Patent ID: 11919630
Assignee: TEXTRON SYSTEMS CORPORATION
Field: Transport (Mechanical engineering)
Classification: CPC B | IPC B

Claim 0:
1. An aircraft, comprising:
an airframe having a lifting surface;
a longitudinal-thrust engine;
a plurality of modular articulated electric rotors attached to the airframe, each rotor being a rotor assembly including a respective electric motor and respective propeller rotated thereby, each rotor being nominally aligned with a respective vertical axis perpendicular to a longitudinal axis of the aircraft, at least some of the rotors being variable-position rotors having variable orientations about their nominal alignment based on rotor position signals supplied thereto;
a source of electrical power for powering the electric rotors;
control circuitry configured and operative to independently control thrust of the longitudinal-thrust engine and rotor thrust and rotor orientation of each of the variable-position rotors, relative to the aircraft lifting surface and longitudinal thrust engine, to provide for commanded thrust-vectoring maneuvering of the aircraft during vertical takeoff and landing (VTOL), fixed wing flight, and intermediate transitional states, including maintenance of a desired pose of the lifting surface independent of the rotor orientations when hovering the aircraft in windy conditions; and
a flight and navigation control system that automates flight maneuvers autonomously or through human-in-the-loop augmentation and is capable of maintaining the desired aircraft system pose and position relative to static or dynamic global coordinates that are autonomously or operator defined when the aircraft is executing station keeping, tracking, avoidance, or convergence maneuvers,
wherein the variable-position rotors are compound-articulated electric rotors having variable orientations in both pitch and roll based on the rotor position, and wherein the control circuitry provides the independent control of the compound-articulated electric rotors to maintain the desired pose of the lifting surface independent of the rotor orientations when hovering the aircraft in crosswind conditions,
the aircraft being further configured and operative in both a lateral-translation case and a longitudinal-translation case, wherein in the lateral-translation case the rotors are articulated in roll to assist while managing a substantially horizontal attitude of the lifting surface to reduce adverse and variable effects of wind-induced lifting and to maintain control authority, and wherein in the longitudinal-translation case the rotors are articulated in pitch to assist while managing the substantially horizontal attitude of the lifting surface to reduce adverse and variable effects of wind-induced lifting components and maintain control authority,
wherein the control circuitry includes a model-based controller incorporating a model of assistive aerodynamic forces experienced by the aircraft including (1) in the lateral-translation case due to airflow laterally and longitudinally across the lifting surface, and (2) in the longitudinal-translation case due to airflow over the lifting surface, and the model-based controller (1) uses the model to determine response of the rotors, and (2) provides reduced energy demand and time to transition to and from fixed-wing flight in the longitudinal-translation case due to active integration of the lifting surface with a controlled transition to, and arresting from, fixed-wing flight.