to a sailing vessel that can substantially obviate the heeling problem experienced by classical sailboats. During navigation, the sailing vessel is driven forward by an aerodynamic force exerted by wind on the sail, and balanced by a hydrodynamic force exerted by water on a float on the stern of the sailing vessel, the aerodynamic force and the hydrodynamic force being parallel or substantially parallel to a longitudinal axis of the sailing vessel.

Traction air device with multiple wing contours for a wind power generation plant and wind power generation plant utilizing the air device.

An asymmetric aircraft (1) and an aircraft (1) that can operate from small ships (8) and be stored in high density with three aircraft or more in one helicopter hangar (107) without needing a landing gear or wing fold. These aircraft slide into and out of the hangar on dollies (90) like circuit boards in a computer and are launched and recovered using a large towed parafoil (6).

An autonomous sailing vessel may include a hull, a mast, a sail, and a rudder. The mast may be mechanically coupled to the hull. The sail may be mechanically coupled to the mast. The rudder may be mechanically coupled to the hull. A heading of the autonomous sailing vessel may be regulated by actively controlling the rudder without actively controlling the sail. Alternatively or additionally, the autonomous sailing vessel may include an anticapsize stabilizer tank, a lidar system, and/or marine mammal monitoring and identification.