Abstract: An aircraft uses trajectory-based control algorithms for blade pitch (or twist). This approach greatly enhances the ability of the actuator to accurately achieve the desired blade pitch and to track the commanded pitch position. An actuator includes an electronic rotor blade controller that converts communicated or desired changes in pitch (or similar parameter) to actual physical effects that match the desired changes as closely as possible. The controller preferably includes a motor drive circuit, such as an h-bridge, a communication circuit for connection to external commands, and a processor with associated enabling circuitry (e.g. memory, I/O) to coordinate and implement the control.

Abstract: An aircraft uses trajectory-based control algorithms for blade pitch (or twist). This approach greatly enhances the ability of the actuator to accurately achieve the desired blade pitch and to track the commanded pitch position. An actuator includes an electronic rotor blade controller that converts communicated or desired changes in pitch (or similar parameter) to actual physical effects that match the desired changes as closely as possible. The controller preferably includes a motor drive circuit, such as an h-bridge, a communication circuit for connection to external commands, and a processor with associated enabling circuitry (e.g. memory, I/O) to coordinate and implement the control.

Abstract: This disclosure provides systems, methods and apparatus of establishing a free-space communication link through a medium. The medium can be an occluded environment with increased absorption and/or scattering effects. The free-space communication link includes a transmitter configured to transmit an optical signal at a wavelength suitable for transmission through the medium without suffering excessive optical losses due to absorption and/or scattering effects. The free-space communication link includes a receiver configured to receive the transmitted optical signal. The transmitter-receiver pair is configured to efficiently transmit optical signals at the suitable wavelength over a distance between about 1 mm and about 50 m. The transmitter and the receiver can be configured as portions of a fiber-optic connector assembly that can be used to connect two fiber-optic cables in an occluded environment.

Abstract: This disclosure provides systems, methods and apparatus of establishing a free-space communication link through a medium. The medium can be an occluded environment with increased absorption and/or scattering effects. The free-space communication link includes a transmitter configured to transmit an optical signal at a wavelength suitable for transmission through the medium without suffering excessive optical losses due to absorption and/or scattering effects. The free-space communication link includes a receiver configured to receive the transmitted optical signal. The transmitter-receiver pair is configured to efficiently transmit optical signals at the suitable wavelength over a distance between about 1 mm and about 50 m. The transmitter and the receiver can be configured as portions of a fiber-optic connector assembly that can be used to connect two fiber-optic cables in an occluded environment.