Amazon Technologies, Inc.

Michael Szmuk

Marco Antonio De Barros Ceze

Christopher McFarland

Marc Ian Feifel

Raymond Kraft

Xiaoqi Wang

Frederic Pierre Lacaux

Simone M Airoldi

Evan Matthew Francis

Umut Zalluhoglu

Kyle W Reeve

Raghu Venkataraman

Max Maria Jacques Opgenoord

Daniel Robert Hentzen

Described are systems and methods for active weathervaning of a hybrid flight aerial vehicle, such as an unmanned aerial vehicle (UAV). Active weathervaning of the hybrid flight aerial vehicle during can be provided during vertical takeoff and landing (VTOL)/hover flight without the assistance of any low-speed wind sensors and during transitions between VTOL/hover flight and fixed-wing, wing-borne, horizontal flight. Additionally, active weathervaning can be provided during propulsion mechanism failure conditions where the aerial vehicle may be experiencing failure conditions associated with one or more propulsion mechanisms.

Weathervaning for hybrid flight aircraft

Disclosed implementations describe systems and methods for stabilizing vertical takeoff and landing ('VTOL') or hover flight of a degraded canted-hex aerial vehicle so that the degraded canted-hex aerial vehicle can safely navigate to a landing area. For example, upon detection of a motor-out event, the disclosed implementations may cause an opposing propulsion mechanism of the aerial vehicle to terminate operation, the prioritization of the flight controller to change, and for a feedback loop of the flight controller to provide a preferred thrust to counteract yaw torques acting on the canted-hex aerial vehicle.

Aerial vehicle having non-standard priority control and blank-to-yaw control architecture

Systems and methods for sensorless motor control may include a back EMF (electromotive force) observer, an adaptive EMF filter, magnitude compensation, hybrid rotor position and speed determination, rotor position and speed blending, and angle compensation. In order to provide accurate and reliable rotor position and speed estimations for a motor over a wide and varied range of speeds, at low speeds, during speed reversals, and/or in the presence of external forces, loads, or torques, the sensorless motor control may utilize a hybrid rotor position and speed determination that leverages both angle-based and magnitude-based methods. Further, the outputs of the two methods may be blended based on a shaping function to generate a final estimated rotor position and speed. Then, the motor may be more accurately and reliably controlled based on the final estimated rotor position and speed.

Sensorless motor control at low speeds and speed reversals for aerial vehicles

This disclosure describes example reconfigurable propulsion mechanisms, example multi-rotor aerial vehicle apparatuses, and methods that may be used to alter the yaw torque polarity produced by one or more propulsion mechanisms in response to a detected loss of thrust produced by another propulsion mechanism of the aerial vehicle. For example, each reconfigurable propulsion mechanism may be configured to move between a normal operating position and a reconfigured operating position. When a reconfigurable propulsion mechanism is in a normal operating position, the yaw torque has a first polarity, such as clockwise. In comparison, when the same reconfigurable propulsion mechanism is in the reconfigured operating position, the yaw torque polarity produced by the propulsion mechanism is reversed and has a second polarity, such as counter-clockwise. Reconfiguration may be done to recover an aerial vehicle from a degraded operational state, for example resulting from a motor-out event, to a non-degraded operational state.

Reconfigurable propulsion mechanisms of a multirotor aerial vehicle

Described is a sensor-less motor reversal ('SLMR') apparatus that aids the reversal of motor rotation of a bidirectional motor, such as a brushless DC motor of an aerial vehicle. The SLMR includes an RPM dependent clutch that is rotated by a drive shaft of the motor and that engages an engageable shaft of the SLMR apparatus during a low RPM range of the motor during which indirect measurement of the RPM of the motor through a back-EMF of the motor is unreliable. As the engageable shaft increases in RPM, energy is stored by an energy storage mechanism of the SLMR. As the RPM of the motor decreases as part of a motor reversal, the energy stored by the energy storage mechanism is discharged and aids in the transition of the reversal of the motor from positive to negative, or negative to positive. As described, the SLMR apparatus is stateless.

Sensor-less motor reversal apparatus

Inverted centrifugal clutch apparatus

Systems and methods to improve controllability of an aerial vehicle responsive to degraded operational conditions are described. For example, one or more propeller blades of an aerial vehicle may be modifiable between two or more configurations. The configurations may include a low torque configuration suitable for normal operational conditions, and a high torque configuration suitable for degraded operational conditions. Various aspects or portions of a propeller blade may be modified to increase torque generated by the propeller blade due to drag or air resistance. The additional generated torque may then be used as a source of additional torque to improve controllability of the aerial vehicle responsive to degraded operational conditions.

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Seattle, WA, United States of America

Michael Szmuk