A monitoring system, a base station, and a control method thereof are provided. The monitoring system includes a drone and a base station. The drone includes a main body and at least two leg holders extending from the main body. The base station includes a platform and a positioning mechanism. The platform has a horizontal plate, and the drone is placed on the platform. The positioning mechanism includes at least two movement members. The movement members are movably disposed on the platform and movable between a first position and a second position. When the movement members are located at the second position, the movement members hold and fix the leg holders of the drone, each of the leg holders forms an inclined angle with respect to the horizontal plate, and the inclined angle is less than 90 degrees.

A propeller blade is provided including a leading edge and a trailing edge. The trailing edge is arranged opposite the leading edge to form an airfoil there between. At least one of the leading edge and the trailing edge include at least one facet.

Sounds are generated by an aerial vehicle during operation. For example, the motors and propellers of an aerial vehicle generate sounds during operation. Systems, methods, and apparatus may actively adjust 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.

The present invention provides a simple method and apparatus capable of accurately measuring the water depth of a field, in particular, the whole field.

SOLUTION: An ultrasonic transmitter/receiver and a drone equipped with an infrared transmitter/receiver or a microwave transmitter/receiver are allowed to fly over the field, and the distance between the ultrasonic wave surface reflection and the microwave or infrared ground reflection. Measure the water depth just below the drone from the difference in measurement. By flying the drone all over the field, the water depth of the entire field can be accurately measured. The measurement is preferably performed only while the drone is flying at a predetermined speed or higher.

The present disclosure pertains to a multi-rotor unmanned aerial vehicle (UAV). Aspects of the present disclosure provide a UAV that includes at least four arms, each configured with a co-axial pair of contra rotating propellers, wherein each propeller has capability of rotating reversibly with associated reversal of direction of thrust, and an autopilot control system that controls rotational direction and speed of the at least four co-axial pairs of propellers to maintain yaw stability, roll stability and pitch stability of the UAV, wherein in an event of failure of any one co-axial pair out of the at least four co-axial pairs of propellers, the autopilot control system reverses direction of rotation and thereby direction of thrust of at least one propeller of any functional pair.

A rotor system is provided in one example embodiment and may include a first pair of rotor blades comprising a first pitch and a first diameter; and a second pair of rotor blades comprising a second pitch and a second diameter, wherein the first pitch of the first pair of rotor blades and the second pitch of the second pair of rotor blades are different.

A multi-propeller assembly for a drone, the multi-propeller includes a housing, a motor coupled having a circular cavity surrounded by a plurality of magnets disposed at the opposing second side of the housing, a first, second, and third three-bladed propeller having drive members rotatably coupled within the circular cavity of the motor and nested within each other, wherein the motor is configured to simultaneously rotate the first and third three-bladed propeller in a first direction and the second three-bladed propeller in an opposite second direction using the plurality of magnets.

A first embodiment relates to a shape-reconfigurable drone and, more specifically, to a shape-reconfigurable drone comprising unit module drones having a rectangular-parallelepiped body capable of applying a thrust in every direction, thereby being capable of flying horizontally without rotating the drone and of forming a drone assembly formed by the coupling of the unit module drones, and thus can fly solo or can fly in various shapes.

The present disclosure provides various embodiments of a multicopter-assisted launch and retrieval system generally including: (1) a multi-rotor modular multicopter attachable to (and detachable from) a fixed-wing aircraft to facilitate launch of the fixed-wing aircraft into wing-borne flight; (2) a storage and launch system usable to store the modular multicopter and to facilitate launch of the fixed-wing aircraft into wing-borne flight; and (3) an anchor system usable (along with the multicopter and a flexible capture member) to retrieve the fixed-wing aircraft from wing-borne flight.

A dual-rotor wing motor includes a sleeve separating an inner shaft from an outer shaft. An external bearing is independently coupled to a shaft cover while an internal bearing is independently coupled to the inner shaft, and thus the external bearing and the internal bearing independently bear a friction force due to the rotation of the respective single shaft, the heat generated by the friction force can be reduced and the lubricant cannot be easily evaporated. Accordingly, the service life of the dual-rotor wing motor of the present invention can be prolonged.