Abstract: Aerial vehicles may include propulsion units having motors with drive shafts that may be aligned at a variety of orientations, propellers with variable pitch blades, and common operators for aligning the drive shafts at one or more orientations and for varying the pitch angles of the blades. The common operators may include plate elements to which a propeller hub is rotatably joined, and which may be supported by one or more linear actuators that may extend or retract to vary both the orientations of the drive shafts and the pitch angles of the blades. Operating the motors and propellers at varying speeds, gimbal angles or pitch angles enables the motors to generate forces in any number of directions and at any magnitudes. Attributes of the propulsion units may be selected in order to shape or control the noise generated thereby.

Abstract: Sounds are generated by an aerial vehicle during operation. For example, the motors and propellers of an aerial vehicle generate sounds during operation. Disclosed are systems, methods, and apparatus for actively adjusting the position and/or configuration of one or more propeller blades of a propulsion mechanism to generate different sounds and/or lifting forces from the propulsion mechanism.

Abstract: This disclosure describes an aerial vehicle, such as an unmanned aerial vehicle (“UAV”), which includes a plurality of maneuverability propulsion mechanisms that enable the aerial vehicle to move in any of the six degrees of freedom (surge, sway, heave, pitch, yaw, and roll). The aerial vehicle may also include a lifting propulsion mechanism that operates to generate a force sufficient to maintain the aerial vehicle at an altitude.

Abstract: This disclosure describes an aerial vehicle, such as an unmanned aerial vehicle (“UAV”), which includes a plurality of maneuverability propulsion mechanisms that enable the aerial vehicle to move in any of the six degrees of freedom (surge, sway, heave, pitch, yaw, and roll). The aerial vehicle may also include a lifting propulsion mechanism that operates to generate a force sufficient to maintain the aerial vehicle at an altitude.

Abstract: Multiple propeller blades may be joined by tip connectors to form a closed propeller apparatus. The tip connectors may create continuous structure between adjacent tips of a first propeller and a second propeller. Use of the tip connectors may reduce vortices created near the tips of the propeller blades, which cause drag and slow the rotation of the propeller blades. The tip connectors may also reduce noise caused by rotation of propeller blades. Further, the tip connectors reduce or eliminate deflection of the propeller blades by creating a support structure to counteract forces that would otherwise cause deflection of the propeller blades, thereby improving propeller blade loading. In some embodiments, the tip connectors may be formed of a malleable material and/or include one or more joints that enable at least one of the propellers to modify a pitch of blades of the propeller.

Abstract: A multi-level (ML) fulfillment center is designed to accommodate landing and takeoff of unmanned aerial vehicles (UAVs), possibly in an urban setting, such as in a densely populated area. Unlike traditional fulfillment centers, the ML fulfillment centers may include many levels (i.e., stories, floors, etc.) as permitted under zoning regulations for respective areas. The fulfillment center may have one or more landing locations and one or more deployment locations to accommodate UAVs, which may delivery at least some of the items from the fulfillment center to locations associated with customers.

Abstract: Multiple motors may drive (rotate) a single shaft coupled to a propeller. The motors may be selected such that a first motor is capable of rotating the drive shaft in an event of a failure of a second motor coupled to the drive shaft. A one-way clutch bearing, or similar device, may interface between a motor and the drive shaft to enable free rotation of the drive shaft in an event of the motor becoming inoperable, such as the motor freezing or locking in a position due to failure caused by overheating or caused by other conditions or events. Use of the second motor may secure a position of the drive shaft which may support the propeller in radial eccentric loading.

Abstract: Aerial vehicles may include propulsion units having motors with drive shafts that may be aligned at a variety of orientations, propellers with variable pitch blades, and common operators for aligning the drive shafts at one or more orientations and for varying the pitch angles of the blades. The common operators may include plate elements to which a propeller hub is rotatably joined, and which may be supported by one or more linear actuators that may extend or retract to vary both the orientations of the drive shafts and the pitch angles of the blades. Operating the motors and propellers at varying speeds, gimbal angles or pitch angles enables the motors to generate forces in any number of directions and at any magnitudes. Attributes of the propulsion units may be selected in order to shape or control the noise generated thereby.

Abstract: This disclosure describes a configuration of an unmanned aerial vehicle (“UAV”) that will facilitate extended flight duration. The UAV may have any number of lifting motors. For example, the UAV may include four lifting motors (also known as a quad-copter), eight lifting motors (also known as an octo-copter), etc. Likewise, to improve the efficiency of horizontal flight, the UAV also includes a pivot assembly that may rotate about an axis from a lifting position to a thrusting position. The pivot assembly may include two or more offset motors that generate a differential force that will cause the pivot assembly to rotate between the lifting position and the thrusting position without the need for any additional motors or gears.

Abstract: This disclosure describes an unmanned aerial vehicle (“UAV”) and system that may perform one or more techniques for protecting objects from damage resulting from an unintended or uncontrolled impact by a UAV. As described herein, various implementations utilize a damage avoidance system that detects a risk of damage to an object caused by an impact from a UAV that has lost control and takes steps to reduce or eliminate that risk. For example, the damage avoidance system may detect that the UAV has lost power and/or is falling at a rapid rate of descent such that, upon impact, there is a risk of damage to an object with which the UAV may collide. Upon detecting the risk of damage and prior to impact, the damage avoidance system activates a damage avoidance system having one or more protection elements that work in concert to reduce or prevent damage to the object upon impact by the UAV.

Abstract: This disclosure is directed to a single blade propeller and systems, devices, and techniques pertaining to assisting in critical stages of flight (e.g., takeoff, landing, emergency situations, etc.) in vertical takeoff and landing (VTOL) aircraft. The single blade propeller may be incorporated into fixed and rotary wing VTOL aircraft as part of a first propulsion system. The first propulsion system may include one or more single blade propellers driven by electric motors, combustion engines, and/or hybrid engines. Each of the single blade propellers may include a lift-producing blade and a counterweight opposite the lift-producing blade. As each of the single blade propellers spins, it may produce lift in a direction approximately perpendicular to the horizon to effect vertical flight.

Abstract: This disclosure describes a configuration of an unmanned aerial vehicle (UAV) that will facilitate extended flight duration. The UAV may have any number of lifting motors. For example, the UAV may include four lifting motors (also known as a quad-copter), eight lifting motors (octo-copter), etc. Likewise, to improve the efficiency of horizontal flight, the UAV also includes a thrusting motor and propeller assembly that is oriented at approximately ninety degrees to one or more of the lifting motors. When the UAV is moving horizontally, it may be determined if the horizontal airspeed of the UAV exceeds an airspeed threshold. If the horizontal airspeed exceeds the airspeed threshold, the thrusting motor may be engaged and the thrusting propeller will aid in the horizontal propulsion of the UAV.

Abstract: This disclosure describes a configuration of an unmanned aerial vehicle (“UAV”) that will facilitate extended flight duration. The UAV may have any number of lifting motors. For example, the UAV may include four lifting motors (also known as a quad-copter), eight lifting motors (also known as an octo-copter), etc. Likewise, to improve the efficiency of horizontal flight, the UAV also includes a pivot assembly that may rotate about an axis from a lifting position to a thrusting position. The pivot assembly may include two or more offset motors that generate a differential force that will cause the pivot assembly to rotate between the lifting position and the thrusting position without the need for any additional motors or gears.

Abstract: This disclosure describes a configuration of an unmanned aerial vehicle (UAV) that includes a substantially polygonal perimeter frame and a central frame. The perimeter frame includes a front wing, a lower rear wing, and an upper rear wing. The wings provide lift to the UAV when the UAV is moving in a direction that includes a horizontal component. The UAV may have any number of lifting motors. For example, the UAV may include four lifting motors (also known as a quad-copter), eight lifting motors (octo-copter), etc. Likewise, to improve the efficiency of horizontal flight, the UAV may also include one or more thrusting motors and corresponding thrusting propellers. When the UAV is moving horizontally, the thrusting motor(s) may be engaged and the thrusting propeller(s) will aid in the horizontal propulsion of the UAV.

Abstract: This disclosure describes a configuration of an unmanned aerial vehicle (“UAV”) that will facilitate extended flight duration. The UAV may have any number of lifting motors. For example, the UAV may include four lifting motors (also known as a quad-copter), eight lifting motors (also known as an octo-copter), etc. Likewise, to improve the efficiency of horizontal flight, the UAV also includes a pivot assembly that may rotate about an axis from a lifting position to a thrusting position. The pivot assembly may include two or more offset motors that generate a differential force that will cause the pivot assembly to rotate between the lifting position and the thrusting position without the need for any additional motors or gears.

Abstract: Aspects of modular airborne delivery are described. When a shipping container is provided to an airborne carrier for delivery, the airborne carrier may assess weather across a route for airborne delivery of the shipping container, evaluate an approach to drop the shipping container at a delivery zone, and calculate a remaining amount of time until a target delivery time, for example. The airborne carrier may then select components to assemble a modular unmanned aerial vehicle (UAV) based on those or other factors, and assemble the UAV using the selected components. The modular UAV may then be directed to deliver the shipping container according to instructions from the airborne carrier. According to the concepts described herein, flexibility and other advantages may be achieved using modular UAVs for airborne delivery.

Abstract: This disclosure describes a configuration of an unmanned aerial vehicle (UAV) that includes a frame that provides both structural support for the UAV and protection for foreign objects that may come into contact with the UAV. The UAV may have any number of lifting motors. For example, the UAV may include four lifting motors (also known as a quad-copter), eight lifting motors (octo-copter), etc. Likewise, to improve the efficiency of horizontal flight, the UAV may also include one or more pushing motor and propeller assemblies that are oriented at approximately ninety degrees to one or more of the lifting motors. When the UAV is moving horizontally, the pushing motor(s) may be engaged and the pushing propeller(s) will aid in the horizontal propulsion of the UAV.

Abstract: Aspects of modular airborne delivery are described. When a shipping container is provided to an airborne carrier for delivery, the airborne carrier may assess weather across a route for airborne delivery of the shipping container, evaluate an approach to drop the shipping container at a delivery zone, and calculate a remaining amount of time until a target delivery time, for example. The airborne carrier may then select components to assemble a modular unmanned aerial vehicle (UAV) based on those or other factors, and assemble the UAV using the selected components. The modular UAV may then be directed to deliver the shipping container according to instructions from the airborne carrier. According to the concepts described herein, flexibility and other advantages may be achieved using modular UAVs for airborne delivery.

Abstract: This disclosure describes a configuration of an unmanned aerial vehicle (UAV) that will facilitate extended flight duration. The UAV may have any number of lifting motors. For example, the UAV may include four lifting motors (also known as a quad-copter), eight lifting motors (octo-copter), etc. Likewise, to improve the efficiency of horizontal flight, the UAV also includes a pushing motor and propeller assembly that is oriented at approximately ninety degrees to one or more of the lifting motors. When the UAV is moving horizontally, the pushing motor may be engaged and the pushing propeller will aid in the horizontal propulsion of the UAV.

Abstract: This disclosure is directed to a single blade propeller and systems, devices, and techniques pertaining to assisting in critical stages of flight (e.g., takeoff, landing, emergency situations, etc.) in vertical takeoff and landing (VTOL) aircraft. The single blade propeller may be incorporated into fixed and rotary wing VTOL aircraft as part of a first propulsion system. The first propulsion system may include one or more single blade propellers driven by electric motors, combustion engines, and/or hybrid engines. Each of the single blade propellers may include a lift-producing blade and a counterweight opposite the lift-producing blade. As each of the single blade propellers spins, it may produce lift in a direction approximately perpendicular to the horizon to effect vertical flight.