Abstract: A transportation network is provided that utilizes autonomous vehicles (e.g., unmanned aerial vehicles) for identifying, acquiring, and transporting items between network locations without requiring human interaction. A travel path for an item through the transportation network may include a passing of the item from one autonomous vehicle to another or otherwise utilizing different autonomous vehicles for transporting the item along different path segments (e.g., between different network locations). Different possible travel paths through the transportation network may be evaluated, and a travel path for an item may be selected based on transportation factors such as travel time, cost, safety, etc., which may include consideration of information regarding current conditions (e.g., related to network congestion, inclement weather, etc.). Autonomous vehicles of different sizes, carrying capacities, travel ranges, travel speeds, etc.

Abstract: Noises that are to be emitted by an aerial vehicle during operations may be predicted using one or more machine learning systems, algorithms or techniques. Anti-noises having equal or similar intensities and equal but out-of-phase frequencies may be identified and generated based on the predicted noises, thereby reducing or eliminating the net effect of the noises. The machine learning systems, algorithms or techniques used to predict such noises may be trained using emitted sound pressure levels observed during prior operations of aerial vehicles, as well as environmental conditions, operational characteristics of the aerial vehicles or locations of the aerial vehicles during such prior operations. Anti-noises may be identified and generated based on an overall sound profile of the aerial vehicle, or on individual sounds emitted by the aerial vehicle by discrete sources.

Abstract: Described is a configuration of an unmanned aerial vehicle (“UAV”) that includes one or more lifting propellers that may be converted between an operational configuration and a transit configuration. When the lifting propeller is in a operational configuration, the leading edge of each propeller blade is aligned in the direction of rotation so that the lifting propeller will generate a positive lifting force when rotated by a lifting motor. When the lifting propeller is in the transit configuration, the leading edge of each of the propeller blades are oriented toward a direction of a transit flight of the aerial vehicle. Likewise, the lifting propeller is maintained in a fixed position during the transit flight so that airflow passing over the propeller blades of the lifting propeller cause vertical lift.

Abstract: Mobile tunnels may be provided on trailers or in association with one or more other vehicles. A mobile tunnel may be towed or otherwise accelerated to a sufficient velocity, thereby causing a fluid such as air or seawater to travel above, below and around the tunnel. The fluid may be diverted into the tunnel and caused to pass over a test object such as an unmanned aerial vehicle or unmanned undersea vehicle within the tunnel, thereby enabling aerodynamic testing or hydrodynamic testing of the test object to be performed. Additionally, one or more materials may be injected into the fluid, thereby enabling destructive testing of the test object to be performed.

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: 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: 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: 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: 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 aerial vehicles and systems for altering the noise generated by the rotation of a propeller during flight of the aerial vehicle. In some implementations, propellers of the aerial vehicle are paired in a coaxially aligned configuration in which the pair of propellers both rotate in the same direction, are rotationally phase aligned, and separated a defined distance so that the noise from high pressure pulse of the induced flow from the lower propeller is at least partially canceled out by the noise of the high pressure pulse of the induced flow from the upper propeller.

Abstract: A configuration of a multirotor aircraft that will facilitate enhanced yaw control includes one or more adjustable members that will twist the frame of the multirotor aircraft, thereby adjusting the orientation of the motors and propellers and enhancing the yaw control of the multirotor aircraft. In some implementations, the adjustable member(s) are passive and twist in response to differential thrusts generated by the propellers. In other implementations, the adjustable members are active and twist in response to a yaw command from the multirotor aircraft control system.

Abstract: This disclosure describes a system and method for operating an automated aerial vehicle wherein influences of a ground effect may be utilized for sensing the ground or other surfaces. In various implementations, an operating parameter of the automated aerial vehicle may be monitored to determine when a ground effect is influencing the parameter, which correspondingly indicates a proximity to a surface (e.g., the ground). In various implementations, the ground effect based sensing techniques may be utilized for determining a proximity to the ground, as a backup for a primary sensor system, for determining if a landing location is uneven, etc.

Abstract: A system and method for operating an automated aerial vehicle are provided wherein influences of ground effects (e.g., which may increase the effective thrusts of propellers by interfering with the respective airflows) are utilized for sensing the ground or other surfaces. In various implementations, operating parameters of the automated aerial vehicle are monitored to determine when ground effects are influencing the parameters associated with each of the propellers, which correspondingly indicate proximities to a surface (e.g., the ground). Utilizing such techniques, different propellers of an automated aerial vehicle may provide different sensing data (e.g., for detecting issues with an uneven landing area, a sloped ground, determining an automated aerial vehicle's location based on a unique ground surface profile, etc.

Abstract: Aerial vehicles may be operated with discrete sets of propellers, which may be selected for a specific purpose or on a specific basis. The discrete sets of propellers may be operated separately or in tandem with one another, and at varying power levels. For example, a set of propellers may be selected to optimize the thrust, lift, maneuverability or efficiency of an aerial vehicle based on a position or other operational characteristic of the aerial vehicle, or an environmental condition encountered by the aerial vehicle. At least one of the propellers may be statically or dynamically imbalanced, such that the propeller emits a predetermined sound during operation. A balanced propeller may be specifically modified to cause the aerial vehicle to emit the predetermined sound by changing one or more parameters of the balanced propeller and causing the balanced propeller to be statically or dynamically imbalanced.

Abstract: This disclosure describes systems and methods for visually tracking a position of an unmanned aerial vehicle (“UAV”) using reflected light. A light source at an origin location, such as the location of an operator of the UAV, is aligned and emitted toward the position of the UAV. The emitted light source reflects off a reflector coupled to the UAV toward a location of the operator or a visual observer working with the operator. The reflected light increases the visibility of the UAV, thereby extending the distance from an operator at which the UAV can be operated while maintaining visible contact between the operator and/or a visual observer working with the operator and the UAV.

Abstract: Described is an aerial vehicle, such as an unmanned aerial vehicle (“UAV”) that includes a delivery shroud. The delivery shroud may be maintained in a retracted position while the aerial vehicle is in transit. The delivery shroud reduces the transmission of sound from the aerial vehicle to the delivery area. Likewise, the delivery shroud may also be used to facilitate delivery of a payload from the aerial vehicle to a delivery location within the delivery area.

Abstract: Intermodal vehicles may be loaded with items and an aerial vehicle, and directed to travel to areas where demand for the items is known or anticipated. The intermodal vehicles may be coupled to locomotives, container ships, road tractors or other vehicles, and equipped with systems for loading one or more items onto the aerial vehicle, and for launching or retrieving the aerial vehicle while the intermodal vehicles are in motion. The areas where the demand is known or anticipated may be identified on any basis, including but not limited to past histories of purchases or deliveries to such areas, or events that are scheduled to occur in such areas. Additionally, intermodal vehicles may be loaded with replacement parts and/or inspection equipment, and configured to conduct repairs, servicing operations or inspections on aerial vehicles within the intermodal vehicles, while the intermodal vehicles are in motion.

Abstract: Aerial vehicles may be operated with discrete sets of propellers, which may be selected for a specific purpose or on a specific basis. The discrete sets of propellers may be operated separately or in tandem with one another, and at varying power levels. For example, a set of propellers may be selected to optimize the thrust, lift, maneuverability or efficiency of an aerial vehicle based on a position or other operational characteristic of the aerial vehicle, or an environmental condition encountered by the aerial vehicle. At least one of the propellers may be statically or dynamically imbalanced, such that the propeller emits a predetermined sound during operation. A balanced propeller may be specifically modified to cause the aerial vehicle to emit the predetermined sound by changing one or more parameters of the balanced propeller and causing the balanced propeller to be statically or dynamically imbalanced.

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 of one or more propeller blade treatments of a propeller blade of an aerial vehicle during operation of the aerial vehicle. For example, the propeller blade may have one or more propeller blade treatments that may be adjusted between two or more positions. Based on the position of the propeller blade treatments, the airflow over the propeller is altered, thereby altering the sound generated by the propeller when rotating. By altering the propeller blade treatments on multiple propeller blades of the aerial vehicle, the different sounds generated by the different propeller blades may effectively cancel, reduce, and/or otherwise alter the total sound generated by the aerial vehicle.

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 of one or more propeller blade treatments of a propeller blade of an aerial vehicle during operation of the aerial vehicle. For example, the propeller blade may have one or more propeller blade treatments that may be adjusted between two or more positions. Based on the position of the propeller blade treatments, the airflow over the propeller is altered, thereby altering the sound generated by the propeller when rotating. By altering the propeller blade treatments on multiple propeller blades of the aerial vehicle, the different sounds generated by the different propeller blades may effectively cancel, reduce, and/or otherwise alter the total sound generated by the aerial vehicle.