Abstract: The present disclosure describes a ground cleaning device that comprises a ground brush, a main body, and a fan. The fan may be located inside the main body and may comprise an air inlet and an air outlet. The main body may comprise a main air outlet channel, a front air outlet channel, and a rear air outlet channel. One end of the main air outlet channel may be connected to a switching device, which has a first state and a second state. Based on the switching device being in the first state, the switching device may close the rear air outlet channel to disconnect the main air outlet channel from the rear air outlet channel. Based on the switching device being in the second state, the switching device may open the rear air outlet channel to connect the main air outlet channel to the rear air outlet channel.

Abstract: The present disclosure provides a locking structure, an arm assembly and a movable platform. The locking structure includes a mounting member, a movable part member and a locking assembly. The movable part member is rotatably connected to the mounting member. The locking assembly is disposed on the mounting member or the movable member. When the mounting member and the movable member are rotated to form a preset angle, the locking assembly may synchronously lock the mounting member and the movable member in the current position, so that the movable member is kept in an unfolded state.

Abstract: A spray-head assembly includes a pipe structure and a valve-spool. The pipe structure includes a liquid inlet, a flow pathway, and a valve-port. The flow pathway includes an air-flow pathway arranged obliquely with respect to a central axis of the liquid inlet. A bottom end of the air-flow pathway communicates with the liquid inlet. The valve-port is arranged at a top end of the air-flow pathway. The valve-spool is arranged in the flow pathway and configured to control opening and closing of the valve-port.

Abstract: An avionics system for an unmanned aerial vehicle (UAV) includes a housing having a mounting hole, a flight control circuit board arranged inside the housing, a wireless communication circuit board integrated with the flight control circuit board on a printed circuit board (PCB), a positioning circuit arranged inside the housing and above or below the PCB, and a connection wire passing through the mounting hole and connecting the flight control circuit board with an electronic governor of the UAV arranged outside the housing.

Abstract: An unmanned aerial vehicle includes a frame, an avionics board assembly detachably mounted at a side of the frame, and a central board assembly detachably mounted at a top of the frame, spaced apart from the avionics board assembly, electrically connected to the avionics board assembly via a wire, and used to transfer at least one of a power signal or a communication signal. The avionics board assembly includes a flight controller used to control flight status of the unmanned aerial vehicle, and a positioning navigation device electrically connected to the flight controller and used to obtain current position information of the unmanned aerial vehicle.

Abstract: Unmanned aerial vehicles and frames thereof are disclosed. The unmanned aerial vehicle includes a frame and a control module. The frame includes a central frame, a first arm set, and a second arm set. Each of the first arm set and the second arm set includes a second arm assembly, a third arm assembly, and a first arm assembly. The first arm assembly is located between the second arm assembly and the third arm assembly. The first arm assembly includes a first rotor assembly. The second arm assembly includes a second rotor assembly. The third arm assembly includes a third rotor assembly. In an output direction of downward-propelling wind fields, one of a rotation plane of the first rotor assembly, a rotation plane of the second rotor assembly, and a rotation plane of the third rotor assembly is located at a different position from the other two.

Abstract: An agricultural unmanned aerial vehicle (UAV) is provided. The UAV includes a central frame, a control circuit, a left arm group, a right arm group and a spraying system. The left and right arm groups each includes a front arm assembly including a second rotor assembly, a rear arm assembly including a third rotor assembly, and a middle arm assembly including a first rotor assembly. In an output direction of downwash flow fields of the left and right arm groups, a height of a rotation plane of the first rotor assembly is lower than heights of rotation planes of the second and third rotor assemblies. The spraying system includes nozzle assemblies. The control circuit is configured to control the left and right arm groups to adjust flight attitude of the UAV. The left and right arm groups output the downwash flow fields in a direction towards the nozzle assemblies.

Abstract: An unmanned aerial vehicle includes a central body having a plurality of sides and a plurality of arms extendable from the central body. Each arm is configured to support one or more propulsion assemblies that provide a propulsion force while the unmanned aerial vehicle is in flight. The arms are configured to transform between a flight configuration in which the arms are extended away from the central body and a compact configuration in which free ends of a first subset of the arms collectively define a rectangular area. Free ends of a second subset of the arms are closer to a yaw-axis of the unmanned aerial vehicle than the free ends of the first subset of the arms. The yaw-axis passes through the rectangular area.

Abstract: A spray assembly includes a spray bar, a spray head assembly, and a connection base. The spray head assembly is connected to an end of the spray bar. The connection base is connected to another end of the spray bar and configured to fix the spray bar at a frame of an agricultural plant protection machine. The connection base includes a flexible connection base. The connection base is configured to cause the spray bar to swing relative to the frame in response to the spray bar being subjected to an external force.

Abstract: An avionics system for an unmanned aerial vehicle (UAV) includes a housing having a mounting hole, a flight control circuit board arranged inside the housing, a wireless communication circuit board integrated with the flight control circuit board on a printed circuit board (PCB), a positioning circuit arranged inside the housing and above or below the PCB, and a connection wire passing through the mounting hole and connecting the flight control circuit board with an electronic governor of the UAV arranged outside the housing.

Abstract: A spray-head assembly includes a pipe structure and a valve-spool. The pipe structure includes a liquid inlet, a flow pathway, and a valve-port. The flow pathway includes an air-flow pathway arranged obliquely with respect to a central axis of the liquid inlet. A bottom end of the air-flow pathway communicates with the liquid inlet. The valve-port is arranged at a top end of the air-flow pathway. The valve-spool is arranged in the flow pathway and configured to control opening and closing of the valve-port.