A self-latching piezocomposite actuator includes a plurality of shape memory ceramic fibers. The actuator can be latched by applying an electrical field to the shape memory ceramic fibers. The actuator remains in a latched state/shape after the electrical field is no longer present. A reverse polarity electric field may be applied to reset the actuator to its unlatched state/shape. Applied electric fields may be utilized to provide a plurality of latch states between the latched and unlatched states of the actuator. The self-latching piezocomposite actuator can be used for active/adaptive airfoils having variable camber, trim tabs, active/deformable engine inlets, adaptive or adjustable vortex generators, active optical components such as mirrors that change shapes, and other morphing structures.

In one embodiment, a local control system for a rotor assembly of an apparatus includes a first actuator disposed in the rotor assembly and configured to control motion of a first controllable element in the rotor assembly. The rotor assembly is mounted to the apparatus and is rotated responsive to torque and rotational energy provided thereto. The local control system also includes a first sensor disposed in the rotor assembly and configured to provide position feedback in relation to the first controllable element. The local control system also includes a first local control computer disposed in the rotor assembly and communicably coupled to a first central control computer disposed in the apparatus external to the rotor assembly, where the first local control computer is configured to transmit a control signal to the first actuator and receive a feedback signal from the first sensor.

A control system for controlling at least one propeller of a compound rotorcraft, the control system generating a control order for collectively controlling a pitch of the blades of at least one propeller. According to the disclosure, the control system comprises: a first piloting control for generating a first control setpoint; a second piloting control for at least generating a second control setpoint different from first control setpoint; and a control unit configured to generate control order depending on the first control setpoint and second control setpoint, the control unit implementing a control law generating the control order as a function of first control setpoint and the second control setpoint.

A control system for controlling at least one propeller of a compound rotorcraft, the control system generating a control order for collectively controlling a pitch of the blades of at least one propeller. According to the disclosure, the control system comprises: a first piloting control for generating a first control setpoint; a second piloting control for at least generating a second control setpoint different from first control setpoint; and a control unit configured to generate control order depending on the first control setpoint and second control setpoint, the control unit implementing a control law generating the control order as a function of first control setpoint and the second control setpoint.

A blade pitch control system includes a plurality of serially stacked swashplate assemblies, each having concentric, ring-shaped inner and outer sections, an associated output pitch link coupled to its outer section and an associated input pitch link coupled to its inner section. The inner and outer sections of each swashplate assembly includes pass through holes to accommodate input pitch links and output pitch links of adjacent ones of the stacked swashplate assemblies. The system also includes a plurality of actuators, each coupled to a respective input pitch link of a respective one of the stacked swashplate assemblies. A central static mast accommodates a rotor drive shaft and the stacked swashplate assemblies are configured to slide axially, parallel to a long axis of the static mast.

A blade pitch control system includes a plurality of serially stacked swashplate assemblies, each having concentric, ring-shaped inner and outer sections, an associated output pitch link coupled to its outer section and an associated input pitch link coupled to its inner section. The inner and outer sections of each swashplate assembly includes pass through holes to accommodate input pitch links and output pitch links of adjacent ones of the stacked swashplate assemblies. The system also includes a plurality of actuators, each coupled to a respective input pitch link of a respective one of the stacked swashplate assemblies. A central static mast accommodates a rotor drive shaft and the stacked swashplate assemblies are configured to slide axially, parallel to a long axis of the static mast.

A blade speed control apparatus and method. The apparatus includes a rotor assembly a first blade assembly movably attached to the rotor assembly at a first initial position, a second blade assembly movably attached to the rotor assembly at a second initial position, and a movement mechanism configured to move the rotor assembly in a first lateral direction along a y-axis such that a first angle exists between the first blade assembly with said respect to the second blade assembly. The movement mechanism is configured to move a portion of the rotor assembly in a first lateral direction along a y-axis such that a first angle exists between the first blade assembly with said respect to the second blade assembly. The first angle does not comprise an angle of 180 degrees.

A blade speed control apparatus and method. The apparatus includes a rotor assembly a first blade assembly movably attached to the rotor assembly at a first initial position, a second blade assembly movably attached to the rotor assembly at a second initial position, and a movement mechanism configured to move the rotor assembly in a first lateral direction along a y-axis such that a first angle exists between the first blade assembly with said respect to the second blade assembly. The movement mechanism is configured to move a portion of the rotor assembly in a first lateral direction along a y-axis such that a first angle exists between the first blade assembly with said respect to the second blade assembly. The first angle does not comprise an angle of 180 degrees.

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.

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.