Abstract: An aircraft may include a fuselage, a propulsion assembly configured to produce thrust for the aircraft, and a gimballing mechanism articulatably coupling the propulsion assembly to the fuselage and configured to rotate the propulsion assembly about a first axis of rotation defined through a center of mass of the propulsion assembly, and rotate the propulsion assembly about a second axis of rotation defined through the center of mass of the propulsion assembly. The first axis of rotation may be perpendicular to the second axis of rotation. The first axis of rotation may be perpendicular to the second axis of rotation.

Abstract: An aircraft may include a body structure, a tail section articulatably coupled to the body structure and including a tail structure, a propulsion system coupled to the tail structure and configured to produce thrust for the aircraft, and a stabilizer coupled to the tail structure, and an actuation system configured to articulate the tail section relative to the body structure to change a thrust vector of the propulsion system and an angle of attack of the stabilizer during flight. The actuation system may be configured to articulate the tail section about at least two perpendicular rotational axes. The propulsion system may be configured to produce the thrust in a first thrust direction in a first flight mode (e.g., a rotor-borne flight mode) and to produce the thrust in a second thrust direction in a second flight mode (e.g., a wing-borne flight mode).

Abstract: An aircraft may include a body structure and a propulsion system coupled to the body structure and including a mounting shaft and a rotor. The rotor may include a rotor hub and a set of rotor blades, wherein the rotor is configured to orient the set of rotor blades at a first collective blade angle during a first flight mode and orient the set of rotor blades at a second collective blade angle during a second flight mode. The propulsion system may further include a motor coupled to the rotor and configured to rotate the rotor in a first rotational direction in the first flight mode to produce thrust in a first thrust direction and rotate the rotor in a second rotational direction opposite the first rotational direction in the second flight mode to produce thrust in a second thrust direction opposite the first thrust direction.

Abstract: An aircraft may include a fuselage, a propulsion assembly configured to produce thrust for the aircraft, and a gimballing mechanism articulatably coupling the propulsion assembly to the fuselage and configured to rotate the propulsion assembly about a first axis of rotation defined through a center of mass of the propulsion assembly, and rotate the propulsion assembly about a second axis of rotation defined through the center of mass of the propulsion assembly. The first axis of rotation may be perpendicular to the second axis of rotation. The first axis of rotation may be perpendicular to the second axis of rotation.

Abstract: An aircraft may include a body structure, a tail section articulatably coupled to the body structure and including a tail structure, a propulsion system coupled to the tail structure and configured to produce thrust for the aircraft, and a stabilizer coupled to the tail structure, and an actuation system configured to articulate the tail section relative to the body structure to change a thrust vector of the propulsion system and an angle of attack of the stabilizer during flight. The actuation system may be configured to articulate the tail section about at least two perpendicular rotational axes. The propulsion system may be configured to produce the thrust in a first thrust direction in a first flight mode (e.g., a rotor-borne flight mode) and to produce the thrust in a second thrust direction in a second flight mode (e.g., a wing-borne flight mode).

Abstract: An aircraft may include a body structure and a propulsion system coupled to the body structure and including a mounting shaft and a rotor. The rotor may include a rotor hub and a set of rotor blades, wherein the rotor is configured to orient the set of rotor blades at a first collective blade angle during a first flight mode and orient the set of rotor blades at a second collective blade angle during a second flight mode. The propulsion system may further include a motor coupled to the rotor and configured to rotate the rotor in a first rotational direction in the first flight mode to produce thrust in a first thrust direction and rotate the rotor in a second rotational direction opposite the first rotational direction in the second flight mode to produce thrust in a second thrust direction opposite the first thrust direction.

Abstract: An apparatus and method for automated launch, retrieval, and servicing of a hovering aircraft is provided. The apparatus includes a line which is elevatable while maintaining a principally horizontal axis. For retrieval, the aircraft translates principally spanwise over the line, following a path which is principally horizontal and normal to the line. At an appropriate moment, the line is elevated and contacts the aircraft's wing. As the aircraft continues translating, the line slides along the wing until captured in a cleat. The aircraft is then stably tethered in hover, and its position can be manipulated by articulating the line, such as to guide the aircraft into a docking station. For launch the aircraft lifts itself into hover while tethered to the line. Articulation of the line guides the aircraft into a launch position, at which point the line is disconnected from the cleat, thereby releasing the aircraft.

Abstract: An apparatus and method for automated launch, retrieval, and servicing of a hovering aircraft is provided. The apparatus includes a line which is elevatable while maintaining a principally horizontal axis. For retrieval, the aircraft translates principally spanwise over the line, following a path which is principally horizontal and normal to the line. At an appropriate moment, the line is elevated and contacts the aircraft's wing. As the aircraft continues translating, the line slides along the wing until captured in a cleat. The aircraft is then stably tethered in hover, and its position can be manipulated by articulating the line, such as to guide the aircraft into a docking station. For launch the aircraft lifts itself into hover while tethered to the line. Articulation of the line guides the aircraft into a launch position, at which point the line is disconnected from the cleat, thereby releasing the aircraft.

Abstract: An apparatus and method for automated launch, retrieval, and servicing of a hovering aircraft is provided. The apparatus includes a line which is elevatable while maintaining a principally horizontal axis. For retrieval, the aircraft translates principally spanwise over the line, following a path which is principally horizontal and normal to the line. At an appropriate moment, the line is elevated and contacts the aircraft's wing. As the aircraft continues translating, the line slides along the wing until captured in a cleat. The aircraft is then stably tethered in hover, and its position can be manipulated by articulating the line, such as to guide the aircraft into a docking station. For launch the aircraft lifts itself into hover while tethered to the line. Articulation of the line guides the aircraft into a launch position, at which point the line is disconnected from the cleat, thereby releasing the aircraft.

Abstract: Various embodiments of the present disclosure provide a tail-sitter aircraft having a leg assembly convertible from landing gear into a rear fuselage and empennage (or a tail assembly) of the aircraft. Generally, the leg assembly includes multiple legs movable from a closed configuration in which the legs form the tail assembly of the tail-sitter aircraft to an open configuration in which the legs form the landing gear of the tail-sitter aircraft (and vice-versa).

Abstract: An electric fence control unit includes a signal generator, a first signal receiver, a second signal receiver, a signal processing and control unit, and a communications interface. The signal generator generates and transmits an adjustable power signal along a conduction path of the electric fence. The signal receivers sample signal outputs at a driven end and at an open end of the fence line. The signal processing and control unit receives and analyzes the first signal output and the second signal output. The communications interface transmits results from processing the first signal output and the second signal output to a service center. The power signal is adjustable to any capacity power level between a maximum power level and a minimum power level to match a load of the electric fence. Methods of monitoring the electric fence, including adjusting a power level of the adjustable power signal, are also disclosed.

Abstract: Various embodiments of the present disclosure provide a tail-sitter aircraft having a leg assembly convertible from landing gear into a rear fuselage and empennage (or a tail assembly) of the aircraft. Generally, the leg assembly includes multiple legs movable from a closed configuration in which the legs form the tail assembly of the tail-sitter aircraft to an open configuration in which the legs form the landing gear of the tail-sitter aircraft (and vice-versa).

Abstract: An electric fence energizer provides automated reporting of faults and other events as well as fault location to reduce effort in diagnosing faults and intrusion events in electric fences by measuring impedance changes using a time-domain reflectometer. In some embodiments, methods determine the location of a fault in distance from the energizer and provide timely and appropriate condition information.

Abstract: An apparatus and method for automated launch, retrieval, and servicing of a hovering aircraft is provided. The apparatus includes a line which is elevatable while maintaining a principally horizontal axis. For retrieval, the aircraft translates principally spanwise over the line, following a path which is principally horizontal and normal to the line. At an appropriate moment, the line is elevated and contacts the aircraft's wing. As the aircraft continues translating, the line slides along the wing until captured in a cleat. The aircraft is then stably tethered in hover, and its position can be manipulated by articulating the line, such as to guide the aircraft into a docking station. For launch the aircraft lifts itself into hover while tethered to the line. Articulation of the line guides the aircraft into a launch position, at which point the line is disconnected from the cleat, thereby releasing the aircraft.

Abstract: An electric fence control unit includes a signal generator, a first signal receiver, a second signal receiver, a signal processing and control unit, and a communications interface. The signal generator generates and transmits an adjustable power signal along a conduction path of the electric fence. The signal receivers sample signal outputs at a driven end and at an open end of the fence line. The signal processing and control unit receives and analyzes the first signal output and the second signal output. The communications interface transmits results from processing the first signal output and the second signal output to a service center. The power signal is adjustable to any capacity power level between a maximum power level and a minimum power level to match a load of the electric fence. Methods of monitoring the electric fence, including adjusting a power level of the adjustable power signal, are also disclosed.

Abstract: An electric fence energizer provides automated reporting of faults and other events as well as fault location to reduce effort in diagnosing faults and intrusion events in electric fences by measuring impedance changes using a time-domain reflectometer. In some embodiments, methods determine the location of a fault in distance from the energizer and provide timely and appropriate condition information.

Abstract: Generation of documentation from a computer readable symbolic representation is described. In an embodiment, a reified version of an input is obtained as coded objects. The input is readable by a programmed computer for execution, and is in an applied form of a symbolic representation of knowledge for a defined domain of knowledge. The reified version is a coded form of the applied form, wherein the coded objects are in a dynamic language. A content sequence library is accessed by the programmed computer responsive to the coded objects to extract content for a document plan. A reasoning library is then accessed by the programmed computer responsive to the content extracted to provide a sequenced organization of phrase structure for the content extracted. A natural language representation of the input is output from a realization of the sequenced organization of phrase structure.

Abstract: A safety circuit used in low-voltage connecting systems leaves the two low-voltage systems disconnected until it determines that it is safe to make a connection. When the safety circuit determines that no unsafe conditions exist and that it is safe to connect the two low-voltage systems, the safety circuit may connect the two systems by way of a “soft start” that provides a connection between the two systems over a period of time that reduces or prevents inductive voltage spikes on one or more of the low-voltage systems. When one of the low-voltage systems has a completely-discharged battery incorporated into it, a method is used for detection of proper polarity of the connections between the low-voltage systems. The polarity of the discharged battery is determined by passing one or more test currents through it and determining whether a corresponding voltage rise is observed.

Abstract: There is provided an aqueous liquid domestic composition comprising (i) one or more active component selected from the group consisting of (A) 3% to 50% by weight, based on the total solids weight of said domestic composition, one or more softening agent, (B) 2% to 90% by weight, based on the total solids weight of said domestic composition, one or more anionic surfactant, and (C) a mixture consisting of (I) 1% to 25% by weight, based on the total solids weight of said domestic composition, one or more softening agent, and (II) 5% to 75% by weight, based on the total solids weight of said domestic composition, one or more anionic surfactant, and (D) 0.1% to 30% by weight, based on the total solids weight of said domestic composition, one or more amphoteric compound; and (ii) one or more cationic polymer latex comprising (I) 0.5% to 6% by weight, based on the dry weight of said polymer, one or more cationic monomer, (II) 30% to 99.

Abstract: Current transformer relays having dual functions as current transformers and electromechanical switches are described. The current transformer relay includes a relay coil and a conducting loop concentric with the relay coil. Additional functions are thus provided in addition to the main relay switching function or functions. The concentric nature of the relay coil and the conducting loop create a current transformer between these elements. The additional functions include the ability to measure an alternating current (AC) current conducted by the conducting loop, the ability to detect and interpret an information signal imposed on power lines connected to the conducting loop, the ability to induce or impose an information signal on the conducting loop for transmission to power lies connected to the conducting loop, and the ability to measure a differential current between currents carried by the conducting loop and a second concentric conducting loop.