An unmanned aerial vehicle (UAV) includes a central part, a frame assembly, and a propulsion assembly mounted to the frame assembly. The UAV also includes a servo mounted to the central part. The servo includes a driving apparatus, a control apparatus operably coupled with the driving apparatus, and a sensor configured to obtain operating parameters of the driving apparatus. The operating parameters include operating positions of the driving apparatus. The control apparatus is configured to control the driving apparatus to rotate to a predetermined position and stay at the predetermined position based on the operating positions of the driving apparatus obtained by the sensor.

A device for the roll-stabilization of a watercraft in motion, at anchor, or at zero speed, and/or for influencing the course of the watercraft, includes a fin-carrying shaft on which a guide fin is disposed. For changing an actual angle of attack of the guide fin in the water, the fin-carrying shaft is drivable by an electromechanical drive unit, and the drive unit is disposed on the hull using a base. An electromechanical drive unit is configured with a synchronous motor that drives the fin-carrying shaft using a reducing eccentric transmission. The device thereby has a significantly reduced installation space requirement, causes only slight operating noises, and is also optimally electronically regulable.

Various aspects provide for parking an apparatus in a parking position. A parking position may be a configuration of an apparatus that minimizes damage resulting from extended exposure during periods of inactivity. An apparatus may comprise a marine apparatus, which may be configured to be disposed in an environment comprising saltwater, salty air, brackish water, freshwater, and the like. An apparatus may comprise a propulsion system (e.g., for a ship) and/or a steering system. Some aspects include a water jet based propulsion system having a scoop and a nozzle operable to redirect the water jet, providing a range of forward/backward and port/starboard thrusts. A control cylinder and/or a linkage may be parked in a configuration that segregates damage incurred during periods of inactivity to portions of an apparatus not needed for normal operation.

Various aspects provide for parking an apparatus in a parking position. A parking position may be a configuration of an apparatus that minimizes damage resulting from extended exposure during periods of inactivity. An apparatus may comprise a marine apparatus, which may be configured to be disposed in an environment comprising saltwater, salty air, brackish water, freshwater, and the like. An apparatus may comprise a propulsion system (e.g., for a ship) and/or a steering system. Some aspects include a water jet based propulsion system having a scoop and a nozzle operable to redirect the water jet, providing a range of forward/backward and port/starboard thrusts. A control cylinder and/or a linkage may be parked in a configuration that segregates damage incurred during periods of inactivity to portions of an apparatus not needed for normal operation.

A rudder assembly, including a steering engine; an axial hollow rudder stock; a rudder blade; a gas release unit; and a tiller. The steering engine is disposed in a vessel stern. The tiller is connected to the steering engine. The axial hollow rudder stock includes a through hole. The through hole is small and disposed along the axis of the axial hollow rudder stock. The gas release unit is disposed in the vessel stern, and includes a control cabinet. The control cabinet includes a reagent storage tank, a reagent conveying hose connected to the reagent storage tank, a compressed air bottle, a pressure hose connected to the compressed air bottle, and a console. The pressure hose and the reagent conveying hose pass through the through hole of the axial hollow rudder stock, and then communicate with the cavity of the rudder blade.

A rudder assembly, including a steering engine; an axial hollow rudder stock; a rudder blade; a gas release unit; and a tiller. The steering engine is disposed in a vessel stern. The tiller is connected to the steering engine. The axial hollow rudder stock includes a through hole. The through hole is small and disposed along the axis of the axial hollow rudder stock. The gas release unit is disposed in the vessel stern, and includes a control cabinet. The control cabinet includes a reagent storage tank, a reagent conveying hose connected to the reagent storage tank, a compressed air bottle, a pressure hose connected to the compressed air bottle, and a console. The pressure hose and the reagent conveying hose pass through the through hole of the axial hollow rudder stock, and then communicate with the cavity of the rudder blade.

An unmanned aerial vehicle (UAV) includes a central part, a frame assembly, and a propulsion assembly mounted to the frame assembly. The UAV also includes a servo mounted to the central part. The servo includes a driving apparatus, a control apparatus operably coupled with the driving apparatus, and a sensor configured to obtain operating parameters of the driving apparatus. The operating parameters include operating positions of the driving apparatus. The control apparatus is configured to control the driving apparatus to rotate to a predetermined position and stay at the predetermined position based on the operating positions of the driving apparatus obtained by the sensor.

Various aspects provide for parking an apparatus in a parking position. A parking position may be a configuration of an apparatus that minimizes damage resulting from extended exposure during periods of inactivity. An apparatus may comprise a marine apparatus, which may be configured to be disposed in an environment comprising saltwater, salty air, brackish water, freshwater, and the like. An apparatus may comprise a propulsion system (e.g., for a ship) and/or a steering system. Some aspects include a water jet based propulsion system having a scoop and a nozzle operable to redirect the water jet, providing a range of forward/backward and port/starboard thrusts. A control cylinder and/or a linkage may be parked in a configuration that segregates damage incurred during periods of inactivity to portions of an apparatus not needed for normal operation.

Various aspects provide for parking an apparatus in a parking position. A parking position may be a configuration of an apparatus that minimizes damage resulting from extended exposure during periods of inactivity. An apparatus may comprise a marine apparatus, which may be configured to be disposed in an environment comprising saltwater, salty air, brackish water, freshwater, and the like. An apparatus may comprise a propulsion system (e.g., for a ship) and/or a steering system. Some aspects include a water jet based propulsion system having a scoop and a nozzle operable to redirect the water jet, providing a range of forward/backward and port/starboard thrusts. A control cylinder and/or a linkage may be parked in a configuration that segregates damage incurred during periods of inactivity to portions of an apparatus not needed for normal operation.

Various aspects provide for parking an apparatus in a parking configuration. A parking configuration may be a configuration of an apparatus that minimizes damage (e.g., corrosion, wear, and the like) resulting from extended exposure during periods of inactivity. An apparatus may comprise a propulsion system (e.g., for a ship) and/or a steering system. An apparatus may comprise a linkage or other device positioned by an actuator. Some aspects include a water jet based propulsion system having a scoop and a nozzle operable to redirect the water jet, providing a range of forward/backward and port/starboard thrusts.