The present disclosure relates to a vertical takeoff and landing (VTOL) aircraft (100) and a propulsion system (600) thereof. The propulsion system (600) comprises a primary rotor (108) configured to couple to an airframe (102) and oriented to generate a vertical thrust relative to the airframe (102), a drivetrain (626) operably coupled to an engine (602) and configured to mechanically drive the primary rotor (108), and a plurality of tiltable secondary rotor assemblies (114) configured to be disposed about the primary rotor (108). The primary rotor (108) comprises a plurality of collective-only variable-pitch blades. Each of the plurality of tiltable secondary rotor assemblies (114) may have a secondary rotor (116) and an electric motor (608) to drive the secondary rotor (116). An electric generator (606) operably coupled to the engine (602) or to the drivetrain (626) may be configured generate electric power for each electric motor (608) of the plurality of tiltable secondary rotor assemblies (114). Each of the plurality of tiltable secondary rotor assemblies (114) is configured to tilt between a vertical configuration (200b) and a horizontal configuration (200a) as a function of a phase of flight of the VTOL aircraft (100).

An unmanned aerial vehicle (UAV) includes a propeller, a driving device, and an elastic abutting member sleeve. The propeller includes a blade base, a blade mounted on the blade base, and a first installation foolproof member disposed on the blade base. The driving device includes a main body, a driving shaft rotatable relative to the main body, a locking member disposed on the main body, and a second installation foolproof member disposed on the locking member. The driving device is coupled with the propeller. The elastic abutting member is coupled with the driving shaft and disposed between the main body and the blade base and abuts against the main body and the blade base.

An unmanned aerial vehicle (UAV) includes a propeller, a driving device, and an elastic abutting member sleeve. The propeller includes a blade base, a blade mounted on the blade base, and a first installation foolproof member disposed on the blade base. The driving device includes a main body, a driving shaft rotatable relative to the main body, a locking member disposed on the main body, and a second installation foolproof member disposed on the locking member. The driving device is coupled with the propeller. The elastic abutting member is coupled with the driving shaft and disposed between the main body and the blade base and abuts against the main body and the blade base.

An aircraft, has an airframe, a transmission, and a liquid inertia vibration elimination (LIVE) system disposed between the airframe and the transmission via spherical bearings of two legs and via a central spherical bearing.

An aircraft, has an airframe, a transmission, and a liquid inertia vibration elimination (LIVE) system disposed between the airframe and the transmission via spherical bearings of two legs and via a central spherical bearing.

Various embodiments of a vision-guided unmanned aerial vehicle (UAV) system to identify and collect foreign objects from the surface of a body of water are disclosed herein. A vision system and methodology has been developed to reduce reflections and glare from a water surface to better identify an object for removal. A linearized polarization filter and a specularity-removal algorithm is used to eliminate excessive reflection and glare. A contour-based detection algorithm is implemented for detecting the targeted objects on water surface. Further, the system includes a boundary layer sliding mode control (BLSMC) methodology to reduce and minimize position and velocity errors between the UAV and object in the presence of modeling and parameter uncertainties due to variation in a moving water surface.

Various embodiments of a vision-guided unmanned aerial vehicle (UAV) system to identify and collect foreign objects from the surface of a body of water are disclosed herein. A vision system and methodology has been developed to reduce reflections and glare from a water surface to better identify an object for removal. A linearized polarization filter and a specularity-removal algorithm is used to eliminate excessive reflection and glare. A contour-based detection algorithm is implemented for detecting the targeted objects on water surface. Further, the system includes a boundary layer sliding mode control (BLSMC) methodology to reduce and minimize position and velocity errors between the UAV and object in the presence of modeling and parameter uncertainties due to variation in a moving water surface.

The invention is directed to an aerial vehicle with a hybrid drive unit (10) and with a rotor unit (1, 1′) wherein the hybrid drive unit (10) comprises at least a combustion engine (11), a generator (12) and a first electric motor (7) and the rotor unit (1, 1′) comprises a first rotor (1), wherein the combustion engine (11) is configured to drive the generator (12) to produce electricity, the generator (12) is coupled to the first electric motor (7) in such a way that the first electric motor (7) is feedable with electricity from the generator (12). The rotor unit (1, 1′) comprises a second rotor (1) and the hybrid drive unit (10) comprises a second electric motor (7′), wherein the generator (12) is coupled to the second electric motor (7′) in such a way that the second electric motor (7′) is feedable with electricity from the generator (12), and wherein the first rotor (1) is driven by the first electric motor (7) and the second rotor (1′) is driven by the second electric motor (7′).

The invention is directed to an aerial vehicle with a hybrid drive unit (10) and with a rotor unit (1, 1′) wherein the hybrid drive unit (10) comprises at least a combustion engine (11), a generator (12) and a first electric motor (7) and the rotor unit (1, 1′) comprises a first rotor (1), wherein the combustion engine (11) is configured to drive the generator (12) to produce electricity, the generator (12) is coupled to the first electric motor (7) in such a way that the first electric motor (7) is feedable with electricity from the generator (12). The rotor unit (1, 1′) comprises a second rotor (1) and the hybrid drive unit (10) comprises a second electric motor (7′), wherein the generator (12) is coupled to the second electric motor (7′) in such a way that the second electric motor (7′) is feedable with electricity from the generator (12), and wherein the first rotor (1) is driven by the first electric motor (7) and the second rotor (1′) is driven by the second electric motor (7′).

An aircraft is described comprising a transmission unit with a first module and a lubrication system; the first module comprises a casing and a movable member; the lubrication system comprises a header, a nozzle fed with the lubricating fluid and designed to feed the lubricating fluid inside the casing of the first module, a collection tank for the lubricating fluid injected by the nozzle, and recirculation means designed to cause the recirculation of the lubricating fluid from the collection tank to the feed header; the first module comprises a valve available in a first configuration, in which it enables the outflow of said lubricating fluid from said module to the recirculation means when the pressure of the lubricating fluid inside the header is greater than a threshold value; and in a second configuration, in which it fluidically isolates the module from the recirculation means when the pressure of the lubricating fluid inside the header is less than the threshold value.